dist2/testdata/testoutput2

# This set of tests is not Perl-compatible. It checks on special features
# of PCRE2's API, error diagnostics, and the compiled code of some patterns.
# It also checks the non-Perl syntax that PCRE2 supports (Python, .NET, 
# Oniguruma). There are also some tests where PCRE2 and Perl differ, 
# either because PCRE2 can't be compatible, or there is a possible Perl 
# bug.

# NOTE: This is a non-UTF set of tests. When UTF support is needed, use
# test 5. 

#forbid_utf
#newline_default lf any anycrlf

# Test binary zeroes in the pattern

# /a\0B/ where 0 is a binary zero
/61 5c 00 62/B,hex
------------------------------------------------------------------
        Bra
        a\x00b
        Ket
        End
------------------------------------------------------------------
    a\x{0}b
 0: a\x00b

# /a0b/ where 0 is a binary zero
/61 00 62/B,hex
------------------------------------------------------------------
        Bra
        a\x00b
        Ket
        End
------------------------------------------------------------------
    a\x{0}b
 0: a\x00b

# /(?#B0C)DE/ where 0 is a binary zero
/28 3f 23 42 00 43 29 44 45/B,hex
------------------------------------------------------------------
        Bra
        DE
        Ket
        End
------------------------------------------------------------------
    DE
 0: DE

/(a)b|/I
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0

/abc/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3
    abc
 0: abc
    defabc
 0: abc
    abc\=anchored
 0: abc
\= Expect no match
    defabc\=anchored
No match
    ABC
No match

/^abc/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
    abc
 0: abc
    abc\=anchored
 0: abc
\= Expect no match
    defabc
No match
    defabc\=anchored
No match

/a+bc/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/a*bc/I
Capturing subpattern count = 0
Starting code units: a b 
Last code unit = 'c'
Subject length lower bound = 2

/a{3}bc/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 5

/(abc|a+z)/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 2

/^abc$/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
    abc
 0: abc
\= Expect no match
    def\nabc
No match

/ab\idef/
Failed: error 103 at offset 3: unrecognized character follows \

/(?X)ab\idef/
Failed: error 111 at offset 2: unrecognized character after (? or (?-

/x{5,4}/
Failed: error 104 at offset 5: numbers out of order in {} quantifier

/z{65536}/
Failed: error 105 at offset 7: number too big in {} quantifier

/[abcd/
Failed: error 106 at offset 5: missing terminating ] for character class

/[\B]/B
Failed: error 107 at offset 2: invalid escape sequence in character class

/[\R]/B
Failed: error 107 at offset 2: invalid escape sequence in character class

/[\X]/B
Failed: error 107 at offset 2: invalid escape sequence in character class

/[z-a]/
Failed: error 108 at offset 3: range out of order in character class

/^*/
Failed: error 109 at offset 1: quantifier does not follow a repeatable item

/(abc/
Failed: error 114 at offset 4: missing closing parenthesis

/(?# abc/
Failed: error 118 at offset 7: missing ) after (?# comment

/(?z)abc/
Failed: error 111 at offset 2: unrecognized character after (? or (?-

/.*b/I
Capturing subpattern count = 0
First code unit at start or follows newline
Last code unit = 'b'
Subject length lower bound = 1

/.*?b/I
Capturing subpattern count = 0
First code unit at start or follows newline
Last code unit = 'b'
Subject length lower bound = 1

/cat|dog|elephant/I
Capturing subpattern count = 0
Starting code units: c d e 
Subject length lower bound = 3
    this sentence eventually mentions a cat
 0: cat
    this sentences rambles on and on for a while and then reaches elephant
 0: elephant

/cat|dog|elephant/I
Capturing subpattern count = 0
Starting code units: c d e 
Subject length lower bound = 3
    this sentence eventually mentions a cat
 0: cat
    this sentences rambles on and on for a while and then reaches elephant
 0: elephant

/cat|dog|elephant/Ii
Capturing subpattern count = 0
Options: caseless
Starting code units: C D E c d e 
Subject length lower bound = 3
    this sentence eventually mentions a CAT cat
 0: CAT
    this sentences rambles on and on for a while to elephant ElePhant
 0: elephant

/a|[bcd]/I
Capturing subpattern count = 0
Starting code units: a b c d 
Subject length lower bound = 1

/(a|[^\dZ])/I
Capturing subpattern count = 1
Starting code units: \x00 \x01 \x02 \x03 \x04 \x05 \x06 \x07 \x08 \x09 \x0a 
  \x0b \x0c \x0d \x0e \x0f \x10 \x11 \x12 \x13 \x14 \x15 \x16 \x17 \x18 \x19 
  \x1a \x1b \x1c \x1d \x1e \x1f \x20 ! " # $ % & ' ( ) * + , - . / : ; < = > 
  ? @ A B C D E F G H I J K L M N O P Q R S T U V W X Y [ \ ] ^ _ ` a b c d 
  e f g h i j k l m n o p q r s t u v w x y z { | } ~ \x7f \x80 \x81 \x82 \x83 
  \x84 \x85 \x86 \x87 \x88 \x89 \x8a \x8b \x8c \x8d \x8e \x8f \x90 \x91 \x92 
  \x93 \x94 \x95 \x96 \x97 \x98 \x99 \x9a \x9b \x9c \x9d \x9e \x9f \xa0 \xa1 
  \xa2 \xa3 \xa4 \xa5 \xa6 \xa7 \xa8 \xa9 \xaa \xab \xac \xad \xae \xaf \xb0 
  \xb1 \xb2 \xb3 \xb4 \xb5 \xb6 \xb7 \xb8 \xb9 \xba \xbb \xbc \xbd \xbe \xbf 
  \xc0 \xc1 \xc2 \xc3 \xc4 \xc5 \xc6 \xc7 \xc8 \xc9 \xca \xcb \xcc \xcd \xce 
  \xcf \xd0 \xd1 \xd2 \xd3 \xd4 \xd5 \xd6 \xd7 \xd8 \xd9 \xda \xdb \xdc \xdd 
  \xde \xdf \xe0 \xe1 \xe2 \xe3 \xe4 \xe5 \xe6 \xe7 \xe8 \xe9 \xea \xeb \xec 
  \xed \xee \xef \xf0 \xf1 \xf2 \xf3 \xf4 \xf5 \xf6 \xf7 \xf8 \xf9 \xfa \xfb 
  \xfc \xfd \xfe \xff 
Subject length lower bound = 1

/(a|b)*[\s]/I
Capturing subpattern count = 1
Starting code units: \x09 \x0a \x0b \x0c \x0d \x20 a b 
Subject length lower bound = 1

/(ab\2)/
Failed: error 115 at offset 4: reference to non-existent subpattern

/{4,5}abc/
Failed: error 109 at offset 4: quantifier does not follow a repeatable item

/(a)(b)(c)\2/I
Capturing subpattern count = 3
Max back reference = 2
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 4
    abcb
 0: abcb
 1: a
 2: b
 3: c
    abcb\=ovector=0
 0: abcb
 1: a
 2: b
 3: c
    abcb\=ovector=1
Matched, but too many substrings
 0: abcb
    abcb\=ovector=2
Matched, but too many substrings
 0: abcb
 1: a
    abcb\=ovector=3
Matched, but too many substrings
 0: abcb
 1: a
 2: b
    abcb\=ovector=4
 0: abcb
 1: a
 2: b
 3: c

/(a)bc|(a)(b)\2/I
Capturing subpattern count = 3
Max back reference = 2
First code unit = 'a'
Subject length lower bound = 3
    abc
 0: abc
 1: a
    abc\=ovector=0
 0: abc
 1: a
    abc\=ovector=1
Matched, but too many substrings
 0: abc
    abc\=ovector=2
 0: abc
 1: a
    aba
 0: aba
 1: <unset>
 2: a
 3: b
    aba\=ovector=0
 0: aba
 1: <unset>
 2: a
 3: b
    aba\=ovector=1
Matched, but too many substrings
 0: aba
    aba\=ovector=2
Matched, but too many substrings
 0: aba
 1: <unset>
    aba\=ovector=3
Matched, but too many substrings
 0: aba
 1: <unset>
 2: a
    aba\=ovector=4
 0: aba
 1: <unset>
 2: a
 3: b

/abc$/I,dollar_endonly
Capturing subpattern count = 0
Options: dollar_endonly
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3
    abc
 0: abc
\= Expect no match
    abc\n
No match
    abc\ndef
No match

/(a)(b)(c)(d)(e)\6/
Failed: error 115 at offset 16: reference to non-existent subpattern

/the quick brown fox/I
Capturing subpattern count = 0
First code unit = 't'
Last code unit = 'x'
Subject length lower bound = 19
    the quick brown fox
 0: the quick brown fox
    this is a line with the quick brown fox
 0: the quick brown fox

/the quick brown fox/I,anchored
Capturing subpattern count = 0
Options: anchored
Subject length lower bound = 19
    the quick brown fox
 0: the quick brown fox
\= Expect no match
    this is a line with the quick brown fox
No match

/ab(?z)cd/
Failed: error 111 at offset 4: unrecognized character after (? or (?-

/^abc|def/I
Capturing subpattern count = 0
Subject length lower bound = 3
    abcdef
 0: abc
    abcdef\=notbol
 0: def

/.*((abc)$|(def))/I
Capturing subpattern count = 3
First code unit at start or follows newline
Subject length lower bound = 3
    defabc
 0: defabc
 1: abc
 2: abc
    defabc\=noteol
 0: def
 1: def
 2: <unset>
 3: def

/)/
Failed: error 122 at offset 0: unmatched closing parenthesis

/a[]b/
Failed: error 106 at offset 4: missing terminating ] for character class

/[^aeiou ]{3,}/I
Capturing subpattern count = 0
Starting code units: \x00 \x01 \x02 \x03 \x04 \x05 \x06 \x07 \x08 \x09 \x0a 
  \x0b \x0c \x0d \x0e \x0f \x10 \x11 \x12 \x13 \x14 \x15 \x16 \x17 \x18 \x19 
  \x1a \x1b \x1c \x1d \x1e \x1f ! " # $ % & ' ( ) * + , - . / 0 1 2 3 4 5 6 
  7 8 9 : ; < = > ? @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z [ 
  \ ] ^ _ ` b c d f g h j k l m n p q r s t v w x y z { | } ~ \x7f \x80 \x81 
  \x82 \x83 \x84 \x85 \x86 \x87 \x88 \x89 \x8a \x8b \x8c \x8d \x8e \x8f \x90 
  \x91 \x92 \x93 \x94 \x95 \x96 \x97 \x98 \x99 \x9a \x9b \x9c \x9d \x9e \x9f 
  \xa0 \xa1 \xa2 \xa3 \xa4 \xa5 \xa6 \xa7 \xa8 \xa9 \xaa \xab \xac \xad \xae 
  \xaf \xb0 \xb1 \xb2 \xb3 \xb4 \xb5 \xb6 \xb7 \xb8 \xb9 \xba \xbb \xbc \xbd 
  \xbe \xbf \xc0 \xc1 \xc2 \xc3 \xc4 \xc5 \xc6 \xc7 \xc8 \xc9 \xca \xcb \xcc 
  \xcd \xce \xcf \xd0 \xd1 \xd2 \xd3 \xd4 \xd5 \xd6 \xd7 \xd8 \xd9 \xda \xdb 
  \xdc \xdd \xde \xdf \xe0 \xe1 \xe2 \xe3 \xe4 \xe5 \xe6 \xe7 \xe8 \xe9 \xea 
  \xeb \xec \xed \xee \xef \xf0 \xf1 \xf2 \xf3 \xf4 \xf5 \xf6 \xf7 \xf8 \xf9 
  \xfa \xfb \xfc \xfd \xfe \xff 
Subject length lower bound = 3
    co-processors, and for
 0: -pr

/<.*>/I
Capturing subpattern count = 0
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 2
    abc<def>ghi<klm>nop
 0: <def>ghi<klm>

/<.*?>/I
Capturing subpattern count = 0
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 2
    abc<def>ghi<klm>nop
 0: <def>

/<.*>/I,ungreedy
Capturing subpattern count = 0
Options: ungreedy
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 2
    abc<def>ghi<klm>nop
 0: <def>

/(?U)<.*>/I
Capturing subpattern count = 0
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 2
    abc<def>ghi<klm>nop
 0: <def>

/<.*?>/I,ungreedy
Capturing subpattern count = 0
Options: ungreedy
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 2
    abc<def>ghi<klm>nop
 0: <def>ghi<klm>

/={3,}/I,ungreedy
Capturing subpattern count = 0
Options: ungreedy
First code unit = '='
Last code unit = '='
Subject length lower bound = 3
    abc========def
 0: ===

/(?U)={3,}?/I
Capturing subpattern count = 0
First code unit = '='
Last code unit = '='
Subject length lower bound = 3
    abc========def
 0: ========

/(?<!bar|cattle)foo/I
Capturing subpattern count = 0
Max lookbehind = 6
First code unit = 'f'
Last code unit = 'o'
Subject length lower bound = 3
    foo
 0: foo
    catfoo
 0: foo
\= Expect no match
    the barfoo
No match
    and cattlefoo
No match

/(?<=a+)b/
Failed: error 125 at offset 6: lookbehind assertion is not fixed length

/(?<=aaa|b{0,3})b/
Failed: error 125 at offset 14: lookbehind assertion is not fixed length

/(?<!(foo)a\1)bar/
Failed: error 125 at offset 12: lookbehind assertion is not fixed length

/(?i)abc/I
Capturing subpattern count = 0
First code unit = 'a' (caseless)
Last code unit = 'c' (caseless)
Subject length lower bound = 3

/(a|(?m)a)/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/(?i)^1234/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 4

/(^b|(?i)^d)/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/(?s).*/I
Capturing subpattern count = 0
May match empty string
Compile options: <none>
Overall options: anchored
Subject length lower bound = 0

/[abcd]/I
Capturing subpattern count = 0
Starting code units: a b c d 
Subject length lower bound = 1

/(?i)[abcd]/I
Capturing subpattern count = 0
Starting code units: A B C D a b c d 
Subject length lower bound = 1

/(?m)[xy]|(b|c)/I
Capturing subpattern count = 1
Starting code units: b c x y 
Subject length lower bound = 1

/(^a|^b)/Im
Capturing subpattern count = 1
Options: multiline
First code unit at start or follows newline
Subject length lower bound = 1

/(?i)(^a|^b)/Im
Capturing subpattern count = 1
Options: multiline
First code unit at start or follows newline
Subject length lower bound = 1

/(a)(?(1)a|b|c)/
Failed: error 127 at offset 13: conditional group contains more than two branches

/(?(?=a)a|b|c)/
Failed: error 127 at offset 12: conditional group contains more than two branches

/(?(1a)/
Failed: error 126 at offset 4: malformed number or name after (?(

/(?(1a))/
Failed: error 126 at offset 4: malformed number or name after (?(

/(?(?i))/
Failed: error 128 at offset 3: assertion expected after (?( or (?(?C)

/(?(abc))/
Failed: error 115 at offset 7: reference to non-existent subpattern

/(?(?<ab))/
Failed: error 128 at offset 3: assertion expected after (?( or (?(?C)

/((?s)blah)\s+\1/I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'b'
Last code unit = 'h'
Subject length lower bound = 9

/((?i)blah)\s+\1/I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'b' (caseless)
Last code unit = 'h' (caseless)
Subject length lower bound = 9

/((?i)b)/IB
------------------------------------------------------------------
        Bra
        CBra 1
     /i b
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
First code unit = 'b' (caseless)
Subject length lower bound = 1

/(a*b|(?i:c*(?-i)d))/I
Capturing subpattern count = 1
Starting code units: C a b c d 
Subject length lower bound = 1

/a$/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1
    a
 0: a
    a\n
 0: a
\= Expect no match
    a\=noteol
No match
    a\n\=noteol
No match

/a$/Im
Capturing subpattern count = 0
Options: multiline
First code unit = 'a'
Subject length lower bound = 1
    a
 0: a
    a\n
 0: a
    a\n\=noteol
 0: a
\= Expect no match
    a\=noteol
No match

/\Aabc/Im
Capturing subpattern count = 0
Max lookbehind = 1
Compile options: multiline
Overall options: anchored multiline
Subject length lower bound = 3

/^abc/Im
Capturing subpattern count = 0
Options: multiline
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3

/^((a+)(?U)([ab]+)(?-U)([bc]+)(\w*))/I
Capturing subpattern count = 5
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
  aaaaabbbbbcccccdef
 0: aaaaabbbbbcccccdef
 1: aaaaabbbbbcccccdef
 2: aaaaa
 3: b
 4: bbbbccccc
 5: def

/(?<=foo)[ab]/I
Capturing subpattern count = 0
Max lookbehind = 3
Starting code units: a b 
Subject length lower bound = 1

/(?<!foo)(alpha|omega)/I
Capturing subpattern count = 1
Max lookbehind = 3
Starting code units: a o 
Last code unit = 'a'
Subject length lower bound = 5

/(?!alphabet)[ab]/I
Capturing subpattern count = 0
Starting code units: a b 
Subject length lower bound = 1

/(?<=foo\n)^bar/Im
Capturing subpattern count = 0
Max lookbehind = 4
Contains explicit CR or LF match
Options: multiline
Last code unit = 'r'
Subject length lower bound = 3
    foo\nbarbar
 0: bar
\= Expect no match
    rhubarb
No match
    barbell
No match
    abc\nbarton
No match

/^(?<=foo\n)bar/Im
Capturing subpattern count = 0
Max lookbehind = 4
Contains explicit CR or LF match
Options: multiline
First code unit at start or follows newline
Last code unit = 'r'
Subject length lower bound = 3
    foo\nbarbar
 0: bar
\= Expect no match
    rhubarb
No match
    barbell
No match
    abc\nbarton
No match

/(?>^abc)/Im
Capturing subpattern count = 0
Options: multiline
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3
    abc
 0: abc
    def\nabc
 0: abc
\= Expect no match
    defabc
No match

/(?<=ab(c+)d)ef/
Failed: error 125 at offset 11: lookbehind assertion is not fixed length

/(?<=ab(?<=c+)d)ef/
Failed: error 125 at offset 12: lookbehind assertion is not fixed length

/(?<=ab(c|de)f)g/
Failed: error 125 at offset 13: lookbehind assertion is not fixed length

/The next three are in testinput2 because they have variable length branches/

/(?<=bullock|donkey)-cart/I
Capturing subpattern count = 0
Max lookbehind = 7
First code unit = '-'
Last code unit = 't'
Subject length lower bound = 5
    the bullock-cart
 0: -cart
    a donkey-cart race
 0: -cart
\= Expect no match
    cart
No match
    horse-and-cart
No match

/(?<=ab(?i)x|y|z)/I
Capturing subpattern count = 0
Max lookbehind = 3
May match empty string
Subject length lower bound = 0

/(?>.*)(?<=(abcd)|(xyz))/I
Capturing subpattern count = 2
Max lookbehind = 4
May match empty string
Subject length lower bound = 0
    alphabetabcd
 0: alphabetabcd
 1: abcd
    endingxyz
 0: endingxyz
 1: <unset>
 2: xyz

/(?<=ab(?i)x(?-i)y|(?i)z|b)ZZ/I
Capturing subpattern count = 0
Max lookbehind = 4
First code unit = 'Z'
Last code unit = 'Z'
Subject length lower bound = 2
    abxyZZ
 0: ZZ
    abXyZZ
 0: ZZ
    ZZZ
 0: ZZ
    zZZ
 0: ZZ
    bZZ
 0: ZZ
    BZZ
 0: ZZ
\= Expect no match
    ZZ
No match
    abXYZZ
No match
    zzz
No match
    bzz
No match

/(?<!(foo)a)bar/I
Capturing subpattern count = 1
Max lookbehind = 4
First code unit = 'b'
Last code unit = 'r'
Subject length lower bound = 3
    bar
 0: bar
    foobbar
 0: bar
\= Expect no match
    fooabar
No match

# This one is here because Perl behaves differently; see also the following.

/^(a\1?){4}$/I
Capturing subpattern count = 1
Max back reference = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 4
\= Expect no match
    aaaa
No match
    aaaaaa
No match
    
# Perl does not fail these two for the final subjects. Neither did PCRE until
# release 8.01. The problem is in backtracking into a subpattern that contains
# a recursive reference to itself. PCRE has now made these into atomic patterns.

/^(xa|=?\1a){2}$/
    xa=xaa
 0: xa=xaa
 1: =xaa
\= Expect no match
    xa=xaaa
No match

/^(xa|=?\1a)+$/
    xa=xaa
 0: xa=xaa
 1: =xaa
\= Expect no match
    xa=xaaa
No match

# These are syntax tests from Perl 5.005

/a[b-a]/
Failed: error 108 at offset 4: range out of order in character class

/a[]b/
Failed: error 106 at offset 4: missing terminating ] for character class

/a[/
Failed: error 106 at offset 2: missing terminating ] for character class

/*a/
Failed: error 109 at offset 0: quantifier does not follow a repeatable item

/(*)b/
Failed: error 109 at offset 1: quantifier does not follow a repeatable item

/abc)/
Failed: error 122 at offset 3: unmatched closing parenthesis

/(abc/
Failed: error 114 at offset 4: missing closing parenthesis

/a**/
Failed: error 109 at offset 2: quantifier does not follow a repeatable item

/)(/
Failed: error 122 at offset 0: unmatched closing parenthesis

/\1/
Failed: error 115 at offset 1: reference to non-existent subpattern

/\2/
Failed: error 115 at offset 1: reference to non-existent subpattern

/(a)|\2/
Failed: error 115 at offset 5: reference to non-existent subpattern

/a[b-a]/Ii
Failed: error 108 at offset 4: range out of order in character class

/a[]b/Ii
Failed: error 106 at offset 4: missing terminating ] for character class

/a[/Ii
Failed: error 106 at offset 2: missing terminating ] for character class

/*a/Ii
Failed: error 109 at offset 0: quantifier does not follow a repeatable item

/(*)b/Ii
Failed: error 109 at offset 1: quantifier does not follow a repeatable item

/abc)/Ii
Failed: error 122 at offset 3: unmatched closing parenthesis

/(abc/Ii
Failed: error 114 at offset 4: missing closing parenthesis

/a**/Ii
Failed: error 109 at offset 2: quantifier does not follow a repeatable item

/)(/Ii
Failed: error 122 at offset 0: unmatched closing parenthesis

/:(?:/
Failed: error 114 at offset 4: missing closing parenthesis

/(?<%)b/
Failed: error 124 at offset 3: letter or underscore expected after (?< or (?'

/a(?{)b/
Failed: error 111 at offset 3: unrecognized character after (? or (?-

/a(?{{})b/
Failed: error 111 at offset 3: unrecognized character after (? or (?-

/a(?{}})b/
Failed: error 111 at offset 3: unrecognized character after (? or (?-

/a(?{"{"})b/
Failed: error 111 at offset 3: unrecognized character after (? or (?-

/a(?{"{"}})b/
Failed: error 111 at offset 3: unrecognized character after (? or (?-

/(?(1?)a|b)/
Failed: error 126 at offset 4: malformed number or name after (?(

/[a[:xyz:/
Failed: error 106 at offset 8: missing terminating ] for character class

/(?<=x+)y/
Failed: error 125 at offset 6: lookbehind assertion is not fixed length

/a{37,17}/
Failed: error 104 at offset 7: numbers out of order in {} quantifier

/abc/\
Failed: error 101 at offset 3: \ at end of pattern

/abc/\i
Failed: error 101 at offset 3: \ at end of pattern

/(a)bc(d)/I
Capturing subpattern count = 2
First code unit = 'a'
Last code unit = 'd'
Subject length lower bound = 4
    abcd
 0: abcd
 1: a
 2: d
    abcd\=copy=2
 0: abcd
 1: a
 2: d
 2C d (1)
    abcd\=copy=5
 0: abcd
 1: a
 2: d
Copy substring 5 failed (-49): unknown substring

/(.{20})/I
Capturing subpattern count = 1
Subject length lower bound = 20
    abcdefghijklmnopqrstuvwxyz
 0: abcdefghijklmnopqrst
 1: abcdefghijklmnopqrst
    abcdefghijklmnopqrstuvwxyz\=copy=1
 0: abcdefghijklmnopqrst
 1: abcdefghijklmnopqrst
 1C abcdefghijklmnopqrst (20)
    abcdefghijklmnopqrstuvwxyz\=get=1
 0: abcdefghijklmnopqrst
 1: abcdefghijklmnopqrst
 1G abcdefghijklmnopqrst (20)

/(.{15})/I
Capturing subpattern count = 1
Subject length lower bound = 15
    abcdefghijklmnopqrstuvwxyz
 0: abcdefghijklmno
 1: abcdefghijklmno
    abcdefghijklmnopqrstuvwxyz\=copy=1,get=1
 0: abcdefghijklmno
 1: abcdefghijklmno
 1C abcdefghijklmno (15)
 1G abcdefghijklmno (15)

/(.{16})/I
Capturing subpattern count = 1
Subject length lower bound = 16
    abcdefghijklmnopqrstuvwxyz
 0: abcdefghijklmnop
 1: abcdefghijklmnop
    abcdefghijklmnopqrstuvwxyz\=copy=1,get=1,getall
 0: abcdefghijklmnop
 1: abcdefghijklmnop
 1C abcdefghijklmnop (16)
 1G abcdefghijklmnop (16)
 0L abcdefghijklmnop
 1L abcdefghijklmnop

/^(a|(bc))de(f)/I
Capturing subpattern count = 3
Compile options: <none>
Overall options: anchored
Subject length lower bound = 4
    adef\=get=1,get=2,get=3,get=4,getall
 0: adef
 1: a
 2: <unset>
 3: f
 1G a (1)
Get substring 2 failed (-55): requested value is not set
 3G f (1)
Get substring 4 failed (-49): unknown substring
 0L adef
 1L a
 2L 
 3L f
    bcdef\=get=1,get=2,get=3,get=4,getall
 0: bcdef
 1: bc
 2: bc
 3: f
 1G bc (2)
 2G bc (2)
 3G f (1)
Get substring 4 failed (-49): unknown substring
 0L bcdef
 1L bc
 2L bc
 3L f
    adefghijk\=copy=0
 0: adef
 1: a
 2: <unset>
 3: f
 0C adef (4)

/^abc\00def/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 7
    abc\00def\=copy=0,getall
 0: abc\x00def
 0C abc\x00def (7)
 0L abc\x00def

/word ((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+
)((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+ )((?:[a-zA-Z0-9]+
)?)?)?)?)?)?)?)?)?otherword/I
Capturing subpattern count = 8
Contains explicit CR or LF match
First code unit = 'w'
Last code unit = 'd'
Subject length lower bound = 14

/.*X/IB
------------------------------------------------------------------
        Bra
        Any*
        X
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit at start or follows newline
Last code unit = 'X'
Subject length lower bound = 1

/.*X/IBs
------------------------------------------------------------------
        Bra
        AllAny*
        X
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: dotall
Overall options: anchored dotall
Last code unit = 'X'
Subject length lower bound = 1

/(.*X|^B)/IB
------------------------------------------------------------------
        Bra
        CBra 1
        Any*
        X
        Alt
        ^
        B
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
First code unit at start or follows newline
Subject length lower bound = 1

/(.*X|^B)/IBs
------------------------------------------------------------------
        Bra
        CBra 1
        AllAny*
        X
        Alt
        ^
        B
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Compile options: dotall
Overall options: anchored dotall
Subject length lower bound = 1

/(?s)(.*X|^B)/IB
------------------------------------------------------------------
        Bra
        CBra 1
        AllAny*
        X
        Alt
        ^
        B
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/(?s:.*X|^B)/IB
------------------------------------------------------------------
        Bra
        Bra
        AllAny*
        X
        Alt
        ^
        B
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/\Biss\B/I,aftertext
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = 'i'
Last code unit = 's'
Subject length lower bound = 3
    Mississippi
 0: iss
 0+ issippi

/iss/I,aftertext,altglobal
Capturing subpattern count = 0
First code unit = 'i'
Last code unit = 's'
Subject length lower bound = 3
    Mississippi
 0: iss
 0+ issippi
 0: iss
 0+ ippi

/\Biss\B/I,aftertext,altglobal
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = 'i'
Last code unit = 's'
Subject length lower bound = 3
    Mississippi
 0: iss
 0+ issippi

/\Biss\B/Ig,aftertext
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = 'i'
Last code unit = 's'
Subject length lower bound = 3
    Mississippi
 0: iss
 0+ issippi
 0: iss
 0+ ippi
\= Expect no match
    Mississippi\=anchored
No match

/(?<=[Ms])iss/Ig,aftertext
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = 'i'
Last code unit = 's'
Subject length lower bound = 3
    Mississippi
 0: iss
 0+ issippi
 0: iss
 0+ ippi

/(?<=[Ms])iss/I,aftertext,altglobal
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = 'i'
Last code unit = 's'
Subject length lower bound = 3
    Mississippi
 0: iss
 0+ issippi

/^iss/Ig,aftertext
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
    ississippi
 0: iss
 0+ issippi

/.*iss/Ig,aftertext
Capturing subpattern count = 0
First code unit at start or follows newline
Last code unit = 's'
Subject length lower bound = 3
    abciss\nxyzisspqr
 0: abciss
 0+ \x0axyzisspqr
 0: xyziss
 0+ pqr

/.i./Ig,aftertext
Capturing subpattern count = 0
Last code unit = 'i'
Subject length lower bound = 3
    Mississippi
 0: Mis
 0+ sissippi
 0: sis
 0+ sippi
 0: sip
 0+ pi
    Mississippi\=anchored
 0: Mis
 0+ sissippi
 0: sis
 0+ sippi
 0: sip
 0+ pi
    Missouri river
 0: Mis
 0+ souri river
 0: ri 
 0+ river
 0: riv
 0+ er
    Missouri river\=anchored
 0: Mis
 0+ souri river

/^.is/Ig,aftertext
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
    Mississippi
 0: Mis
 0+ sissippi

/^ab\n/Ig,aftertext
Capturing subpattern count = 0
Contains explicit CR or LF match
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
    ab\nab\ncd
 0: ab\x0a
 0+ ab\x0acd

/^ab\n/Igm,aftertext
Capturing subpattern count = 0
Contains explicit CR or LF match
Options: multiline
First code unit at start or follows newline
Last code unit = \x0a
Subject length lower bound = 3
    ab\nab\ncd
 0: ab\x0a
 0+ ab\x0acd
 0: ab\x0a
 0+ cd

/^/gm,newline=any
    a\rb\nc\r\nxyz\=aftertext
 0: 
 0+ a\x0db\x0ac\x0d\x0axyz
 0: 
 0+ b\x0ac\x0d\x0axyz
 0: 
 0+ c\x0d\x0axyz
 0: 
 0+ xyz

/abc/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/abc|bac/I
Capturing subpattern count = 0
Starting code units: a b 
Last code unit = 'c'
Subject length lower bound = 3

/(abc|bac)/I
Capturing subpattern count = 1
Starting code units: a b 
Last code unit = 'c'
Subject length lower bound = 3

/(abc|(c|dc))/I
Capturing subpattern count = 2
Starting code units: a c d 
Last code unit = 'c'
Subject length lower bound = 1

/(abc|(d|de)c)/I
Capturing subpattern count = 2
Starting code units: a d 
Last code unit = 'c'
Subject length lower bound = 2

/a*/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0

/a+/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1

/(baa|a+)/I
Capturing subpattern count = 1
Starting code units: a b 
Last code unit = 'a'
Subject length lower bound = 1

/a{0,3}/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0

/baa{3,}/I
Capturing subpattern count = 0
First code unit = 'b'
Last code unit = 'a'
Subject length lower bound = 5

/"([^\\"]+|\\.)*"/I
Capturing subpattern count = 1
First code unit = '"'
Last code unit = '"'
Subject length lower bound = 2

/(abc|ab[cd])/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 3

/(a|.)/I
Capturing subpattern count = 1
Subject length lower bound = 1

/a|ba|\w/I
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P 
  Q R S T U V W X Y Z _ a b c d e f g h i j k l m n o p q r s t u v w x y z 
Subject length lower bound = 1

/abc(?=pqr)/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'r'
Subject length lower bound = 3

/...(?<=abc)/I
Capturing subpattern count = 0
Max lookbehind = 3
Subject length lower bound = 3

/abc(?!pqr)/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/ab./I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3

/ab[xyz]/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3

/abc*/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/ab.c*/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3

/a.c*/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 2

/.c*/I
Capturing subpattern count = 0
Subject length lower bound = 1

/ac*/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1

/(a.c*|b.c*)/I
Capturing subpattern count = 1
Starting code units: a b 
Subject length lower bound = 2

/a.c*|aba/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 2

/.+a/I
Capturing subpattern count = 0
Last code unit = 'a'
Subject length lower bound = 2

/(?=abcda)a.*/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'a'
Subject length lower bound = 1

/(?=a)a.*/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1

/a(b)*/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/a\d*/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1

/ab\d*/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/a(\d)*/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/abcde{0,0}/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'd'
Subject length lower bound = 4

/ab\d+/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3

/a(?(1)b)(.)/I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'a'
Subject length lower bound = 2

/a(?(1)bag|big)(.)/I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'a'
Last code unit = 'g'
Subject length lower bound = 5

/a(?(1)bag|big)*(.)/I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'a'
Subject length lower bound = 2

/a(?(1)bag|big)+(.)/I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'a'
Last code unit = 'g'
Subject length lower bound = 5

/a(?(1)b..|b..)(.)/I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 5

/ab\d{0}e/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'e'
Subject length lower bound = 3

/a?b?/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    a
 0: a
    b
 0: b
    ab
 0: ab
    \
 0: 
\= Expect no match
    \=notempty
No match

/|-/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    abcd
 0: 
    -abc
 0: 
    ab-c\=notempty
 0: -
\= Expect no match
    abc\=notempty
No match

/^.?abcd/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Last code unit = 'd'
Subject length lower bound = 4

/\(             # ( at start
  (?:           # Non-capturing bracket
  (?>[^()]+)    # Either a sequence of non-brackets (no backtracking)
  |             # Or
  (?R)          # Recurse - i.e. nested bracketed string
  )*            # Zero or more contents
  \)            # Closing )
  /Ix
Capturing subpattern count = 0
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (abcd)
 0: (abcd)
    (abcd)xyz
 0: (abcd)
    xyz(abcd)
 0: (abcd)
    (ab(xy)cd)pqr
 0: (ab(xy)cd)
    (ab(xycd)pqr
 0: (xycd)
    () abc ()
 0: ()
    12(abcde(fsh)xyz(foo(bar))lmno)89
 0: (abcde(fsh)xyz(foo(bar))lmno)
\= Expect no match
    abcd
No match
    abcd)
No match
    (abcd
No match

/\(  ( (?>[^()]+) | (?R) )* \) /Igx
Capturing subpattern count = 1
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (ab(xy)cd)pqr
 0: (ab(xy)cd)
 1: cd
    1(abcd)(x(y)z)pqr
 0: (abcd)
 1: abcd
 0: (x(y)z)
 1: z

/\(  (?: (?>[^()]+) | (?R) ) \) /Ix
Capturing subpattern count = 0
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 3
    (abcd)
 0: (abcd)
    (ab(xy)cd)
 0: (xy)
    (a(b(c)d)e)
 0: (c)
    ((ab))
 0: ((ab))
\= Expect no match
    ()
No match

/\(  (?: (?>[^()]+) | (?R) )? \) /Ix
Capturing subpattern count = 0
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    ()
 0: ()
    12(abcde(fsh)xyz(foo(bar))lmno)89
 0: (fsh)

/\(  ( (?>[^()]+) | (?R) )* \) /Ix
Capturing subpattern count = 1
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: cd

/\( ( ( (?>[^()]+) | (?R) )* ) \) /Ix
Capturing subpattern count = 2
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: ab(xy)cd
 2: cd

/\( (123)? ( ( (?>[^()]+) | (?R) )* ) \) /Ix
Capturing subpattern count = 3
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: <unset>
 2: ab(xy)cd
 3: cd
    (123ab(xy)cd)
 0: (123ab(xy)cd)
 1: 123
 2: ab(xy)cd
 3: cd

/\( ( (123)? ( (?>[^()]+) | (?R) )* ) \) /Ix
Capturing subpattern count = 3
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: ab(xy)cd
 2: <unset>
 3: cd
    (123ab(xy)cd)
 0: (123ab(xy)cd)
 1: 123ab(xy)cd
 2: 123
 3: cd

/\( (((((((((( ( (?>[^()]+) | (?R) )* )))))))))) \) /Ix
Capturing subpattern count = 11
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (ab(xy)cd)
 0: (ab(xy)cd)
 1: ab(xy)cd
 2: ab(xy)cd
 3: ab(xy)cd
 4: ab(xy)cd
 5: ab(xy)cd
 6: ab(xy)cd
 7: ab(xy)cd
 8: ab(xy)cd
 9: ab(xy)cd
10: ab(xy)cd
11: cd

/\( ( ( (?>[^()<>]+) | ((?>[^()]+)) | (?R) )* ) \) /Ix
Capturing subpattern count = 3
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (abcd(xyz<p>qrs)123)
 0: (abcd(xyz<p>qrs)123)
 1: abcd(xyz<p>qrs)123
 2: 123

/\( ( ( (?>[^()]+) | ((?R)) )* ) \) /Ix
Capturing subpattern count = 3
Options: extended
First code unit = '('
Last code unit = ')'
Subject length lower bound = 2
    (ab(cd)ef)
 0: (ab(cd)ef)
 1: ab(cd)ef
 2: ef
 3: (cd)
    (ab(cd(ef)gh)ij)
 0: (ab(cd(ef)gh)ij)
 1: ab(cd(ef)gh)ij
 2: ij
 3: (cd(ef)gh)

/^[[:alnum:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [0-9A-Za-z]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:^alnum:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x00-/:-@[-`{-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:alpha:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [A-Za-z]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:^alpha:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x00-@[-`{-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/[_[:alpha:]]/I
Capturing subpattern count = 0
Starting code units: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
  _ a b c d e f g h i j k l m n o p q r s t u v w x y z 
Subject length lower bound = 1

/^[[:ascii:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x00-\x7f]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:^ascii:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x80-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:blank:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x09 ]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:^blank:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x00-\x08\x0a-\x1f!-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/[\n\x0b\x0c\x0d[:blank:]]/I
Capturing subpattern count = 0
Contains explicit CR or LF match
Starting code units: \x09 \x0a \x0b \x0c \x0d \x20 
Subject length lower bound = 1

/^[[:cntrl:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x00-\x1f\x7f]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:digit:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [0-9]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:graph:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [!-~]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:lower:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [a-z]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:print:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [ -~]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:punct:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [!-/:-@[-`{-~]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:space:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x09-\x0d ]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:upper:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [A-Z]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:xdigit:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [0-9A-Fa-f]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:word:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [0-9A-Z_a-z]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:^cntrl:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [ -~\x80-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[12[:^digit:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x00-/12:-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/^[[:^blank:]]/IB
------------------------------------------------------------------
        Bra
        ^
        [\x00-\x08\x0a-\x1f!-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1

/[01[:alpha:]%]/IB
------------------------------------------------------------------
        Bra
        [%01A-Za-z]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: % 0 1 A B C D E F G H I J K L M N O P Q R S T U V W 
  X Y Z a b c d e f g h i j k l m n o p q r s t u v w x y z 
Subject length lower bound = 1

/[[.ch.]]/I
Failed: error 113 at offset 1: POSIX collating elements are not supported

/[[=ch=]]/I
Failed: error 113 at offset 1: POSIX collating elements are not supported

/[[:rhubarb:]]/I
Failed: error 130 at offset 3: unknown POSIX class name

/[[:upper:]]/Ii
Capturing subpattern count = 0
Options: caseless
Starting code units: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
  a b c d e f g h i j k l m n o p q r s t u v w x y z 
Subject length lower bound = 1
    A
 0: A
    a
 0: a

/[[:lower:]]/Ii
Capturing subpattern count = 0
Options: caseless
Starting code units: A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
  a b c d e f g h i j k l m n o p q r s t u v w x y z 
Subject length lower bound = 1
    A
 0: A
    a
 0: a

/((?-i)[[:lower:]])[[:lower:]]/Ii
Capturing subpattern count = 1
Options: caseless
Starting code units: a b c d e f g h i j k l m n o p q r s t u v w x y z 
Subject length lower bound = 2
    ab
 0: ab
 1: a
    aB
 0: aB
 1: a
\= Expect no match
    Ab
No match
    AB
No match

/[\200-\110]/I
Failed: error 108 at offset 9: range out of order in character class

/^(?(0)f|b)oo/I
Failed: error 135 at offset 6: invalid condition (?(0)

# This one's here because of the large output vector needed

/(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\d+(?:\s|$))(\w+)\s+(\270)/I
Capturing subpattern count = 271
Max back reference = 270
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Subject length lower bound = 272
     1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 ABC ABC\=ovector=300
 0: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 ABC ABC
 1: 1 
 2: 2 
 3: 3 
 4: 4 
 5: 5 
 6: 6 
 7: 7 
 8: 8 
 9: 9 
10: 10 
11: 11 
12: 12 
13: 13 
14: 14 
15: 15 
16: 16 
17: 17 
18: 18 
19: 19 
20: 20 
21: 21 
22: 22 
23: 23 
24: 24 
25: 25 
26: 26 
27: 27 
28: 28 
29: 29 
30: 30 
31: 31 
32: 32 
33: 33 
34: 34 
35: 35 
36: 36 
37: 37 
38: 38 
39: 39 
40: 40 
41: 41 
42: 42 
43: 43 
44: 44 
45: 45 
46: 46 
47: 47 
48: 48 
49: 49 
50: 50 
51: 51 
52: 52 
53: 53 
54: 54 
55: 55 
56: 56 
57: 57 
58: 58 
59: 59 
60: 60 
61: 61 
62: 62 
63: 63 
64: 64 
65: 65 
66: 66 
67: 67 
68: 68 
69: 69 
70: 70 
71: 71 
72: 72 
73: 73 
74: 74 
75: 75 
76: 76 
77: 77 
78: 78 
79: 79 
80: 80 
81: 81 
82: 82 
83: 83 
84: 84 
85: 85 
86: 86 
87: 87 
88: 88 
89: 89 
90: 90 
91: 91 
92: 92 
93: 93 
94: 94 
95: 95 
96: 96 
97: 97 
98: 98 
99: 99 
100: 100 
101: 101 
102: 102 
103: 103 
104: 104 
105: 105 
106: 106 
107: 107 
108: 108 
109: 109 
110: 110 
111: 111 
112: 112 
113: 113 
114: 114 
115: 115 
116: 116 
117: 117 
118: 118 
119: 119 
120: 120 
121: 121 
122: 122 
123: 123 
124: 124 
125: 125 
126: 126 
127: 127 
128: 128 
129: 129 
130: 130 
131: 131 
132: 132 
133: 133 
134: 134 
135: 135 
136: 136 
137: 137 
138: 138 
139: 139 
140: 140 
141: 141 
142: 142 
143: 143 
144: 144 
145: 145 
146: 146 
147: 147 
148: 148 
149: 149 
150: 150 
151: 151 
152: 152 
153: 153 
154: 154 
155: 155 
156: 156 
157: 157 
158: 158 
159: 159 
160: 160 
161: 161 
162: 162 
163: 163 
164: 164 
165: 165 
166: 166 
167: 167 
168: 168 
169: 169 
170: 170 
171: 171 
172: 172 
173: 173 
174: 174 
175: 175 
176: 176 
177: 177 
178: 178 
179: 179 
180: 180 
181: 181 
182: 182 
183: 183 
184: 184 
185: 185 
186: 186 
187: 187 
188: 188 
189: 189 
190: 190 
191: 191 
192: 192 
193: 193 
194: 194 
195: 195 
196: 196 
197: 197 
198: 198 
199: 199 
200: 200 
201: 201 
202: 202 
203: 203 
204: 204 
205: 205 
206: 206 
207: 207 
208: 208 
209: 209 
210: 210 
211: 211 
212: 212 
213: 213 
214: 214 
215: 215 
216: 216 
217: 217 
218: 218 
219: 219 
220: 220 
221: 221 
222: 222 
223: 223 
224: 224 
225: 225 
226: 226 
227: 227 
228: 228 
229: 229 
230: 230 
231: 231 
232: 232 
233: 233 
234: 234 
235: 235 
236: 236 
237: 237 
238: 238 
239: 239 
240: 240 
241: 241 
242: 242 
243: 243 
244: 244 
245: 245 
246: 246 
247: 247 
248: 248 
249: 249 
250: 250 
251: 251 
252: 252 
253: 253 
254: 254 
255: 255 
256: 256 
257: 257 
258: 258 
259: 259 
260: 260 
261: 261 
262: 262 
263: 263 
264: 264 
265: 265 
266: 266 
267: 267 
268: 268 
269: 269 
270: ABC
271: ABC

# This one's here because Perl does this differently and PCRE2 can't at present

/(main(O)?)+/I
Capturing subpattern count = 2
First code unit = 'm'
Last code unit = 'n'
Subject length lower bound = 4
    mainmain
 0: mainmain
 1: main
    mainOmain
 0: mainOmain
 1: main
 2: O

# These are all cases where Perl does it differently (nested captures)

/^(a(b)?)+$/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1
    aba
 0: aba
 1: a
 2: b

/^(aa(bb)?)+$/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: aa
 2: bb

/^(aa|aa(bb))+$/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: aa
 2: bb

/^(aa(bb)??)+$/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: aa
 2: bb

/^(?:aa(bb)?)+$/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: bb

/^(aa(b(b))?)+$/I
Capturing subpattern count = 3
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: aa
 2: bb
 3: b

/^(?:aa(b(b))?)+$/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: bb
 2: b

/^(?:aa(b(?:b))?)+$/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: bb

/^(?:aa(bb(?:b))?)+$/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbbaa
 0: aabbbaa
 1: bbb

/^(?:aa(b(?:bb))?)+$/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbbaa
 0: aabbbaa
 1: bbb

/^(?:aa(?:b(b))?)+$/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbaa
 0: aabbaa
 1: b

/^(?:aa(?:b(bb))?)+$/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbbaa
 0: aabbbaa
 1: bb

/^(aa(b(bb))?)+$/I
Capturing subpattern count = 3
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbbaa
 0: aabbbaa
 1: aa
 2: bbb
 3: bb

/^(aa(bb(bb))?)+$/I
Capturing subpattern count = 3
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    aabbbbaa
 0: aabbbbaa
 1: aa
 2: bbbb
 3: bb

# ----------------

/#/IBx
------------------------------------------------------------------
        Bra
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
May match empty string
Options: extended
Subject length lower bound = 0

/a#/IBx
------------------------------------------------------------------
        Bra
        a
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: extended
First code unit = 'a'
Subject length lower bound = 1

/[\s]/IB
------------------------------------------------------------------
        Bra
        [\x09-\x0d ]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: \x09 \x0a \x0b \x0c \x0d \x20 
Subject length lower bound = 1

/[\S]/IB
------------------------------------------------------------------
        Bra
        [\x00-\x08\x0e-\x1f!-\xff] (neg)
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: \x00 \x01 \x02 \x03 \x04 \x05 \x06 \x07 \x08 \x0e \x0f 
  \x10 \x11 \x12 \x13 \x14 \x15 \x16 \x17 \x18 \x19 \x1a \x1b \x1c \x1d \x1e 
  \x1f ! " # $ % & ' ( ) * + , - . / 0 1 2 3 4 5 6 7 8 9 : ; < = > ? @ A B C 
  D E F G H I J K L M N O P Q R S T U V W X Y Z [ \ ] ^ _ ` a b c d e f g h 
  i j k l m n o p q r s t u v w x y z { | } ~ \x7f \x80 \x81 \x82 \x83 \x84 
  \x85 \x86 \x87 \x88 \x89 \x8a \x8b \x8c \x8d \x8e \x8f \x90 \x91 \x92 \x93 
  \x94 \x95 \x96 \x97 \x98 \x99 \x9a \x9b \x9c \x9d \x9e \x9f \xa0 \xa1 \xa2 
  \xa3 \xa4 \xa5 \xa6 \xa7 \xa8 \xa9 \xaa \xab \xac \xad \xae \xaf \xb0 \xb1 
  \xb2 \xb3 \xb4 \xb5 \xb6 \xb7 \xb8 \xb9 \xba \xbb \xbc \xbd \xbe \xbf \xc0 
  \xc1 \xc2 \xc3 \xc4 \xc5 \xc6 \xc7 \xc8 \xc9 \xca \xcb \xcc \xcd \xce \xcf 
  \xd0 \xd1 \xd2 \xd3 \xd4 \xd5 \xd6 \xd7 \xd8 \xd9 \xda \xdb \xdc \xdd \xde 
  \xdf \xe0 \xe1 \xe2 \xe3 \xe4 \xe5 \xe6 \xe7 \xe8 \xe9 \xea \xeb \xec \xed 
  \xee \xef \xf0 \xf1 \xf2 \xf3 \xf4 \xf5 \xf6 \xf7 \xf8 \xf9 \xfa \xfb \xfc 
  \xfd \xfe \xff 
Subject length lower bound = 1

/a(?i)b/IB
------------------------------------------------------------------
        Bra
        a
     /i b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b' (caseless)
Subject length lower bound = 2
    ab
 0: ab
    aB
 0: aB
\= Expect no match
    AB
No match

/(a(?i)b)/IB
------------------------------------------------------------------
        Bra
        CBra 1
        a
     /i b
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b' (caseless)
Subject length lower bound = 2
    ab
 0: ab
 1: ab
    aB
 0: aB
 1: aB
\= Expect no match
    AB
No match

/   (?i)abc/IBx
------------------------------------------------------------------
        Bra
     /i abc
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: extended
First code unit = 'a' (caseless)
Last code unit = 'c' (caseless)
Subject length lower bound = 3

/#this is a comment
  (?i)abc/IBx
------------------------------------------------------------------
        Bra
     /i abc
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: extended
First code unit = 'a' (caseless)
Last code unit = 'c' (caseless)
Subject length lower bound = 3

/123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890/IB
------------------------------------------------------------------
        Bra
        123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = '1'
Last code unit = '0'
Subject length lower bound = 300

/\Q123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890/IB
------------------------------------------------------------------
        Bra
        123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = '1'
Last code unit = '0'
Subject length lower bound = 300

/\Q\E/IB
------------------------------------------------------------------
        Bra
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    \
 0: 

/\Q\Ex/IB
------------------------------------------------------------------
        Bra
        x
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'x'
Subject length lower bound = 1

/ \Q\E/IB
------------------------------------------------------------------
        Bra
         
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = ' '
Subject length lower bound = 1

/a\Q\E/IB
------------------------------------------------------------------
        Bra
        a
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1
  abc
 0: a
  bca
 0: a
  bac
 0: a

/a\Q\Eb/IB
------------------------------------------------------------------
        Bra
        ab
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
  abc
 0: ab

/\Q\Eabc/IB
------------------------------------------------------------------
        Bra
        abc
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/x*+\w/IB
------------------------------------------------------------------
        Bra
        x*+
        \w
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P 
  Q R S T U V W X Y Z _ a b c d e f g h i j k l m n o p q r s t u v w x y z 
Subject length lower bound = 1
\= Expect no match
    xxxxx
No match

/x?+/IB
------------------------------------------------------------------
        Bra
        x?+
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0

/x++/IB
------------------------------------------------------------------
        Bra
        x++
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'x'
Subject length lower bound = 1

/x{1,3}+/B,no_auto_possess
------------------------------------------------------------------
        Bra
        x
        x{0,2}+
        Ket
        End
------------------------------------------------------------------

/x{1,3}+/Bi,no_auto_possess
------------------------------------------------------------------
        Bra
     /i x
     /i x{0,2}+
        Ket
        End
------------------------------------------------------------------

/[^x]{1,3}+/B,no_auto_possess
------------------------------------------------------------------
        Bra
        [^x]
        [^x]{0,2}+
        Ket
        End
------------------------------------------------------------------

/[^x]{1,3}+/Bi,no_auto_possess
------------------------------------------------------------------
        Bra
     /i [^x]
     /i [^x]{0,2}+
        Ket
        End
------------------------------------------------------------------

/(x)*+/IB
------------------------------------------------------------------
        Bra
        Braposzero
        CBraPos 1
        x
        KetRpos
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0

/^(\w++|\s++)*$/I
Capturing subpattern count = 1
May match empty string
Compile options: <none>
Overall options: anchored
Subject length lower bound = 0
    now is the time for all good men to come to the aid of the party
 0: now is the time for all good men to come to the aid of the party
 1: party
\= Expect no match
    this is not a line with only words and spaces!
No match

/(\d++)(\w)/I
Capturing subpattern count = 2
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Subject length lower bound = 2
    12345a
 0: 12345a
 1: 12345
 2: a
\= Expect no match
    12345+
No match

/a++b/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
    aaab
 0: aaab

/(a++b)/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
    aaab
 0: aaab
 1: aaab

/(a++)b/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
    aaab
 0: aaab
 1: aaa

/([^()]++|\([^()]*\))+/I
Capturing subpattern count = 1
Starting code units: \x00 \x01 \x02 \x03 \x04 \x05 \x06 \x07 \x08 \x09 \x0a 
  \x0b \x0c \x0d \x0e \x0f \x10 \x11 \x12 \x13 \x14 \x15 \x16 \x17 \x18 \x19 
  \x1a \x1b \x1c \x1d \x1e \x1f \x20 ! " # $ % & ' ( * + , - . / 0 1 2 3 4 5 
  6 7 8 9 : ; < = > ? @ A B C D E F G H I J K L M N O P Q R S T U V W X Y Z 
  [ \ ] ^ _ ` a b c d e f g h i j k l m n o p q r s t u v w x y z { | } ~ \x7f 
  \x80 \x81 \x82 \x83 \x84 \x85 \x86 \x87 \x88 \x89 \x8a \x8b \x8c \x8d \x8e 
  \x8f \x90 \x91 \x92 \x93 \x94 \x95 \x96 \x97 \x98 \x99 \x9a \x9b \x9c \x9d 
  \x9e \x9f \xa0 \xa1 \xa2 \xa3 \xa4 \xa5 \xa6 \xa7 \xa8 \xa9 \xaa \xab \xac 
  \xad \xae \xaf \xb0 \xb1 \xb2 \xb3 \xb4 \xb5 \xb6 \xb7 \xb8 \xb9 \xba \xbb 
  \xbc \xbd \xbe \xbf \xc0 \xc1 \xc2 \xc3 \xc4 \xc5 \xc6 \xc7 \xc8 \xc9 \xca 
  \xcb \xcc \xcd \xce \xcf \xd0 \xd1 \xd2 \xd3 \xd4 \xd5 \xd6 \xd7 \xd8 \xd9 
  \xda \xdb \xdc \xdd \xde \xdf \xe0 \xe1 \xe2 \xe3 \xe4 \xe5 \xe6 \xe7 \xe8 
  \xe9 \xea \xeb \xec \xed \xee \xef \xf0 \xf1 \xf2 \xf3 \xf4 \xf5 \xf6 \xf7 
  \xf8 \xf9 \xfa \xfb \xfc \xfd \xfe \xff 
Subject length lower bound = 1
    ((abc(ade)ufh()()x
 0: abc(ade)ufh()()x
 1: x

/\(([^()]++|\([^()]+\))+\)/I
Capturing subpattern count = 1
First code unit = '('
Last code unit = ')'
Subject length lower bound = 3
    (abc)
 0: (abc)
 1: abc
    (abc(def)xyz)
 0: (abc(def)xyz)
 1: xyz
\= Expect no match
    ((()aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
No match

/(abc){1,3}+/IB
------------------------------------------------------------------
        Bra
        Once
        CBra 1
        abc
        Ket
        Brazero
        Bra
        CBra 1
        abc
        Ket
        Brazero
        CBra 1
        abc
        Ket
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/a+?+/I
Failed: error 109 at offset 3: quantifier does not follow a repeatable item

/a{2,3}?+b/I
Failed: error 109 at offset 7: quantifier does not follow a repeatable item

/(?U)a+?+/I
Failed: error 109 at offset 7: quantifier does not follow a repeatable item

/a{2,3}?+b/I,ungreedy
Failed: error 109 at offset 7: quantifier does not follow a repeatable item

/x(?U)a++b/IB
------------------------------------------------------------------
        Bra
        x
        a++
        b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'x'
Last code unit = 'b'
Subject length lower bound = 3
    xaaaab
 0: xaaaab

/(?U)xa++b/IB
------------------------------------------------------------------
        Bra
        x
        a++
        b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'x'
Last code unit = 'b'
Subject length lower bound = 3
    xaaaab
 0: xaaaab

/^((a+)(?U)([ab]+)(?-U)([bc]+)(\w*))/IB
------------------------------------------------------------------
        Bra
        ^
        CBra 1
        CBra 2
        a+
        Ket
        CBra 3
        [ab]+?
        Ket
        CBra 4
        [bc]+
        Ket
        CBra 5
        \w*+
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 5
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3

/^x(?U)a+b/IB
------------------------------------------------------------------
        Bra
        ^
        x
        a++
        b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Last code unit = 'b'
Subject length lower bound = 3

/^x(?U)(a+)b/IB
------------------------------------------------------------------
        Bra
        ^
        x
        CBra 1
        a+?
        Ket
        b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Last code unit = 'b'
Subject length lower bound = 3

/[.x.]/I
Failed: error 113 at offset 0: POSIX collating elements are not supported

/[=x=]/I
Failed: error 113 at offset 0: POSIX collating elements are not supported

/[:x:]/I
Failed: error 112 at offset 0: POSIX named classes are supported only within a class

/\l/I
Failed: error 137 at offset 1: PCRE does not support \L, \l, \N{name}, \U, or \u

/\L/I
Failed: error 137 at offset 1: PCRE does not support \L, \l, \N{name}, \U, or \u

/\N{name}/I
Failed: error 137 at offset 1: PCRE does not support \L, \l, \N{name}, \U, or \u

/\u/I
Failed: error 137 at offset 1: PCRE does not support \L, \l, \N{name}, \U, or \u

/\U/I
Failed: error 137 at offset 1: PCRE does not support \L, \l, \N{name}, \U, or \u

/a{1,3}b/ungreedy
    ab
 0: ab

/[/I
Failed: error 106 at offset 1: missing terminating ] for character class

/[a-/I
Failed: error 106 at offset 3: missing terminating ] for character class

/[[:space:]/I
Failed: error 106 at offset 10: missing terminating ] for character class

/[\s]/IB
------------------------------------------------------------------
        Bra
        [\x09-\x0d ]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: \x09 \x0a \x0b \x0c \x0d \x20 
Subject length lower bound = 1

/[[:space:]]/IB
------------------------------------------------------------------
        Bra
        [\x09-\x0d ]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: \x09 \x0a \x0b \x0c \x0d \x20 
Subject length lower bound = 1

/[[:space:]abcde]/IB
------------------------------------------------------------------
        Bra
        [\x09-\x0d a-e]
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: \x09 \x0a \x0b \x0c \x0d \x20 a b c d e 
Subject length lower bound = 1

/< (?: (?(R) \d++  | [^<>]*+) | (?R)) * >/Ix
Capturing subpattern count = 0
Options: extended
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 2
    <>
 0: <>
    <abcd>
 0: <abcd>
    <abc <123> hij>
 0: <abc <123> hij>
    <abc <def> hij>
 0: <def>
    <abc<>def>
 0: <abc<>def>
    <abc<>
 0: <>
\= Expect no match
    <abc
No match

/8J\$WE\<\.rX\+ix\[d1b\!H\#\?vV0vrK\:ZH1\=2M\>iV\;\?aPhFB\<\*vW\@QW\@sO9\}cfZA\-i\'w\%hKd6gt1UJP\,15_\#QY\$M\^Mss_U\/\]\&LK9\[5vQub\^w\[KDD\<EjmhUZ\?\.akp2dF\>qmj\;2\}YWFdYx\.Ap\]hjCPTP\(n28k\+3\;o\&WXqs\/gOXdr\$\:r\'do0\;b4c\(f_Gr\=\"\\4\)\[01T7ajQJvL\$W\~mL_sS\/4h\:x\*\[ZN\=KLs\&L5zX\/\/\>it\,o\:aU\(\;Z\>pW\&T7oP\'2K\^E\:x9\'c\[\%z\-\,64JQ5AeH_G\#KijUKghQw\^\\vea3a\?kka_G\$8\#\`\*kynsxzBLru\'\]k_\[7FrVx\}\^\=\$blx\>s\-N\%j\;D\*aZDnsw\:YKZ\%Q\.Kne9\#hP\?\+b3\(SOvL\,\^\;\&u5\@\?5C5Bhb\=m\-vEh_L15Jl\]U\)0RP6\{q\%L\^_z5E\'Dw6X\b/IB
------------------------------------------------------------------
        Bra
        8J$WE<.rX+ix[d1b!H#?vV0vrK:ZH1=2M>iV;?aPhFB<*vW@QW@sO9}cfZA-i'w%hKd6gt1UJP,15_#QY$M^Mss_U/]&LK9[5vQub^w[KDD<EjmhUZ?.akp2dF>qmj;2}YWFdYx.Ap]hjCPTP(n28k+3;o&WXqs/gOXdr$:r'do0;b4c(f_Gr="\4)[01T7ajQJvL$W~mL_sS/4h:x*[ZN=KLs&L5zX//>it,o:aU(;Z>pW&T7oP'2K^E:x9'c[%z-,64JQ5AeH_G#KijUKghQw^\vea3a?kka_G$8#`*kynsxzBLru']k_[7FrVx}^=$blx>s-N%j;D*aZDnsw:YKZ%Q.Kne9#hP?+b3(SOvL,^;&u5@?5C5Bhb=m-vEh_L15Jl]U)0RP6{q%L^_z5E'Dw6X
        \b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = '8'
Last code unit = 'X'
Subject length lower bound = 409

/\$\<\.X\+ix\[d1b\!H\#\?vV0vrK\:ZH1\=2M\>iV\;\?aPhFB\<\*vW\@QW\@sO9\}cfZA\-i\'w\%hKd6gt1UJP\,15_\#QY\$M\^Mss_U\/\]\&LK9\[5vQub\^w\[KDD\<EjmhUZ\?\.akp2dF\>qmj\;2\}YWFdYx\.Ap\]hjCPTP\(n28k\+3\;o\&WXqs\/gOXdr\$\:r\'do0\;b4c\(f_Gr\=\"\\4\)\[01T7ajQJvL\$W\~mL_sS\/4h\:x\*\[ZN\=KLs\&L5zX\/\/\>it\,o\:aU\(\;Z\>pW\&T7oP\'2K\^E\:x9\'c\[\%z\-\,64JQ5AeH_G\#KijUKghQw\^\\vea3a\?kka_G\$8\#\`\*kynsxzBLru\'\]k_\[7FrVx\}\^\=\$blx\>s\-N\%j\;D\*aZDnsw\:YKZ\%Q\.Kne9\#hP\?\+b3\(SOvL\,\^\;\&u5\@\?5C5Bhb\=m\-vEh_L15Jl\]U\)0RP6\{q\%L\^_z5E\'Dw6X\b/IB
------------------------------------------------------------------
        Bra
        $<.X+ix[d1b!H#?vV0vrK:ZH1=2M>iV;?aPhFB<*vW@QW@sO9}cfZA-i'w%hKd6gt1UJP,15_#QY$M^Mss_U/]&LK9[5vQub^w[KDD<EjmhUZ?.akp2dF>qmj;2}YWFdYx.Ap]hjCPTP(n28k+3;o&WXqs/gOXdr$:r'do0;b4c(f_Gr="\4)[01T7ajQJvL$W~mL_sS/4h:x*[ZN=KLs&L5zX//>it,o:aU(;Z>pW&T7oP'2K^E:x9'c[%z-,64JQ5AeH_G#KijUKghQw^\vea3a?kka_G$8#`*kynsxzBLru']k_[7FrVx}^=$blx>s-N%j;D*aZDnsw:YKZ%Q.Kne9#hP?+b3(SOvL,^;&u5@?5C5Bhb=m-vEh_L15Jl]U)0RP6{q%L^_z5E'Dw6X
        \b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = '$'
Last code unit = 'X'
Subject length lower bound = 404

/(.*)\d+\1/I
Capturing subpattern count = 1
Max back reference = 1
Subject length lower bound = 1

/(.*)\d+/I
Capturing subpattern count = 1
First code unit at start or follows newline
Subject length lower bound = 1

/(.*)\d+\1/Is
Capturing subpattern count = 1
Max back reference = 1
Options: dotall
Subject length lower bound = 1

/(.*)\d+/Is
Capturing subpattern count = 1
Compile options: dotall
Overall options: anchored dotall
Subject length lower bound = 1

/(.*(xyz))\d+\2/I
Capturing subpattern count = 2
Max back reference = 2
First code unit at start or follows newline
Last code unit = 'z'
Subject length lower bound = 7

/((.*))\d+\1/I
Capturing subpattern count = 2
Max back reference = 1
Subject length lower bound = 1
    abc123bc
 0: bc123bc
 1: bc
 2: bc

/a[b]/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/(?=a).*/I
Capturing subpattern count = 0
May match empty string
First code unit = 'a'
Subject length lower bound = 0

/(?=abc).xyz/Ii
Capturing subpattern count = 0
Options: caseless
First code unit = 'a' (caseless)
Last code unit = 'z' (caseless)
Subject length lower bound = 4

/(?=abc)(?i).xyz/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'z' (caseless)
Subject length lower bound = 4

/(?=a)(?=b)/I
Capturing subpattern count = 0
May match empty string
First code unit = 'a'
Subject length lower bound = 0

/(?=.)a/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1

/((?=abcda)a)/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'a'
Subject length lower bound = 1

/((?=abcda)ab)/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/()a/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/(?:(?=.)|(?<!x))a/I
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = 'a'
Subject length lower bound = 1

/(?(1)ab|ac)(.)/I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'a'
Subject length lower bound = 3

/(?(1)abz|acz)(.)/I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'a'
Last code unit = 'z'
Subject length lower bound = 4

/(?(1)abz)(.)/I
Capturing subpattern count = 1
Max back reference = 1
Subject length lower bound = 1

/(?(1)abz)(1)23/I
Capturing subpattern count = 1
Max back reference = 1
Last code unit = '3'
Subject length lower bound = 3

/(a)+/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/(a){2,3}/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'a'
Subject length lower bound = 2

/(a)*/I
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0

/[a]/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1

/[ab]/I
Capturing subpattern count = 0
Starting code units: a b 
Subject length lower bound = 1

/[ab]/I
Capturing subpattern count = 0
Starting code units: a b 
Subject length lower bound = 1

/[^a]/I
Capturing subpattern count = 0
Subject length lower bound = 1

/\d456/I
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Last code unit = '6'
Subject length lower bound = 4

/\d456/I
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Last code unit = '6'
Subject length lower bound = 4

/a^b/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/^a/Im
Capturing subpattern count = 0
Options: multiline
First code unit at start or follows newline
Last code unit = 'a'
Subject length lower bound = 1
  abcde
 0: a
  xy\nabc
 0: a
\= Expect no match
  xyabc
No match

/c|abc/I
Capturing subpattern count = 0
Starting code units: a c 
Last code unit = 'c'
Subject length lower bound = 1

/(?i)[ab]/I
Capturing subpattern count = 0
Starting code units: A B a b 
Subject length lower bound = 1

/[ab](?i)cd/I
Capturing subpattern count = 0
Starting code units: a b 
Last code unit = 'd' (caseless)
Subject length lower bound = 3

/abc(?C)def/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'f'
Subject length lower bound = 6
    abcdef
--->abcdef
  0 ^  ^       d
 0: abcdef
    1234abcdef
--->1234abcdef
  0     ^  ^       d
 0: abcdef
\= Expect no match
    abcxyz
No match
    abcxyzf
--->abcxyzf
  0 ^  ^        d
No match

/abc(?C)de(?C1)f/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'f'
Subject length lower bound = 6
    123abcdef
--->123abcdef
  0    ^  ^       d
  1    ^    ^     f
 0: abcdef

/(?C1)\dabc(?C2)def/I
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Last code unit = 'f'
Subject length lower bound = 7
    1234abcdef
--->1234abcdef
  1 ^              \d
  1  ^             \d
  1   ^            \d
  1    ^           \d
  2    ^   ^       d
 0: 4abcdef
\= Expect no match
    abcdef
No match

/(?C1)\dabc(?C2)def/I
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Last code unit = 'f'
Subject length lower bound = 7
    1234abcdef
--->1234abcdef
  1 ^              \d
  1  ^             \d
  1   ^            \d
  1    ^           \d
  2    ^   ^       d
 0: 4abcdef
\= Expect no match
    abcdef
No match

/(?C255)ab/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/(?C256)ab/I
Failed: error 138 at offset 6: number after (?C is greater than 255

/(?Cab)xx/I
Failed: error 182 at offset 3: unrecognized string delimiter follows (?C

/(?C12vr)x/I
Failed: error 139 at offset 5: closing parenthesis for (?C expected

/abc(?C)def/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'f'
Subject length lower bound = 6
    \x83\x0\x61bcdef
--->\x83\x00abcdef
  0         ^  ^       d
 0: abcdef

/(abc)(?C)de(?C1)f/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'f'
Subject length lower bound = 6
    123abcdef
--->123abcdef
  0    ^  ^       d
  1    ^    ^     f
 0: abcdef
 1: abc
    123abcdef\=callout_capture
Callout 0: last capture = 1
 0: <unset>
 1: abc
--->123abcdef
       ^  ^       d
Callout 1: last capture = 1
 0: <unset>
 1: abc
--->123abcdef
       ^    ^     f
 0: abcdef
 1: abc
    123abcdefC-\=callout_none
 0: abcdef
 1: abc
\= Expect no match
    123abcdef\=callout_fail=1
--->123abcdef
  0    ^  ^       d
  1    ^    ^     f
No match

/(?C0)(abc(?C1))*/I
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0
    abcabcabc
--->abcabcabc
  0 ^             (abc(?C1))*
  1 ^  ^          )
  1 ^     ^       )
  1 ^        ^    )
 0: abcabcabc
 1: abc
    abcabc\=callout_fail=1:3
--->abcabc
  0 ^          (abc(?C1))*
  1 ^  ^       )
  1 ^     ^    )
 0: abcabc
 1: abc
    abcabcabc\=callout_fail=1:3
--->abcabcabc
  0 ^             (abc(?C1))*
  1 ^  ^          )
  1 ^     ^       )
  1 ^        ^    )
 0: abcabc
 1: abc

/(\d{3}(?C))*/I
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0
    123\=callout_capture
Callout 0: last capture = 0
 0: <unset>
--->123
    ^  ^    )
 0: 123
 1: 123
    123456\=callout_capture
Callout 0: last capture = 0
 0: <unset>
--->123456
    ^  ^       )
Callout 0: last capture = 1
 0: <unset>
 1: 123
--->123456
    ^     ^    )
 0: 123456
 1: 456
    123456789\=callout_capture
Callout 0: last capture = 0
 0: <unset>
--->123456789
    ^  ^          )
Callout 0: last capture = 1
 0: <unset>
 1: 123
--->123456789
    ^     ^       )
Callout 0: last capture = 1
 0: <unset>
 1: 456
--->123456789
    ^        ^    )
 0: 123456789
 1: 789

/((xyz)(?C)p|(?C1)xyzabc)/I
Capturing subpattern count = 2
First code unit = 'x'
Subject length lower bound = 4
    xyzabc\=callout_capture
Callout 0: last capture = 2
 0: <unset>
 1: <unset>
 2: xyz
--->xyzabc
    ^  ^       p
Callout 1: last capture = 0
 0: <unset>
--->xyzabc
    ^          x
 0: xyzabc
 1: xyzabc

/(X)((xyz)(?C)p|(?C1)xyzabc)/I
Capturing subpattern count = 3
First code unit = 'X'
Last code unit = 'x'
Subject length lower bound = 5
    Xxyzabc\=callout_capture
Callout 0: last capture = 3
 0: <unset>
 1: X
 2: <unset>
 3: xyz
--->Xxyzabc
    ^   ^       p
Callout 1: last capture = 1
 0: <unset>
 1: X
--->Xxyzabc
    ^^          x
 0: Xxyzabc
 1: X
 2: xyzabc

/(?=(abc))(?C)abcdef/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'f'
Subject length lower bound = 6
    abcdef\=callout_capture
Callout 0: last capture = 1
 0: <unset>
 1: abc
--->abcdef
    ^          a
 0: abcdef
 1: abc

/(?!(abc)(?C1)d)(?C2)abcxyz/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'z'
Subject length lower bound = 6
    abcxyz\=callout_capture
Callout 1: last capture = 1
 0: <unset>
 1: abc
--->abcxyz
    ^  ^       d
Callout 2: last capture = 0
 0: <unset>
--->abcxyz
    ^          a
 0: abcxyz

/(?<=(abc)(?C))xyz/I
Capturing subpattern count = 1
Max lookbehind = 3
First code unit = 'x'
Last code unit = 'z'
Subject length lower bound = 3
   abcxyz\=callout_capture
Callout 0: last capture = 1
 0: <unset>
 1: abc
--->abcxyz
       ^       )
 0: xyz
 1: abc

/a(b+)(c*)(?C1)/I
Capturing subpattern count = 2
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
\= Expect no match
    abbbbbccc\=callout_data=1
--->abbbbbccc
  1 ^        ^    
Callout data = 1
No match

/a(b+?)(c*?)(?C1)/I
Capturing subpattern count = 2
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
\= Expect no match
    abbbbbccc\=callout_data=1
--->abbbbbccc
  1 ^ ^           
Callout data = 1
  1 ^  ^          
Callout data = 1
  1 ^   ^         
Callout data = 1
  1 ^    ^        
Callout data = 1
  1 ^     ^       
Callout data = 1
  1 ^      ^      
Callout data = 1
  1 ^       ^     
Callout data = 1
  1 ^        ^    
Callout data = 1
No match

/(?C)abc/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/(?C)^abc/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3

/(?C)a|b/I
Capturing subpattern count = 0
Starting code units: a b 
Subject length lower bound = 1

/x(ab|(bc|(de|(?R))))/I
Capturing subpattern count = 3
First code unit = 'x'
Subject length lower bound = 3
    xab
 0: xab
 1: ab
    xbc
 0: xbc
 1: bc
 2: bc
    xde
 0: xde
 1: de
 2: de
 3: de
    xxab
 0: xxab
 1: xab
 2: xab
 3: xab
    xxxab
 0: xxxab
 1: xxab
 2: xxab
 3: xxab
\= Expect no match
    xyab
No match

/^([^()]|\((?1)*\))*$/I
Capturing subpattern count = 1
May match empty string
Compile options: <none>
Overall options: anchored
Subject length lower bound = 0
    abc
 0: abc
 1: c
    a(b)c
 0: a(b)c
 1: c
    a(b(c))d
 0: a(b(c))d
 1: d
\= Expect no match)
    a(b(c)d
No match

/^>abc>([^()]|\((?1)*\))*<xyz<$/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Last code unit = '<'
Subject length lower bound = 10
   >abc>123<xyz<
 0: >abc>123<xyz<
 1: 3
   >abc>1(2)3<xyz<
 0: >abc>1(2)3<xyz<
 1: 3
   >abc>(1(2)3)<xyz<
 0: >abc>(1(2)3)<xyz<
 1: (1(2)3)

/(a(?1)b)/IB
------------------------------------------------------------------
        Bra
        CBra 1
        a
        Recurse
        b
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/(a(?1)+b)/IB
------------------------------------------------------------------
        Bra
        CBra 1
        a
        Once
        Recurse
        KetRmax
        b
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/^(\d+|\((?1)([+*-])(?1)\)|-(?1))$/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1
    12
 0: 12
 1: 12
    (((2+2)*-3)-7)
 0: (((2+2)*-3)-7)
 1: (((2+2)*-3)-7)
 2: -
    -12
 0: -12
 1: -12
\= Expect no match
    ((2+2)*-3)-7)
No match

/^(x(y|(?1){2})z)/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
    xyz
 0: xyz
 1: xyz
 2: y
    xxyzxyzz
 0: xxyzxyzz
 1: xxyzxyzz
 2: xyzxyz
\= Expect no match
    xxyzz
No match
    xxyzxyzxyzz
No match

/((< (?: (?(R) \d++  | [^<>]*+) | (?2)) * >))/Ix
Capturing subpattern count = 2
Options: extended
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 2
    <>
 0: <>
 1: <>
 2: <>
    <abcd>
 0: <abcd>
 1: <abcd>
 2: <abcd>
    <abc <123> hij>
 0: <abc <123> hij>
 1: <abc <123> hij>
 2: <abc <123> hij>
    <abc <def> hij>
 0: <def>
 1: <def>
 2: <def>
    <abc<>def>
 0: <abc<>def>
 1: <abc<>def>
 2: <abc<>def>
    <abc<>
 0: <>
 1: <>
 2: <>
\= Expect no match
    <abc
No match

/(?1)/I
Failed: error 115 at offset 3: reference to non-existent subpattern

/((?2)(abc)/I
Failed: error 114 at offset 10: missing closing parenthesis

/^(abc)def(?1)/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 9
    abcdefabc
 0: abcdefabc
 1: abc

/^(a|b|c)=(?1)+/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3
    a=a
 0: a=a
 1: a
    a=b
 0: a=b
 1: a
    a=bc
 0: a=bc
 1: a

/^(a|b|c)=((?1))+/I
Capturing subpattern count = 2
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2
    a=a
 0: a=a
 1: a
 2: a
    a=b
 0: a=b
 1: a
 2: b
    a=bc
 0: a=bc
 1: a
 2: c

/a(?P<name1>b|c)d(?P<longername2>e)/IB
------------------------------------------------------------------
        Bra
        a
        CBra 1
        b
        Alt
        c
        Ket
        d
        CBra 2
        e
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 2
Named capturing subpatterns:
  longername2   2
  name1         1
First code unit = 'a'
Last code unit = 'e'
Subject length lower bound = 4
    abde
 0: abde
 1: b
 2: e
    acde
 0: acde
 1: c
 2: e

/(?:a(?P<c>c(?P<d>d)))(?P<a>a)/IB
------------------------------------------------------------------
        Bra
        Bra
        a
        CBra 1
        c
        CBra 2
        d
        Ket
        Ket
        Ket
        CBra 3
        a
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 3
Named capturing subpatterns:
  a   3
  c   1
  d   2
First code unit = 'a'
Last code unit = 'a'
Subject length lower bound = 4

/(?P<a>a)...(?P=a)bbb(?P>a)d/IB
------------------------------------------------------------------
        Bra
        CBra 1
        a
        Ket
        Any
        Any
        Any
        \1
        bbb
        Recurse
        d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Max back reference = 1
Named capturing subpatterns:
  a   1
First code unit = 'a'
Last code unit = 'd'
Subject length lower bound = 10

/^\W*(?:(?P<one>(?P<two>.)\W*(?P>one)\W*(?P=two)|)|(?P<three>(?P<four>.)\W*(?P>three)\W*(?P=four)|\W*.\W*))\W*$/Ii
Capturing subpattern count = 4
Max back reference = 4
Named capturing subpatterns:
  four    4
  one     1
  three   3
  two     2
May match empty string
Compile options: caseless
Overall options: anchored caseless
Subject length lower bound = 0
    1221
 0: 1221
 1: 1221
 2: 1
    Satan, oscillate my metallic sonatas!
 0: Satan, oscillate my metallic sonatas!
 1: <unset>
 2: <unset>
 3: Satan, oscillate my metallic sonatas
 4: S
    A man, a plan, a canal: Panama!
 0: A man, a plan, a canal: Panama!
 1: <unset>
 2: <unset>
 3: A man, a plan, a canal: Panama
 4: A
    Able was I ere I saw Elba.
 0: Able was I ere I saw Elba.
 1: <unset>
 2: <unset>
 3: Able was I ere I saw Elba
 4: A
\= Expect no match
    The quick brown fox
No match

/((?(R)a|b))\1(?1)?/I
Capturing subpattern count = 1
Max back reference = 1
Subject length lower bound = 2
  bb
 0: bb
 1: b
  bbaa
 0: bba
 1: b

/(.*)a/Is
Capturing subpattern count = 1
Compile options: dotall
Overall options: anchored dotall
Last code unit = 'a'
Subject length lower bound = 1

/(.*)a\1/Is
Capturing subpattern count = 1
Max back reference = 1
Options: dotall
Last code unit = 'a'
Subject length lower bound = 1

/(.*)a(b)\2/Is
Capturing subpattern count = 2
Max back reference = 2
Compile options: dotall
Overall options: anchored dotall
Last code unit = 'b'
Subject length lower bound = 3

/((.*)a|(.*)b)z/Is
Capturing subpattern count = 3
Compile options: dotall
Overall options: anchored dotall
Last code unit = 'z'
Subject length lower bound = 2

/((.*)a|(.*)b)z\1/Is
Capturing subpattern count = 3
Max back reference = 1
Options: dotall
Last code unit = 'z'
Subject length lower bound = 3

/((.*)a|(.*)b)z\2/Is
Capturing subpattern count = 3
Max back reference = 2
Options: dotall
Last code unit = 'z'
Subject length lower bound = 2

/((.*)a|(.*)b)z\3/Is
Capturing subpattern count = 3
Max back reference = 3
Options: dotall
Last code unit = 'z'
Subject length lower bound = 2

/((.*)a|^(.*)b)z\3/Is
Capturing subpattern count = 3
Max back reference = 3
Compile options: dotall
Overall options: anchored dotall
Last code unit = 'z'
Subject length lower bound = 2

/(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)a/Is
Capturing subpattern count = 31
May match empty string
Compile options: dotall
Overall options: anchored dotall
Subject length lower bound = 0

/(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)a\31/Is
Capturing subpattern count = 31
Max back reference = 31
May match empty string
Options: dotall
Subject length lower bound = 0

/(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)|(.*)a\32/Is
Capturing subpattern count = 32
Max back reference = 32
May match empty string
Options: dotall
Subject length lower bound = 0

/(a)(bc)/IB,no_auto_capture
------------------------------------------------------------------
        Bra
        Bra
        a
        Ket
        Bra
        bc
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: no_auto_capture
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3
  abc
 0: abc

/(?P<one>a)(bc)/IB,no_auto_capture
------------------------------------------------------------------
        Bra
        CBra 1
        a
        Ket
        Bra
        bc
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Named capturing subpatterns:
  one   1
Options: no_auto_capture
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3
  abc
 0: abc
 1: a

/(a)(?P<named>bc)/IB,no_auto_capture
------------------------------------------------------------------
        Bra
        Bra
        a
        Ket
        CBra 1
        bc
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Named capturing subpatterns:
  named   1
Options: no_auto_capture
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 3

/(aaa(?C1)bbb|ab)/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
   aaabbb
--->aaabbb
  1 ^  ^       b
 0: aaabbb
 1: aaabbb
   aaabbb\=callout_data=0
--->aaabbb
  1 ^  ^       b
 0: aaabbb
 1: aaabbb
   aaabbb\=callout_data=1
--->aaabbb
  1 ^  ^       b
Callout data = 1
 0: ab
 1: ab
\= Expect no match    
   aaabbb\=callout_data=-1
--->aaabbb
  1 ^  ^       b
Callout data = -1
No match

/ab(?P<one>cd)ef(?P<two>gh)/I
Capturing subpattern count = 2
Named capturing subpatterns:
  one   1
  two   2
First code unit = 'a'
Last code unit = 'h'
Subject length lower bound = 8
    abcdefgh
 0: abcdefgh
 1: cd
 2: gh
    abcdefgh\=copy=1,get=two
 0: abcdefgh
 1: cd
 2: gh
 1C cd (2)
  G gh (2) two (group 2)
    abcdefgh\=copy=one,copy=two
 0: abcdefgh
 1: cd
 2: gh
  C cd (2) one (group 1)
  C gh (2) two (group 2)
    abcdefgh\=copy=three
 0: abcdefgh
 1: cd
 2: gh
Number not found for group 'three'
Copy substring 'three' failed (-49): unknown substring

/(?P<Tes>)(?P<Test>)/IB
------------------------------------------------------------------
        Bra
        CBra 1
        Ket
        CBra 2
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 2
Named capturing subpatterns:
  Tes    1
  Test   2
May match empty string
Subject length lower bound = 0

/(?P<Test>)(?P<Tes>)/IB
------------------------------------------------------------------
        Bra
        CBra 1
        Ket
        CBra 2
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 2
Named capturing subpatterns:
  Tes    2
  Test   1
May match empty string
Subject length lower bound = 0

/(?P<Z>zz)(?P<A>aa)/I
Capturing subpattern count = 2
Named capturing subpatterns:
  A   2
  Z   1
First code unit = 'z'
Last code unit = 'a'
Subject length lower bound = 4
    zzaa\=copy=Z
 0: zzaa
 1: zz
 2: aa
  C zz (2) Z (group 1)
    zzaa\=copy=A
 0: zzaa
 1: zz
 2: aa
  C aa (2) A (group 2)

/(?P<x>eks)(?P<x>eccs)/I
Failed: error 143 at offset 15: two named subpatterns have the same name (PCRE2_DUPNAMES not set)

/(?P<abc>abc(?P<def>def)(?P<abc>xyz))/I
Failed: error 143 at offset 30: two named subpatterns have the same name (PCRE2_DUPNAMES not set)

"\[((?P<elem>\d+)(,(?P>elem))*)\]"I
Capturing subpattern count = 3
Named capturing subpatterns:
  elem   2
First code unit = '['
Last code unit = ']'
Subject length lower bound = 3
    [10,20,30,5,5,4,4,2,43,23,4234]
 0: [10,20,30,5,5,4,4,2,43,23,4234]
 1: 10,20,30,5,5,4,4,2,43,23,4234
 2: 10
 3: ,4234
\= Expect no match
    []
No match

"\[((?P<elem>\d+)(,(?P>elem))*)?\]"I
Capturing subpattern count = 3
Named capturing subpatterns:
  elem   2
First code unit = '['
Last code unit = ']'
Subject length lower bound = 2
    [10,20,30,5,5,4,4,2,43,23,4234]
 0: [10,20,30,5,5,4,4,2,43,23,4234]
 1: 10,20,30,5,5,4,4,2,43,23,4234
 2: 10
 3: ,4234
    []
 0: []

/(a(b(?2)c))?/IB
------------------------------------------------------------------
        Bra
        Brazero
        CBra 1
        a
        CBra 2
        b
        Recurse
        c
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 2
May match empty string
Subject length lower bound = 0

/(a(b(?2)c))*/IB
------------------------------------------------------------------
        Bra
        Brazero
        CBra 1
        a
        CBra 2
        b
        Recurse
        c
        Ket
        KetRmax
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 2
May match empty string
Subject length lower bound = 0

/(a(b(?2)c)){0,2}/IB
------------------------------------------------------------------
        Bra
        Brazero
        Bra
        CBra 1
        a
        CBra 2
        b
        Recurse
        c
        Ket
        Ket
        Brazero
        CBra 1
        a
        CBra 2
        b
        Recurse
        c
        Ket
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 2
May match empty string
Subject length lower bound = 0

/[ab]{1}+/B
------------------------------------------------------------------
        Bra
        [ab]
        Ket
        End
------------------------------------------------------------------

/()(?1){1}/B
------------------------------------------------------------------
        Bra
        CBra 1
        Ket
        Recurse
        Ket
        End
------------------------------------------------------------------

/()(?1)/B
------------------------------------------------------------------
        Bra
        CBra 1
        Ket
        Recurse
        Ket
        End
------------------------------------------------------------------

/((w\/|-|with)*(free|immediate)*.*?shipping\s*[!.-]*)/Ii
Capturing subpattern count = 3
Options: caseless
Last code unit = 'g' (caseless)
Subject length lower bound = 8
     Baby Bjorn Active Carrier - With free SHIPPING!!
 0: Baby Bjorn Active Carrier - With free SHIPPING!!
 1: Baby Bjorn Active Carrier - With free SHIPPING!!

/((w\/|-|with)*(free|immediate)*.*?shipping\s*[!.-]*)/Ii
Capturing subpattern count = 3
Options: caseless
Last code unit = 'g' (caseless)
Subject length lower bound = 8
     Baby Bjorn Active Carrier - With free SHIPPING!!
 0: Baby Bjorn Active Carrier - With free SHIPPING!!
 1: Baby Bjorn Active Carrier - With free SHIPPING!!

/a*.*b/IB
------------------------------------------------------------------
        Bra
        a*
        Any*
        b
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Last code unit = 'b'
Subject length lower bound = 1

/(a|b)*.?c/IB
------------------------------------------------------------------
        Bra
        Brazero
        CBra 1
        a
        Alt
        b
        KetRmax
        Any?
        c
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Last code unit = 'c'
Subject length lower bound = 1

/abc(?C255)de(?C)f/IB
------------------------------------------------------------------
        Bra
        abc
        Callout 255 10 1
        de
        Callout 0 16 1
        f
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'f'
Subject length lower bound = 6

/abcde/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 1
        a
        Callout 255 1 1
        b
        Callout 255 2 1
        c
        Callout 255 3 1
        d
        Callout 255 4 1
        e
        Callout 255 5 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: auto_callout
First code unit = 'a'
Last code unit = 'e'
Subject length lower bound = 5
  abcde
--->abcde
 +0 ^         a
 +1 ^^        b
 +2 ^ ^       c
 +3 ^  ^      d
 +4 ^   ^     e
 +5 ^    ^    
 0: abcde
\= Expect no match
  abcdfe
--->abcdfe
 +0 ^          a
 +1 ^^         b
 +2 ^ ^        c
 +3 ^  ^       d
 +4 ^   ^      e
No match

/a*b/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 2
        a*+
        Callout 255 2 1
        b
        Callout 255 3 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: auto_callout
Starting code units: a b 
Last code unit = 'b'
Subject length lower bound = 1
  ab
--->ab
 +0 ^      a*
 +2 ^^     b
 +3 ^ ^    
 0: ab
  aaaab
--->aaaab
 +0 ^         a*
 +2 ^   ^     b
 +3 ^    ^    
 0: aaaab
  aaaacb
--->aaaacb
 +0 ^          a*
 +2 ^   ^      b
 +0  ^         a*
 +2  ^  ^      b
 +0   ^        a*
 +2   ^ ^      b
 +0    ^       a*
 +2    ^^      b
 +0      ^     a*
 +2      ^     b
 +3      ^^    
 0: b

/a*b/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 2
        a*+
        Callout 255 2 1
        b
        Callout 255 3 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: auto_callout
Starting code units: a b 
Last code unit = 'b'
Subject length lower bound = 1
  ab
--->ab
 +0 ^      a*
 +2 ^^     b
 +3 ^ ^    
 0: ab
  aaaab
--->aaaab
 +0 ^         a*
 +2 ^   ^     b
 +3 ^    ^    
 0: aaaab
  aaaacb
--->aaaacb
 +0 ^          a*
 +2 ^   ^      b
 +0  ^         a*
 +2  ^  ^      b
 +0   ^        a*
 +2   ^ ^      b
 +0    ^       a*
 +2    ^^      b
 +0      ^     a*
 +2      ^     b
 +3      ^^    
 0: b

/a+b/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 2
        a++
        Callout 255 2 1
        b
        Callout 255 3 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Options: auto_callout
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
  ab
--->ab
 +0 ^      a+
 +2 ^^     b
 +3 ^ ^    
 0: ab
  aaaab
--->aaaab
 +0 ^         a+
 +2 ^   ^     b
 +3 ^    ^    
 0: aaaab
\= Expect no match 
  aaaacb
--->aaaacb
 +0 ^          a+
 +2 ^   ^      b
 +0  ^         a+
 +2  ^  ^      b
 +0   ^        a+
 +2   ^ ^      b
 +0    ^       a+
 +2    ^^      b
No match

/(abc|def)x/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 9
        CBra 1
        Callout 255 1 1
        a
        Callout 255 2 1
        b
        Callout 255 3 1
        c
        Callout 255 4 0
        Alt
        Callout 255 5 1
        d
        Callout 255 6 1
        e
        Callout 255 7 1
        f
        Callout 255 8 0
        Ket
        Callout 255 9 1
        x
        Callout 255 10 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Options: auto_callout
Starting code units: a d 
Last code unit = 'x'
Subject length lower bound = 4
  abcx
--->abcx
 +0 ^        (abc|def)
 +1 ^        a
 +2 ^^       b
 +3 ^ ^      c
 +4 ^  ^     |
 +9 ^  ^     x
+10 ^   ^    
 0: abcx
 1: abc
  defx
--->defx
 +0 ^        (abc|def)
 +1 ^        a
 +5 ^        d
 +6 ^^       e
 +7 ^ ^      f
 +8 ^  ^     )
 +9 ^  ^     x
+10 ^   ^    
 0: defx
 1: def
\= Expect no match 
  abcdefzx
--->abcdefzx
 +0 ^            (abc|def)
 +1 ^            a
 +2 ^^           b
 +3 ^ ^          c
 +4 ^  ^         |
 +9 ^  ^         x
 +5 ^            d
 +0    ^         (abc|def)
 +1    ^         a
 +5    ^         d
 +6    ^^        e
 +7    ^ ^       f
 +8    ^  ^      )
 +9    ^  ^      x
No match

/(abc|def)x/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 9
        CBra 1
        Callout 255 1 1
        a
        Callout 255 2 1
        b
        Callout 255 3 1
        c
        Callout 255 4 0
        Alt
        Callout 255 5 1
        d
        Callout 255 6 1
        e
        Callout 255 7 1
        f
        Callout 255 8 0
        Ket
        Callout 255 9 1
        x
        Callout 255 10 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Options: auto_callout
Starting code units: a d 
Last code unit = 'x'
Subject length lower bound = 4
  abcx
--->abcx
 +0 ^        (abc|def)
 +1 ^        a
 +2 ^^       b
 +3 ^ ^      c
 +4 ^  ^     |
 +9 ^  ^     x
+10 ^   ^    
 0: abcx
 1: abc
  defx
--->defx
 +0 ^        (abc|def)
 +1 ^        a
 +5 ^        d
 +6 ^^       e
 +7 ^ ^      f
 +8 ^  ^     )
 +9 ^  ^     x
+10 ^   ^    
 0: defx
 1: def
\= Expect no match 
  abcdefzx
--->abcdefzx
 +0 ^            (abc|def)
 +1 ^            a
 +2 ^^           b
 +3 ^ ^          c
 +4 ^  ^         |
 +9 ^  ^         x
 +5 ^            d
 +0    ^         (abc|def)
 +1    ^         a
 +5    ^         d
 +6    ^^        e
 +7    ^ ^       f
 +8    ^  ^      )
 +9    ^  ^      x
No match

/(ab|cd){3,4}/I,auto_callout
Capturing subpattern count = 1
Options: auto_callout
Starting code units: a c 
Subject length lower bound = 6
  ababab
--->ababab
 +0 ^          (ab|cd){3,4}
 +1 ^          a
 +2 ^^         b
 +3 ^ ^        |
 +1 ^ ^        a
 +2 ^  ^       b
 +3 ^   ^      |
 +1 ^   ^      a
 +2 ^    ^     b
 +3 ^     ^    |
 +1 ^     ^    a
 +4 ^     ^    c
+12 ^     ^    
 0: ababab
 1: ab
  abcdabcd
--->abcdabcd
 +0 ^            (ab|cd){3,4}
 +1 ^            a
 +2 ^^           b
 +3 ^ ^          |
 +1 ^ ^          a
 +4 ^ ^          c
 +5 ^  ^         d
 +6 ^   ^        )
 +1 ^   ^        a
 +2 ^    ^       b
 +3 ^     ^      |
 +1 ^     ^      a
 +4 ^     ^      c
 +5 ^      ^     d
 +6 ^       ^    )
+12 ^       ^    
 0: abcdabcd
 1: cd
  abcdcdcdcdcd
--->abcdcdcdcdcd
 +0 ^                (ab|cd){3,4}
 +1 ^                a
 +2 ^^               b
 +3 ^ ^              |
 +1 ^ ^              a
 +4 ^ ^              c
 +5 ^  ^             d
 +6 ^   ^            )
 +1 ^   ^            a
 +4 ^   ^            c
 +5 ^    ^           d
 +6 ^     ^          )
 +1 ^     ^          a
 +4 ^     ^          c
 +5 ^      ^         d
 +6 ^       ^        )
+12 ^       ^        
 0: abcdcdcd
 1: cd

/([ab]{,4}c|xy)/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 14
        CBra 1
        Callout 255 1 4
        [ab]
        Callout 255 5 1
        {
        Callout 255 6 1
        ,
        Callout 255 7 1
        4
        Callout 255 8 1
        }
        Callout 255 9 1
        c
        Callout 255 10 0
        Alt
        Callout 255 11 1
        x
        Callout 255 12 1
        y
        Callout 255 13 0
        Ket
        Callout 255 14 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Options: auto_callout
Starting code units: a b x 
Subject length lower bound = 2
\= Expect no match 
    Note: that { does NOT introduce a quantifier
--->Note: that { does NOT introduce a quantifier
 +0         ^                                        ([ab]{,4}c|xy)
 +1         ^                                        [ab]
 +5         ^^                                       {
+11         ^                                        x
 +0                                 ^                ([ab]{,4}c|xy)
 +1                                 ^                [ab]
 +5                                 ^^               {
+11                                 ^                x
 +0                                     ^            ([ab]{,4}c|xy)
 +1                                     ^            [ab]
 +5                                     ^^           {
+11                                     ^            x
No match

/([ab]{,4}c|xy)/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 14
        CBra 1
        Callout 255 1 4
        [ab]
        Callout 255 5 1
        {
        Callout 255 6 1
        ,
        Callout 255 7 1
        4
        Callout 255 8 1
        }
        Callout 255 9 1
        c
        Callout 255 10 0
        Alt
        Callout 255 11 1
        x
        Callout 255 12 1
        y
        Callout 255 13 0
        Ket
        Callout 255 14 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Options: auto_callout
Starting code units: a b x 
Subject length lower bound = 2
\= Expect no match 
    Note: that { does NOT introduce a quantifier
--->Note: that { does NOT introduce a quantifier
 +0         ^                                        ([ab]{,4}c|xy)
 +1         ^                                        [ab]
 +5         ^^                                       {
+11         ^                                        x
 +0                                 ^                ([ab]{,4}c|xy)
 +1                                 ^                [ab]
 +5                                 ^^               {
+11                                 ^                x
 +0                                     ^            ([ab]{,4}c|xy)
 +1                                     ^            [ab]
 +5                                     ^^           {
+11                                     ^            x
No match

/([ab]{1,4}c|xy){4,5}?123/IB,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 21
        CBra 1
        Callout 255 1 9
        [ab]{1,4}+
        Callout 255 10 1
        c
        Callout 255 11 0
        Alt
        Callout 255 12 1
        x
        Callout 255 13 1
        y
        Callout 255 14 0
        Ket
        CBra 1
        Callout 255 1 9
        [ab]{1,4}+
        Callout 255 10 1
        c
        Callout 255 11 0
        Alt
        Callout 255 12 1
        x
        Callout 255 13 1
        y
        Callout 255 14 0
        Ket
        CBra 1
        Callout 255 1 9
        [ab]{1,4}+
        Callout 255 10 1
        c
        Callout 255 11 0
        Alt
        Callout 255 12 1
        x
        Callout 255 13 1
        y
        Callout 255 14 0
        Ket
        CBra 1
        Callout 255 1 9
        [ab]{1,4}+
        Callout 255 10 1
        c
        Callout 255 11 0
        Alt
        Callout 255 12 1
        x
        Callout 255 13 1
        y
        Callout 255 14 0
        Ket
        Braminzero
        CBra 1
        Callout 255 1 9
        [ab]{1,4}+
        Callout 255 10 1
        c
        Callout 255 11 0
        Alt
        Callout 255 12 1
        x
        Callout 255 13 1
        y
        Callout 255 14 0
        Ket
        Callout 255 21 1
        1
        Callout 255 22 1
        2
        Callout 255 23 1
        3
        Callout 255 24 0
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
Options: auto_callout
Starting code units: a b x 
Last code unit = '3'
Subject length lower bound = 11
    aacaacaacaacaac123
--->aacaacaacaacaac123
 +0 ^                      ([ab]{1,4}c|xy){4,5}?
 +1 ^                      [ab]{1,4}
+10 ^ ^                    c
+11 ^  ^                   |
 +1 ^  ^                   [ab]{1,4}
+10 ^    ^                 c
+11 ^     ^                |
 +1 ^     ^                [ab]{1,4}
+10 ^       ^              c
+11 ^        ^             |
 +1 ^        ^             [ab]{1,4}
+10 ^          ^           c
+11 ^           ^          |
+21 ^           ^          1
 +1 ^           ^          [ab]{1,4}
+10 ^             ^        c
+11 ^              ^       |
+21 ^              ^       1
+22 ^               ^      2
+23 ^                ^     3
+24 ^                 ^    
 0: aacaacaacaacaac123
 1: aac

/\b.*/I
Capturing subpattern count = 0
Max lookbehind = 1
May match empty string
Subject length lower bound = 0
  ab cd\=offset=1
 0:  cd

/\b.*/Is
Capturing subpattern count = 0
Max lookbehind = 1
May match empty string
Options: dotall
Subject length lower bound = 0
  ab cd\=startoffset=1
 0:  cd

/(?!.bcd).*/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
  Xbcd12345
 0: bcd12345

/abcde/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'e'
Subject length lower bound = 5
    ab\=ps
Partial match: ab
    abc\=ps
Partial match: abc
    abcd\=ps
Partial match: abcd
    abcde\=ps
 0: abcde
    the quick brown abc\=ps
Partial match: abc
\= Expect no match\=ps
    the quick brown abxyz fox\=ps
No match

"^(0?[1-9]|[12][0-9]|3[01])/(0?[1-9]|1[012])/(20)?\d\d$"I
Capturing subpattern count = 3
Compile options: <none>
Overall options: anchored
Last code unit = '/'
Subject length lower bound = 6
    13/05/04\=ps
 0: 13/05/04
 1: 13
 2: 05
    13/5/2004\=ps
 0: 13/5/2004
 1: 13
 2: 5
 3: 20
    02/05/09\=ps
 0: 02/05/09
 1: 02
 2: 05
    1\=ps
Partial match: 1
    1/2\=ps
Partial match: 1/2
    1/2/0\=ps
Partial match: 1/2/0
    1/2/04\=ps
 0: 1/2/04
 1: 1
 2: 2
    0\=ps
Partial match: 0
    02/\=ps
Partial match: 02/
    02/0\=ps
Partial match: 02/0
    02/1\=ps
Partial match: 02/1
\= Expect no match\=ps
    \=ps
No match
    123\=ps
No match
    33/4/04\=ps
No match
    3/13/04\=ps
No match
    0/1/2003\=ps
No match
    0/\=ps
No match
    02/0/\=ps
No match
    02/13\=ps
No match

/0{0,2}ABC/I
Capturing subpattern count = 0
Starting code units: 0 A 
Last code unit = 'C'
Subject length lower bound = 3

/\d{3,}ABC/I
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Last code unit = 'C'
Subject length lower bound = 6

/\d*ABC/I
Capturing subpattern count = 0
Starting code units: 0 1 2 3 4 5 6 7 8 9 A 
Last code unit = 'C'
Subject length lower bound = 3

/[abc]+DE/I
Capturing subpattern count = 0
Starting code units: a b c 
Last code unit = 'E'
Subject length lower bound = 3

/[abc]?123/I
Capturing subpattern count = 0
Starting code units: 1 a b c 
Last code unit = '3'
Subject length lower bound = 3
    123\=ps
 0: 123
    a\=ps
Partial match: a
    b\=ps
Partial match: b
    c\=ps
Partial match: c
    c12\=ps
Partial match: c12
    c123\=ps
 0: c123

/^(?:\d){3,5}X/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Last code unit = 'X'
Subject length lower bound = 4
    1\=ps
Partial match: 1
    123\=ps
Partial match: 123
    123X
 0: 123X
    1234\=ps
Partial match: 1234
    1234X
 0: 1234X
    12345\=ps
Partial match: 12345
    12345X
 0: 12345X
\= Expect no match
    1X
No match
    123456\=ps
No match

"<(\w+)/?>(.)*</(\1)>"Igms
Capturing subpattern count = 3
Max back reference = 1
Options: dotall multiline
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 7
    <!DOCTYPE seite SYSTEM "http://www.lco.lineas.de/xmlCms.dtd">\n<seite>\n<dokumenteninformation>\n<seitentitel>Partner der LCO</seitentitel>\n<sprache>de</sprache>\n<seitenbeschreibung>Partner der LINEAS Consulting\nGmbH</seitenbeschreibung>\n<schluesselworte>LINEAS Consulting GmbH Hamburg\nPartnerfirmen</schluesselworte>\n<revisit>30 days</revisit>\n<robots>index,follow</robots>\n<menueinformation>\n<aktiv>ja</aktiv>\n<menueposition>3</menueposition>\n<menuetext>Partner</menuetext>\n</menueinformation>\n<lastedited>\n<autor>LCO</autor>\n<firma>LINEAS Consulting</firma>\n<datum>15.10.2003</datum>\n</lastedited>\n</dokumenteninformation>\n<inhalt>\n\n<absatzueberschrift>Die Partnerfirmen der LINEAS Consulting\nGmbH</absatzueberschrift>\n\n<absatz><link ziel="http://www.ca.com/" zielfenster="_blank">\n<bild name="logo_ca.gif" rahmen="no"/></link> <link\nziel="http://www.ey.com/" zielfenster="_blank"><bild\nname="logo_euy.gif" rahmen="no"/></link>\n</absatz>\n\n<absatz><link ziel="http://www.cisco.de/" zielfenster="_blank">\n<bild name="logo_cisco.gif" rahmen="ja"/></link></absatz>\n\n<absatz><link ziel="http://www.atelion.de/"\nzielfenster="_blank"><bild\nname="logo_atelion.gif" rahmen="no"/></link>\n</absatz>\n\n<absatz><link ziel="http://www.line-information.de/"\nzielfenster="_blank">\n<bild name="logo_line_information.gif" rahmen="no"/></link>\n</absatz>\n\n<absatz><bild name="logo_aw.gif" rahmen="no"/></absatz>\n\n<absatz><link ziel="http://www.incognis.de/"\nzielfenster="_blank"><bild\nname="logo_incognis.gif" rahmen="no"/></link></absatz>\n\n<absatz><link ziel="http://www.addcraft.com/"\nzielfenster="_blank"><bild\nname="logo_addcraft.gif" rahmen="no"/></link></absatz>\n\n<absatz><link ziel="http://www.comendo.com/"\nzielfenster="_blank"><bild\nname="logo_comendo.gif" rahmen="no"/></link></absatz>\n\n</inhalt>\n</seite>\=jitstack=1024
 0: <seite>\x0a<dokumenteninformation>\x0a<seitentitel>Partner der LCO</seitentitel>\x0a<sprache>de</sprache>\x0a<seitenbeschreibung>Partner der LINEAS Consulting\x0aGmbH</seitenbeschreibung>\x0a<schluesselworte>LINEAS Consulting GmbH Hamburg\x0aPartnerfirmen</schluesselworte>\x0a<revisit>30 days</revisit>\x0a<robots>index,follow</robots>\x0a<menueinformation>\x0a<aktiv>ja</aktiv>\x0a<menueposition>3</menueposition>\x0a<menuetext>Partner</menuetext>\x0a</menueinformation>\x0a<lastedited>\x0a<autor>LCO</autor>\x0a<firma>LINEAS Consulting</firma>\x0a<datum>15.10.2003</datum>\x0a</lastedited>\x0a</dokumenteninformation>\x0a<inhalt>\x0a\x0a<absatzueberschrift>Die Partnerfirmen der LINEAS Consulting\x0aGmbH</absatzueberschrift>\x0a\x0a<absatz><link ziel="http://www.ca.com/" zielfenster="_blank">\x0a<bild name="logo_ca.gif" rahmen="no"/></link> <link\x0aziel="http://www.ey.com/" zielfenster="_blank"><bild\x0aname="logo_euy.gif" rahmen="no"/></link>\x0a</absatz>\x0a\x0a<absatz><link ziel="http://www.cisco.de/" zielfenster="_blank">\x0a<bild name="logo_cisco.gif" rahmen="ja"/></link></absatz>\x0a\x0a<absatz><link ziel="http://www.atelion.de/"\x0azielfenster="_blank"><bild\x0aname="logo_atelion.gif" rahmen="no"/></link>\x0a</absatz>\x0a\x0a<absatz><link ziel="http://www.line-information.de/"\x0azielfenster="_blank">\x0a<bild name="logo_line_information.gif" rahmen="no"/></link>\x0a</absatz>\x0a\x0a<absatz><bild name="logo_aw.gif" rahmen="no"/></absatz>\x0a\x0a<absatz><link ziel="http://www.incognis.de/"\x0azielfenster="_blank"><bild\x0aname="logo_incognis.gif" rahmen="no"/></link></absatz>\x0a\x0a<absatz><link ziel="http://www.addcraft.com/"\x0azielfenster="_blank"><bild\x0aname="logo_addcraft.gif" rahmen="no"/></link></absatz>\x0a\x0a<absatz><link ziel="http://www.comendo.com/"\x0azielfenster="_blank"><bild\x0aname="logo_comendo.gif" rahmen="no"/></link></absatz>\x0a\x0a</inhalt>\x0a</seite>
 1: seite
 2: \x0a
 3: seite

/line\nbreak/I
Capturing subpattern count = 0
Contains explicit CR or LF match
First code unit = 'l'
Last code unit = 'k'
Subject length lower bound = 10
    this is a line\nbreak
 0: line\x0abreak
    line one\nthis is a line\nbreak in the second line
 0: line\x0abreak

/line\nbreak/I,firstline
Capturing subpattern count = 0
Contains explicit CR or LF match
Options: firstline
First code unit = 'l'
Last code unit = 'k'
Subject length lower bound = 10
    this is a line\nbreak
 0: line\x0abreak
\= Expect no match
    line one\nthis is a line\nbreak in the second line
No match

/line\nbreak/Im,firstline
Capturing subpattern count = 0
Contains explicit CR or LF match
Options: firstline multiline
First code unit = 'l'
Last code unit = 'k'
Subject length lower bound = 10
    this is a line\nbreak
 0: line\x0abreak
\= Expect no match
    line one\nthis is a line\nbreak in the second line
No match

/(?i)(?-i)AbCd/I
Capturing subpattern count = 0
First code unit = 'A'
Last code unit = 'd'
Subject length lower bound = 4
    AbCd
 0: AbCd
\= Expect no match
    abcd
No match

/a{11111111111111111111}/I
Failed: error 105 at offset 8: number too big in {} quantifier

/(){64294967295}/I
Failed: error 105 at offset 9: number too big in {} quantifier

/(){2,4294967295}/I
Failed: error 105 at offset 11: number too big in {} quantifier

"(?i:a)(?i:b)(?i:c)(?i:d)(?i:e)(?i:f)(?i:g)(?i:h)(?i:i)(?i:j)(k)(?i:l)A\1B"I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'a' (caseless)
Last code unit = 'B'
Subject length lower bound = 15
    abcdefghijklAkB
 0: abcdefghijklAkB
 1: k

"(?P<n0>a)(?P<n1>b)(?P<n2>c)(?P<n3>d)(?P<n4>e)(?P<n5>f)(?P<n6>g)(?P<n7>h)(?P<n8>i)(?P<n9>j)(?P<n10>k)(?P<n11>l)A\11B"I
Capturing subpattern count = 12
Max back reference = 11
Named capturing subpatterns:
  n0    1
  n1    2
  n10  11
  n11  12
  n2    3
  n3    4
  n4    5
  n5    6
  n6    7
  n7    8
  n8    9
  n9   10
First code unit = 'a'
Last code unit = 'B'
Subject length lower bound = 15
    abcdefghijklAkB
 0: abcdefghijklAkB
 1: a
 2: b
 3: c
 4: d
 5: e
 6: f
 7: g
 8: h
 9: i
10: j
11: k
12: l

"(a)(b)(c)(d)(e)(f)(g)(h)(i)(j)(k)(l)A\11B"I
Capturing subpattern count = 12
Max back reference = 11
First code unit = 'a'
Last code unit = 'B'
Subject length lower bound = 15
    abcdefghijklAkB
 0: abcdefghijklAkB
 1: a
 2: b
 3: c
 4: d
 5: e
 6: f
 7: g
 8: h
 9: i
10: j
11: k
12: l

"(?P<name0>a)(?P<name1>a)(?P<name2>a)(?P<name3>a)(?P<name4>a)(?P<name5>a)(?P<name6>a)(?P<name7>a)(?P<name8>a)(?P<name9>a)(?P<name10>a)(?P<name11>a)(?P<name12>a)(?P<name13>a)(?P<name14>a)(?P<name15>a)(?P<name16>a)(?P<name17>a)(?P<name18>a)(?P<name19>a)(?P<name20>a)(?P<name21>a)(?P<name22>a)(?P<name23>a)(?P<name24>a)(?P<name25>a)(?P<name26>a)(?P<name27>a)(?P<name28>a)(?P<name29>a)(?P<name30>a)(?P<name31>a)(?P<name32>a)(?P<name33>a)(?P<name34>a)(?P<name35>a)(?P<name36>a)(?P<name37>a)(?P<name38>a)(?P<name39>a)(?P<name40>a)(?P<name41>a)(?P<name42>a)(?P<name43>a)(?P<name44>a)(?P<name45>a)(?P<name46>a)(?P<name47>a)(?P<name48>a)(?P<name49>a)(?P<name50>a)(?P<name51>a)(?P<name52>a)(?P<name53>a)(?P<name54>a)(?P<name55>a)(?P<name56>a)(?P<name57>a)(?P<name58>a)(?P<name59>a)(?P<name60>a)(?P<name61>a)(?P<name62>a)(?P<name63>a)(?P<name64>a)(?P<name65>a)(?P<name66>a)(?P<name67>a)(?P<name68>a)(?P<name69>a)(?P<name70>a)(?P<name71>a)(?P<name72>a)(?P<name73>a)(?P<name74>a)(?P<name75>a)(?P<name76>a)(?P<name77>a)(?P<name78>a)(?P<name79>a)(?P<name80>a)(?P<name81>a)(?P<name82>a)(?P<name83>a)(?P<name84>a)(?P<name85>a)(?P<name86>a)(?P<name87>a)(?P<name88>a)(?P<name89>a)(?P<name90>a)(?P<name91>a)(?P<name92>a)(?P<name93>a)(?P<name94>a)(?P<name95>a)(?P<name96>a)(?P<name97>a)(?P<name98>a)(?P<name99>a)(?P<name100>a)"I
Capturing subpattern count = 101
Named capturing subpatterns:
  name0     1
  name1     2
  name10   11
  name100 101
  name11   12
  name12   13
  name13   14
  name14   15
  name15   16
  name16   17
  name17   18
  name18   19
  name19   20
  name2     3
  name20   21
  name21   22
  name22   23
  name23   24
  name24   25
  name25   26
  name26   27
  name27   28
  name28   29
  name29   30
  name3     4
  name30   31
  name31   32
  name32   33
  name33   34
  name34   35
  name35   36
  name36   37
  name37   38
  name38   39
  name39   40
  name4     5
  name40   41
  name41   42
  name42   43
  name43   44
  name44   45
  name45   46
  name46   47
  name47   48
  name48   49
  name49   50
  name5     6
  name50   51
  name51   52
  name52   53
  name53   54
  name54   55
  name55   56
  name56   57
  name57   58
  name58   59
  name59   60
  name6     7
  name60   61
  name61   62
  name62   63
  name63   64
  name64   65
  name65   66
  name66   67
  name67   68
  name68   69
  name69   70
  name7     8
  name70   71
  name71   72
  name72   73
  name73   74
  name74   75
  name75   76
  name76   77
  name77   78
  name78   79
  name79   80
  name8     9
  name80   81
  name81   82
  name82   83
  name83   84
  name84   85
  name85   86
  name86   87
  name87   88
  name88   89
  name89   90
  name9    10
  name90   91
  name91   92
  name92   93
  name93   94
  name94   95
  name95   96
  name96   97
  name97   98
  name98   99
  name99  100
First code unit = 'a'
Last code unit = 'a'
Subject length lower bound = 101
    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
Matched, but too many substrings
 0: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 1: a
 2: a
 3: a
 4: a
 5: a
 6: a
 7: a
 8: a
 9: a
10: a
11: a
12: a
13: a
14: a

"(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)(a)"I
Capturing subpattern count = 101
First code unit = 'a'
Last code unit = 'a'
Subject length lower bound = 101
    aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
Matched, but too many substrings
 0: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
 1: a
 2: a
 3: a
 4: a
 5: a
 6: a
 7: a
 8: a
 9: a
10: a
11: a
12: a
13: a
14: a

/[^()]*(?:\((?R)\)[^()]*)*/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    (this(and)that
 0: 
    (this(and)that)
 0: (this(and)that)
    (this(and)that)stuff
 0: (this(and)that)stuff

/[^()]*(?:\((?>(?R))\)[^()]*)*/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    (this(and)that
 0: 
    (this(and)that)
 0: (this(and)that)

/[^()]*(?:\((?R)\))*[^()]*/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    (this(and)that
 0: 
    (this(and)that)
 0: (this(and)that)

/(?:\((?R)\))*[^()]*/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    (this(and)that
 0: 
    (this(and)that)
 0: 
    ((this))
 0: ((this))

/(?:\((?R)\))|[^()]*/I
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    (this(and)that
 0: 
    (this(and)that)
 0: 
    (this)
 0: (this)
    ((this))
 0: ((this))

/\x{0000ff}/I
Capturing subpattern count = 0
First code unit = \xff
Subject length lower bound = 1

/^((?P<A>a1)|(?P<A>a2)b)/I
Failed: error 143 at offset 17: two named subpatterns have the same name (PCRE2_DUPNAMES not set)

/^((?P<A>a1)|(?P<A>a2)b)/I,dupnames
Capturing subpattern count = 3
Named capturing subpatterns:
  A   2
  A   3
Compile options: dupnames
Overall options: anchored dupnames
Subject length lower bound = 2
    a1b\=copy=A
 0: a1
 1: a1
 2: a1
  C a1 (2) A (non-unique)
    a2b\=copy=A
 0: a2b
 1: a2b
 2: <unset>
 3: a2
  C a2 (2) A (non-unique)
    a1b\=copy=Z,copy=A
 0: a1
 1: a1
 2: a1
Number not found for group 'Z'
Copy substring 'Z' failed (-49): unknown substring
  C a1 (2) A (non-unique)
    
/(?|(?<a>)(?<b>)(?<a>)|(?<a>)(?<b>)(?<a>))/I,dupnames
Capturing subpattern count = 3
Named capturing subpatterns:
  a   1
  a   3
  b   2
May match empty string
Options: dupnames
Subject length lower bound = 0

/^(?P<A>a)(?P<A>b)/I,dupnames
Capturing subpattern count = 2
Named capturing subpatterns:
  A   1
  A   2
Compile options: dupnames
Overall options: anchored dupnames
Subject length lower bound = 2
    ab\=copy=A
 0: ab
 1: a
 2: b
  C a (1) A (non-unique)

/^(?P<A>a)(?P<A>b)|cd/I,dupnames
Capturing subpattern count = 2
Named capturing subpatterns:
  A   1
  A   2
Options: dupnames
Subject length lower bound = 2
    ab\=copy=A
 0: ab
 1: a
 2: b
  C a (1) A (non-unique)
    cd\=copy=A
 0: cd
Copy substring 'A' failed (-55): requested value is not set

/^(?P<A>a)(?P<A>b)|cd(?P<A>ef)(?P<A>gh)/I,dupnames
Capturing subpattern count = 4
Named capturing subpatterns:
  A   1
  A   2
  A   3
  A   4
Options: dupnames
Subject length lower bound = 2
    cdefgh\=copy=A
 0: cdefgh
 1: <unset>
 2: <unset>
 3: ef
 4: gh
  C ef (2) A (non-unique)

/^((?P<A>a1)|(?P<A>a2)b)/I,dupnames
Capturing subpattern count = 3
Named capturing subpatterns:
  A   2
  A   3
Compile options: dupnames
Overall options: anchored dupnames
Subject length lower bound = 2
    a1b\=get=A
 0: a1
 1: a1
 2: a1
  G a1 (2) A (non-unique)
    a2b\=get=A
 0: a2b
 1: a2b
 2: <unset>
 3: a2
  G a2 (2) A (non-unique)
    a1b\=get=Z,get=A
 0: a1
 1: a1
 2: a1
Number not found for group 'Z'
Get substring 'Z' failed (-49): unknown substring
  G a1 (2) A (non-unique)

/^(?P<A>a)(?P<A>b)/I,dupnames
Capturing subpattern count = 2
Named capturing subpatterns:
  A   1
  A   2
Compile options: dupnames
Overall options: anchored dupnames
Subject length lower bound = 2
    ab\=get=A
 0: ab
 1: a
 2: b
  G a (1) A (non-unique)

/^(?P<A>a)(?P<A>b)|cd/I,dupnames
Capturing subpattern count = 2
Named capturing subpatterns:
  A   1
  A   2
Options: dupnames
Subject length lower bound = 2
    ab\=get=A
 0: ab
 1: a
 2: b
  G a (1) A (non-unique)
    cd\=get=A
 0: cd
Get substring 'A' failed (-55): requested value is not set

/^(?P<A>a)(?P<A>b)|cd(?P<A>ef)(?P<A>gh)/I,dupnames
Capturing subpattern count = 4
Named capturing subpatterns:
  A   1
  A   2
  A   3
  A   4
Options: dupnames
Subject length lower bound = 2
    cdefgh\=get=A
 0: cdefgh
 1: <unset>
 2: <unset>
 3: ef
 4: gh
  G ef (2) A (non-unique)

/(?J)^((?P<A>a1)|(?P<A>a2)b)/I
Capturing subpattern count = 3
Named capturing subpatterns:
  A   2
  A   3
Compile options: <none>
Overall options: anchored
Duplicate name status changes
Subject length lower bound = 2
    a1b\=copy=A
 0: a1
 1: a1
 2: a1
  C a1 (2) A (non-unique)
    a2b\=copy=A
 0: a2b
 1: a2b
 2: <unset>
 3: a2
  C a2 (2) A (non-unique)

/^(?P<A>a) (?J:(?P<B>b)(?P<B>c)) (?P<A>d)/I
Failed: error 143 at offset 37: two named subpatterns have the same name (PCRE2_DUPNAMES not set)

# In this next test, J is not set at the outer level; consequently it isn't set
# in the pattern's options; consequently pcre2_substring_get_byname() produces
# a random value.

/^(?P<A>a) (?J:(?P<B>b)(?P<B>c)) (?P<C>d)/I
Capturing subpattern count = 4
Named capturing subpatterns:
  A   1
  B   2
  B   3
  C   4
Compile options: <none>
Overall options: anchored
Duplicate name status changes
Subject length lower bound = 6
    a bc d\=copy=A,copy=B,copy=C
 0: a bc d
 1: a
 2: b
 3: c
 4: d
  C a (1) A (group 1)
  C b (1) B (non-unique)
  C d (1) C (group 4)

/^(?P<A>a)?(?(A)a|b)/I
Capturing subpattern count = 1
Max back reference = 1
Named capturing subpatterns:
  A   1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 1
    aabc
 0: aa
 1: a
    bc
 0: b
\= Expect no match
    abc
No match

/(?:(?(ZZ)a|b)(?P<ZZ>X))+/I
Capturing subpattern count = 1
Max back reference = 1
Named capturing subpatterns:
  ZZ   1
Last code unit = 'X'
Subject length lower bound = 2
    bXaX
 0: bXaX
 1: X

/(?:(?(2y)a|b)(X))+/I
Failed: error 126 at offset 7: malformed number or name after (?(

/(?:(?(ZA)a|b)(?P<ZZ>X))+/I
Failed: error 115 at offset 9: reference to non-existent subpattern

/(?:(?(ZZ)a|b)(?(ZZ)a|b)(?P<ZZ>X))+/I
Capturing subpattern count = 1
Max back reference = 1
Named capturing subpatterns:
  ZZ   1
Last code unit = 'X'
Subject length lower bound = 3
    bbXaaX
 0: bbXaaX
 1: X

/(?:(?(ZZ)a|\(b\))\\(?P<ZZ>X))+/I
Capturing subpattern count = 1
Max back reference = 1
Named capturing subpatterns:
  ZZ   1
Last code unit = 'X'
Subject length lower bound = 3
    (b)\\Xa\\X
 0: (b)\Xa\X
 1: X

/(?P<ABC/I
Failed: error 142 at offset 7: syntax error in subpattern name (missing terminator)

/(?:(?(A)(?P=A)a|b)(?P<A>X|Y))+/I
Capturing subpattern count = 1
Max back reference = 1
Named capturing subpatterns:
  A   1
Subject length lower bound = 2
    bXXaYYaY
 0: bXXaYYaY
 1: Y
    bXYaXXaX
 0: bX
 1: X

/()()()()()()()()()(?:(?(A)(?P=A)a|b)(?P<A>X|Y))+/I
Capturing subpattern count = 10
Max back reference = 10
Named capturing subpatterns:
  A  10
Subject length lower bound = 2
    bXXaYYaY
 0: bXXaYYaY
 1: 
 2: 
 3: 
 4: 
 5: 
 6: 
 7: 
 8: 
 9: 
10: Y

/\s*,\s*/I
Capturing subpattern count = 0
Starting code units: \x09 \x0a \x0b \x0c \x0d \x20 , 
Last code unit = ','
Subject length lower bound = 1
    \x0b,\x0b
 0: \x0b,\x0b
    \x0c,\x0d
 0: \x0c,\x0d

/^abc/Im,newline=lf
Capturing subpattern count = 0
Options: multiline
Forced newline is LF
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3
    xyz\nabc
 0: abc
    xyz\r\nabc
 0: abc
\= Expect no match
    xyz\rabc
No match
    xyzabc\r
No match
    xyzabc\rpqr
No match
    xyzabc\r\n
No match
    xyzabc\r\npqr
No match

/^abc/Im,newline=crlf
Capturing subpattern count = 0
Options: multiline
Forced newline is CRLF
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3
    xyz\r\nabclf>
 0: abc
\= Expect no match
    xyz\nabclf
No match
    xyz\rabclf
No match
    
/^abc/Im,newline=cr
Capturing subpattern count = 0
Options: multiline
Forced newline is CR
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3
    xyz\rabc
 0: abc
\= Expect no match
    xyz\nabc
No match
    xyz\r\nabc
No match

/^abc/Im,newline=bad
** Invalid value in 'newline=bad'

/.*/I,newline=lf
Capturing subpattern count = 0
May match empty string
Forced newline is LF
First code unit at start or follows newline
Subject length lower bound = 0
    abc\ndef
 0: abc
    abc\rdef
 0: abc\x0ddef
    abc\r\ndef
 0: abc\x0d

/.*/I,newline=cr
Capturing subpattern count = 0
May match empty string
Forced newline is CR
First code unit at start or follows newline
Subject length lower bound = 0
    abc\ndef
 0: abc\x0adef
    abc\rdef
 0: abc
    abc\r\ndef
 0: abc

/.*/I,newline=crlf
Capturing subpattern count = 0
May match empty string
Forced newline is CRLF
First code unit at start or follows newline
Subject length lower bound = 0
    abc\ndef
 0: abc\x0adef
    abc\rdef
 0: abc\x0ddef
    abc\r\ndef
 0: abc

/\w+(.)(.)?def/Is
Capturing subpattern count = 2
Options: dotall
Starting code units: 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P 
  Q R S T U V W X Y Z _ a b c d e f g h i j k l m n o p q r s t u v w x y z 
Last code unit = 'f'
Subject length lower bound = 5
    abc\ndef
 0: abc\x0adef
 1: \x0a
    abc\rdef
 0: abc\x0ddef
 1: \x0d
    abc\r\ndef
 0: abc\x0d\x0adef
 1: \x0d
 2: \x0a

/(?P<B>25[0-5]|2[0-4]\d|[01]?\d?\d)(?:\.(?P>B)){3}/I
Capturing subpattern count = 1
Named capturing subpatterns:
  B   1
Starting code units: 0 1 2 3 4 5 6 7 8 9 
Last code unit = '.'
Subject length lower bound = 7

/()()()()()()()()()()()()()()()()()()()()
 ()()()()()()()()()()()()()()()()()()()()
 ()()()()()()()()()()()()()()()()()()()()
 ()()()()()()()()()()()()()()()()()()()()
 ()()()()()()()()()()()()()()()()()()()()
 (.(.))/Ix
Capturing subpattern count = 102
Options: extended
Subject length lower bound = 2
    XY\=ovector=133
 0: XY
 1: 
 2: 
 3: 
 4: 
 5: 
 6: 
 7: 
 8: 
 9: 
10: 
11: 
12: 
13: 
14: 
15: 
16: 
17: 
18: 
19: 
20: 
21: 
22: 
23: 
24: 
25: 
26: 
27: 
28: 
29: 
30: 
31: 
32: 
33: 
34: 
35: 
36: 
37: 
38: 
39: 
40: 
41: 
42: 
43: 
44: 
45: 
46: 
47: 
48: 
49: 
50: 
51: 
52: 
53: 
54: 
55: 
56: 
57: 
58: 
59: 
60: 
61: 
62: 
63: 
64: 
65: 
66: 
67: 
68: 
69: 
70: 
71: 
72: 
73: 
74: 
75: 
76: 
77: 
78: 
79: 
80: 
81: 
82: 
83: 
84: 
85: 
86: 
87: 
88: 
89: 
90: 
91: 
92: 
93: 
94: 
95: 
96: 
97: 
98: 
99: 
100: 
101: XY
102: Y

/(a*b|(?i:c*(?-i)d))/I
Capturing subpattern count = 1
Starting code units: C a b c d 
Subject length lower bound = 1

/()[ab]xyz/I
Capturing subpattern count = 1
Starting code units: a b 
Last code unit = 'z'
Subject length lower bound = 4

/(|)[ab]xyz/I
Capturing subpattern count = 1
Starting code units: a b 
Last code unit = 'z'
Subject length lower bound = 4

/(|c)[ab]xyz/I
Capturing subpattern count = 1
Starting code units: a b c 
Last code unit = 'z'
Subject length lower bound = 4

/(|c?)[ab]xyz/I
Capturing subpattern count = 1
Starting code units: a b c 
Last code unit = 'z'
Subject length lower bound = 4

/(d?|c?)[ab]xyz/I
Capturing subpattern count = 1
Starting code units: a b c d 
Last code unit = 'z'
Subject length lower bound = 4

/(d?|c)[ab]xyz/I
Capturing subpattern count = 1
Starting code units: a b c d 
Last code unit = 'z'
Subject length lower bound = 4

/^a*b\d/IB
------------------------------------------------------------------
        Bra
        ^
        a*+
        b
        \d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Last code unit = 'b'
Subject length lower bound = 2

/^a*+b\d/IB
------------------------------------------------------------------
        Bra
        ^
        a*+
        b
        \d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Last code unit = 'b'
Subject length lower bound = 2

/^a*?b\d/IB
------------------------------------------------------------------
        Bra
        ^
        a*+
        b
        \d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Last code unit = 'b'
Subject length lower bound = 2

/^a+A\d/IB
------------------------------------------------------------------
        Bra
        ^
        a++
        A
        \d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Last code unit = 'A'
Subject length lower bound = 3
    aaaA5
 0: aaaA5
\= Expect no match
    aaaa5
No match

/^a*A\d/IBi
------------------------------------------------------------------
        Bra
        ^
     /i a*
     /i A
        \d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Compile options: caseless
Overall options: anchored caseless
Last code unit = 'A' (caseless)
Subject length lower bound = 2
    aaaA5
 0: aaaA5
    aaaa5
 0: aaaa5

/(a*|b*)[cd]/I
Capturing subpattern count = 1
Starting code units: a b c d 
Subject length lower bound = 1

/(a+|b*)[cd]/I
Capturing subpattern count = 1
Starting code units: a b c d 
Subject length lower bound = 1

/(a*|b+)[cd]/I
Capturing subpattern count = 1
Starting code units: a b c d 
Subject length lower bound = 1

/(a+|b+)[cd]/I
Capturing subpattern count = 1
Starting code units: a b 
Subject length lower bound = 2

/((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((
 ((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((
 (((
 a
 ))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
 ))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
 )))
/Ix
Capturing subpattern count = 203
Options: extended
First code unit = 'a'
Subject length lower bound = 1
  large nest
Matched, but too many substrings
 0: a
 1: a
 2: a
 3: a
 4: a
 5: a
 6: a
 7: a
 8: a
 9: a
10: a
11: a
12: a
13: a
14: a

/a*\d/B
------------------------------------------------------------------
        Bra
        a*+
        \d
        Ket
        End
------------------------------------------------------------------

/a*\D/B
------------------------------------------------------------------
        Bra
        a*
        \D
        Ket
        End
------------------------------------------------------------------

/0*\d/B
------------------------------------------------------------------
        Bra
        0*
        \d
        Ket
        End
------------------------------------------------------------------

/0*\D/B
------------------------------------------------------------------
        Bra
        0*+
        \D
        Ket
        End
------------------------------------------------------------------

/a*\s/B
------------------------------------------------------------------
        Bra
        a*+
        \s
        Ket
        End
------------------------------------------------------------------

/a*\S/B
------------------------------------------------------------------
        Bra
        a*
        \S
        Ket
        End
------------------------------------------------------------------

/ *\s/B
------------------------------------------------------------------
        Bra
         *
        \s
        Ket
        End
------------------------------------------------------------------

/ *\S/B
------------------------------------------------------------------
        Bra
         *+
        \S
        Ket
        End
------------------------------------------------------------------

/a*\w/B
------------------------------------------------------------------
        Bra
        a*
        \w
        Ket
        End
------------------------------------------------------------------

/a*\W/B
------------------------------------------------------------------
        Bra
        a*+
        \W
        Ket
        End
------------------------------------------------------------------

/=*\w/B
------------------------------------------------------------------
        Bra
        =*+
        \w
        Ket
        End
------------------------------------------------------------------

/=*\W/B
------------------------------------------------------------------
        Bra
        =*
        \W
        Ket
        End
------------------------------------------------------------------

/\d*a/B
------------------------------------------------------------------
        Bra
        \d*+
        a
        Ket
        End
------------------------------------------------------------------

/\d*2/B
------------------------------------------------------------------
        Bra
        \d*
        2
        Ket
        End
------------------------------------------------------------------

/\d*\d/B
------------------------------------------------------------------
        Bra
        \d*
        \d
        Ket
        End
------------------------------------------------------------------

/\d*\D/B
------------------------------------------------------------------
        Bra
        \d*+
        \D
        Ket
        End
------------------------------------------------------------------

/\d*\s/B
------------------------------------------------------------------
        Bra
        \d*+
        \s
        Ket
        End
------------------------------------------------------------------

/\d*\S/B
------------------------------------------------------------------
        Bra
        \d*
        \S
        Ket
        End
------------------------------------------------------------------

/\d*\w/B
------------------------------------------------------------------
        Bra
        \d*
        \w
        Ket
        End
------------------------------------------------------------------

/\d*\W/B
------------------------------------------------------------------
        Bra
        \d*+
        \W
        Ket
        End
------------------------------------------------------------------

/\D*a/B
------------------------------------------------------------------
        Bra
        \D*
        a
        Ket
        End
------------------------------------------------------------------

/\D*2/B
------------------------------------------------------------------
        Bra
        \D*+
        2
        Ket
        End
------------------------------------------------------------------

/\D*\d/B
------------------------------------------------------------------
        Bra
        \D*+
        \d
        Ket
        End
------------------------------------------------------------------

/\D*\D/B
------------------------------------------------------------------
        Bra
        \D*
        \D
        Ket
        End
------------------------------------------------------------------

/\D*\s/B
------------------------------------------------------------------
        Bra
        \D*
        \s
        Ket
        End
------------------------------------------------------------------

/\D*\S/B
------------------------------------------------------------------
        Bra
        \D*
        \S
        Ket
        End
------------------------------------------------------------------

/\D*\w/B
------------------------------------------------------------------
        Bra
        \D*
        \w
        Ket
        End
------------------------------------------------------------------

/\D*\W/B
------------------------------------------------------------------
        Bra
        \D*
        \W
        Ket
        End
------------------------------------------------------------------

/\s*a/B
------------------------------------------------------------------
        Bra
        \s*+
        a
        Ket
        End
------------------------------------------------------------------

/\s*2/B
------------------------------------------------------------------
        Bra
        \s*+
        2
        Ket
        End
------------------------------------------------------------------

/\s*\d/B
------------------------------------------------------------------
        Bra
        \s*+
        \d
        Ket
        End
------------------------------------------------------------------

/\s*\D/B
------------------------------------------------------------------
        Bra
        \s*
        \D
        Ket
        End
------------------------------------------------------------------

/\s*\s/B
------------------------------------------------------------------
        Bra
        \s*
        \s
        Ket
        End
------------------------------------------------------------------

/\s*\S/B
------------------------------------------------------------------
        Bra
        \s*+
        \S
        Ket
        End
------------------------------------------------------------------

/\s*\w/B
------------------------------------------------------------------
        Bra
        \s*+
        \w
        Ket
        End
------------------------------------------------------------------

/\s*\W/B
------------------------------------------------------------------
        Bra
        \s*
        \W
        Ket
        End
------------------------------------------------------------------

/\S*a/B
------------------------------------------------------------------
        Bra
        \S*
        a
        Ket
        End
------------------------------------------------------------------

/\S*2/B
------------------------------------------------------------------
        Bra
        \S*
        2
        Ket
        End
------------------------------------------------------------------

/\S*\d/B
------------------------------------------------------------------
        Bra
        \S*
        \d
        Ket
        End
------------------------------------------------------------------

/\S*\D/B
------------------------------------------------------------------
        Bra
        \S*
        \D
        Ket
        End
------------------------------------------------------------------

/\S*\s/B
------------------------------------------------------------------
        Bra
        \S*+
        \s
        Ket
        End
------------------------------------------------------------------

/\S*\S/B
------------------------------------------------------------------
        Bra
        \S*
        \S
        Ket
        End
------------------------------------------------------------------

/\S*\w/B
------------------------------------------------------------------
        Bra
        \S*
        \w
        Ket
        End
------------------------------------------------------------------

/\S*\W/B
------------------------------------------------------------------
        Bra
        \S*
        \W
        Ket
        End
------------------------------------------------------------------

/\w*a/B
------------------------------------------------------------------
        Bra
        \w*
        a
        Ket
        End
------------------------------------------------------------------

/\w*2/B
------------------------------------------------------------------
        Bra
        \w*
        2
        Ket
        End
------------------------------------------------------------------

/\w*\d/B
------------------------------------------------------------------
        Bra
        \w*
        \d
        Ket
        End
------------------------------------------------------------------

/\w*\D/B
------------------------------------------------------------------
        Bra
        \w*
        \D
        Ket
        End
------------------------------------------------------------------

/\w*\s/B
------------------------------------------------------------------
        Bra
        \w*+
        \s
        Ket
        End
------------------------------------------------------------------

/\w*\S/B
------------------------------------------------------------------
        Bra
        \w*
        \S
        Ket
        End
------------------------------------------------------------------

/\w*\w/B
------------------------------------------------------------------
        Bra
        \w*
        \w
        Ket
        End
------------------------------------------------------------------

/\w*\W/B
------------------------------------------------------------------
        Bra
        \w*+
        \W
        Ket
        End
------------------------------------------------------------------

/\W*a/B
------------------------------------------------------------------
        Bra
        \W*+
        a
        Ket
        End
------------------------------------------------------------------

/\W*2/B
------------------------------------------------------------------
        Bra
        \W*+
        2
        Ket
        End
------------------------------------------------------------------

/\W*\d/B
------------------------------------------------------------------
        Bra
        \W*+
        \d
        Ket
        End
------------------------------------------------------------------

/\W*\D/B
------------------------------------------------------------------
        Bra
        \W*
        \D
        Ket
        End
------------------------------------------------------------------

/\W*\s/B
------------------------------------------------------------------
        Bra
        \W*
        \s
        Ket
        End
------------------------------------------------------------------

/\W*\S/B
------------------------------------------------------------------
        Bra
        \W*
        \S
        Ket
        End
------------------------------------------------------------------

/\W*\w/B
------------------------------------------------------------------
        Bra
        \W*+
        \w
        Ket
        End
------------------------------------------------------------------

/\W*\W/B
------------------------------------------------------------------
        Bra
        \W*
        \W
        Ket
        End
------------------------------------------------------------------

/[^a]+a/B
------------------------------------------------------------------
        Bra
        [^a]++
        a
        Ket
        End
------------------------------------------------------------------

/[^a]+a/Bi
------------------------------------------------------------------
        Bra
     /i [^a]++
     /i a
        Ket
        End
------------------------------------------------------------------

/[^a]+A/Bi
------------------------------------------------------------------
        Bra
     /i [^a]++
     /i A
        Ket
        End
------------------------------------------------------------------

/[^a]+b/B
------------------------------------------------------------------
        Bra
        [^a]+
        b
        Ket
        End
------------------------------------------------------------------

/[^a]+\d/B
------------------------------------------------------------------
        Bra
        [^a]+
        \d
        Ket
        End
------------------------------------------------------------------

/a*[^a]/B
------------------------------------------------------------------
        Bra
        a*+
        [^a]
        Ket
        End
------------------------------------------------------------------

/(?P<abc>x)(?P<xyz>y)/I
Capturing subpattern count = 2
Named capturing subpatterns:
  abc   1
  xyz   2
First code unit = 'x'
Last code unit = 'y'
Subject length lower bound = 2
    xy\=copy=abc,copy=xyz
 0: xy
 1: x
 2: y
  C x (1) abc (group 1)
  C y (1) xyz (group 2)

/(?<abc>x)(?'xyz'y)/I
Capturing subpattern count = 2
Named capturing subpatterns:
  abc   1
  xyz   2
First code unit = 'x'
Last code unit = 'y'
Subject length lower bound = 2
    xy\=copy=abc,copy=xyz
 0: xy
 1: x
 2: y
  C x (1) abc (group 1)
  C y (1) xyz (group 2)

/(?<abc'x)(?'xyz'y)/I
Failed: error 142 at offset 6: syntax error in subpattern name (missing terminator)

/(?<abc>x)(?'xyz>y)/I
Failed: error 142 at offset 15: syntax error in subpattern name (missing terminator)

/(?P'abc'x)(?P<xyz>y)/I
Failed: error 141 at offset 3: unrecognized character after (?P

/^(?:(?(ZZ)a|b)(?<ZZ>X))+/
    bXaX
 0: bXaX
 1: X
    bXbX
 0: bX
 1: X
\= Expect no match
    aXaX
No match
    aXbX
No match

/^(?P>abc)(?<abcd>xxx)/
Failed: error 115 at offset 8: reference to non-existent subpattern

/^(?P>abc)(?<abc>x|y)/
    xx
 0: xx
 1: x
    xy
 0: xy
 1: y
    yy
 0: yy
 1: y
    yx
 0: yx
 1: x

/^(?P>abc)(?P<abc>x|y)/
    xx
 0: xx
 1: x
    xy
 0: xy
 1: y
    yy
 0: yy
 1: y
    yx
 0: yx
 1: x

/^((?(abc)a|b)(?<abc>x|y))+/
    bxay
 0: bxay
 1: ay
 2: y
    bxby
 0: bx
 1: bx
 2: x
\= Expect no match
    axby
No match

/^(((?P=abc)|X)(?<abc>x|y))+/
    XxXxxx
 0: XxXxxx
 1: xx
 2: x
 3: x
    XxXyyx
 0: XxXyyx
 1: yx
 2: y
 3: x
    XxXyxx
 0: XxXy
 1: Xy
 2: X
 3: y
\= Expect no match
    x
No match

/^(?1)(abc)/
    abcabc
 0: abcabc
 1: abc

/^(?:(?:\1|X)(a|b))+/
    Xaaa
 0: Xaaa
 1: a
    Xaba
 0: Xa
 1: a

/^[\E\Qa\E-\Qz\E]+/B
------------------------------------------------------------------
        Bra
        ^
        [a-z]++
        Ket
        End
------------------------------------------------------------------

/^[a\Q]bc\E]/B
------------------------------------------------------------------
        Bra
        ^
        [\]a-c]
        Ket
        End
------------------------------------------------------------------

/^[a-\Q\E]/B
------------------------------------------------------------------
        Bra
        ^
        [\-a]
        Ket
        End
------------------------------------------------------------------

/^(?P>abc)[()](?<abc>)/B
------------------------------------------------------------------
        Bra
        ^
        Recurse
        [()]
        CBra 1
        Ket
        Ket
        End
------------------------------------------------------------------

/^((?(abc)y)[()](?P<abc>x))+/B
------------------------------------------------------------------
        Bra
        ^
        CBra 1
        Cond
      2 Cond ref
        y
        Ket
        [()]
        CBra 2
        x
        Ket
        KetRmax
        Ket
        End
------------------------------------------------------------------
    (xy)x
 0: (xy)x
 1: y)x
 2: x

/^(?P>abc)\Q()\E(?<abc>)/B
------------------------------------------------------------------
        Bra
        ^
        Recurse
        ()
        CBra 1
        Ket
        Ket
        End
------------------------------------------------------------------

/^(?P>abc)[a\Q(]\E(](?<abc>)/B
------------------------------------------------------------------
        Bra
        ^
        Recurse
        [(\]a]
        CBra 1
        Ket
        Ket
        End
------------------------------------------------------------------

/^(?P>abc) # this is (a comment)
  (?<abc>)/Bx
------------------------------------------------------------------
        Bra
        ^
        Recurse
        CBra 1
        Ket
        Ket
        End
------------------------------------------------------------------

/^\W*(?:(?<one>(?<two>.)\W*(?&one)\W*\k<two>|)|(?<three>(?<four>.)\W*(?&three)\W*\k'four'|\W*.\W*))\W*$/Ii
Capturing subpattern count = 4
Max back reference = 4
Named capturing subpatterns:
  four    4
  one     1
  three   3
  two     2
May match empty string
Compile options: caseless
Overall options: anchored caseless
Subject length lower bound = 0
    1221
 0: 1221
 1: 1221
 2: 1
    Satan, oscillate my metallic sonatas!
 0: Satan, oscillate my metallic sonatas!
 1: <unset>
 2: <unset>
 3: Satan, oscillate my metallic sonatas
 4: S
    A man, a plan, a canal: Panama!
 0: A man, a plan, a canal: Panama!
 1: <unset>
 2: <unset>
 3: A man, a plan, a canal: Panama
 4: A
    Able was I ere I saw Elba.
 0: Able was I ere I saw Elba.
 1: <unset>
 2: <unset>
 3: Able was I ere I saw Elba
 4: A
\= Expect no match
    The quick brown fox
No match

/(?=(\w+))\1:/I
Capturing subpattern count = 1
Max back reference = 1
Starting code units: 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P 
  Q R S T U V W X Y Z _ a b c d e f g h i j k l m n o p q r s t u v w x y z 
Last code unit = ':'
Subject length lower bound = 2
    abcd:
 0: abcd:
 1: abcd

/(?=(?'abc'\w+))\k<abc>:/I
Capturing subpattern count = 1
Max back reference = 1
Named capturing subpatterns:
  abc   1
Starting code units: 0 1 2 3 4 5 6 7 8 9 A B C D E F G H I J K L M N O P 
  Q R S T U V W X Y Z _ a b c d e f g h i j k l m n o p q r s t u v w x y z 
Last code unit = ':'
Subject length lower bound = 2
    abcd:
 0: abcd:
 1: abcd

/(?'abc'a|b)(?<abc>d|e)\k<abc>{2}/dupnames
    adaa
 0: adaa
 1: a
 2: d
\= Expect no match
    addd
No match
    adbb
No match

/(?'abc'a|b)(?<abc>d|e)(?&abc){2}/dupnames
    bdaa
 0: bdaa
 1: b
 2: d
    bdab
 0: bdab
 1: b
 2: d
\= Expect no match
    bddd
No match

/(?(<bc))/
Failed: error 126 at offset 6: malformed number or name after (?(

/(?(''))/
Failed: error 128 at offset 4: assertion expected after (?( or (?(?C)

/(?('R')stuff)/
Failed: error 115 at offset 7: reference to non-existent subpattern

/((abc (?(R) (?(R1)1) (?(R2)2) X  |  (?1)  (?2)   (?R) ))) /x
    abcabc1Xabc2XabcXabcabc
 0: abcabc1Xabc2XabcX
 1: abcabc1Xabc2XabcX
 2: abcabc1Xabc2XabcX

/(?<A> (?'B' abc (?(R) (?(R&A)1) (?(R&B)2) X  |  (?1)  (?2)   (?R) ))) /x
    abcabc1Xabc2XabcXabcabc
 0: abcabc1Xabc2XabcX
 1: abcabc1Xabc2XabcX
 2: abcabc1Xabc2XabcX

/(?<A> (?'B' abc (?(R) (?(R&C)1) (?(R&B)2) X  |  (?1)  (?2)   (?R) ))) /x
Failed: error 115 at offset 29: reference to non-existent subpattern

/^(?(DEFINE) abc | xyz ) /x
Failed: error 154 at offset 22: DEFINE group contains more than one branch

/(?(DEFINE) abc) xyz/Ix
Capturing subpattern count = 0
Options: extended
First code unit = 'x'
Last code unit = 'z'
Subject length lower bound = 3

/(a|)*\d/
  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa4\=ovector=0
 0: aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa4
 1: 
\= Expect no match
  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa\=ovector=0
No match

/^a.b/newline=lf
    a\rb
 0: a\x0db
\= Expect no match
    a\nb
No match

/^a.b/newline=cr
    a\nb
 0: a\x0ab
\= Expect no match
    a\rb
No match

/^a.b/newline=anycrlf
    a\x85b
 0: a\x85b
\= Expect no match
    a\rb
No match

/^a.b/newline=any
\= Expect no match
    a\nb
No match
    a\rb
No match
    a\x85b
No match

/^abc./gmx,newline=any
    abc1 \x0aabc2 \x0babc3xx \x0cabc4 \x0dabc5xx \x0d\x0aabc6 \x85abc7 JUNK
 0: abc1
 0: abc2
 0: abc3
 0: abc4
 0: abc5
 0: abc6
 0: abc7

/abc.$/gmx,newline=any
    abc1\x0a abc2\x0b abc3\x0c abc4\x0d abc5\x0d\x0a abc6\x85 abc7 abc9
 0: abc1
 0: abc2
 0: abc3
 0: abc4
 0: abc5
 0: abc6
 0: abc9

/^a\Rb/bsr=unicode
    a\nb
 0: a\x0ab
    a\rb
 0: a\x0db
    a\r\nb
 0: a\x0d\x0ab
    a\x0bb
 0: a\x0bb
    a\x0cb
 0: a\x0cb
    a\x85b
 0: a\x85b
\= Expect no match
    a\n\rb
No match

/^a\R*b/bsr=unicode
    ab
 0: ab
    a\nb
 0: a\x0ab
    a\rb
 0: a\x0db
    a\r\nb
 0: a\x0d\x0ab
    a\x0bb
 0: a\x0bb
    a\x0cb
 0: a\x0cb
    a\x85b
 0: a\x85b
    a\n\rb
 0: a\x0a\x0db
    a\n\r\x85\x0cb
 0: a\x0a\x0d\x85\x0cb

/^a\R+b/bsr=unicode
    a\nb
 0: a\x0ab
    a\rb
 0: a\x0db
    a\r\nb
 0: a\x0d\x0ab
    a\x0bb
 0: a\x0bb
    a\x0cb
 0: a\x0cb
    a\x85b
 0: a\x85b
    a\n\rb
 0: a\x0a\x0db
    a\n\r\x85\x0cb
 0: a\x0a\x0d\x85\x0cb
\= Expect no match
    ab
No match

/^a\R{1,3}b/bsr=unicode
    a\nb
 0: a\x0ab
    a\n\rb
 0: a\x0a\x0db
    a\n\r\x85b
 0: a\x0a\x0d\x85b
    a\r\n\r\nb
 0: a\x0d\x0a\x0d\x0ab
    a\r\n\r\n\r\nb
 0: a\x0d\x0a\x0d\x0a\x0d\x0ab
    a\n\r\n\rb
 0: a\x0a\x0d\x0a\x0db
    a\n\n\r\nb
 0: a\x0a\x0a\x0d\x0ab
\= Expect no match
    a\n\n\n\rb
No match
    a\r
No match

/(?&abc)X(?<abc>P)/I
Capturing subpattern count = 1
Named capturing subpatterns:
  abc   1
Last code unit = 'P'
Subject length lower bound = 3
    abcPXP123
 0: PXP
 1: P

/(?1)X(?<abc>P)/I
Capturing subpattern count = 1
Named capturing subpatterns:
  abc   1
Last code unit = 'P'
Subject length lower bound = 3
    abcPXP123
 0: PXP
 1: P

/(?:a(?&abc)b)*(?<abc>x)/
    123axbaxbaxbx456
 0: axbaxbaxbx
 1: x
    123axbaxbaxb456
 0: x
 1: x

/(?:a(?&abc)b){1,5}(?<abc>x)/
    123axbaxbaxbx456
 0: axbaxbaxbx
 1: x

/(?:a(?&abc)b){2,5}(?<abc>x)/
    123axbaxbaxbx456
 0: axbaxbaxbx
 1: x

/(?:a(?&abc)b){2,}(?<abc>x)/
    123axbaxbaxbx456
 0: axbaxbaxbx
 1: x

/(abc)(?i:(?1))/
    defabcabcxyz
 0: abcabc
 1: abc
\= Expect no match
    DEFabcABCXYZ
No match

/(abc)(?:(?i)(?1))/
    defabcabcxyz
 0: abcabc
 1: abc
\= Expect no match
    DEFabcABCXYZ
No match

/^(a)\g-2/
Failed: error 115 at offset 7: reference to non-existent subpattern

/^(a)\g/
Failed: error 158 at offset 5: a numbered reference must not be zero

/^(a)\g{0}/
Failed: error 158 at offset 8: a numbered reference must not be zero

/^(a)\g{3/
Failed: error 157 at offset 8: \g is not followed by a braced, angle-bracketed, or quoted name/number or by a plain number

/^(a)\g{aa}/
Failed: error 115 at offset 9: reference to non-existent subpattern

/^a.b/newline=lf
    a\rb
 0: a\x0db
\= Expect no match
    a\nb
No match

/.+foo/
    afoo
 0: afoo
\= Expect no match
    \r\nfoo
No match
    \nfoo
No match

/.+foo/newline=crlf
    afoo
 0: afoo
    \nfoo
 0: \x0afoo
\= Expect no match
    \r\nfoo
No match

/.+foo/newline=any
    afoo
 0: afoo
\= Expect no match
    \nfoo
No match
    \r\nfoo
No match

/.+foo/s
    afoo
 0: afoo
    \r\nfoo
 0: \x0d\x0afoo
    \nfoo
 0: \x0afoo
    
/^$/gm,newline=any
    abc\r\rxyz
 0: 
    abc\n\rxyz  
 0: 
\= Expect no match 
    abc\r\nxyz
No match

/(?m)^$/g,newline=any,aftertext
    abc\r\n\r\n
 0: 
 0+ \x0d\x0a

/(?m)^$|^\r\n/g,newline=any,aftertext
    abc\r\n\r\n
 0: 
 0+ \x0d\x0a
 0: \x0d\x0a
 0+ 
    
/(?m)$/g,newline=any,aftertext
    abc\r\n\r\n
 0: 
 0+ \x0d\x0a\x0d\x0a
 0: 
 0+ \x0d\x0a
 0: 
 0+ 

/abc.$/gmx,newline=anycrlf
    abc1\x0a abc2\x0b abc3\x0c abc4\x0d abc5\x0d\x0a abc6\x85 abc9
 0: abc1
 0: abc4
 0: abc5
 0: abc9

/^X/m
    XABC
 0: X
\= Expect no match 
    XABC\=notbol
No match

/(ab|c)(?-1)/B
------------------------------------------------------------------
        Bra
        CBra 1
        ab
        Alt
        c
        Ket
        Recurse
        Ket
        End
------------------------------------------------------------------
    abc
 0: abc
 1: ab

/xy(?+1)(abc)/B
------------------------------------------------------------------
        Bra
        xy
        Recurse
        CBra 1
        abc
        Ket
        Ket
        End
------------------------------------------------------------------
    xyabcabc
 0: xyabcabc
 1: abc
\= Expect no match
    xyabc  
No match
    
/x(?-0)y/
Failed: error 158 at offset 5: a numbered reference must not be zero

/x(?-1)y/
Failed: error 115 at offset 5: reference to non-existent subpattern

/x(?+0)y/
Failed: error 158 at offset 5: a numbered reference must not be zero

/x(?+1)y/
Failed: error 115 at offset 5: reference to non-existent subpattern

/^(abc)?(?(-1)X|Y)/B
------------------------------------------------------------------
        Bra
        ^
        Brazero
        CBra 1
        abc
        Ket
        Cond
      1 Cond ref
        X
        Alt
        Y
        Ket
        Ket
        End
------------------------------------------------------------------
    abcX
 0: abcX
 1: abc
    Y
 0: Y
\= Expect no match
    abcY   
No match
    
/^((?(+1)X|Y)(abc))+/B
------------------------------------------------------------------
        Bra
        ^
        CBra 1
        Cond
      2 Cond ref
        X
        Alt
        Y
        Ket
        CBra 2
        abc
        Ket
        KetRmax
        Ket
        End
------------------------------------------------------------------
    YabcXabc
 0: YabcXabc
 1: Xabc
 2: abc
    YabcXabcXabc
 0: YabcXabcXabc
 1: Xabc
 2: abc
\= Expect no match
    XabcXabc  
No match

/(?(-1)a)/B
Failed: error 115 at offset 6: reference to non-existent subpattern

/((?(-1)a))/B
------------------------------------------------------------------
        Bra
        CBra 1
        Cond
      1 Cond ref
        a
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

/((?(-2)a))/B
Failed: error 115 at offset 7: reference to non-existent subpattern

/^(?(+1)X|Y)(.)/B
------------------------------------------------------------------
        Bra
        ^
        Cond
      1 Cond ref
        X
        Alt
        Y
        Ket
        CBra 1
        Any
        Ket
        Ket
        End
------------------------------------------------------------------
    Y!
 0: Y!
 1: !

/(?<A>tom|bon)-\k{A}/
    tom-tom
 0: tom-tom
 1: tom
    bon-bon 
 0: bon-bon
 1: bon
\= Expect no match
    tom-bon  
No match

/\g{A/
Failed: error 142 at offset 4: syntax error in subpattern name (missing terminator)

/(?|(abc)|(xyz))/B
------------------------------------------------------------------
        Bra
        Bra
        CBra 1
        abc
        Ket
        Alt
        CBra 1
        xyz
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------
   >abc<
 0: abc
 1: abc
   >xyz< 
 0: xyz
 1: xyz

/(x)(?|(abc)|(xyz))(x)/B
------------------------------------------------------------------
        Bra
        CBra 1
        x
        Ket
        Bra
        CBra 2
        abc
        Ket
        Alt
        CBra 2
        xyz
        Ket
        Ket
        CBra 3
        x
        Ket
        Ket
        End
------------------------------------------------------------------
    xabcx
 0: xabcx
 1: x
 2: abc
 3: x
    xxyzx 
 0: xxyzx
 1: x
 2: xyz
 3: x

/(x)(?|(abc)(pqr)|(xyz))(x)/B
------------------------------------------------------------------
        Bra
        CBra 1
        x
        Ket
        Bra
        CBra 2
        abc
        Ket
        CBra 3
        pqr
        Ket
        Alt
        CBra 2
        xyz
        Ket
        Ket
        CBra 4
        x
        Ket
        Ket
        End
------------------------------------------------------------------
    xabcpqrx
 0: xabcpqrx
 1: x
 2: abc
 3: pqr
 4: x
    xxyzx 
 0: xxyzx
 1: x
 2: xyz
 3: <unset>
 4: x

/\H++X/B
------------------------------------------------------------------
        Bra
        \H++
        X
        Ket
        End
------------------------------------------------------------------
\= Expect no match
    XXXX
No match
    
/\H+\hY/B
------------------------------------------------------------------
        Bra
        \H++
        \h
        Y
        Ket
        End
------------------------------------------------------------------
    XXXX Y 
 0: XXXX Y

/\H+ Y/B
------------------------------------------------------------------
        Bra
        \H++
         Y
        Ket
        End
------------------------------------------------------------------

/\h+A/B
------------------------------------------------------------------
        Bra
        \h++
        A
        Ket
        End
------------------------------------------------------------------

/\v*B/B
------------------------------------------------------------------
        Bra
        \v*+
        B
        Ket
        End
------------------------------------------------------------------

/\V+\x0a/B
------------------------------------------------------------------
        Bra
        \V++
        \x0a
        Ket
        End
------------------------------------------------------------------

/A+\h/B
------------------------------------------------------------------
        Bra
        A++
        \h
        Ket
        End
------------------------------------------------------------------

/ *\H/B
------------------------------------------------------------------
        Bra
         *+
        \H
        Ket
        End
------------------------------------------------------------------

/A*\v/B
------------------------------------------------------------------
        Bra
        A*+
        \v
        Ket
        End
------------------------------------------------------------------

/\x0b*\V/B
------------------------------------------------------------------
        Bra
        \x0b*+
        \V
        Ket
        End
------------------------------------------------------------------

/\d+\h/B
------------------------------------------------------------------
        Bra
        \d++
        \h
        Ket
        End
------------------------------------------------------------------

/\d*\v/B
------------------------------------------------------------------
        Bra
        \d*+
        \v
        Ket
        End
------------------------------------------------------------------

/S+\h\S+\v/B
------------------------------------------------------------------
        Bra
        S++
        \h
        \S++
        \v
        Ket
        End
------------------------------------------------------------------

/\w{3,}\h\w+\v/B
------------------------------------------------------------------
        Bra
        \w{3}
        \w*+
        \h
        \w++
        \v
        Ket
        End
------------------------------------------------------------------

/\h+\d\h+\w\h+\S\h+\H/B
------------------------------------------------------------------
        Bra
        \h++
        \d
        \h++
        \w
        \h++
        \S
        \h++
        \H
        Ket
        End
------------------------------------------------------------------

/\v+\d\v+\w\v+\S\v+\V/B
------------------------------------------------------------------
        Bra
        \v++
        \d
        \v++
        \w
        \v++
        \S
        \v++
        \V
        Ket
        End
------------------------------------------------------------------

/\H+\h\H+\d/B
------------------------------------------------------------------
        Bra
        \H++
        \h
        \H+
        \d
        Ket
        End
------------------------------------------------------------------

/\V+\v\V+\w/B
------------------------------------------------------------------
        Bra
        \V++
        \v
        \V+
        \w
        Ket
        End
------------------------------------------------------------------

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/[\E]AAA/
Failed: error 106 at offset 7: missing terminating ] for character class

/[\Q\E]AAA/
Failed: error 106 at offset 9: missing terminating ] for character class

/[^\E]AAA/
Failed: error 106 at offset 8: missing terminating ] for character class

/[^\Q\E]AAA/
Failed: error 106 at offset 10: missing terminating ] for character class

/[\E^]AAA/
Failed: error 106 at offset 8: missing terminating ] for character class

/[\Q\E^]AAA/
Failed: error 106 at offset 10: missing terminating ] for character class

/A(*PRUNE)B(*SKIP)C(*THEN)D(*COMMIT)E(*F)F(*FAIL)G(?!)H(*ACCEPT)I/B
------------------------------------------------------------------
        Bra
        A
        *PRUNE
        B
        *SKIP
        C
        *THEN
        D
        *COMMIT
        E
        *FAIL
        F
        *FAIL
        G
        *FAIL
        H
        *ACCEPT
        I
        Ket
        End
------------------------------------------------------------------

/^a+(*FAIL)/auto_callout
\= Expect no match
    aaaaaa
--->aaaaaa
 +0 ^          ^
 +1 ^          a+
 +3 ^     ^    (*FAIL)
 +3 ^    ^     (*FAIL)
 +3 ^   ^      (*FAIL)
 +3 ^  ^       (*FAIL)
 +3 ^ ^        (*FAIL)
 +3 ^^         (*FAIL)
No match
    
/a+b?c+(*FAIL)/auto_callout
\= Expect no match
    aaabccc
--->aaabccc
 +0 ^           a+
 +2 ^  ^        b?
 +4 ^   ^       c+
 +6 ^      ^    (*FAIL)
 +6 ^     ^     (*FAIL)
 +6 ^    ^      (*FAIL)
 +0  ^          a+
 +2  ^ ^        b?
 +4  ^  ^       c+
 +6  ^     ^    (*FAIL)
 +6  ^    ^     (*FAIL)
 +6  ^   ^      (*FAIL)
 +0   ^         a+
 +2   ^^        b?
 +4   ^ ^       c+
 +6   ^    ^    (*FAIL)
 +6   ^   ^     (*FAIL)
 +6   ^  ^      (*FAIL)
No match

/a+b?(*PRUNE)c+(*FAIL)/auto_callout
\= Expect no match
    aaabccc
--->aaabccc
 +0 ^           a+
 +2 ^  ^        b?
 +4 ^   ^       (*PRUNE)
+12 ^   ^       c+
+14 ^      ^    (*FAIL)
+14 ^     ^     (*FAIL)
+14 ^    ^      (*FAIL)
 +0  ^          a+
 +2  ^ ^        b?
 +4  ^  ^       (*PRUNE)
+12  ^  ^       c+
+14  ^     ^    (*FAIL)
+14  ^    ^     (*FAIL)
+14  ^   ^      (*FAIL)
 +0   ^         a+
 +2   ^^        b?
 +4   ^ ^       (*PRUNE)
+12   ^ ^       c+
+14   ^    ^    (*FAIL)
+14   ^   ^     (*FAIL)
+14   ^  ^      (*FAIL)
No match

/a+b?(*COMMIT)c+(*FAIL)/auto_callout
\= Expect no match
    aaabccc
--->aaabccc
 +0 ^           a+
 +2 ^  ^        b?
 +4 ^   ^       (*COMMIT)
+13 ^   ^       c+
+15 ^      ^    (*FAIL)
+15 ^     ^     (*FAIL)
+15 ^    ^      (*FAIL)
No match
    
/a+b?(*SKIP)c+(*FAIL)/auto_callout
\= Expect no match
    aaabcccaaabccc
--->aaabcccaaabccc
 +0 ^                  a+
 +2 ^  ^               b?
 +4 ^   ^              (*SKIP)
+11 ^   ^              c+
+13 ^      ^           (*FAIL)
+13 ^     ^            (*FAIL)
+13 ^    ^             (*FAIL)
 +0        ^           a+
 +2        ^  ^        b?
 +4        ^   ^       (*SKIP)
+11        ^   ^       c+
+13        ^      ^    (*FAIL)
+13        ^     ^     (*FAIL)
+13        ^    ^      (*FAIL)
No match

/a+b?(*THEN)c+(*FAIL)/auto_callout
\= Expect no match
    aaabccc
--->aaabccc
 +0 ^           a+
 +2 ^  ^        b?
 +4 ^   ^       (*THEN)
+11 ^   ^       c+
+13 ^      ^    (*FAIL)
+13 ^     ^     (*FAIL)
+13 ^    ^      (*FAIL)
 +0  ^          a+
 +2  ^ ^        b?
 +4  ^  ^       (*THEN)
+11  ^  ^       c+
+13  ^     ^    (*FAIL)
+13  ^    ^     (*FAIL)
+13  ^   ^      (*FAIL)
 +0   ^         a+
 +2   ^^        b?
 +4   ^ ^       (*THEN)
+11   ^ ^       c+
+13   ^    ^    (*FAIL)
+13   ^   ^     (*FAIL)
+13   ^  ^      (*FAIL)
No match
    
/a(*MARK)b/
Failed: error 166 at offset 7: (*MARK) must have an argument

/(?i:A{1,}\6666666666)/
Failed: error 161 at offset 19: number is too big

/\g6666666666/
Failed: error 161 at offset 11: number is too big

/[\g6666666666]/B
------------------------------------------------------------------
        Bra
        [6g]
        Ket
        End
------------------------------------------------------------------

/(?1)\c[/
Failed: error 115 at offset 3: reference to non-existent subpattern

/.+A/newline=crlf
\= Expect no match
    \r\nA
No match
    
/\nA/newline=crlf
    \r\nA 
 0: \x0aA

/[\r\n]A/newline=crlf
    \r\nA 
 0: \x0aA

/(\r|\n)A/newline=crlf
    \r\nA 
 0: \x0aA
 1: \x0a

/a(*CR)b/
Failed: error 160 at offset 5: (*VERB) not recognized or malformed

/(*CR)a.b/
    a\nb
 0: a\x0ab
\= Expect no match
    a\rb  
No match

/(*CR)a.b/newline=lf
    a\nb
 0: a\x0ab
\= Expect no match
    a\rb  
No match

/(*LF)a.b/newline=CRLF
    a\rb
 0: a\x0db
\= Expect no match
    a\nb  
No match

/(*CRLF)a.b/
    a\rb
 0: a\x0db
    a\nb  
 0: a\x0ab
\= Expect no match
    a\r\nb  
No match

/(*ANYCRLF)a.b/newline=CR
\= Expect no match
    a\rb
No match
    a\nb  
No match
    a\r\nb  
No match

/(*ANY)a.b/newline=cr
\= Expect no match
    a\rb
No match
    a\nb  
No match
    a\r\nb  
No match
    a\x85b 
No match
    
/(*ANY).*/g
    abc\r\ndef
 0: abc
 0: 
 0: def
 0: 

/(*ANYCRLF).*/g
    abc\r\ndef
 0: abc
 0: 
 0: def
 0: 

/(*CRLF).*/g
    abc\r\ndef
 0: abc
 0: 
 0: def
 0: 

/a\Rb/I,bsr=anycrlf
Capturing subpattern count = 0
\R matches CR, LF, or CRLF
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3
    a\rb
 0: a\x0db
    a\nb
 0: a\x0ab
    a\r\nb
 0: a\x0d\x0ab
\= Expect no match
    a\x85b
No match
    a\x0bb     
No match

/a\Rb/I,bsr=unicode
Capturing subpattern count = 0
\R matches any Unicode newline
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3
    a\rb
 0: a\x0db
    a\nb
 0: a\x0ab
    a\r\nb
 0: a\x0d\x0ab
    a\x85b
 0: a\x85b
    a\x0bb     
 0: a\x0bb
    
/a\R?b/I,bsr=anycrlf
Capturing subpattern count = 0
\R matches CR, LF, or CRLF
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
    a\rb
 0: a\x0db
    a\nb
 0: a\x0ab
    a\r\nb
 0: a\x0d\x0ab
\= Expect no match
    a\x85b
No match
    a\x0bb     
No match

/a\R?b/I,bsr=unicode
Capturing subpattern count = 0
\R matches any Unicode newline
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2
    a\rb
 0: a\x0db
    a\nb
 0: a\x0ab
    a\r\nb
 0: a\x0d\x0ab
    a\x85b
 0: a\x85b
    a\x0bb     
 0: a\x0bb
    
/a\R{2,4}b/I,bsr=anycrlf
Capturing subpattern count = 0
\R matches CR, LF, or CRLF
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 4
    a\r\n\nb
 0: a\x0d\x0a\x0ab
    a\n\r\rb
 0: a\x0a\x0d\x0db
    a\r\n\r\n\r\n\r\nb
 0: a\x0d\x0a\x0d\x0a\x0d\x0a\x0d\x0ab
\= Expect no match
    a\x85\x85b
No match
    a\x0b\x0bb     
No match

/a\R{2,4}b/I,bsr=unicode
Capturing subpattern count = 0
\R matches any Unicode newline
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 4
    a\r\rb
 0: a\x0d\x0db
    a\n\n\nb
 0: a\x0a\x0a\x0ab
    a\r\n\n\r\rb
 0: a\x0d\x0a\x0a\x0d\x0db
    a\x85\x85b
 0: a\x85\x85b
    a\x0b\x0bb     
 0: a\x0b\x0bb
\= Expect no match 
    a\r\r\r\r\rb 
No match
 
/(*BSR_ANYCRLF)a\Rb/I
Capturing subpattern count = 0
\R matches CR, LF, or CRLF
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3
    a\nb
 0: a\x0ab
    a\rb 
 0: a\x0db

/(*BSR_UNICODE)a\Rb/I
Capturing subpattern count = 0
\R matches any Unicode newline
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3
    a\x85b
 0: a\x85b

/(*BSR_ANYCRLF)(*CRLF)a\Rb/I
Capturing subpattern count = 0
\R matches CR, LF, or CRLF
Forced newline is CRLF
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3
    a\nb
 0: a\x0ab
    a\rb 
 0: a\x0db

/(*CRLF)(*BSR_UNICODE)a\Rb/I
Capturing subpattern count = 0
\R matches any Unicode newline
Forced newline is CRLF
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 3
    a\x85b
 0: a\x85b

/(*CRLF)(*BSR_ANYCRLF)(*CR)ab/I
Capturing subpattern count = 0
\R matches CR, LF, or CRLF
Forced newline is CR
First code unit = 'a'
Last code unit = 'b'
Subject length lower bound = 2

/(?<a>)(?&)/
Failed: error 162 at offset 9: subpattern name expected

/(?<abc>)(?&a)/
Failed: error 115 at offset 12: reference to non-existent subpattern

/(?<a>)(?&aaaaaaaaaaaaaaaaaaaaaaa)/
Failed: error 115 at offset 32: reference to non-existent subpattern

/(?+-a)/
Failed: error 163 at offset 3: digit expected after (?+

/(?-+a)/
Failed: error 111 at offset 3: unrecognized character after (? or (?-

/(?(-1))/
Failed: error 115 at offset 6: reference to non-existent subpattern

/(?(+10))/
Failed: error 115 at offset 7: reference to non-existent subpattern

/(?(10))/
Failed: error 115 at offset 6: reference to non-existent subpattern

/(?(+2))()()/

/(?(2))()()/

/\k''/
Failed: error 162 at offset 3: subpattern name expected

/\k<>/
Failed: error 162 at offset 3: subpattern name expected

/\k{}/
Failed: error 162 at offset 3: subpattern name expected

/\k/
Failed: error 169 at offset 1: \k is not followed by a braced, angle-bracketed, or quoted name

/\kabc/
Failed: error 169 at offset 1: \k is not followed by a braced, angle-bracketed, or quoted name

/(?P=)/
Failed: error 162 at offset 4: subpattern name expected

/(?P>)/
Failed: error 162 at offset 4: subpattern name expected

/[[:foo:]]/
Failed: error 130 at offset 3: unknown POSIX class name

/[[:1234:]]/
Failed: error 130 at offset 3: unknown POSIX class name

/[[:f\oo:]]/
Failed: error 130 at offset 3: unknown POSIX class name

/[[: :]]/
Failed: error 130 at offset 3: unknown POSIX class name

/[[:...:]]/
Failed: error 130 at offset 3: unknown POSIX class name

/[[:l\ower:]]/
Failed: error 130 at offset 3: unknown POSIX class name

/[[:abc\:]]/
Failed: error 130 at offset 3: unknown POSIX class name

/[abc[:x\]pqr:]]/
Failed: error 130 at offset 6: unknown POSIX class name

/[[:a\dz:]]/
Failed: error 130 at offset 3: unknown POSIX class name

/(^(a|b\g<-1'c))/
Failed: error 157 at offset 8: \g is not followed by a braced, angle-bracketed, or quoted name/number or by a plain number

/^(?+1)(?<a>x|y){0}z/
    xzxx
 0: xz
    yzyy 
 0: yz
\= Expect no match
    xxz  
No match

/(\3)(\1)(a)/
\= Expect no match
    cat
No match

/(\3)(\1)(a)/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    cat
 0: a
 1: 
 2: 
 3: a
    
/TA]/
    The ACTA] comes 
 0: TA]

/TA]/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    The ACTA] comes 
 0: TA]

/(?2)[]a()b](abc)/
Failed: error 115 at offset 3: reference to non-existent subpattern
    abcbabc

/(?2)[^]a()b](abc)/
Failed: error 115 at offset 3: reference to non-existent subpattern
    abcbabc

/(?1)[]a()b](abc)/
    abcbabc
 0: abcbabc
 1: abc
\= Expect no match 
    abcXabc
No match

/(?1)[^]a()b](abc)/
    abcXabc
 0: abcXabc
 1: abc
\= Expect no match 
    abcbabc
No match

/(?2)[]a()b](abc)(xyz)/
    xyzbabcxyz
 0: xyzbabcxyz
 1: abc
 2: xyz

/(?&N)[]a(?<N>)](?<M>abc)/
Failed: error 115 at offset 4: reference to non-existent subpattern
   abc<abc

/(?&N)[]a(?<N>)](abc)/
Failed: error 115 at offset 4: reference to non-existent subpattern
   abc<abc

/a[]b/
Failed: error 106 at offset 4: missing terminating ] for character class

/a[^]b/
Failed: error 106 at offset 5: missing terminating ] for character class

/a[]b/alt_bsux,allow_empty_class,match_unset_backref,dupnames
\= Expect no match
    ab
No match

/a[]+b/alt_bsux,allow_empty_class,match_unset_backref,dupnames
\= Expect no match
    ab 
No match

/a[]*+b/alt_bsux,allow_empty_class,match_unset_backref,dupnames
\= Expect no match
    ab 
No match

/a[^]b/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    aXb
 0: aXb
    a\nb 
 0: a\x0ab
\= Expect no match
    ab  
No match
    
/a[^]+b/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    aXb
 0: aXb
    a\nX\nXb 
 0: a\x0aX\x0aXb
\= Expect no match
    ab  
No match

/a(?!)b/B
------------------------------------------------------------------
        Bra
        a
        *FAIL
        b
        Ket
        End
------------------------------------------------------------------

/(?!)?a/B
------------------------------------------------------------------
        Bra
        Brazero
        Assert not
        Ket
        a
        Ket
        End
------------------------------------------------------------------
    ab
 0: a

/a(*FAIL)+b/
Failed: error 109 at offset 8: quantifier does not follow a repeatable item

/(abc|pqr|123){0}[xyz]/I
Capturing subpattern count = 1
Starting code units: x y z 
Subject length lower bound = 1

/(?(?=.*b)b|^)/I,auto_callout
Capturing subpattern count = 0
May match empty string
Options: auto_callout
Subject length lower bound = 0
   adc
--->adc
 +0 ^       (?(?=.*b)b|^)
 +2 ^       (?=.*b)
 +5 ^       .*
 +7 ^  ^    b
 +7 ^ ^     b
 +7 ^^      b
 +7 ^       b
+11 ^       ^
+12 ^       )
+13 ^       
 0: 
   abc 
--->abc
 +0 ^       (?(?=.*b)b|^)
 +2 ^       (?=.*b)
 +5 ^       .*
 +7 ^  ^    b
 +7 ^ ^     b
 +7 ^^      b
 +8 ^ ^     )
 +9 ^       b
 +0  ^      (?(?=.*b)b|^)
 +2  ^      (?=.*b)
 +5  ^      .*
 +7  ^ ^    b
 +7  ^^     b
 +7  ^      b
 +8  ^^     )
 +9  ^      b
+10  ^^     |
+13  ^^     
 0: b
   
/(?(?=b).*b|^d)/I
Capturing subpattern count = 0
Subject length lower bound = 1

/(?(?=.*b).*b|^d)/I
Capturing subpattern count = 0
First code unit at start or follows newline
Subject length lower bound = 1

/xyz/auto_callout
  xyz 
--->xyz
 +0 ^       x
 +1 ^^      y
 +2 ^ ^     z
 +3 ^  ^    
 0: xyz
  abcxyz 
--->abcxyz
 +0    ^       x
 +1    ^^      y
 +2    ^ ^     z
 +3    ^  ^    
 0: xyz
\= Expect no match 
  abc
No match
  abcxypqr  
No match
  
/xyz/auto_callout,no_start_optimize
  abcxyz 
--->abcxyz
 +0 ^          x
 +0  ^         x
 +0   ^        x
 +0    ^       x
 +1    ^^      y
 +2    ^ ^     z
 +3    ^  ^    
 0: xyz
\= Expect no match 
  abc
--->abc
 +0 ^       x
 +0  ^      x
 +0   ^     x
 +0    ^    x
No match
  abcxypqr  
--->abcxypqr
 +0 ^            x
 +0  ^           x
 +0   ^          x
 +0    ^         x
 +1    ^^        y
 +2    ^ ^       z
 +0     ^        x
 +0      ^       x
 +0       ^      x
 +0        ^     x
 +0         ^    x
No match
  
/(*NO_START_OPT)xyz/auto_callout
  abcxyz
--->abcxyz
+15 ^          x
+15  ^         x
+15   ^        x
+15    ^       x
+16    ^^      y
+17    ^ ^     z
+18    ^  ^    
 0: xyz
  
/(*NO_AUTO_POSSESS)a+b/B
------------------------------------------------------------------
        Bra
        a+
        b
        Ket
        End
------------------------------------------------------------------

/xyz/auto_callout,no_start_optimize
  abcxyz 
--->abcxyz
 +0 ^          x
 +0  ^         x
 +0   ^        x
 +0    ^       x
 +1    ^^      y
 +2    ^ ^     z
 +3    ^  ^    
 0: xyz

/^"((?(?=[a])[^"])|b)*"$/auto_callout
    "ab"
--->"ab"
 +0 ^        ^
 +1 ^        "
 +2 ^^       ((?(?=[a])[^"])|b)*
 +3 ^^       (?(?=[a])[^"])
 +5 ^^       (?=[a])
 +8 ^^       [a]
+11 ^ ^      )
+12 ^^       [^"]
+16 ^ ^      )
+17 ^ ^      |
 +3 ^ ^      (?(?=[a])[^"])
 +5 ^ ^      (?=[a])
 +8 ^ ^      [a]
+17 ^ ^      |
+21 ^ ^      "
+18 ^ ^      b
+19 ^  ^     )
 +3 ^  ^     (?(?=[a])[^"])
 +5 ^  ^     (?=[a])
 +8 ^  ^     [a]
+17 ^  ^     |
+21 ^  ^     "
+22 ^   ^    $
+23 ^   ^    
 0: "ab"
 1: 

/^"((?(?=[a])[^"])|b)*"$/
    "ab"
 0: "ab"
 1: 

/^X(?5)(a)(?|(b)|(q))(c)(d)Y/
Failed: error 115 at offset 5: reference to non-existent subpattern
    XYabcdY

/^X(?&N)(a)(?|(b)|(q))(c)(d)(?<N>Y)/
    XYabcdY
 0: XYabcdY
 1: a
 2: b
 3: c
 4: d
 5: Y
 
/Xa{2,4}b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/Xa{2,4}?b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/Xa{2,4}+b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/X\d{2,4}b/
    X\=ps
Partial match: X
    X3\=ps
Partial match: X3
    X33\=ps
Partial match: X33
    X333\=ps
Partial match: X333
    X3333\=ps
Partial match: X3333
    
/X\d{2,4}?b/
    X\=ps
Partial match: X
    X3\=ps
Partial match: X3
    X33\=ps
Partial match: X33
    X333\=ps
Partial match: X333
    X3333\=ps
Partial match: X3333
    
/X\d{2,4}+b/
    X\=ps
Partial match: X
    X3\=ps
Partial match: X3
    X33\=ps
Partial match: X33
    X333\=ps
Partial match: X333
    X3333\=ps
Partial match: X3333
    
/X\D{2,4}b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/X\D{2,4}?b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/X\D{2,4}+b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/X[abc]{2,4}b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/X[abc]{2,4}?b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/X[abc]{2,4}+b/
    X\=ps
Partial match: X
    Xa\=ps
Partial match: Xa
    Xaa\=ps
Partial match: Xaa
    Xaaa\=ps
Partial match: Xaaa
    Xaaaa\=ps
Partial match: Xaaaa
    
/X[^a]{2,4}b/
    X\=ps
Partial match: X
    Xz\=ps
Partial match: Xz
    Xzz\=ps
Partial match: Xzz
    Xzzz\=ps
Partial match: Xzzz
    Xzzzz\=ps
Partial match: Xzzzz
    
/X[^a]{2,4}?b/
    X\=ps
Partial match: X
    Xz\=ps
Partial match: Xz
    Xzz\=ps
Partial match: Xzz
    Xzzz\=ps
Partial match: Xzzz
    Xzzzz\=ps
Partial match: Xzzzz
    
/X[^a]{2,4}+b/
    X\=ps
Partial match: X
    Xz\=ps
Partial match: Xz
    Xzz\=ps
Partial match: Xzz
    Xzzz\=ps
Partial match: Xzzz
    Xzzzz\=ps
Partial match: Xzzzz
    
/(Y)X\1{2,4}b/
    YX\=ps
Partial match: YX
    YXY\=ps
Partial match: YXY
    YXYY\=ps
Partial match: YXYY
    YXYYY\=ps
Partial match: YXYYY
    YXYYYY\=ps
Partial match: YXYYYY
    
/(Y)X\1{2,4}?b/
    YX\=ps
Partial match: YX
    YXY\=ps
Partial match: YXY
    YXYY\=ps
Partial match: YXYY
    YXYYY\=ps
Partial match: YXYYY
    YXYYYY\=ps
Partial match: YXYYYY
    
/(Y)X\1{2,4}+b/
    YX\=ps
Partial match: YX
    YXY\=ps
Partial match: YXY
    YXYY\=ps
Partial match: YXYY
    YXYYY\=ps
Partial match: YXYYY
    YXYYYY\=ps
Partial match: YXYYYY
    
/\++\KZ|\d+X|9+Y/startchar
    ++++123999\=ps
Partial match: 123999
    ++++123999Y\=ps
 0: 999Y
    ++++Z1234\=ps
 0: ++++Z
    ^^^^

/Z(*F)/
\= Expect no match
    Z\=ps
No match
    ZA\=ps
No match
    
/Z(?!)/
\= Expect no match
    Z\=ps
No match
    ZA\=ps
No match

/dog(sbody)?/
    dogs\=ps
 0: dog
    dogs\=ph
Partial match: dogs
    
/dog(sbody)??/
    dogs\=ps
 0: dog
    dogs\=ph
 0: dog

/dog|dogsbody/
    dogs\=ps
 0: dog
    dogs\=ph
 0: dog
 
/dogsbody|dog/
    dogs\=ps
 0: dog
    dogs\=ph
Partial match: dogs

/\bthe cat\b/
    the cat\=ps
 0: the cat
    the cat\=ph
Partial match: the cat

/abc/
   abc\=ps
 0: abc
   abc\=ph
 0: abc
   
/abc\K123/startchar
    xyzabc123pqr
 0: abc123
    ^^^
    xyzabc12\=ps
Partial match: abc12
    xyzabc12\=ph
Partial match: abc12
    
/(?<=abc)123/
    xyzabc123pqr 
 0: 123
    xyzabc12\=ps
Partial match: abc12
               <<<
    xyzabc12\=ph
Partial match: abc12
               <<<

/\babc\b/
    +++abc+++
 0: abc
    +++ab\=ps
Partial match: +ab
               <
    +++ab\=ph
Partial match: +ab
               <

/(?&word)(?&element)(?(DEFINE)(?<element><[^m][^>]>[^<])(?<word>\w*+))/B
------------------------------------------------------------------
        Bra
        Recurse
        Recurse
        Cond
        Cond false
        CBra 1
        <
        [^m]
        [^>]
        >
        [^<]
        Ket
        CBra 2
        \w*+
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

/(?&word)(?&element)(?(DEFINE)(?<element><[^\d][^>]>[^<])(?<word>\w*+))/B
------------------------------------------------------------------
        Bra
        Recurse
        Recurse
        Cond
        Cond false
        CBra 1
        <
        [\x00-/:-\xff] (neg)
        [^>]
        >
        [^<]
        Ket
        CBra 2
        \w*+
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

/(ab)(x(y)z(cd(*ACCEPT)))pq/B
------------------------------------------------------------------
        Bra
        CBra 1
        ab
        Ket
        CBra 2
        x
        CBra 3
        y
        Ket
        z
        CBra 4
        cd
        Close 4
        Close 2
        *ACCEPT
        Ket
        Ket
        pq
        Ket
        End
------------------------------------------------------------------

/abc\K/aftertext,startchar
    abcdef
 0: abc
    ^^^
 0+ def
    abcdef\=notempty_atstart
 0: abc
    ^^^
 0+ def
    xyzabcdef\=notempty_atstart
 0: abc
    ^^^
 0+ def
\= Expect no match
    abcdef\=notempty
No match
    xyzabcdef\=notempty
No match
    
/^(?:(?=abc)|abc\K)/aftertext,startchar
    abcdef
 0: 
 0+ abcdef
    abcdef\=notempty_atstart
 0: abc
    ^^^
 0+ def
\= Expect no match 
    abcdef\=notempty
No match

/a?b?/aftertext
    xyz
 0: 
 0+ xyz
    xyzabc
 0: 
 0+ xyzabc
    xyzabc\=notempty
 0: ab
 0+ c
    xyzabc\=notempty_atstart
 0: 
 0+ yzabc
    xyz\=notempty_atstart
 0: 
 0+ yz
\= Expect no match 
    xyz\=notempty
No match

/^a?b?/aftertext
    xyz
 0: 
 0+ xyz
    xyzabc
 0: 
 0+ xyzabc
\= Expect no match 
    xyzabc\=notempty
No match
    xyzabc\=notempty_atstart
No match
    xyz\=notempty_atstart
No match
    xyz\=notempty
No match
    
/^(?<name>a|b\g<name>c)/
    aaaa
 0: a
 1: a
    bacxxx
 0: bac
 1: bac
    bbaccxxx 
 0: bbacc
 1: bbacc
    bbbacccxx
 0: bbbaccc
 1: bbbaccc

/^(?<name>a|b\g'name'c)/
    aaaa
 0: a
 1: a
    bacxxx
 0: bac
 1: bac
    bbaccxxx 
 0: bbacc
 1: bbacc
    bbbacccxx
 0: bbbaccc
 1: bbbaccc

/^(a|b\g<1>c)/
    aaaa
 0: a
 1: a
    bacxxx
 0: bac
 1: bac
    bbaccxxx 
 0: bbacc
 1: bbacc
    bbbacccxx
 0: bbbaccc
 1: bbbaccc

/^(a|b\g'1'c)/
    aaaa
 0: a
 1: a
    bacxxx
 0: bac
 1: bac
    bbaccxxx 
 0: bbacc
 1: bbacc
    bbbacccxx
 0: bbbaccc
 1: bbbaccc

/^(a|b\g'-1'c)/
    aaaa
 0: a
 1: a
    bacxxx
 0: bac
 1: bac
    bbaccxxx 
 0: bbacc
 1: bbacc
    bbbacccxx
 0: bbbaccc
 1: bbbaccc

/(^(a|b\g<-1>c))/
    aaaa
 0: a
 1: a
 2: a
    bacxxx
 0: bac
 1: bac
 2: bac
    bbaccxxx 
 0: bbacc
 1: bbacc
 2: bbacc
    bbbacccxx
 0: bbbaccc
 1: bbbaccc
 2: bbbaccc

/(?-i:\g<name>)(?i:(?<name>a))/
    XaaX
 0: aa
 1: a
    XAAX 
 0: AA
 1: A

/(?i:\g<name>)(?-i:(?<name>a))/
    XaaX
 0: aa
 1: a
\= Expect no match 
    XAAX 
No match

/(?-i:\g<+1>)(?i:(a))/
    XaaX
 0: aa
 1: a
    XAAX 
 0: AA
 1: A

/(?=(?<regex>(?#simplesyntax)\$(?<name>[a-zA-Z_\x{7f}-\x{ff}][a-zA-Z0-9_\x{7f}-\x{ff}]*)(?:\[(?<index>[a-zA-Z0-9_\x{7f}-\x{ff}]+|\$\g<name>)\]|->\g<name>(\(.*?\))?)?|(?#simple syntax withbraces)\$\{(?:\g<name>(?<indices>\[(?:\g<index>|'(?:\\.|[^'\\])*'|"(?:\g<regex>|\\.|[^"\\])*")\])?|\g<complex>|\$\{\g<complex>\})\}|(?#complexsyntax)\{(?<complex>\$(?<segment>\g<name>(\g<indices>*|\(.*?\))?)(?:->\g<segment>)*|\$\g<complex>|\$\{\g<complex>\})\}))\{/

/(?<n>a|b|c)\g<n>*/
   abc
 0: abc
 1: a
   accccbbb 
 0: accccbbb
 1: a

/^X(?7)(a)(?|(b)|(q)(r)(s))(c)(d)(Y)/
    XYabcdY
 0: XYabcdY
 1: a
 2: b
 3: <unset>
 4: <unset>
 5: c
 6: d
 7: Y

/(?<=b(?1)|zzz)(a)/
    xbaax
 0: a
 1: a
    xzzzax 
 0: a
 1: a

/(a)(?<=b\1)/
Failed: error 125 at offset 10: lookbehind assertion is not fixed length

/(a)(?<=b+(?1))/
Failed: error 125 at offset 13: lookbehind assertion is not fixed length

/(a+)(?<=b(?1))/
Failed: error 125 at offset 14: lookbehind assertion is not fixed length

/(a(?<=b(?1)))/
Failed: error 125 at offset 13: lookbehind assertion is not fixed length

/(?<=b(?1))xyz/
Failed: error 115 at offset 8: reference to non-existent subpattern

/(?<=b(?1))xyz(b+)pqrstuvew/
Failed: error 125 at offset 26: lookbehind assertion is not fixed length

/(a|bc)\1/I
Capturing subpattern count = 1
Max back reference = 1
Starting code units: a b 
Subject length lower bound = 2

/(a|bc)\1{2,3}/I
Capturing subpattern count = 1
Max back reference = 1
Starting code units: a b 
Subject length lower bound = 3

/(a|bc)(?1)/I
Capturing subpattern count = 1
Starting code units: a b 
Subject length lower bound = 2

/(a|b\1)(a|b\1)/I
Capturing subpattern count = 2
Max back reference = 1
Starting code units: a b 
Subject length lower bound = 2

/(a|b\1){2}/I
Capturing subpattern count = 1
Max back reference = 1
Starting code units: a b 
Subject length lower bound = 2

/(a|bbbb\1)(a|bbbb\1)/I
Capturing subpattern count = 2
Max back reference = 1
Starting code units: a b 
Subject length lower bound = 2

/(a|bbbb\1){2}/I
Capturing subpattern count = 1
Max back reference = 1
Starting code units: a b 
Subject length lower bound = 2

/^From +([^ ]+) +[a-zA-Z][a-zA-Z][a-zA-Z] +[a-zA-Z][a-zA-Z][a-zA-Z] +[0-9]?[0-9] +[0-9][0-9]:[0-9][0-9]/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Last code unit = ':'
Subject length lower bound = 22

/<tr([\w\W\s\d][^<>]{0,})><TD([\w\W\s\d][^<>]{0,})>([\d]{0,}\.)(.*)((<BR>([\w\W\s\d][^<>]{0,})|[\s]{0,}))<\/a><\/TD><TD([\w\W\s\d][^<>]{0,})>([\w\W\s\d][^<>]{0,})<\/TD><TD([\w\W\s\d][^<>]{0,})>([\w\W\s\d][^<>]{0,})<\/TD><\/TR>/Iis
Capturing subpattern count = 11
Options: caseless dotall
First code unit = '<'
Last code unit = '>'
Subject length lower bound = 47

"(?>.*/)foo"I
Capturing subpattern count = 0
Last code unit = 'o'
Subject length lower bound = 4

/(?(?=[^a-z]+[a-z])  \d{2}-[a-z]{3}-\d{2}  |  \d{2}-\d{2}-\d{2} ) /Ix
Capturing subpattern count = 0
Options: extended
Last code unit = '-'
Subject length lower bound = 8

/(?:(?:(?:(?:(?:(?:(?:(?:(?:(a|b|c))))))))))/Ii
Capturing subpattern count = 1
Options: caseless
Starting code units: A B C a b c 
Subject length lower bound = 1

/(?:c|d)(?:)(?:aaaaaaaa(?:)(?:bbbbbbbb)(?:bbbbbbbb(?:))(?:bbbbbbbb(?:)(?:bbbbbbbb)))/I
Capturing subpattern count = 0
Starting code units: c d 
Last code unit = 'b'
Subject length lower bound = 41

/<a[\s]+href[\s]*=[\s]*          # find <a href=
 ([\"\'])?                       # find single or double quote
 (?(1) (.*?)\1 | ([^\s]+))       # if quote found, match up to next matching
                                 # quote, otherwise match up to next space
/Iisx
Capturing subpattern count = 3
Max back reference = 1
Options: caseless dotall extended
First code unit = '<'
Last code unit = '='
Subject length lower bound = 9

/^(?!:)                       # colon disallowed at start
  (?:                         # start of item
    (?: [0-9a-f]{1,4} |       # 1-4 hex digits or
    (?(1)0 | () ) )           # if null previously matched, fail; else null
    :                         # followed by colon
  ){1,7}                      # end item; 1-7 of them required               
  [0-9a-f]{1,4} $             # final hex number at end of string
  (?(1)|.)                    # check that there was an empty component
  /Iix
Capturing subpattern count = 1
Max back reference = 1
Compile options: caseless extended
Overall options: anchored caseless extended
Last code unit = ':'
Subject length lower bound = 2

/(?|(?<a>A)|(?<a>B))/I
Capturing subpattern count = 1
Named capturing subpatterns:
  a   1
Starting code units: A B 
Subject length lower bound = 1
    AB\=copy=a
 0: A
 1: A
  C A (1) a (group 1)
    BA\=copy=a
 0: B
 1: B
  C B (1) a (group 1)

/(?|(?<a>A)|(?<b>B))/
Failed: error 165 at offset 15: different names for subpatterns of the same number are not allowed

/(?:a(?<quote> (?<apostrophe>')|(?<realquote>")) |
    b(?<quote> (?<apostrophe>')|(?<realquote>")) ) 
    (?('quote')[a-z]+|[0-9]+)/Ix,dupnames
Capturing subpattern count = 6
Max back reference = 4
Named capturing subpatterns:
  apostrophe   2
  apostrophe   5
  quote        1
  quote        4
  realquote    3
  realquote    6
Options: dupnames extended
Starting code units: a b 
Subject length lower bound = 3
    a"aaaaa
 0: a"aaaaa
 1: "
 2: <unset>
 3: "
    b"aaaaa 
 0: b"aaaaa
 1: <unset>
 2: <unset>
 3: <unset>
 4: "
 5: <unset>
 6: "
\= Expect no match 
    b"11111
No match
    a"11111 
No match
    
/^(?|(a)(b)(c)(?<D>d)|(?<D>e)) (?('D')X|Y)/IBx,dupnames
------------------------------------------------------------------
        Bra
        ^
        Bra
        CBra 1
        a
        Ket
        CBra 2
        b
        Ket
        CBra 3
        c
        Ket
        CBra 4
        d
        Ket
        Alt
        CBra 1
        e
        Ket
        Ket
        Cond
        Cond ref <D>2
        X
        Alt
        Y
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 4
Max back reference = 4
Named capturing subpatterns:
  D   4
  D   1
Compile options: dupnames extended
Overall options: anchored dupnames extended
Subject length lower bound = 2
    abcdX
 0: abcdX
 1: a
 2: b
 3: c
 4: d
    eX
 0: eX
 1: e
\= Expect no match
    abcdY
No match
    ey     
No match
    
/(?<A>a) (b)(c)  (?<A>d  (?(R&A)$ | (?4)) )/IBx,dupnames
------------------------------------------------------------------
        Bra
        CBra 1
        a
        Ket
        CBra 2
        b
        Ket
        CBra 3
        c
        Ket
        CBra 4
        d
        Cond
        Cond recurse <A>2
        $
        Alt
        Recurse
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 4
Max back reference = 4
Named capturing subpatterns:
  A   1
  A   4
Options: dupnames extended
First code unit = 'a'
Last code unit = 'd'
Subject length lower bound = 4
    abcdd
 0: abcdd
 1: a
 2: b
 3: c
 4: dd
\= Expect no match
    abcdde  
No match

/abcd*/
    xxxxabcd\=ps
 0: abcd
    xxxxabcd\=ph
Partial match: abcd

/abcd*/i
    xxxxabcd\=ps
 0: abcd
    xxxxabcd\=ph
Partial match: abcd
    XXXXABCD\=ps
 0: ABCD
    XXXXABCD\=ph
Partial match: ABCD

/abc\d*/
    xxxxabc1\=ps
 0: abc1
    xxxxabc1\=ph
Partial match: abc1

/(a)bc\1*/
    xxxxabca\=ps
 0: abca
 1: a
    xxxxabca\=ph
Partial match: abca

/abc[de]*/
    xxxxabcde\=ps
 0: abcde
    xxxxabcde\=ph
Partial match: abcde

# This is not in the Perl-compatible test because Perl seems currently to be
# broken and not behaving as specified in that it *does* bumpalong after
# hitting (*COMMIT). 

/(?1)(A(*COMMIT)|B)D/
    ABD
 0: ABD
 1: B
    XABD
 0: ABD
 1: B
    BAD
 0: BAD
 1: A
    ABXABD  
 0: ABD
 1: B
\= Expect no match 
    ABX 
No match
    BAXBAD  
No match

/(\3)(\1)(a)/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    cat
 0: a
 1: 
 2: 
 3: a

/(\3)(\1)(a)/I,alt_bsux,allow_empty_class,match_unset_backref,dupnames
Capturing subpattern count = 3
Max back reference = 3
Options: alt_bsux allow_empty_class dupnames match_unset_backref
Last code unit = 'a'
Subject length lower bound = 1
    cat
 0: a
 1: 
 2: 
 3: a

/(\3)(\1)(a)/I
Capturing subpattern count = 3
Max back reference = 3
Last code unit = 'a'
Subject length lower bound = 3
\= Expect no match
    cat
No match

/i(?(DEFINE)(?<s>a))/I
Capturing subpattern count = 1
Named capturing subpatterns:
  s   1
First code unit = 'i'
Subject length lower bound = 1
    i
 0: i
    
/()i(?(1)a)/I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'i'
Subject length lower bound = 1
    ia
 0: ia
 1: 

/(?i)a(?-i)b|c/B
------------------------------------------------------------------
        Bra
     /i a
        b
        Alt
        c
        Ket
        End
------------------------------------------------------------------
    XabX
 0: ab
    XAbX
 0: Ab
    CcC 
 0: c
\= Expect no match
    XABX   
No match

/(?i)a(?s)b|c/B
------------------------------------------------------------------
        Bra
     /i ab
        Alt
     /i c
        Ket
        End
------------------------------------------------------------------

/(?i)a(?s-i)b|c/B
------------------------------------------------------------------
        Bra
     /i a
        b
        Alt
        c
        Ket
        End
------------------------------------------------------------------

/^(ab(c\1)d|x){2}$/B
------------------------------------------------------------------
        Bra
        ^
        Once
        CBra 1
        ab
        CBra 2
        c
        \1
        Ket
        d
        Alt
        x
        Ket
        Ket
        Once
        CBra 1
        ab
        CBra 2
        c
        \1
        Ket
        d
        Alt
        x
        Ket
        Ket
        $
        Ket
        End
------------------------------------------------------------------
    xabcxd
 0: xabcxd
 1: abcxd
 2: cx
    
/^(?&t)*+(?(DEFINE)(?<t>.))$/B
------------------------------------------------------------------
        Bra
        ^
        Braposzero
        SBraPos
        Recurse
        KetRpos
        Cond
        Cond false
        CBra 1
        Any
        Ket
        Ket
        $
        Ket
        End
------------------------------------------------------------------

/^(?&t)*(?(DEFINE)(?<t>.))$/B
------------------------------------------------------------------
        Bra
        ^
        Brazero
        Once
        Recurse
        KetRmax
        Cond
        Cond false
        CBra 1
        Any
        Ket
        Ket
        $
        Ket
        End
------------------------------------------------------------------

# This one is here because Perl gives the match as "b" rather than "ab". I
# believe this to be a Perl bug.
      
/(?>a\Kb)z|(ab)/
    ab\=startchar 
 0: ab
 1: ab

/(?P<L1>(?P<L2>0|)|(?P>L2)(?P>L1))/
    abcd
 0: 
 1: 
 2: 
    0abc 
 0: 0
 1: 0
 2: 0

/abc(*MARK:)pqr/
Failed: error 166 at offset 10: (*MARK) must have an argument

/abc(*:)pqr/
Failed: error 166 at offset 6: (*MARK) must have an argument

/abc(*FAIL:123)xyz/
Failed: error 159 at offset 13: an argument is not allowed for (*ACCEPT), (*FAIL), or (*COMMIT)

# This should, and does, fail. In Perl, it does not, which I think is a 
# bug because replacing the B in the pattern by (B|D) does make it fail.

/A(*COMMIT)B/aftertext,mark
\= Expect no match
    ACABX
No match

# These should be different, but in Perl they are not, which I think
# is a bug in Perl.

/A(*THEN)B|A(*THEN)C/mark
    AC
 0: AC

/A(*PRUNE)B|A(*PRUNE)C/mark
\= Expect no match
    AC
No match
    
# Mark names can be duplicated. Perl doesn't give a mark for this one,
# though PCRE2 does.

/^A(*:A)B|^X(*:A)Y/mark
\= Expect no match
    XAQQ
No match, mark = A
    
# COMMIT at the start of a pattern should be the same as an anchor. Perl 
# optimizations defeat this. So does the PCRE2 optimization unless we disable
# it.

/(*COMMIT)ABC/
    ABCDEFG
 0: ABC
    
/(*COMMIT)ABC/no_start_optimize
\= Expect no match
    DEFGABC
No match
    
/^(ab (c+(*THEN)cd) | xyz)/x
\= Expect no match
    abcccd  
No match

/^(ab (c+(*PRUNE)cd) | xyz)/x
\= Expect no match
    abcccd  
No match

/^(ab (c+(*FAIL)cd) | xyz)/x
\= Expect no match
    abcccd  
No match
    
# Perl gets some of these wrong

/(?>.(*ACCEPT))*?5/
    abcde
 0: a

/(.(*ACCEPT))*?5/
    abcde
 0: a
 1: a

/(.(*ACCEPT))5/
    abcde
 0: a
 1: a

/(.(*ACCEPT))*5/
    abcde
 0: a
 1: a

/A\NB./B
------------------------------------------------------------------
        Bra
        A
        Any
        B
        Any
        Ket
        End
------------------------------------------------------------------
    ACBD
 0: ACBD
\= Expect no match
    A\nB
No match
    ACB\n   
No match

/A\NB./Bs
------------------------------------------------------------------
        Bra
        A
        Any
        B
        AllAny
        Ket
        End
------------------------------------------------------------------
    ACBD
 0: ACBD
    ACB\n 
 0: ACB\x0a
\= Expect no match
    A\nB  
No match
  
/A\NB/newline=crlf
    A\nB
 0: A\x0aB
    A\rB
 0: A\x0dB
\= Expect no match
    A\r\nB    
No match

/\R+b/B
------------------------------------------------------------------
        Bra
        \R++
        b
        Ket
        End
------------------------------------------------------------------

/\R+\n/B
------------------------------------------------------------------
        Bra
        \R+
        \x0a
        Ket
        End
------------------------------------------------------------------

/\R+\d/B
------------------------------------------------------------------
        Bra
        \R++
        \d
        Ket
        End
------------------------------------------------------------------

/\d*\R/B
------------------------------------------------------------------
        Bra
        \d*+
        \R
        Ket
        End
------------------------------------------------------------------

/\s*\R/B
------------------------------------------------------------------
        Bra
        \s*
        \R
        Ket
        End
------------------------------------------------------------------
    \x20\x0a
 0:  \x0a
    \x20\x0d
 0:  \x0d
    \x20\x0d\x0a
 0:  \x0d\x0a

/\S*\R/B
------------------------------------------------------------------
        Bra
        \S*+
        \R
        Ket
        End
------------------------------------------------------------------
    a\x0a
 0: a\x0a

/X\h*\R/B
------------------------------------------------------------------
        Bra
        X
        \h*+
        \R
        Ket
        End
------------------------------------------------------------------
    X\x20\x0a
 0: X \x0a

/X\H*\R/B
------------------------------------------------------------------
        Bra
        X
        \H*
        \R
        Ket
        End
------------------------------------------------------------------
    X\x0d\x0a
 0: X\x0d\x0a

/X\H+\R/B
------------------------------------------------------------------
        Bra
        X
        \H+
        \R
        Ket
        End
------------------------------------------------------------------
    X\x0d\x0a
 0: X\x0d\x0a

/X\H++\R/B
------------------------------------------------------------------
        Bra
        X
        \H++
        \R
        Ket
        End
------------------------------------------------------------------
\= Expect no match
    X\x0d\x0a
No match

/(?<=abc)def/
    abc\=ph
Partial match: abc
               <<<

/abc$/
    abc
 0: abc
    abc\=ps
 0: abc
    abc\=ph
Partial match: abc

/abc$/m
    abc
 0: abc
    abc\n
 0: abc
    abc\=ph
Partial match: abc
    abc\n\=ph
 0: abc
    abc\=ps
 0: abc
    abc\n\=ps
 0: abc

/abc\z/
    abc
 0: abc
    abc\=ps
 0: abc
    abc\=ph
Partial match: abc

/abc\Z/
    abc
 0: abc
    abc\=ps
 0: abc
    abc\=ph
Partial match: abc

/abc\b/
    abc
 0: abc
    abc\=ps
 0: abc
    abc\=ph
Partial match: abc

/abc\B/
    abc\=ps
Partial match: abc
    abc\=ph
Partial match: abc
\= Expect no match
    abc
No match

/.+/
\= Bad offsets
    abc\=offset=4
Failed: error -33: bad offset value
    abc\=offset=-4 
** Invalid value in 'offset=-4'
\= Valid data
    abc\=offset=0
 0: abc
    abc\=offset=1
 0: bc
    abc\=offset=2
 0: c
\= Expect no match
    abc\=offset=3
No match

/^\cģ/
Failed: error 168 at offset 3: \c must be followed by a printable ASCII character

/(?P<abn>(?P=abn)xxx)/B
------------------------------------------------------------------
        Bra
        Once
        CBra 1
        \1
        xxx
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

/(a\1z)/B
------------------------------------------------------------------
        Bra
        Once
        CBra 1
        a
        \1
        z
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

/(?P<abn>(?P=abn)(?<badstufxxx)/B
Failed: error 142 at offset 29: syntax error in subpattern name (missing terminator)

/(?P<abn>(?P=axn)xxx)/B
Failed: error 115 at offset 15: reference to non-existent subpattern

/(?P<abn>(?P=axn)xxx)(?<axn>yy)/B
------------------------------------------------------------------
        Bra
        CBra 1
        \2
        xxx
        Ket
        CBra 2
        yy
        Ket
        Ket
        End
------------------------------------------------------------------

# These tests are here because Perl gets the first one wrong. 

/(\R*)(.)/s
    \r\n
 0: \x0d
 1: 
 2: \x0d
    \r\r\n\n\r 
 0: \x0d\x0d\x0a\x0a\x0d
 1: \x0d\x0d\x0a\x0a
 2: \x0d
    \r\r\n\n\r\n 
 0: \x0d\x0d\x0a\x0a\x0d
 1: \x0d\x0d\x0a\x0a
 2: \x0d

/(\R)*(.)/s
    \r\n
 0: \x0d
 1: <unset>
 2: \x0d
    \r\r\n\n\r 
 0: \x0d\x0d\x0a\x0a\x0d
 1: \x0a
 2: \x0d
    \r\r\n\n\r\n 
 0: \x0d\x0d\x0a\x0a\x0d
 1: \x0a
 2: \x0d

/((?>\r\n|\n|\x0b|\f|\r|\x85)*)(.)/s
    \r\n
 0: \x0d
 1: 
 2: \x0d
    \r\r\n\n\r 
 0: \x0d\x0d\x0a\x0a\x0d
 1: \x0d\x0d\x0a\x0a
 2: \x0d
    \r\r\n\n\r\n 
 0: \x0d\x0d\x0a\x0a\x0d
 1: \x0d\x0d\x0a\x0a
 2: \x0d

# ------------- 

/^abc$/B
------------------------------------------------------------------
        Bra
        ^
        abc
        $
        Ket
        End
------------------------------------------------------------------

/^abc$/Bm
------------------------------------------------------------------
        Bra
     /m ^
        abc
     /m $
        Ket
        End
------------------------------------------------------------------

/^(a)*+(\w)/
    aaaaX
 0: aaaaX
 1: a
 2: X
\= Expect no match 
    aaaa
No match

/^(?:a)*+(\w)/
    aaaaX
 0: aaaaX
 1: X
\= Expect no match 
    aaaa
No match

/(a)++1234/IB
------------------------------------------------------------------
        Bra
        CBraPos 1
        a
        KetRpos
        1234
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = '4'
Subject length lower bound = 5

/([abc])++1234/I
Capturing subpattern count = 1
Starting code units: a b c 
Last code unit = '4'
Subject length lower bound = 5

/(?<=(abc)+)X/
Failed: error 125 at offset 10: lookbehind assertion is not fixed length

/(^ab)/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2

/(^ab)++/I
Capturing subpattern count = 1
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2

/(^ab|^)+/I
Capturing subpattern count = 1
May match empty string
Compile options: <none>
Overall options: anchored
Subject length lower bound = 0

/(^ab|^)++/I
Capturing subpattern count = 1
May match empty string
Compile options: <none>
Overall options: anchored
Subject length lower bound = 0

/(?:^ab)/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2

/(?:^ab)++/I
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 2

/(?:^ab|^)+/I
Capturing subpattern count = 0
May match empty string
Compile options: <none>
Overall options: anchored
Subject length lower bound = 0

/(?:^ab|^)++/I
Capturing subpattern count = 0
May match empty string
Compile options: <none>
Overall options: anchored
Subject length lower bound = 0

/(.*ab)/I
Capturing subpattern count = 1
First code unit at start or follows newline
Last code unit = 'b'
Subject length lower bound = 2

/(.*ab)++/I
Capturing subpattern count = 1
First code unit at start or follows newline
Last code unit = 'b'
Subject length lower bound = 2

/(.*ab|.*)+/I
Capturing subpattern count = 1
May match empty string
First code unit at start or follows newline
Subject length lower bound = 0

/(.*ab|.*)++/I
Capturing subpattern count = 1
May match empty string
First code unit at start or follows newline
Subject length lower bound = 0

/(?:.*ab)/I
Capturing subpattern count = 0
First code unit at start or follows newline
Last code unit = 'b'
Subject length lower bound = 2

/(?:.*ab)++/I
Capturing subpattern count = 0
First code unit at start or follows newline
Last code unit = 'b'
Subject length lower bound = 2

/(?:.*ab|.*)+/I
Capturing subpattern count = 0
May match empty string
First code unit at start or follows newline
Subject length lower bound = 0

/(?:.*ab|.*)++/I
Capturing subpattern count = 0
May match empty string
First code unit at start or follows newline
Subject length lower bound = 0

/(?=a)[bcd]/I
Capturing subpattern count = 0
First code unit = 'a'
Subject length lower bound = 1

/((?=a))[bcd]/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/((?=a))+[bcd]/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/((?=a))++[bcd]/I
Capturing subpattern count = 1
First code unit = 'a'
Subject length lower bound = 1

/(?=a+)[bcd]/Ii
Capturing subpattern count = 0
Options: caseless
First code unit = 'a' (caseless)
Subject length lower bound = 1

/(?=a+?)[bcd]/Ii
Capturing subpattern count = 0
Options: caseless
First code unit = 'a' (caseless)
Subject length lower bound = 1

/(?=a++)[bcd]/Ii
Capturing subpattern count = 0
Options: caseless
First code unit = 'a' (caseless)
Subject length lower bound = 1

/(?=a{3})[bcd]/Ii
Capturing subpattern count = 0
Options: caseless
First code unit = 'a' (caseless)
Last code unit = 'a' (caseless)
Subject length lower bound = 1

/(abc)\1+/

# Perl doesn't get these right IMO (the 3rd is PCRE2-specific) 

/(?1)(?:(b(*ACCEPT))){0}/
    b
 0: b

/(?1)(?:(b(*ACCEPT))){0}c/
    bc
 0: bc
\= Expect no match 
    b 
No match

/(?1)(?:((*ACCEPT))){0}c/
    c
 0: c
    c\=notempty
 0: c

/^.*?(?(?=a)a|b(*THEN)c)/
\= Expect no match 
    ba
No match

/^.*?(?(?=a)a|bc)/
    ba
 0: ba

/^.*?(?(?=a)a(*THEN)b|c)/
\= Expect no match 
    ac
No match

/^.*?(?(?=a)a(*THEN)b)c/
\= Expect no match 
    ac
No match

/^.*?(a(*THEN)b)c/
\= Expect no match 
    aabc
No match
    
/^.*? (?1) c (?(DEFINE)(a(*THEN)b))/x
    aabc
 0: aabc

/^.*?(a(*THEN)b|z)c/
    aabc
 0: aabc
 1: ab

/^.*?(z|a(*THEN)b)c/
    aabc
 0: aabc
 1: ab

# These are here because they are not Perl-compatible; the studying means the
# mark is not seen.

/(*MARK:A)(*SKIP:B)(C|X)/mark
    C
 0: C
 1: C
MK: A
\= Expect no match 
    D
No match, mark = A
     
/(*:A)A+(*SKIP:A)(B|Z)/mark
\= Expect no match 
    AAAC
No match, mark = A

# ----------------------------

"(?=a*(*ACCEPT)b)c"
    c
 0: c
    c\=notempty
 0: c
    
/(?1)c(?(DEFINE)((*ACCEPT)b))/
    c
 0: c
    c\=notempty
 0: c
    
/(?>(*ACCEPT)b)c/
    c
 0: 
\= Expect no match 
    c\=notempty
No match

/(?:(?>(a)))+a%/allaftertext
    %aa%
 0: aa%
 0+ 
 1: a
 1+ a%

/(a)b|ac/allaftertext
    ac\=ovector=1
 0: ac
 0+ 
    
/(a)(b)x|abc/allaftertext
     abc\=ovector=2
 0: abc
 0+ 

/(a)bc|(a)(b)\2/
    abc\=ovector=1
Matched, but too many substrings
 0: abc
    abc\=ovector=2
 0: abc
 1: a
    aba\=ovector=1
Matched, but too many substrings
 0: aba
    aba\=ovector=2
Matched, but too many substrings
 0: aba
 1: <unset>
    aba\=ovector=3
Matched, but too many substrings
 0: aba
 1: <unset>
 2: a
    aba\=ovector=4
 0: aba
 1: <unset>
 2: a
 3: b

/(?(DEFINE)(a(?2)|b)(b(?1)|a))(?:(?1)|(?2))/I
Capturing subpattern count = 2
Subject length lower bound = 1

/(a(?2)|b)(b(?1)|a)(?:(?1)|(?2))/I
Capturing subpattern count = 2
Starting code units: a b 
Subject length lower bound = 3

/(a(?2)|b)(b(?1)|a)(?1)(?2)/I
Capturing subpattern count = 2
Starting code units: a b 
Subject length lower bound = 4

/(abc)(?1)/I
Capturing subpattern count = 1
First code unit = 'a'
Last code unit = 'c'
Subject length lower bound = 6

/(?:(foo)|(bar)|(baz))X/allcaptures
    bazfooX
 0: fooX
 1: foo
 2: <unset>
 3: <unset>
    foobazbarX
 0: barX
 1: <unset>
 2: bar
 3: <unset>
    barfooX
 0: fooX
 1: foo
 2: <unset>
 3: <unset>
    bazX
 0: bazX
 1: <unset>
 2: <unset>
 3: baz
    foobarbazX    
 0: bazX
 1: <unset>
 2: <unset>
 3: baz
    bazfooX\=ovector=0
 0: fooX
 1: foo
 2: <unset>
 3: <unset>
    bazfooX\=ovector=1
Matched, but too many substrings
 0: fooX
    bazfooX\=ovector=2
 0: fooX
 1: foo
    bazfooX\=ovector=3
 0: fooX
 1: foo
 2: <unset>

/(?=abc){3}abc/B
------------------------------------------------------------------
        Bra
        Assert
        abc
        Ket
        abc
        Ket
        End
------------------------------------------------------------------

/(?=abc)+abc/B
------------------------------------------------------------------
        Bra
        Assert
        abc
        Ket
        abc
        Ket
        End
------------------------------------------------------------------

/(?=abc)++abc/B
------------------------------------------------------------------
        Bra
        Assert
        abc
        Ket
        abc
        Ket
        End
------------------------------------------------------------------

/(?=abc){0}xyz/B
------------------------------------------------------------------
        Bra
        Skip zero
        Assert
        abc
        Ket
        xyz
        Ket
        End
------------------------------------------------------------------

/(?=(a))?./B
------------------------------------------------------------------
        Bra
        Brazero
        Assert
        CBra 1
        a
        Ket
        Ket
        Any
        Ket
        End
------------------------------------------------------------------

/(?=(a))??./B
------------------------------------------------------------------
        Bra
        Braminzero
        Assert
        CBra 1
        a
        Ket
        Ket
        Any
        Ket
        End
------------------------------------------------------------------

/^(?=(a)){0}b(?1)/B
------------------------------------------------------------------
        Bra
        ^
        Skip zero
        Assert
        CBra 1
        a
        Ket
        Ket
        b
        Recurse
        Ket
        End
------------------------------------------------------------------

/(?(DEFINE)(a))?b(?1)/B
------------------------------------------------------------------
        Bra
        Cond
        Cond false
        CBra 1
        a
        Ket
        Ket
        b
        Recurse
        Ket
        End
------------------------------------------------------------------

/^(?=(?1))?[az]([abc])d/B
------------------------------------------------------------------
        Bra
        ^
        Brazero
        Assert
        Recurse
        Ket
        [az]
        CBra 1
        [a-c]
        Ket
        d
        Ket
        End
------------------------------------------------------------------

/^(?!a){0}\w+/B
------------------------------------------------------------------
        Bra
        ^
        Skip zero
        Assert not
        a
        Ket
        \w++
        Ket
        End
------------------------------------------------------------------

/(?<=(abc))?xyz/B
------------------------------------------------------------------
        Bra
        Brazero
        AssertB
        Reverse
        CBra 1
        abc
        Ket
        Ket
        xyz
        Ket
        End
------------------------------------------------------------------

/[:a[:abc]b:]/B
------------------------------------------------------------------
        Bra
        [:[a-c]
        b:]
        Ket
        End
------------------------------------------------------------------

/^(a(*:A)(d|e(*:B))z|aeq)/auto_callout
    adz
--->adz
 +0 ^       ^
 +1 ^       (a(*:A)(d|e(*:B))z|aeq)
 +2 ^       a
 +3 ^^      (*:A)
 +8 ^^      (d|e(*:B))
Latest Mark: A
 +9 ^^      d
+10 ^ ^     |
+18 ^ ^     z
+19 ^  ^    |
+24 ^  ^    
 0: adz
 1: adz
 2: d
    aez
--->aez
 +0 ^       ^
 +1 ^       (a(*:A)(d|e(*:B))z|aeq)
 +2 ^       a
 +3 ^^      (*:A)
 +8 ^^      (d|e(*:B))
Latest Mark: A
 +9 ^^      d
+11 ^^      e
+12 ^ ^     (*:B)
+17 ^ ^     )
Latest Mark: B
+18 ^ ^     z
+19 ^  ^    |
+24 ^  ^    
 0: aez
 1: aez
 2: e
    aeqwerty
--->aeqwerty
 +0 ^            ^
 +1 ^            (a(*:A)(d|e(*:B))z|aeq)
 +2 ^            a
 +3 ^^           (*:A)
 +8 ^^           (d|e(*:B))
Latest Mark: A
 +9 ^^           d
+11 ^^           e
+12 ^ ^          (*:B)
+17 ^ ^          )
Latest Mark: B
+18 ^ ^          z
+20 ^            a
+21 ^^           e
+22 ^ ^          q
+23 ^  ^         )
+24 ^  ^         
 0: aeq
 1: aeq

/.(*F)/
\= Expect no match
    abc\=ph
No match

/\btype\b\W*?\btext\b\W*?\bjavascript\b/I
Capturing subpattern count = 0
Max lookbehind = 1
First code unit = 't'
Last code unit = 't'
Subject length lower bound = 18

/\btype\b\W*?\btext\b\W*?\bjavascript\b|\burl\b\W*?\bshell:|<input\b.*?\btype\b\W*?\bimage\b|\bonkeyup\b\W*?\=/I
Capturing subpattern count = 0
Max lookbehind = 1
Starting code units: < o t u 
Subject length lower bound = 8

/a(*SKIP)c|b(*ACCEPT)|/I,aftertext
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    a
 0: 
 0+ 

/a(*SKIP)c|b(*ACCEPT)cd(*ACCEPT)|x/I
Capturing subpattern count = 0
Starting code units: a b x 
Subject length lower bound = 0
    ax
 0: x

'a*(*ACCEPT)b'aftertext
    abc\=notempty_atstart
 0: a
 0+ bc
    bbb\=notempty_atstart
 0: 
 0+ bb
\= Expect no match
    \=notempty_atstart
No match

/(*ACCEPT)a/I,aftertext
Capturing subpattern count = 0
Subject length lower bound = 0
    bax
 0: 
 0+ bax

/z(*ACCEPT)a/I,aftertext
Capturing subpattern count = 0
First code unit = 'z'
Subject length lower bound = 0
    baxzbx
 0: z
 0+ bx

/^(?>a+)(?>(z+))\w/B
------------------------------------------------------------------
        Bra
        ^
        Once_NC
        a++
        Ket
        Once
        CBra 1
        z++
        Ket
        Ket
        \w
        Ket
        End
------------------------------------------------------------------
    aaaazzzzb
 0: aaaazzzzb
 1: zzzz
\= Expect no match
    aazz  
No match

/(.)(\1|a(?2))/
    bab
 0: bab
 1: b
 2: ab
    
/\1|(.)(?R)\1/
    cbbbc
 0: cbbbc
 1: c
    
/(.)((?(1)c|a)|a(?2))/
\= Expect no match
    baa  
No match

/(?P<abn>(?P=abn)xxx)/B
------------------------------------------------------------------
        Bra
        Once
        CBra 1
        \1
        xxx
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

/(a\1z)/B
------------------------------------------------------------------
        Bra
        Once
        CBra 1
        a
        \1
        z
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

/^a\x41z/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    aAz
 0: aAz
\= Expect no match
    ax41z
No match

/^a[m\x41]z/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    aAz
 0: aAz

/^a\x1z/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    ax1z
 0: ax1z

/^a\u0041z/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    aAz
 0: aAz
\= Expect no match
    au0041z
No match

/^a[m\u0041]z/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    aAz
 0: aAz

/^a\u041z/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    au041z
 0: au041z
\= Expect no match
    aAz
No match

/^a\U0041z/alt_bsux,allow_empty_class,match_unset_backref,dupnames
    aU0041z
 0: aU0041z
\= Expect no match
    aAz
No match

/(?(?=c)c|d)++Y/B
------------------------------------------------------------------
        Bra
        BraPos
        Cond
        Assert
        c
        Ket
        c
        Alt
        d
        Ket
        KetRpos
        Y
        Ket
        End
------------------------------------------------------------------

/(?(?=c)c|d)*+Y/B
------------------------------------------------------------------
        Bra
        Braposzero
        BraPos
        Cond
        Assert
        c
        Ket
        c
        Alt
        d
        Ket
        KetRpos
        Y
        Ket
        End
------------------------------------------------------------------

/a[\NB]c/
Failed: error 171 at offset 3: \N is not supported in a class
    aNc
    
/a[B-\Nc]/
Failed: error 150 at offset 5: invalid range in character class

/a[B\Nc]/
Failed: error 171 at offset 4: \N is not supported in a class

/(a)(?2){0,1999}?(b)/

/(a)(?(DEFINE)(b))(?2){0,1999}?(?2)/

# This test, with something more complicated than individual letters, causes
# different behaviour in Perl. Perhaps it disables some optimization; no tag is
# passed back for the failures, whereas in PCRE2 there is a tag.
    
/(A|P)(*:A)(B|P) | (X|P)(X|P)(*:B)(Y|P)/x,mark
    AABC
 0: AB
 1: A
 2: B
MK: A
    XXYZ 
 0: XXY
 1: <unset>
 2: <unset>
 3: X
 4: X
 5: Y
MK: B
\= Expect no match
    XAQQ  
No match, mark = A
    XAQQXZZ  
No match, mark = A
    AXQQQ 
No match, mark = A
    AXXQQQ 
No match, mark = B

# Perl doesn't give marks for these, though it does if the alternatives are
# replaced by single letters. 
    
/(b|q)(*:m)f|a(*:n)w/mark
    aw 
 0: aw
MK: n
\= Expect no match 
    abc
No match, mark = m

/(q|b)(*:m)f|a(*:n)w/mark
    aw 
 0: aw
MK: n
\= Expect no match 
    abc
No match, mark = m

# After a partial match, the behaviour is as for a failure. 

/^a(*:X)bcde/mark
   abc\=ps
Partial match, mark=X: abc
   
# These are here because Perl doesn't return a mark, except for the first.

/(?=(*:x))(q|)/aftertext,mark
    abc
 0: 
 0+ abc
 1: 
MK: x

/(?=(*:x))((*:y)q|)/aftertext,mark
    abc
 0: 
 0+ abc
 1: 
MK: x

/(?=(*:x))(?:(*:y)q|)/aftertext,mark
    abc
 0: 
 0+ abc
MK: x

/(?=(*:x))(?>(*:y)q|)/aftertext,mark
    abc
 0: 
 0+ abc
MK: x

/(?=a(*:x))(?!a(*:y)c)/aftertext,mark
    ab
 0: 
 0+ ab
MK: x

/(?=a(*:x))(?=a(*:y)c|)/aftertext,mark
    ab
 0: 
 0+ ab
MK: x

/(..)\1/
    ab\=ps
Partial match: ab
    aba\=ps
Partial match: aba
    abab\=ps
 0: abab
 1: ab

/(..)\1/i
    ab\=ps
Partial match: ab
    abA\=ps
Partial match: abA
    aBAb\=ps
 0: aBAb
 1: aB

/(..)\1{2,}/
    ab\=ps
Partial match: ab
    aba\=ps
Partial match: aba
    abab\=ps
Partial match: abab
    ababa\=ps
Partial match: ababa
    ababab\=ps
 0: ababab
 1: ab
    ababab\=ph
Partial match: ababab
    abababa\=ps
 0: ababab
 1: ab
    abababa\=ph
Partial match: abababa

/(..)\1{2,}/i
    ab\=ps
Partial match: ab
    aBa\=ps
Partial match: aBa
    aBAb\=ps
Partial match: aBAb
    AbaBA\=ps
Partial match: AbaBA
    abABAb\=ps
 0: abABAb
 1: ab
    aBAbaB\=ph
Partial match: aBAbaB
    abABabA\=ps
 0: abABab
 1: ab
    abaBABa\=ph
Partial match: abaBABa

/(..)\1{2,}?x/i
    ab\=ps
Partial match: ab
    abA\=ps
Partial match: abA
    aBAb\=ps
Partial match: aBAb
    abaBA\=ps
Partial match: abaBA
    abAbaB\=ps
Partial match: abAbaB
    abaBabA\=ps
Partial match: abaBabA
    abAbABaBx\=ps
 0: abAbABaBx
 1: ab

/^(..)\1/
    aba\=ps
Partial match: aba

/^(..)\1{2,3}x/
    aba\=ps
Partial match: aba
    ababa\=ps
Partial match: ababa
    ababa\=ph
Partial match: ababa
    abababx
 0: abababx
 1: ab
    ababababx  
 0: ababababx
 1: ab

/^(..)\1{2,3}?x/
    aba\=ps
Partial match: aba
    ababa\=ps
Partial match: ababa
    ababa\=ph
Partial match: ababa
    abababx
 0: abababx
 1: ab
    ababababx  
 0: ababababx
 1: ab
    
/^(..)(\1{2,3})ab/
    abababab
 0: abababab
 1: ab
 2: abab

/^\R/
    \r\=ps
 0: \x0d
    \r\=ph
Partial match: \x0d
    
/^\R{2,3}x/
    \r\=ps
Partial match: \x0d
    \r\=ph
Partial match: \x0d
    \r\r\=ps
Partial match: \x0d\x0d
    \r\r\=ph
Partial match: \x0d\x0d
    \r\r\r\=ps
Partial match: \x0d\x0d\x0d
    \r\r\r\=ph
Partial match: \x0d\x0d\x0d
    \r\rx
 0: \x0d\x0dx
    \r\r\rx    
 0: \x0d\x0d\x0dx

/^\R{2,3}?x/
    \r\=ps
Partial match: \x0d
    \r\=ph
Partial match: \x0d
    \r\r\=ps
Partial match: \x0d\x0d
    \r\r\=ph
Partial match: \x0d\x0d
    \r\r\r\=ps
Partial match: \x0d\x0d\x0d
    \r\r\r\=ph
Partial match: \x0d\x0d\x0d
    \r\rx
 0: \x0d\x0dx
    \r\r\rx    
 0: \x0d\x0d\x0dx
    
/^\R?x/
    \r\=ps
Partial match: \x0d
    \r\=ph
Partial match: \x0d
    x
 0: x
    \rx  
 0: \x0dx

/^\R+x/
    \r\=ps
Partial match: \x0d
    \r\=ph
Partial match: \x0d
    \r\n\=ps
Partial match: \x0d\x0a
    \r\n\=ph
Partial match: \x0d\x0a
    \rx  
 0: \x0dx

/^a$/newline=crlf
    a\r\=ps
Partial match: a\x0d
    a\r\=ph
Partial match: a\x0d

/^a$/m,newline=crlf
    a\r\=ps
Partial match: a\x0d
    a\r\=ph
Partial match: a\x0d

/^(a$|a\r)/newline=crlf
    a\r\=ps
 0: a\x0d
 1: a\x0d
    a\r\=ph
Partial match: a\x0d

/^(a$|a\r)/m,newline=crlf
    a\r\=ps
 0: a\x0d
 1: a\x0d
    a\r\=ph
Partial match: a\x0d

/./newline=crlf
    \r\=ps
 0: \x0d
    \r\=ph
Partial match: \x0d
  
/.{2,3}/newline=crlf
    \r\=ps
Partial match: \x0d
    \r\=ph
Partial match: \x0d
    \r\r\=ps
 0: \x0d\x0d
    \r\r\=ph
Partial match: \x0d\x0d
    \r\r\r\=ps
 0: \x0d\x0d\x0d
    \r\r\r\=ph
Partial match: \x0d\x0d\x0d

/.{2,3}?/newline=crlf
    \r\=ps
Partial match: \x0d
    \r\=ph
Partial match: \x0d
    \r\r\=ps
 0: \x0d\x0d
    \r\r\=ph
Partial match: \x0d\x0d
    \r\r\r\=ps
 0: \x0d\x0d
    \r\r\r\=ph
 0: \x0d\x0d

"AB(C(D))(E(F))?(?(?=\2)(?=\4))"
    ABCDGHI\=ovector=01
Matched, but too many substrings
 0: ABCD
    
# These are all run as real matches in test 1; here we are just checking the
# settings of the anchored and startline bits.  

/(?>.*?a)(?<=ba)/I
Capturing subpattern count = 0
Max lookbehind = 2
Last code unit = 'a'
Subject length lower bound = 1

/(?:.*?a)(?<=ba)/I
Capturing subpattern count = 0
Max lookbehind = 2
First code unit at start or follows newline
Last code unit = 'a'
Subject length lower bound = 1

/.*?a(*PRUNE)b/I
Capturing subpattern count = 0
Last code unit = 'b'
Subject length lower bound = 2

/.*?a(*PRUNE)b/Is
Capturing subpattern count = 0
Options: dotall
Last code unit = 'b'
Subject length lower bound = 2

/^a(*PRUNE)b/Is
Capturing subpattern count = 0
Compile options: dotall
Overall options: anchored dotall
Subject length lower bound = 2

/.*?a(*SKIP)b/I
Capturing subpattern count = 0
Last code unit = 'b'
Subject length lower bound = 2

/(?>.*?a)b/Is
Capturing subpattern count = 0
Options: dotall
Last code unit = 'b'
Subject length lower bound = 2

/(?>.*?a)b/I
Capturing subpattern count = 0
Last code unit = 'b'
Subject length lower bound = 2

/(?>^a)b/Is
Capturing subpattern count = 0
Compile options: dotall
Overall options: anchored dotall
Subject length lower bound = 2

/(?>.*?)(?<=(abcd)|(wxyz))/I
Capturing subpattern count = 2
Max lookbehind = 4
May match empty string
Subject length lower bound = 0

/(?>.*)(?<=(abcd)|(wxyz))/I
Capturing subpattern count = 2
Max lookbehind = 4
May match empty string
Subject length lower bound = 0

"(?>.*)foo"I
Capturing subpattern count = 0
Last code unit = 'o'
Subject length lower bound = 3

"(?>.*?)foo"I
Capturing subpattern count = 0
Last code unit = 'o'
Subject length lower bound = 3

/(?>^abc)/Im
Capturing subpattern count = 0
Options: multiline
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3

/(?>.*abc)/Im
Capturing subpattern count = 0
Options: multiline
Last code unit = 'c'
Subject length lower bound = 3

/(?:.*abc)/Im
Capturing subpattern count = 0
Options: multiline
First code unit at start or follows newline
Last code unit = 'c'
Subject length lower bound = 3

/(?:(a)+(?C1)bb|aa(?C2)b)/
    aab\=callout_capture
Callout 1: last capture = 1
 0: <unset>
 1: a
--->aab
    ^ ^     b
Callout 1: last capture = 1
 0: <unset>
 1: a
--->aab
    ^^      b
Callout 2: last capture = 0
 0: <unset>
--->aab
    ^ ^     b
 0: aab
   
/(?:(a)++(?C1)bb|aa(?C2)b)/
    aab\=callout_capture
Callout 1: last capture = 1
 0: <unset>
 1: a
--->aab
    ^ ^     b
Callout 2: last capture = 0
 0: <unset>
--->aab
    ^ ^     b
 0: aab
    
/(?:(?>(a))(?C1)bb|aa(?C2)b)/
    aab\=callout_capture
Callout 1: last capture = 1
 0: <unset>
 1: a
--->aab
    ^^      b
Callout 2: last capture = 0
 0: <unset>
--->aab
    ^ ^     b
 0: aab

/(?:(?1)(?C1)x|ab(?C2))((a)){0}/
    aab\=callout_capture
Callout 1: last capture = 0
 0: <unset>
--->aab
    ^^      x
Callout 1: last capture = 0
 0: <unset>
--->aab
     ^^     x
Callout 2: last capture = 0
 0: <unset>
--->aab
     ^ ^    )
 0: ab

/(?1)(?C1)((a)(?C2)){0}/
    aab\=callout_capture
Callout 2: last capture = 2
 0: <unset>
 1: <unset>
 2: a
--->aab
    ^^      )
Callout 1: last capture = 0
 0: <unset>
--->aab
    ^^      ((a)(?C2)){0}
 0: a

/(?:(a)+(?C1)bb|aa(?C2)b)++/
    aab\=callout_capture
Callout 1: last capture = 1
 0: <unset>
 1: a
--->aab
    ^ ^     b
Callout 1: last capture = 1
 0: <unset>
 1: a
--->aab
    ^^      b
Callout 2: last capture = 0
 0: <unset>
--->aab
    ^ ^     b
 0: aab
    aab\=callout_capture,ovector=1
Callout 1: last capture = 1
 0: <unset>
--->aab
    ^ ^     b
Callout 1: last capture = 1
 0: <unset>
--->aab
    ^^      b
Callout 2: last capture = 0
 0: <unset>
--->aab
    ^ ^     b
 0: aab

/(ab)x|ab/
    ab\=ovector=0
 0: ab
    ab\=ovector=1
 0: ab
  
/(?<=123)(*MARK:xx)abc/mark
    xxxx123a\=ph
Partial match, mark=xx: 123a
                        <<<
    xxxx123a\=ps
Partial match, mark=xx: 123a
                        <<<
    
/123\Kabc/startchar
    xxxx123a\=ph
Partial match: 123a
    xxxx123a\=ps
Partial match: 123a

/^(?(?=a)aa|bb)/auto_callout
    bb
--->bb
 +0 ^      ^
 +1 ^      (?(?=a)aa|bb)
 +3 ^      (?=a)
 +6 ^      a
+11 ^      b
+12 ^^     b
+13 ^ ^    )
+14 ^ ^    
 0: bb

/(?C1)^(?C2)(?(?C99)(?=(?C3)a(?C4))(?C5)a(?C6)a(?C7)|(?C8)b(?C9)b(?C10))(?C11)/
    bb
--->bb
  1 ^      ^
  2 ^      (?(?C99)(?=(?C3)a(?C4))(?C5)a(?C6)a(?C7)|(?C8)b(?C9)b(?C10))
 99 ^      (?=(?C3)a(?C4))
  3 ^      a
  8 ^      b
  9 ^^     b
 10 ^ ^    )
 11 ^ ^    
 0: bb

# Perl seems to have a bug with this one.

/aaaaa(*COMMIT)(*PRUNE)b|a+c/
    aaaaaac
 0: aaaac
    
# Here are some that Perl treats differently because of the way it handles
# backtracking verbs. 

/(?!a(*COMMIT)b)ac|ad/
     ac
 0: ac
     ad 
 0: ad

/^(?!a(*THEN)b|ac)../
     ad 
 0: ad
\= Expect no match
     ac
No match

/^(?=a(*THEN)b|ac)/
    ac
 0: 
    
/\A.*?(?:a|b(*THEN)c)/
    ba
 0: ba

/\A.*?(?:a|b(*THEN)c)++/
    ba
 0: ba

/\A.*?(?:a|b(*THEN)c|d)/
    ba
 0: ba

/(?:(a(*MARK:X)a+(*SKIP:X)b)){0}(?:(?1)|aac)/
    aac 
 0: aac

/\A.*?(a|b(*THEN)c)/
    ba
 0: ba
 1: a

/^(A(*THEN)B|A(*THEN)D)/
    AD           
 0: AD
 1: AD
    
/(?!b(*THEN)a)bn|bnn/
    bnn
 0: bn

/(?(?=b(*SKIP)a)bn|bnn)/
\= Expect no match
    bnn
No match

/(?=b(*THEN)a|)bn|bnn/
    bnn
 0: bn

# This test causes a segfault with Perl 5.18.0 

/^(?=(a)){0}b(?1)/
    backgammon
 0: ba

/(?|(?<n>f)|(?<n>b))/I,dupnames
Capturing subpattern count = 1
Named capturing subpatterns:
  n   1
Options: dupnames
Starting code units: b f 
Subject length lower bound = 1

/(?<a>abc)(?<a>z)\k<a>()/IB,dupnames
------------------------------------------------------------------
        Bra
        CBra 1
        abc
        Ket
        CBra 2
        z
        Ket
        \k<a>2
        CBra 3
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 3
Max back reference = 2
Named capturing subpatterns:
  a   1
  a   2
Options: dupnames
First code unit = 'a'
Last code unit = 'z'
Subject length lower bound = 5

/a*[bcd]/B
------------------------------------------------------------------
        Bra
        a*+
        [b-d]
        Ket
        End
------------------------------------------------------------------

/[bcd]*a/B
------------------------------------------------------------------
        Bra
        [b-d]*+
        a
        Ket
        End
------------------------------------------------------------------

# A complete set of tests for auto-possessification of character types, but
# omitting \C because it might be disabled (it has its own tests).

/\D+\D \D+\d \D+\S \D+\s \D+\W \D+\w \D+. \D+\R \D+\H \D+\h \D+\V \D+\v \D+\Z \D+\z \D+$/Bx
------------------------------------------------------------------
        Bra
        \D+
        \D
        \D++
        \d
        \D+
        \S
        \D+
        \s
        \D+
        \W
        \D+
        \w
        \D+
        Any
        \D+
        \R
        \D+
        \H
        \D+
        \h
        \D+
        \V
        \D+
        \v
        \D+
        \Z
        \D++
        \z
        \D+
        $
        Ket
        End
------------------------------------------------------------------

/\d+\D \d+\d \d+\S \d+\s \d+\W \d+\w \d+. \d+\R \d+\H \d+\h \d+\V \d+\v \d+\Z \d+\z \d+$/Bx
------------------------------------------------------------------
        Bra
        \d++
        \D
        \d+
        \d
        \d+
        \S
        \d++
        \s
        \d++
        \W
        \d+
        \w
        \d+
        Any
        \d++
        \R
        \d+
        \H
        \d++
        \h
        \d+
        \V
        \d++
        \v
        \d++
        \Z
        \d++
        \z
        \d++
        $
        Ket
        End
------------------------------------------------------------------

/\S+\D \S+\d \S+\S \S+\s \S+\W \S+\w \S+. \S+\R \S+\H \S+\h \S+\V \S+\v \S+\Z \S+\z \S+$/Bx
------------------------------------------------------------------
        Bra
        \S+
        \D
        \S+
        \d
        \S+
        \S
        \S++
        \s
        \S+
        \W
        \S+
        \w
        \S+
        Any
        \S++
        \R
        \S+
        \H
        \S++
        \h
        \S+
        \V
        \S++
        \v
        \S++
        \Z
        \S++
        \z
        \S++
        $
        Ket
        End
------------------------------------------------------------------

/\s+\D \s+\d \s+\S \s+\s \s+\W \s+\w \s+. \s+\R \s+\H \s+\h \s+\V \s+\v \s+\Z \s+\z \s+$/Bx
------------------------------------------------------------------
        Bra
        \s+
        \D
        \s++
        \d
        \s++
        \S
        \s+
        \s
        \s+
        \W
        \s++
        \w
        \s+
        Any
        \s+
        \R
        \s+
        \H
        \s+
        \h
        \s+
        \V
        \s+
        \v
        \s+
        \Z
        \s++
        \z
        \s+
        $
        Ket
        End
------------------------------------------------------------------

/\W+\D \W+\d \W+\S \W+\s \W+\W \W+\w \W+. \W+\R \W+\H \W+\h \W+\V \W+\v \W+\Z \W+\z \W+$/Bx
------------------------------------------------------------------
        Bra
        \W+
        \D
        \W++
        \d
        \W+
        \S
        \W+
        \s
        \W+
        \W
        \W++
        \w
        \W+
        Any
        \W+
        \R
        \W+
        \H
        \W+
        \h
        \W+
        \V
        \W+
        \v
        \W+
        \Z
        \W++
        \z
        \W+
        $
        Ket
        End
------------------------------------------------------------------

/\w+\D \w+\d \w+\S \w+\s \w+\W \w+\w \w+. \w+\R \w+\H \w+\h \w+\V \w+\v \w+\Z \w+\z \w+$/Bx
------------------------------------------------------------------
        Bra
        \w+
        \D
        \w+
        \d
        \w+
        \S
        \w++
        \s
        \w++
        \W
        \w+
        \w
        \w+
        Any
        \w++
        \R
        \w+
        \H
        \w++
        \h
        \w+
        \V
        \w++
        \v
        \w++
        \Z
        \w++
        \z
        \w++
        $
        Ket
        End
------------------------------------------------------------------

/\R+\D \R+\d \R+\S \R+\s \R+\W \R+\w \R+. \R+\R \R+\H \R+\h \R+\V \R+\v \R+\Z \R+\z \R+$/Bx
------------------------------------------------------------------
        Bra
        \R+
        \D
        \R++
        \d
        \R+
        \S
        \R++
        \s
        \R+
        \W
        \R++
        \w
        \R++
        Any
        \R+
        \R
        \R+
        \H
        \R++
        \h
        \R+
        \V
        \R+
        \v
        \R+
        \Z
        \R++
        \z
        \R+
        $
        Ket
        End
------------------------------------------------------------------

/\H+\D \H+\d \H+\S \H+\s \H+\W \H+\w \H+. \H+\R \H+\H \H+\h \H+\V \H+\v \H+\Z \H+\z \H+$/Bx
------------------------------------------------------------------
        Bra
        \H+
        \D
        \H+
        \d
        \H+
        \S
        \H+
        \s
        \H+
        \W
        \H+
        \w
        \H+
        Any
        \H+
        \R
        \H+
        \H
        \H++
        \h
        \H+
        \V
        \H+
        \v
        \H+
        \Z
        \H++
        \z
        \H+
        $
        Ket
        End
------------------------------------------------------------------

/\h+\D \h+\d \h+\S \h+\s \h+\W \h+\w \h+. \h+\R \h+\H \h+\h \h+\V \h+\v \h+\Z \h+\z \h+$/Bx
------------------------------------------------------------------
        Bra
        \h+
        \D
        \h++
        \d
        \h++
        \S
        \h+
        \s
        \h+
        \W
        \h++
        \w
        \h+
        Any
        \h++
        \R
        \h++
        \H
        \h+
        \h
        \h+
        \V
        \h++
        \v
        \h+
        \Z
        \h++
        \z
        \h+
        $
        Ket
        End
------------------------------------------------------------------

/\V+\D \V+\d \V+\S \V+\s \V+\W \V+\w \V+. \V+\R \V+\H \V+\h \V+\V \V+\v \V+\Z \V+\z \V+$/Bx
------------------------------------------------------------------
        Bra
        \V+
        \D
        \V+
        \d
        \V+
        \S
        \V+
        \s
        \V+
        \W
        \V+
        \w
        \V+
        Any
        \V++
        \R
        \V+
        \H
        \V+
        \h
        \V+
        \V
        \V++
        \v
        \V+
        \Z
        \V++
        \z
        \V+
        $
        Ket
        End
------------------------------------------------------------------

/\v+\D \v+\d \v+\S \v+\s \v+\W \v+\w \v+. \v+\R \v+\H \v+\h \v+\V \v+\v \v+\Z \v+\z \v+$/Bx
------------------------------------------------------------------
        Bra
        \v+
        \D
        \v++
        \d
        \v++
        \S
        \v+
        \s
        \v+
        \W
        \v++
        \w
        \v+
        Any
        \v+
        \R
        \v+
        \H
        \v++
        \h
        \v++
        \V
        \v+
        \v
        \v+
        \Z
        \v++
        \z
        \v+
        $
        Ket
        End
------------------------------------------------------------------

/ a+\D  a+\d  a+\S  a+\s  a+\W  a+\w  a+.  a+\R  a+\H  a+\h  a+\V  a+\v  a+\Z  a+\z  a+$/Bx
------------------------------------------------------------------
        Bra
        a+
        \D
        a++
        \d
        a+
        \S
        a++
        \s
        a++
        \W
        a+
        \w
        a+
        Any
        a++
        \R
        a+
        \H
        a++
        \h
        a+
        \V
        a++
        \v
        a++
        \Z
        a++
        \z
        a++
        $
        Ket
        End
------------------------------------------------------------------

/\n+\D \n+\d \n+\S \n+\s \n+\W \n+\w \n+. \n+\R \n+\H \n+\h \n+\V \n+\v \n+\Z \n+\z \n+$/Bx
------------------------------------------------------------------
        Bra
        \x0a+
        \D
        \x0a++
        \d
        \x0a++
        \S
        \x0a+
        \s
        \x0a+
        \W
        \x0a++
        \w
        \x0a+
        Any
        \x0a+
        \R
        \x0a+
        \H
        \x0a++
        \h
        \x0a++
        \V
        \x0a+
        \v
        \x0a+
        \Z
        \x0a++
        \z
        \x0a+
        $
        Ket
        End
------------------------------------------------------------------

/ .+\D  .+\d  .+\S  .+\s  .+\W  .+\w  .+.  .+\R  .+\H  .+\h  .+\V  .+\v  .+\Z  .+\z  .+$/Bx
------------------------------------------------------------------
        Bra
        Any+
        \D
        Any+
        \d
        Any+
        \S
        Any+
        \s
        Any+
        \W
        Any+
        \w
        Any+
        Any
        Any++
        \R
        Any+
        \H
        Any+
        \h
        Any+
        \V
        Any+
        \v
        Any+
        \Z
        Any++
        \z
        Any+
        $
        Ket
        End
------------------------------------------------------------------

/ .+\D  .+\d  .+\S  .+\s  .+\W  .+\w  .+.  .+\R  .+\H  .+\h  .+\V  .+\v  .+\Z  .+\z  .+$/Bsx
------------------------------------------------------------------
        Bra
        AllAny+
        \D
        AllAny+
        \d
        AllAny+
        \S
        AllAny+
        \s
        AllAny+
        \W
        AllAny+
        \w
        AllAny+
        AllAny
        AllAny+
        \R
        AllAny+
        \H
        AllAny+
        \h
        AllAny+
        \V
        AllAny+
        \v
        AllAny+
        \Z
        AllAny++
        \z
        AllAny+
        $
        Ket
        End
------------------------------------------------------------------

/ \D+$  \d+$  \S+$  \s+$  \W+$  \w+$  \R+$  \H+$  \h+$  \V+$ \v+$  a+$   \n+$  .+$  .+$/Bmx
------------------------------------------------------------------
        Bra
        \D+
     /m $
        \d++
     /m $
        \S++
     /m $
        \s+
     /m $
        \W+
     /m $
        \w++
     /m $
        \R+
     /m $
        \H+
     /m $
        \h+
     /m $
        \V+
     /m $
        \v+
     /m $
        a+
     /m $
        \x0a+
     /m $
        Any+
     /m $
        Any+
     /m $
        Ket
        End
------------------------------------------------------------------

/(?=a+)a(a+)++a/B
------------------------------------------------------------------
        Bra
        Assert
        a++
        Ket
        a
        CBraPos 1
        a++
        KetRpos
        a
        Ket
        End
------------------------------------------------------------------

/a+(bb|cc)a+(?:bb|cc)a+(?>bb|cc)a+(?:bb|cc)+a+(aa)a+(?:bb|aa)/B
------------------------------------------------------------------
        Bra
        a++
        CBra 1
        bb
        Alt
        cc
        Ket
        a++
        Bra
        bb
        Alt
        cc
        Ket
        a++
        Once_NC
        bb
        Alt
        cc
        Ket
        a++
        Bra
        bb
        Alt
        cc
        KetRmax
        a+
        CBra 2
        aa
        Ket
        a+
        Bra
        bb
        Alt
        aa
        Ket
        Ket
        End
------------------------------------------------------------------

/a+(bb|cc)?#a+(?:bb|cc)??#a+(?:bb|cc)?+#a+(?:bb|cc)*#a+(bb|cc)?a#a+(?:aa)?/B
------------------------------------------------------------------
        Bra
        a++
        Brazero
        CBra 1
        bb
        Alt
        cc
        Ket
        #
        a++
        Braminzero
        Bra
        bb
        Alt
        cc
        Ket
        #
        a++
        Once
        Brazero
        Bra
        bb
        Alt
        cc
        Ket
        Ket
        #
        a++
        Brazero
        Bra
        bb
        Alt
        cc
        KetRmax
        #
        a+
        Brazero
        CBra 2
        bb
        Alt
        cc
        Ket
        a#
        a+
        Brazero
        Bra
        aa
        Ket
        Ket
        End
------------------------------------------------------------------

/a+(?:bb)?a#a+(?:|||)#a+(?:|b)a#a+(?:|||)?a/B
------------------------------------------------------------------
        Bra
        a+
        Brazero
        Bra
        bb
        Ket
        a#
        a++
        Bra
        Alt
        Alt
        Alt
        Ket
        #
        a+
        Bra
        Alt
        b
        Ket
        a#
        a+
        Brazero
        Bra
        Alt
        Alt
        Alt
        Ket
        a
        Ket
        End
------------------------------------------------------------------

/[ab]*/B
------------------------------------------------------------------
        Bra
        [ab]*+
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: aaaa

/[ab]*?/B
------------------------------------------------------------------
        Bra
        [ab]*?
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: 

/[ab]?/B
------------------------------------------------------------------
        Bra
        [ab]?+
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: a

/[ab]??/B
------------------------------------------------------------------
        Bra
        [ab]??
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: 

/[ab]+/B
------------------------------------------------------------------
        Bra
        [ab]++
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: aaaa

/[ab]+?/B
------------------------------------------------------------------
        Bra
        [ab]+?
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: a

/[ab]{2,3}/B
------------------------------------------------------------------
        Bra
        [ab]{2,3}+
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: aaa

/[ab]{2,3}?/B
------------------------------------------------------------------
        Bra
        [ab]{2,3}?
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: aa

/[ab]{2,}/B
------------------------------------------------------------------
        Bra
        [ab]{2,}+
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: aaaa

/[ab]{2,}?/B
------------------------------------------------------------------
        Bra
        [ab]{2,}?
        Ket
        End
------------------------------------------------------------------
    aaaa
 0: aa

/\d+\s{0,5}=\s*\S?=\w{0,4}\W*/B
------------------------------------------------------------------
        Bra
        \d++
        \s{0,5}+
        =
        \s*+
        \S?
        =
        \w{0,4}+
        \W*+
        Ket
        End
------------------------------------------------------------------

/[a-d]{5,12}[e-z0-9]*#[^a-z]+[b-y]*a[2-7]?[^0-9a-z]+/B
------------------------------------------------------------------
        Bra
        [a-d]{5,12}+
        [0-9e-z]*+
        #
        [\x00-`{-\xff] (neg)++
        [b-y]*+
        a
        [2-7]?+
        [\x00-/:-`{-\xff] (neg)++
        Ket
        End
------------------------------------------------------------------

/[a-z]*\s#[ \t]?\S#[a-c]*\S#[C-G]+?\d#[4-8]*\D#[4-9,]*\D#[!$]{0,5}\w#[M-Xf-l]+\W#[a-c,]?\W/B
------------------------------------------------------------------
        Bra
        [a-z]*+
        \s
        #
        [\x09 ]?+
        \S
        #
        [a-c]*
        \S
        #
        [C-G]++
        \d
        #
        [4-8]*+
        \D
        #
        [,4-9]*
        \D
        #
        [!$]{0,5}+
        \w
        #
        [M-Xf-l]++
        \W
        #
        [,a-c]?
        \W
        Ket
        End
------------------------------------------------------------------

/a+(aa|bb)*c#a*(bb|cc)*a#a?(bb|cc)*d#[a-f]*(g|hh)*f/B
------------------------------------------------------------------
        Bra
        a+
        Brazero
        CBra 1
        aa
        Alt
        bb
        KetRmax
        c#
        a*
        Brazero
        CBra 2
        bb
        Alt
        cc
        KetRmax
        a#
        a?+
        Brazero
        CBra 3
        bb
        Alt
        cc
        KetRmax
        d#
        [a-f]*
        Brazero
        CBra 4
        g
        Alt
        hh
        KetRmax
        f
        Ket
        End
------------------------------------------------------------------

/[a-f]*(g|hh|i)*i#[a-x]{4,}(y{0,6})*y#[a-k]+(ll|mm)+n/B
------------------------------------------------------------------
        Bra
        [a-f]*+
        Brazero
        CBra 1
        g
        Alt
        hh
        Alt
        i
        KetRmax
        i#
        [a-x]{4,}
        Brazero
        SCBra 2
        y{0,6}
        KetRmax
        y#
        [a-k]++
        CBra 3
        ll
        Alt
        mm
        KetRmax
        n
        Ket
        End
------------------------------------------------------------------

/[a-f]*(?>gg|hh)+#[a-f]*(?>gg|hh)?#[a-f]*(?>gg|hh)*a#[a-f]*(?>gg|hh)*h/B
------------------------------------------------------------------
        Bra
        [a-f]*+
        Once_NC
        gg
        Alt
        hh
        KetRmax
        #
        [a-f]*+
        Brazero
        Once_NC
        gg
        Alt
        hh
        Ket
        #
        [a-f]*
        Brazero
        Once_NC
        gg
        Alt
        hh
        KetRmax
        a#
        [a-f]*+
        Brazero
        Once_NC
        gg
        Alt
        hh
        KetRmax
        h
        Ket
        End
------------------------------------------------------------------

/[a-c]*d/IB
------------------------------------------------------------------
        Bra
        [a-c]*+
        d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: a b c d 
Last code unit = 'd'
Subject length lower bound = 1

/[a-c]+d/IB
------------------------------------------------------------------
        Bra
        [a-c]++
        d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: a b c 
Last code unit = 'd'
Subject length lower bound = 2

/[a-c]?d/IB
------------------------------------------------------------------
        Bra
        [a-c]?+
        d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: a b c d 
Last code unit = 'd'
Subject length lower bound = 1

/[a-c]{4,6}d/IB
------------------------------------------------------------------
        Bra
        [a-c]{4,6}+
        d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: a b c 
Last code unit = 'd'
Subject length lower bound = 5

/[a-c]{0,6}d/IB
------------------------------------------------------------------
        Bra
        [a-c]{0,6}+
        d
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
Starting code units: a b c d 
Last code unit = 'd'
Subject length lower bound = 1

# End of special auto-possessive tests 

/^A\o{1239}B/
Failed: error 164 at offset 8: non-octal character in \o{} (closing brace missing?)
    A\123B

/^A\oB/
Failed: error 155 at offset 3: missing opening brace after \o
    
/^A\x{zz}B/
Failed: error 167 at offset 5: non-hex character in \x{} (closing brace missing?)

/^A\x{12Z/
Failed: error 167 at offset 7: non-hex character in \x{} (closing brace missing?)

/^A\x{/
Failed: error 167 at offset 5: non-hex character in \x{} (closing brace missing?)

/[ab]++/B,no_auto_possess
------------------------------------------------------------------
        Bra
        [ab]++
        Ket
        End
------------------------------------------------------------------

/[^ab]*+/B,no_auto_possess
------------------------------------------------------------------
        Bra
        [\x00-`c-\xff] (neg)*+
        Ket
        End
------------------------------------------------------------------

/a{4}+/B,no_auto_possess
------------------------------------------------------------------
        Bra
        a{4}
        Ket
        End
------------------------------------------------------------------

/a{4}+/Bi,no_auto_possess
------------------------------------------------------------------
        Bra
     /i a{4}
        Ket
        End
------------------------------------------------------------------

/[a-[:digit:]]+/
Failed: error 150 at offset 3: invalid range in character class

/[A-[:digit:]]+/
Failed: error 150 at offset 3: invalid range in character class

/[a-[.xxx.]]+/
Failed: error 150 at offset 3: invalid range in character class

/[a-[=xxx=]]+/
Failed: error 150 at offset 3: invalid range in character class

/[a-[!xxx!]]+/
Failed: error 108 at offset 3: range out of order in character class

/[A-[!xxx!]]+/
    A]]]
 0: A]]]

/[a-\d]+/
Failed: error 150 at offset 4: invalid range in character class

/(?<0abc>xx)/
Failed: error 144 at offset 3: group name must start with a non-digit

/(?&1abc)xx(?<1abc>y)/
Failed: error 144 at offset 13: group name must start with a non-digit

/(?<ab-cd>xx)/
Failed: error 142 at offset 5: syntax error in subpattern name (missing terminator)

/(?'0abc'xx)/
Failed: error 144 at offset 3: group name must start with a non-digit

/(?P<0abc>xx)/
Failed: error 144 at offset 4: group name must start with a non-digit

/\k<5ghj>/
Failed: error 144 at offset 3: group name must start with a non-digit

/\k'5ghj'/
Failed: error 144 at offset 3: group name must start with a non-digit

/\k{2fgh}/
Failed: error 144 at offset 3: group name must start with a non-digit

/(?P=8yuki)/
Failed: error 144 at offset 4: group name must start with a non-digit

/\g{4df}/
Failed: error 144 at offset 3: group name must start with a non-digit

/(?&1abc)xx(?<1abc>y)/
Failed: error 144 at offset 13: group name must start with a non-digit

/(?P>1abc)xx(?<1abc>y)/
Failed: error 144 at offset 14: group name must start with a non-digit

/\g'3gh'/
Failed: error 157 at offset 2: \g is not followed by a braced, angle-bracketed, or quoted name/number or by a plain number

/\g<5fg>/
Failed: error 157 at offset 2: \g is not followed by a braced, angle-bracketed, or quoted name/number or by a plain number

/(?(<4gh>)abc)/
Failed: error 144 at offset 4: group name must start with a non-digit

/(?('4gh')abc)/
Failed: error 144 at offset 4: group name must start with a non-digit

/(?(4gh)abc)/
Failed: error 126 at offset 4: malformed number or name after (?(

/(?(R&6yh)abc)/
Failed: error 144 at offset 5: group name must start with a non-digit

/(((a\2)|(a*)\g<-1>))*a?/B
------------------------------------------------------------------
        Bra
        Brazero
        SCBra 1
        Once
        CBra 2
        CBra 3
        a
        \2
        Ket
        Alt
        CBra 4
        a*
        Ket
        Recurse
        Ket
        Ket
        KetRmax
        a?+
        Ket
        End
------------------------------------------------------------------

# Test the ugly "start or end of word" compatibility syntax.

/[[:<:]]red[[:>:]]/B
------------------------------------------------------------------
        Bra
        \b
        Assert
        \w
        Ket
        red
        \b
        AssertB
        Reverse
        \w
        Ket
        Ket
        End
------------------------------------------------------------------
    little red riding hood
 0: red
    a /red/ thing 
 0: red
    red is a colour
 0: red
    put it all on red  
 0: red
\= Expect no match
    no reduction
No match
    Alfred Winifred
No match
    
/[a[:<:]] should give error/
Failed: error 130 at offset 4: unknown POSIX class name

/(?=ab\K)/aftertext
    abcd\=startchar
Start of matched string is beyond its end - displaying from end to start.
 0: ab
 0+ abcd

/abcd/newline=lf,firstline
\= Expect no match
    xx\nxabcd
No match
    
# Test stack guard external calls.

/(((a)))/stackguard=1
Failed: error 133 at offset 2: parentheses are too deeply nested (stack check)

/(((a)))/stackguard=2
Failed: error 133 at offset 3: parentheses are too deeply nested (stack check)

/(((a)))/stackguard=3

/(((((a)))))/

# End stack guard tests

/^\w+(?>\s*)(?<=\w)/B
------------------------------------------------------------------
        Bra
        ^
        \w+
        Once_NC
        \s*+
        Ket
        AssertB
        Reverse
        \w
        Ket
        Ket
        End
------------------------------------------------------------------

/\othing/
Failed: error 155 at offset 1: missing opening brace after \o

/\o{}/
Failed: error 178 at offset 1: digits missing in \x{} or \o{}

/\o{whatever}/
Failed: error 164 at offset 3: non-octal character in \o{} (closing brace missing?)

/\xthing/

/\x{}/
Failed: error 178 at offset 3: digits missing in \x{} or \o{}

/\x{whatever}/
Failed: error 167 at offset 3: non-hex character in \x{} (closing brace missing?)

/A\8B/
Failed: error 115 at offset 2: reference to non-existent subpattern

/A\9B/
Failed: error 115 at offset 2: reference to non-existent subpattern

# This one is here because Perl fails to match "12" for this pattern when the $ 
# is present.
    
/^(?(?=abc)\w{3}:|\d\d)$/
    abc:
 0: abc:
    12
 0: 12
\= Expect no match
    123
No match
    xyz    
No match

# Perl gets this one wrong, giving "a" as the after text for ca and failing to 
# match for cd.

/(?(?=ab)ab)/aftertext
    abxxx
 0: ab
 0+ xxx
    ca
 0: 
 0+ ca
    cd 
 0: 
 0+ cd
    
# This should test both paths for processing OP_RECURSE. 

/(?(R)a+|(?R)b)/
    aaaabcde
 0: aaaab
    aaaabcde\=ovector=100
 0: aaaab

/a*?b*?/
    ab
 0: 

/(*NOTEMPTY)a*?b*?/
    ab
 0: a
    ba
 0: b
    cb  
 0: b

/(*NOTEMPTY_ATSTART)a*?b*?/aftertext
    ab
 0: a
 0+ b
    cdab 
 0: 
 0+ dab

/(?(VERSION>=10.0)yes|no)/I
Capturing subpattern count = 0
Subject length lower bound = 2
    yesno
 0: yes
    
/(?(VERSION=8)yes){3}/BI,aftertext
------------------------------------------------------------------
        Bra
        Cond
        Cond false
        yes
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 0
May match empty string
Subject length lower bound = 0
    yesno
 0: 
 0+ yesno

/(?(VERSION=8)yes|no){3}/I
Capturing subpattern count = 0
Subject length lower bound = 6
    yesnononoyes
 0: nonono
\= Expect no match
    yesno   
No match

/(?:(?<VERSION>abc)|xyz)(?(VERSION)yes|no)/I
Capturing subpattern count = 1
Max back reference = 1
Named capturing subpatterns:
  VERSION   1
Starting code units: a x 
Subject length lower bound = 5
    abcyes
 0: abcyes
 1: abc
    xyzno
 0: xyzno
\= Expect no match
    abcno
No match
    xyzyes    
No match

/(?(VERSION<10)yes|no)/
Failed: error 179 at offset 10: syntax error in (?(VERSION condition

/(?(VERSION>10)yes|no)/
Failed: error 179 at offset 11: syntax error in (?(VERSION condition

/(?(VERSION>=10.0.0)yes|no)/
Failed: error 179 at offset 16: syntax error in (?(VERSION condition

/(?(VERSION=10.101)yes|no)/
Failed: error 179 at offset 17: syntax error in (?(VERSION condition

/abcd/I
Capturing subpattern count = 0
First code unit = 'a'
Last code unit = 'd'
Subject length lower bound = 4

/abcd/I,no_start_optimize
Capturing subpattern count = 0
Options: no_start_optimize
Subject length lower bound = 0

/(|ab)*?d/I
Capturing subpattern count = 1
Starting code units: a d 
Last code unit = 'd'
Subject length lower bound = 1
   abd
 0: abd
 1: ab
   xyd 
 0: d

/(|ab)*?d/I,no_start_optimize
Capturing subpattern count = 1
Options: no_start_optimize
Last code unit = 'd'
Subject length lower bound = 0
   abd
 0: abd
 1: ab
   xyd 
 0: d

/\k<A>*(?<A>aa)(?<A>bb)/match_unset_backref,dupnames
    aabb
 0: aabb
 1: aa
 2: bb

/(((((a)))))/parens_nest_limit=2
Failed: error 119 at offset 3: parentheses are too deeply nested

/abc/replace=XYZ
    123123
 0: 123123
    123abc123
 1: 123XYZ123
    123abc123abc123
 1: 123XYZ123abc123
    123123\=zero_terminate
 0: 123123
    123abc123\=zero_terminate
 1: 123XYZ123
    123abc123abc123\=zero_terminate
 1: 123XYZ123abc123

/abc/g,replace=XYZ
    123abc123
 1: 123XYZ123
    123abc123abc123
 2: 123XYZ123XYZ123

/abc/replace=X$$Z
    123abc123
 1: 123X$Z123

/abc/g,replace=X$$Z
    123abc123abc123
 2: 123X$Z123X$Z123

/a(b)c(d)e/replace=X$1Y${2}Z
    "abcde"
 1: "XbYdZ"

/a(b)c(d)e/replace=X$1Y${2}Z,global
    "abcde-abcde"
 2: "XbYdZ-XbYdZ"

/a(?<ONE>b)c(?<TWO>d)e/replace=X$ONE+${TWO}Z
    "abcde"
 1: "Xb+dZ"

/a(?<ONE>b)c(?<TWO>d)e/g,replace=X$ONE+${TWO}Z
    "abcde-abcde-"
 2: "Xb+dZ-Xb+dZ-"

/abc/replace=a$++
    123abc
Failed: error -35 at offset 2 in replacement: invalid replacement string

/abc/replace=a$bad
    123abc
Failed: error -49 at offset 5 in replacement: unknown substring

/abc/replace=a${A234567890123456789_123456789012}z
    123abc
Failed: error -49 at offset 36 in replacement: unknown substring

/abc/replace=a${A23456789012345678901234567890123}z
    123abc
Failed: error -35 at offset 35 in replacement: invalid replacement string

/abc/replace=a${bcd
    123abc
Failed: error -58 at offset 6 in replacement: expected closing curly bracket in replacement string

/abc/replace=a${b+d}z
    123abc
Failed: error -58 at offset 4 in replacement: expected closing curly bracket in replacement string

/abc/replace=[10]XYZ
    123abc123
 1: 123XYZ123

/abc/replace=[9]XYZ
    123abc123
Failed: error -48: no more memory
    
/abc/replace=xyz
    1abc2\=partial_hard
Failed: error -34: bad option value

/abc/replace=xyz
    123abc456
 1: 123xyz456
    123abc456\=replace=pqr
 1: 123pqr456
    123abc456abc789
 1: 123xyz456abc789
    123abc456abc789\=g
 2: 123xyz456xyz789

/(?<=abc)(|def)/g,replace=<$0>
    123abcxyzabcdef789abcpqr
 4: 123abc<>xyzabc<><def>789abc<>pqr
    
/./replace=$0
    a
 1: a
    
/(.)(.)/replace=$2+$1
    abc
 1: b+ac
    
/(?<A>.)(?<B>.)/replace=$B+$A
    abc
 1: b+ac
    
/(.)(.)/g,replace=$2$1
    abcdefgh  
 4: badcfehg
    
/(*:pear)apple|(*:orange)lemon|(*:strawberry)blackberry/g,replace=${*MARK}
    apple lemon blackberry
 3: pear orange strawberry
    apple strudel
 1: pear strudel
    fruitless  
 0: fruitless

/(*:pear)apple|(*:orange)lemon|(*:strawberry)blackberry/replace=${*MARK} sauce,
    apple lemon blackberry
 1: pear sauce lemon blackberry

/(*:pear)apple|(*:orange)lemon|(*:strawberry)blackberry/g,replace=<$*MARK>
    apple lemon blackberry
 3: <pear> <orange> <strawberry>
    apple strudel
 1: <pear> strudel
    fruitless  
 0: fruitless
    
/(*:pear)apple/g,replace=${*MARKING} 
    apple lemon blackberry
Failed: error -35 at offset 11 in replacement: invalid replacement string

/(*:pear)apple/g,replace=${*MARK-time
    apple lemon blackberry
Failed: error -58 at offset 7 in replacement: expected closing curly bracket in replacement string

/(*:pear)apple/g,replace=${*mark} 
    apple lemon blackberry
Failed: error -35 at offset 8 in replacement: invalid replacement string

/(*:pear)apple|(*:orange)lemon|(*:strawberry)blackberry/g,replace=<$*MARKET>
    apple lemon blackberry
Failed: error -35 at offset 9 in replacement: invalid replacement string

/(*:pear)apple|(*:orange)lemon|(*:strawberry)blackberry/g,replace=[22]${*MARK}
    apple lemon blackberry
Failed: error -48: no more memory
    apple lemon blackberry\=substitute_overflow_length
Failed: error -48: no more memory: 23 code units are needed

/(*:pear)apple|(*:orange)lemon|(*:strawberry)blackberry/g,replace=[23]${*MARK}
    apple lemon blackberry
 3: pear orange strawberry

/abc/
    123abc123\=replace=[9]XYZ
Failed: error -48: no more memory
    123abc123\=substitute_overflow_length,replace=[9]XYZ
Failed: error -48: no more memory: 10 code units are needed
    123abc123\=substitute_overflow_length,replace=[6]XYZ
Failed: error -48: no more memory: 10 code units are needed
    123abc123\=substitute_overflow_length,replace=[1]XYZ
Failed: error -48: no more memory: 10 code units are needed
    123abc123\=substitute_overflow_length,replace=[0]XYZ
Failed: error -48: no more memory: 10 code units are needed

/a(b)c/
    123abc123\=replace=[9]x$1z
Failed: error -48: no more memory
    123abc123\=substitute_overflow_length,replace=[9]x$1z
Failed: error -48: no more memory: 10 code units are needed
    123abc123\=substitute_overflow_length,replace=[6]x$1z
Failed: error -48: no more memory: 10 code units are needed
    123abc123\=substitute_overflow_length,replace=[1]x$1z
Failed: error -48: no more memory: 10 code units are needed
    123abc123\=substitute_overflow_length,replace=[0]x$1z
Failed: error -48: no more memory: 10 code units are needed

"((?=(?(?=(?(?=(?(?=()))))))))"
    a
 0: 
 1: 
 2: 

"(?(?=)==)(((((((((?=)))))))))"
\= Expect no match
    a
No match

/(a)(b)|(c)/
    XcX\=ovector=2,get=1,get=2,get=3,get=4,getall
Matched, but too many substrings
 0: c
 1: <unset>
Get substring 1 failed (-55): requested value is not set
Get substring 2 failed (-54): requested value is not available
Get substring 3 failed (-54): requested value is not available
Get substring 4 failed (-49): unknown substring
 0L c
 1L 
    
/x(?=ab\K)/
    xab\=get=0 
Start of matched string is beyond its end - displaying from end to start.
 0: ab
 0G  (0)
    xab\=copy=0 
Start of matched string is beyond its end - displaying from end to start.
 0: ab
 0C  (0)
    xab\=getall
Start of matched string is beyond its end - displaying from end to start.
 0: ab
 0L 

/(?<A>a)|(?<A>b)/dupnames
    a\=ovector=1,copy=A,get=A,get=2
Matched, but too many substrings
 0: a
Copy substring 'A' failed (-54): requested value is not available
Get substring 2 failed (-54): requested value is not available
Get substring 'A' failed (-54): requested value is not available
    a\=ovector=2,copy=A,get=A,get=2
 0: a
 1: a
  C a (1) A (non-unique)
Get substring 2 failed (-54): requested value is not available
  G a (1) A (non-unique)
    b\=ovector=2,copy=A,get=A,get=2
Matched, but too many substrings
 0: b
 1: <unset>
Copy substring 'A' failed (-55): requested value is not set
Get substring 2 failed (-54): requested value is not available
Get substring 'A' failed (-55): requested value is not set

/a(b)c(d)/
    abc\=ph,copy=0,copy=1,getall
Partial match: abc
 0C abc (3)
Copy substring 1 failed (-2): partial match
get substring list failed (-2): partial match

/^abc/info
Capturing subpattern count = 0
Compile options: <none>
Overall options: anchored
Subject length lower bound = 3

/^abc/info,no_dotstar_anchor
Capturing subpattern count = 0
Compile options: no_dotstar_anchor
Overall options: anchored no_dotstar_anchor
Subject length lower bound = 3

/.*\d/info,auto_callout
Capturing subpattern count = 0
Options: auto_callout
First code unit at start or follows newline
Subject length lower bound = 1
\= Expect no match
    aaa
--->aaa
 +0 ^       .*
 +2 ^  ^    \d
 +2 ^ ^     \d
 +2 ^^      \d
 +2 ^       \d
No match

/.*\d/info,no_dotstar_anchor,auto_callout
Capturing subpattern count = 0
Options: auto_callout no_dotstar_anchor
Subject length lower bound = 1
\= Expect no match
    aaa
--->aaa
 +0 ^       .*
 +2 ^  ^    \d
 +2 ^ ^     \d
 +2 ^^      \d
 +2 ^       \d
 +0  ^      .*
 +2  ^ ^    \d
 +2  ^^     \d
 +2  ^      \d
 +0   ^     .*
 +2   ^^    \d
 +2   ^     \d
No match

/.*\d/dotall,info
Capturing subpattern count = 0
Compile options: dotall
Overall options: anchored dotall
Subject length lower bound = 1

/.*\d/dotall,no_dotstar_anchor,info
Capturing subpattern count = 0
Options: dotall no_dotstar_anchor
Subject length lower bound = 1

/(*NO_DOTSTAR_ANCHOR)(?s).*\d/info
Capturing subpattern count = 0
Compile options: <none>
Overall options: no_dotstar_anchor
Subject length lower bound = 1

'^(?:(a)|b)(?(1)A|B)'
    aA123\=ovector=1
Matched, but too many substrings
 0: aA
    aA123\=ovector=2
 0: aA
 1: a

'^(?:(?<AA>a)|b)(?(<AA>)A|B)'
    aA123\=ovector=1
Matched, but too many substrings
 0: aA
    aA123\=ovector=2
 0: aA
 1: a

'^(?<AA>)(?:(?<AA>a)|b)(?(<AA>)A|B)'dupnames
    aA123\=ovector=1
Matched, but too many substrings
 0: aA
    aA123\=ovector=2
Matched, but too many substrings
 0: aA
 1: 
    aA123\=ovector=3
 0: aA
 1: 
 2: a

'^(?:(?<AA>X)|)(?:(?<AA>a)|b)\k{AA}'dupnames
    aa123\=ovector=1
Matched, but too many substrings
 0: aa
    aa123\=ovector=2
Matched, but too many substrings
 0: aa
 1: <unset>
    aa123\=ovector=3
 0: aa
 1: <unset>
 2: a

/(?<N111>(?J)(?<N111>1(111111)11|)1|1|)(?(<N111>)1)/

/(?<N>(?J)(?<N>))(?-J)\k<N>/

# Quantifiers are not allowed on condition assertions, but are otherwise
# OK in conditions.

/(?(?=0)?)+/
Failed: error 109 at offset 7: quantifier does not follow a repeatable item

/(?(?=0)(?=00)?00765)/
     00765
 0: 00765

/(?(?=0)(?=00)?00765|(?!3).56)/
     00765
 0: 00765
     456
 0: 456
\= Expect no match
     356   
No match

'^(a)*+(\w)'
    g
 0: g
 1: <unset>
 2: g
    g\=ovector=1 
Matched, but too many substrings
 0: g

'^(?:a)*+(\w)'
    g
 0: g
 1: g
    g\=ovector=1 
Matched, but too many substrings
 0: g
    
# These two pattern showeds up compile-time bugs

"((?2){0,1999}())?"

/((?+1)(\1))/B
------------------------------------------------------------------
        Bra
        Once
        CBra 1
        Recurse
        CBra 2
        \1
        Ket
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

# Callouts with string arguments

/a(?C"/
Failed: error 181 at offset 4: missing terminating delimiter for callout with string argument

/a(?C"a/
Failed: error 181 at offset 4: missing terminating delimiter for callout with string argument

/a(?C"a"/
Failed: error 139 at offset 7: closing parenthesis for (?C expected

/a(?C"a"bcde(?C"b")xyz/
Failed: error 139 at offset 7: closing parenthesis for (?C expected

/a(?C"a)b""c")/B
------------------------------------------------------------------
        Bra
        a
        CalloutStr "a)b"c" 5 13 0
        Ket
        End
------------------------------------------------------------------

/ab(?C" any text with spaces ")cde/B
------------------------------------------------------------------
        Bra
        ab
        CalloutStr " any text with spaces " 6 30 1
        cde
        Ket
        End
------------------------------------------------------------------
    abcde
Callout (6): " any text with spaces "
--->abcde
    ^ ^       c
 0: abcde
    12abcde
Callout (6): " any text with spaces "
--->12abcde
      ^ ^       c
 0: abcde

/^a(b)c(?C1)def/
      abcdef
--->abcdef
  1 ^  ^       d
 0: abcdef
 1: b

/^a(b)c(?C"AB")def/
      abcdef
Callout (10): "AB"
--->abcdef
    ^  ^       d
 0: abcdef
 1: b

/^a(b)c(?C1)def/
      abcdef\=callout_capture
Callout 1: last capture = 1
 0: <unset>
 1: b
--->abcdef
    ^  ^       d
 0: abcdef
 1: b

/^a(b)c(?C{AB})def/B
------------------------------------------------------------------
        Bra
        ^
        a
        CBra 1
        b
        Ket
        c
        CalloutStr {AB} 10 14 1
        def
        Ket
        End
------------------------------------------------------------------
      abcdef\=callout_capture
Callout (10): {AB} last capture = 1
 0: <unset>
 1: b
--->abcdef
    ^  ^       d
 0: abcdef
 1: b

/(?C`a``b`)(?C'a''b')(?C"a""b")(?C^a^^b^)(?C%a%%b%)(?C#a##b#)(?C$a$$b$)(?C{a}}b})/B,callout_info
------------------------------------------------------------------
        Bra
        CalloutStr `a`b` 4 10 0
        CalloutStr 'a'b' 14 20 0
        CalloutStr "a"b" 24 30 0
        CalloutStr ^a^b^ 34 40 0
        CalloutStr %a%b% 44 50 0
        CalloutStr #a#b# 54 60 0
        CalloutStr $a$b$ 64 70 0
        CalloutStr {a}b} 74 80 0
        Ket
        End
------------------------------------------------------------------
Callout `a`b`  (
Callout 'a'b'  (
Callout "a"b"  (
Callout ^a^b^  (
Callout %a%b%  (
Callout #a#b#  (
Callout $a$b$  (
Callout {a}b}  

/(?:a(?C`code`)){3}/B
------------------------------------------------------------------
        Bra
        Bra
        a
        CalloutStr `code` 8 14 0
        Ket
        Bra
        a
        CalloutStr `code` 8 14 0
        Ket
        Bra
        a
        CalloutStr `code` 8 14 0
        Ket
        Ket
        End
------------------------------------------------------------------

/^(?(?C25)(?=abc)abcd|xyz)/B,callout_info
------------------------------------------------------------------
        Bra
        ^
        Cond
        Callout 25 9 7
        Assert
        abc
        Ket
        abcd
        Alt
        xyz
        Ket
        Ket
        End
------------------------------------------------------------------
Callout 25  (?=abc)
    abcdefg
--->abcdefg
 25 ^           (?=abc)
 0: abcd
    xyz123 
--->xyz123
 25 ^          (?=abc)
 0: xyz

/^(?(?C$abc$)(?=abc)abcd|xyz)/B
------------------------------------------------------------------
        Bra
        ^
        Cond
        CalloutStr $abc$ 7 12 7
        Assert
        abc
        Ket
        abcd
        Alt
        xyz
        Ket
        Ket
        End
------------------------------------------------------------------
    abcdefg
Callout (7): $abc$
--->abcdefg
    ^           (?=abc)
 0: abcd
    xyz123 
Callout (7): $abc$
--->xyz123
    ^          (?=abc)
 0: xyz

/^ab(?C'first')cd(?C"second")ef/
    abcdefg
Callout (7): 'first'
--->abcdefg
    ^ ^         c
Callout (20): "second"
--->abcdefg
    ^   ^       e
 0: abcdef

/(?:a(?C`code`)){3}X/
    aaaXY
Callout (8): `code`
--->aaaXY
    ^^        )
Callout (8): `code`
--->aaaXY
    ^ ^       )
Callout (8): `code`
--->aaaXY
    ^  ^      )
 0: aaaX

# Binary zero in callout string
#  a  (  ?  C  '  x     z  '  )  b
/ 61 28 3f 43 27 78 00 7a 27 29 62/hex,callout_info
Callout 'x\x00z'  b
    abcdefgh
Callout (5): 'x\x00z'
--->abcdefgh
    ^^           b
 0: ab

/(?(?!)^)/

/(?(?!)a|b)/
    bbb
 0: b
\= Expect no match 
    aaa 
No match

# JIT gives a different error message for the infinite recursion

"(*NO_JIT)((?2)+)((?1)){"
    abcd{
Failed: error -52: nested recursion at the same subject position

# Perl fails to diagnose the absence of an assertion

"(?(?<E>.*!.*)?)"
Failed: error 128 at offset 3: assertion expected after (?( or (?(?C)

"X((?2)()*+){2}+"B
------------------------------------------------------------------
        Bra
        X
        Once
        CBra 1
        Recurse
        Braposzero
        SCBraPos 2
        KetRpos
        Ket
        CBra 1
        Recurse
        Braposzero
        SCBraPos 2
        KetRpos
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------

"X((?2)()*+){2}"B
------------------------------------------------------------------
        Bra
        X
        CBra 1
        Recurse
        Braposzero
        SCBraPos 2
        KetRpos
        Ket
        CBra 1
        Recurse
        Braposzero
        SCBraPos 2
        KetRpos
        Ket
        Ket
        End
------------------------------------------------------------------

/(?<=\bABQ(3(?-7)))/
Failed: error 115 at offset 15: reference to non-existent subpattern

/(?<=\bABQ(3(?+7)))/
Failed: error 115 at offset 15: reference to non-existent subpattern

";(?<=()((?3))((?2)))"
Failed: error 125 at offset 20: lookbehind assertion is not fixed length

# Perl loops on this (PCRE2 used to!)

/(?<=\Ka)/g,aftertext
    aaaaa
 0: a
 0+ aaaa
 0: a
 0+ aaa
 0: a
 0+ aa
 0: a
 0+ a
 0: a
 0+ 

/(?<=\Ka)/altglobal,aftertext
    aaaaa
 0: a
 0+ aaaa
 0: a
 0+ aaa
 0: a
 0+ aa
 0: a
 0+ a
 0: a
 0+ 

/((?2){73}(?2))((?1))/info
Capturing subpattern count = 2
May match empty string
Subject length lower bound = 0

/abc/
\= Expect no match
    \[9x!xxx(]{9999}
No match
    
/(abc)*/
    \[abc]{5} 
 0: abcabcabcabcabc
 1: abc

/^/gm
    \n\n\n
 0: 
 0: 
 0: 

/^/gm,alt_circumflex
    \n\n\n
 0: 
 0: 
 0: 
 0: 

/((((((((x))))))))\81/
Failed: error 115 at offset 19: reference to non-existent subpattern
    xx1

/((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((((x))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))\80/
    xx
Matched, but too many substrings
 0: xx
 1: x
 2: x
 3: x
 4: x
 5: x
 6: x
 7: x
 8: x
 9: x
10: x
11: x
12: x
13: x
14: x

/\80/
Failed: error 115 at offset 2: reference to non-existent subpattern

/A\8B\9C/
Failed: error 115 at offset 2: reference to non-existent subpattern
    A8B9C
    
/(?x:((?'a')) # comment (with parentheses) and | vertical
(?-x:#not a comment (?'b')) # this is a comment ()
(?'c')) # not a comment (?'d')/info
Capturing subpattern count = 5
Named capturing subpatterns:
  a   2
  b   3
  c   4
  d   5
First code unit = '#'
Last code unit = ' '
Subject length lower bound = 32

/(?|(?'a')(2)(?'b')|(?'a')(?'a')(3))/I,dupnames
Capturing subpattern count = 3
Named capturing subpatterns:
  a   1
  a   2
  b   3
Options: dupnames
Starting code units: 2 3 
Subject length lower bound = 1
    A23B
 0: 2
 1: 
 2: 2
 3: 
    B32A 
 0: 3
 1: 
 2: 
 3: 3

# These are some patterns that used to cause buffer overflows or other errors
# while compiling. 

/.((?2)(?R)|\1|$)()/B
------------------------------------------------------------------
        Bra
        Any
        Once
        CBra 1
        Recurse
        Recurse
        Alt
        \1
        Alt
        $
        Ket
        Ket
        CBra 2
        Ket
        Ket
        End
------------------------------------------------------------------

/.((?3)(?R)()(?2)|\1|$)()/B
------------------------------------------------------------------
        Bra
        Any
        Once
        CBra 1
        Recurse
        Recurse
        CBra 2
        Ket
        Recurse
        Alt
        \1
        Alt
        $
        Ket
        Ket
        CBra 3
        Ket
        Ket
        End
------------------------------------------------------------------

/(\9*+(?2);\3++()2|)++{/
Failed: error 115 at offset 2: reference to non-existent subpattern

/\V\x85\9*+((?2)\3++()2)*:2/
Failed: error 115 at offset 7: reference to non-existent subpattern

/(((?(R)){0,2}) (?'x'((?'R')((?'R')))))/dupnames

/(((?(X)){0,2}) (?'x'((?'X')((?'X')))))/dupnames

/(((?(R)){0,2}) (?'x'((?'X')((?'R')))))/

"(?J)(?'d'(?'d'\g{d}))"

"(?=!((?2)(?))({8(?<=(?1){29}8bbbb\x16\xd\xc6^($(\xa9H4){4}h}?1)B))\x15')"
Failed: error 125 at offset 72: lookbehind assertion is not fixed length

/A(?'')Z/
Failed: error 162 at offset 4: subpattern name expected

"(?J:(?|(?'R')(\k'R')|((?'R'))))"

/(?<=|(\,\$(?73591620449005828816)\xa8.{7}){6}\x09)/
Failed: error 161 at offset 32: number is too big

/^(?:(?(1)x|)+)+$()/B
------------------------------------------------------------------
        Bra
        ^
        SBra
        SCond
      1 Cond ref
        x
        Alt
        KetRmax
        KetRmax
        $
        CBra 1
        Ket
        Ket
        End
------------------------------------------------------------------

/[[:>:]](?<)/
Failed: error 124 at offset 10: letter or underscore expected after (?< or (?'

/((?x)(*:0))#(?'/
Failed: error 124 at offset 15: letter or underscore expected after (?< or (?'

/(?C$[$)(?<]/
Failed: error 124 at offset 10: letter or underscore expected after (?< or (?'

/(?C$)$)(?<]/
Failed: error 124 at offset 10: letter or underscore expected after (?< or (?'

/(?(R))*+/B
------------------------------------------------------------------
        Bra
        Braposzero
        SBraPos
        SCond
        Cond recurse any
        Ket
        KetRpos
        Ket
        End
------------------------------------------------------------------
    abcd
 0: 

/((?x)(?#))#(?'/
Failed: error 124 at offset 14: letter or underscore expected after (?< or (?'

/((?x)(?#))#(?'abc')/I
Capturing subpattern count = 2
Named capturing subpatterns:
  abc   2
First code unit = '#'
Subject length lower bound = 1

/[[:\\](?<[::]/
Failed: error 124 at offset 9: letter or underscore expected after (?< or (?'

/[[:\\](?'abc')[a:]/I
Capturing subpattern count = 1
Named capturing subpatterns:
  abc   1
Starting code units: : [ \ 
Subject length lower bound = 2

"[[[.\xe8Nq\xffq\xff\xe0\x2|||::Nq\xffq\xff\xe0\x6\x2|||::[[[:[::::::[[[[[::::::::[:[[[:[:::[[[[[[[[[[[[:::::::::::::::::[[.\xe8Nq\xffq\xff\xe0\x2|||::Nq\xffq\xff\xe0\x6\x2|||::[[[:[::::::[[[[[::::::::[:[[[:[:::[[[[[[[[[[[[[[:::E[[[:[:[[:[:::[[:::E[[[:[:[[:'[:::::E[[[:[::::::[[[:[[[[[[[::E[[[:[::::::[[[:[[[[[[[[:[[::[::::[[:::::::[[:[[[[[[[:[[::[:[[:[~"
Failed: error 106 at offset 353: missing terminating ] for character class

/()(?(R)0)*+/B
------------------------------------------------------------------
        Bra
        CBra 1
        Ket
        Braposzero
        SBraPos
        SCond
        Cond recurse any
        0
        Ket
        KetRpos
        Ket
        End
------------------------------------------------------------------

/(?R-:(?</
Failed: error 129 at offset 3: (?R or (?[+-]digits must be followed by )

/(?(?C{\Q})(?!(?'/
Failed: error 124 at offset 16: letter or underscore expected after (?< or (?'

/(?(?C{\Q})(?!(?'abc')))/I
Capturing subpattern count = 1
Named capturing subpatterns:
  abc   1
May match empty string
Subject length lower bound = 0

/(?1){3918}(((((0(\k'R'))))(?J)(?'R'(?'R'\3){99})))/I
Capturing subpattern count = 8
Max back reference = 8
Named capturing subpatterns:
  R   7
  R   8
Duplicate name status changes
Last code unit = '0'
Subject length lower bound = 65535

/(?|(aaa)|(b))\g{1}/I
Capturing subpattern count = 1
Max back reference = 1
Starting code units: a b 
Subject length lower bound = 0

/(?|(aaa)|(b))(?1)/I
Capturing subpattern count = 1
Starting code units: a b 
Subject length lower bound = 4

/(?|(aaa)|(b))/I
Capturing subpattern count = 1
Starting code units: a b 
Subject length lower bound = 1

/(?|(?'a'aaa)|(?'a'b))\k'a'/I
Capturing subpattern count = 1
Max back reference = 1
Named capturing subpatterns:
  a   1
Starting code units: a b 
Subject length lower bound = 0

/(?|(?'a'aaa)|(?'a'b))(?'a'cccc)\k'a'/I,dupnames
Capturing subpattern count = 2
Max back reference = 2
Named capturing subpatterns:
  a   1
  a   2
Options: dupnames
Starting code units: a b 
Last code unit = 'c'
Subject length lower bound = 0

/ab{3cd/
    ab{3cd
 0: ab{3cd

/ab{3,cd/
    ab{3,cd
 0: ab{3,cd

/ab{3,4a}cd/
    ab{3,4a}cd
 0: ab{3,4a}cd

/{4,5a}bc/
    {4,5a}bc
 0: {4,5a}bc

/\x0{ab}/
    \0{ab} 
 0: \x00{ab}

/^(a(b))\1\g1\g{1}\g-1\g{-1}\g{-02}Z/
    ababababbbabZXXXX
 0: ababababbbabZ
 1: ab
 2: b

/.*?a(*PRUNE)b/
    aab
 0: ab

/.*?a(*PRUNE)b/s
    aab
 0: ab

/^a(*PRUNE)b/s
\= Expect no match
    aab
No match

/.*?a(*SKIP)b/
    aab
 0: ab

/(?(8000000000/
Failed: error 161 at offset 13: number is too big

/((?(R8000000000)))/
Failed: error 161 at offset 16: number is too big

/0(?0)|(1)(*THEN)(*SKIP:0)(*FAIL)/
\= Expect no match
    01
No match

/(?(1)()\983040\2)/
Failed: error 115 at offset 13: reference to non-existent subpattern

/(*LIMIT_MATCH=)abc/
Failed: error 160 at offset 14: (*VERB) not recognized or malformed

/(*CRLF)(*LIMIT_MATCH=)abc/
Failed: error 160 at offset 21: (*VERB) not recognized or malformed

/(?:ab)?(?:ab)(?:ab)/
    abab
 0: abab
    ababab
 0: ababab
\= Expect no match
    aba
No match

/((*MARK:A))++a(*SKIP:B)b/
\= Expect no match
    aacb
No match

/(*MARK:a\zb)z/alt_verbnames 
Failed: error 140 at offset 9: invalid escape sequence in (*VERB) name
    
/(*:ab\t(d\)c)xxx/
Failed: error 122 at offset 12: unmatched closing parenthesis

/(*:ab\t(d\)c)xxx/alt_verbnames,mark
    cxxxz
 0: xxx
MK: ab\x09(d)c

/(*:A\Qxx)x\EB)x/alt_verbnames,mark
    x
 0: x
MK: Axx)xB
    
/(*:A\ExxxB)x/alt_verbnames,mark
    x 
 0: x
MK: AxxxB
    
/(*: A \ and #comment
     \ B)x/x,alt_verbnames,mark
    x  
 0: x
MK: A and B
    
/(*:A
B)x/alt_verbnames,mark 
    x
 0: x
MK: A\x0aB

/(*:abc\Qpqr)/alt_verbnames
Failed: error 160 at offset 12: (*VERB) not recognized or malformed

/abc/use_offset_limit
    1234abcde\=offset_limit=100
 0: abc
    1234abcde\=offset_limit=9
 0: abc
    1234abcde\=offset_limit=4
 0: abc
    1234abcde\=offset_limit=4,offset=4
 0: abc
\= Expect no match
    1234abcde\=offset_limit=4,offset=5
No match
    1234abcde\=offset_limit=3
No match

/(?<=abc)/use_offset_limit
    1234abc\=offset_limit=7
 0: 
\= Expect no match
    1234abc\=offset_limit=6
No match
    
/A/g,replace=-,use_offset_limit
    XAXAXAXAXA\=offset_limit=4
 2: X-X-XAXAXA

/abc/
\= Expect error
    1234abcde\=offset_limit=4
Failed: error -56: offset limit set without PCRE2_USE_OFFSET_LIMIT

/^\w/m,use_offset_limit
    \n..\naa\=offset_limit=3
No match
    \n..\naa\=offset_limit=4
 0: a

/abcd/null_context
    abcd\=null_context
 0: abcd
\= Expect error     
    abcd\=null_context,find_limits
** Not allowed together: find_limits null_context
    abcd\=allusedtext,startchar 
** Not allowed together: allusedtext startchar

/abcd/replace=w\rx\x82y\o{333}z(\Q12\$34$$\x34\E5$$),substitute_extended
    abcd
 1: w\x0dx\x82y\xdbz(12\$34$$\x345$)
    
/a(bc)(DE)/replace=a\u$1\U$1\E$1\l$2\L$2\Eab\Uab\LYZ\EDone,substitute_extended
    abcDE
 1: aBcBCbcdEdeabAByzDone
 
/abcd/replace=xy\kz,substitute_extended
    abcd
Failed: error -57 at offset 4 in replacement: bad escape sequence in replacement string

/a(?:(b)|(c))/substitute_extended,replace=X${1:+1:-1}X${2:+2:-2}
    ab
 1: X1X-2
    ac
 1: X-1X2
    ab\=replace=${1:+$1\:$1:$2}
 1: b:b
    ac\=replace=${1:+$1\:$1:$2}
 1: c

/a(?:(b)|(c))/substitute_extended,replace=X${1:-1:-1}X${2:-2:-2}
    ab
 1: XbX2:-2
    ac
 1: X1:-1Xc

/(a)/substitute_extended,replace=>${1:+\Q$1:{}$$\E+\U$1}<
    a
 1: >$1:{}$$+A<

/X(b)Y/substitute_extended
    XbY\=replace=x${1:+$1\U$1}y
 1: xbBY
    XbY\=replace=\Ux${1:+$1$1}y
 1: XBBY

/a/substitute_extended,replace=${*MARK:+a:b}
    a
Failed: error -58 at offset 7 in replacement: expected closing curly bracket in replacement string

/(abcd)/replace=${1:+xy\kz},substitute_extended
    abcd
Failed: error -57 at offset 8 in replacement: bad escape sequence in replacement string

/(abcd)/
    abcd\=replace=${1:+xy\kz},substitute_extended
Failed: error -57 at offset 8 in replacement: bad escape sequence in replacement string

/abcd/substitute_extended,replace=>$1<
    abcd
Failed: error -49 at offset 3 in replacement: unknown substring

/abcd/substitute_extended,replace=>xxx${xyz}<<<
    abcd
Failed: error -49 at offset 10 in replacement: unknown substring

/(?J)(?:(?<A>a)|(?<A>b))/replace=<$A>
    [a]
 1: [<a>]
    [b] 
 1: [<b>]
\= Expect error     
    (a)\=ovector=1
Failed: error -54 at offset 3 in replacement: requested value is not available

/(a)|(b)/replace=<$1>
\= Expect error
    b
Failed: error -55 at offset 3 in replacement: requested value is not set

/(aa)(BB)/substitute_extended,replace=\U$1\L$2\E$1..\U$1\l$2$1
    aaBB
 1: AAbbaa..AAbBaa

/^(o(\1{72}{\"{\\{00000059079}\d*){74}}){19}/I
Capturing subpattern count = 2
Max back reference = 1
Compile options: <none>
Overall options: anchored
Last code unit = '}'
Subject length lower bound = 65535

/((p(?'K/
Failed: error 142 at offset 7: syntax error in subpattern name (missing terminator)

/((p(?'K/no_auto_capture
Failed: error 142 at offset 7: syntax error in subpattern name (missing terminator)

/abc/replace=A$3123456789Z
    abc
Failed: error -49 at offset 3 in replacement: unknown substring

/(?<!a{65535}a{5})x/I
Failed: error 187 at offset 16: lookbehind assertion is too long

/(?<!a{65535})x/I
Capturing subpattern count = 0
Max lookbehind = 65535
First code unit = 'x'
Subject length lower bound = 1

/(?=a\K)/replace=z
    BaCaD
Failed: error -60: match with end before start is not supported
    
/(?'abcdefghijklmnopqrstuvwxyzABCDEFG'toolong)/
Failed: error 148 at offset 36: subpattern name is too long (maximum 32 characters)
 
/(?'abcdefghijklmnopqrstuvwxyzABCDEF'justright)/ 

# These two use zero-termination
/abcd/max_pattern_length=3
Failed: error 188 at offset 0: pattern string is longer than the limit set by the application

/abc/max_pattern_length=3

# These two, being hex, pass the length
/abcdefab/hex,max_pattern_length=3
Failed: error 188 at offset 0: pattern string is longer than the limit set by the application

/abcdef/hex,max_pattern_length=3

# These two patterns used to take a long time to compile

"(.*)
((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))
((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))
((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))"xI
Capturing subpattern count = 12
May match empty string
Options: extended
First code unit at start or follows newline
Subject length lower bound = 0

"(?<=a()
((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))
((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))
((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))
a)"xI
Capturing subpattern count = 12
Max lookbehind = 2
May match empty string
Options: extended
Subject length lower bound = 0

# When (?| is used and groups of the same number may be different,
# we have to rely on a count to catch overly complicated patterns.

"(?|()|())(.*)
((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))
((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))
((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))"xI
Failed: error 186 at offset 148: regular expression is too complicated

"(?|()|())(?<=a()
((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))
((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))
((?-2)(?-2))((?-2)(?-2))((?-2)(?-2))
a)"xI
Failed: error 186 at offset 154: regular expression is too complicated

# Test the use of malloc for caching group information when there are more
# groups than fit into the on-stack workspace.

/\[()]{1024}/I,expand
Expanded: ()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()()
Capturing subpattern count = 1024
May match empty string
Subject length lower bound = 0

# Test minlength capped at 65535

/(A{65000})\1{65000}/I
Capturing subpattern count = 1
Max back reference = 1
First code unit = 'A'
Last code unit = 'A'
Subject length lower bound = 65535

# Test group scans when numbers are not unique

/(?|()+|(a)+)/BI
------------------------------------------------------------------
        Bra
        Bra
        SCBra 1
        KetRmax
        Alt
        CBra 1
        a
        KetRmax
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0

/(?|(a)+|()+)/BI
------------------------------------------------------------------
        Bra
        Bra
        CBra 1
        a
        KetRmax
        Alt
        SCBra 1
        KetRmax
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0

/(?|()|(a))/BI
------------------------------------------------------------------
        Bra
        Bra
        CBra 1
        Ket
        Alt
        CBra 1
        a
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0

/(?|(a)|())/BI
------------------------------------------------------------------
        Bra
        Bra
        CBra 1
        a
        Ket
        Alt
        CBra 1
        Ket
        Ket
        Ket
        End
------------------------------------------------------------------
Capturing subpattern count = 1
May match empty string
Subject length lower bound = 0

# Test CRLF handling in empty string substitutions

/^$/gm,newline=anycrlf,replace=-
    X\r\n\r\nY
 1: X\x0d\x0a-\x0d\x0aY

/^$/gm,newline=crlf,replace=-
    X\r\n\r\nY
 1: X\x0d\x0a-\x0d\x0aY

/^$/gm,newline=any,replace=-
    X\r\n\r\nY
 1: X\x0d\x0a-\x0d\x0aY

"(*ANYCRLF)(?m)^(.*[^0-9\r\n].*|)$"g,replace=NaN
    15\r\nfoo\r\n20\r\nbar\r\nbaz\r\n\r\n20
 4: 15\x0d\x0aNaN\x0d\x0a20\x0d\x0aNaN\x0d\x0aNaN\x0d\x0aNaN\x0d\x0a20

/a[[:punct:]b]/bincode
------------------------------------------------------------------
        Bra
        a
        [!-/:-@[-`b{-~]
        Ket
        End
------------------------------------------------------------------

/a[b[:punct:]]/bincode
------------------------------------------------------------------
        Bra
        a
        [!-/:-@[-`b{-~]
        Ket
        End
------------------------------------------------------------------

/L(?#(|++<!(2)?/B
------------------------------------------------------------------
        Bra
        L?+
        Ket
        End
------------------------------------------------------------------

/L(?#(|++<!(2)?/B,no_auto_possess
------------------------------------------------------------------
        Bra
        L?
        Ket
        End
------------------------------------------------------------------

/L(?#(|++<!(2)?/B,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 14
        L?+
        Callout 255 14 0
        Ket
        End
------------------------------------------------------------------

/L(?#(|++<!(2)?/B,no_auto_possess,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 14
        L?
        Callout 255 14 0
        Ket
        End
------------------------------------------------------------------

/(A*)\E+/B,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 7
        SCBra 1
        Callout 255 1 2
        A*
        Callout 255 3 0
        KetRmax
        Callout 255 7 0
        Ket
        End
------------------------------------------------------------------

/()\Q\E*]/B,auto_callout
------------------------------------------------------------------
        Bra
        Callout 255 0 7
        Brazero
        SCBra 1
        Callout 255 1 0
        KetRmax
        Callout 255 7 1
        ]
        Callout 255 8 0
        Ket
        End
------------------------------------------------------------------
    a[bc]d
--->a[bc]d
 +0     ^      ()\Q\E*
 +1     ^      )
 +7     ^      ]
 +8     ^^     
 0: ]
 1: 

/\x8a+f|;T?(*:;.'?`(\xeap ){![^()!y*''C*(?';]{1;(\x08)/B,alt_verbnames,dupnames,extended
------------------------------------------------------------------
        Bra
        \x{8a}++
        f
        Alt
        ;
        T?
        *MARK ;.'?`(\x{ea}p
        {!
        [\x00- "-&+-:<->@-BD-xz-\xff] (neg)
        {1;
        CBra 1
        \x08
        Ket
        Ket
        End
------------------------------------------------------------------

# Tests for NULL characters in comments and verb "names" and callouts

# /A#B\x00C\x0aZ/
/41 23 42 00 43 0a 5a/Bx,hex
------------------------------------------------------------------
        Bra
        AZ
        Ket
        End
------------------------------------------------------------------

# /A+#B\x00C\x0a+/
/41 2b 23 42 00 43 0a 2b/Bx,hex
------------------------------------------------------------------
        Bra
        A++
        Ket
        End
------------------------------------------------------------------

# /A(*:B\x00W#X\00Y\x0aC)Z/
/41 28 2a 3a 42 00 57 23 58 00 59 0a 43 29 5a/Bx,hex,alt_verbnames
------------------------------------------------------------------
        Bra
        A
        *MARK B\x{0}WC
        Z
        Ket
        End
------------------------------------------------------------------

# /A(*:B\x00W#X\00Y\x0aC)Z/
/41 28 2a 3a 42 00 57 23 58 00 59 0a 43 29 5a/Bx,hex
------------------------------------------------------------------
        Bra
        A
        *MARK B\x{0}W#X\x{0}Y\x{a}C
        Z
        Ket
        End
------------------------------------------------------------------

# /A(?C{X\x00Y})B/
/41 28 3f 43 7b 58 00 59 7d 29 42/B,hex
------------------------------------------------------------------
        Bra
        A
        CalloutStr {X\x{0}Y} 5 10 1
        B
        Ket
        End
------------------------------------------------------------------

# /A(?#X\x00Y)B/
/41 28 3f 23 7b 00 7d 29 42/B,hex
------------------------------------------------------------------
        Bra
        AB
        Ket
        End
------------------------------------------------------------------

# Tests for leading comment in extended patterns

/ (?-x):?/extended

/(?-x):?/extended

/0b 28 3f 2d 78 29 3a/hex,extended

/#comment
(?-x):?/extended

/(8(*:6^\x09x\xa6l\)6!|\xd0:[^:|)\x09d\Z\d{85*m(?'(?<1!)*\W[*\xff]!!h\w]*\xbe;/alt_bsux,alt_verbnames,allow_empty_class,dollar_endonly,extended,multiline,never_utf,no_dotstar_anchor,no_start_optimize
Failed: error 124 at offset 49: letter or underscore expected after (?< or (?'

/a|(b)c/replace=>$1<,substitute_unset_empty
    cat
 1: c><t
    xbcom 
 1: x>b<om

/a|(b)c/
    cat\=replace=>$1<
Failed: error -55 at offset 3 in replacement: requested value is not set
    cat\=replace=>$1<,substitute_unset_empty
 1: c><t
    xbcom\=replace=>$1<,substitute_unset_empty
 1: x>b<om

/a|(b)c/substitute_extended
    cat\=replace=>${2:-xx}<
Failed: error -49 at offset 9 in replacement: unknown substring
    cat\=replace=>${2:-xx}<,substitute_unknown_unset
 1: c>xx<t
    cat\=replace=>${X:-xx}<,substitute_unknown_unset
 1: c>xx<t

/a|(?'X'b)c/replace=>$X<,substitute_unset_empty
    cat
 1: c><t
    xbcom 
 1: x>b<om

/a|(?'X'b)c/replace=>$Y<,substitute_unset_empty
    cat
Failed: error -49 at offset 3 in replacement: unknown substring
    cat\=substitute_unknown_unset 
 1: c><t
    cat\=substitute_unknown_unset,-substitute_unset_empty 
Failed: error -55 at offset 3 in replacement: requested value is not set

/a|(b)c/replace=>$2<,substitute_unset_empty
    cat
Failed: error -49 at offset 3 in replacement: unknown substring
    cat\=substitute_unknown_unset 
 1: c><t
    cat\=substitute_unknown_unset,-substitute_unset_empty 
Failed: error -55 at offset 3 in replacement: requested value is not set

/()()()/use_offset_limit
    \=ovector=11000000000
** Invalid value in 'ovector=11000000000'
    \=callout_fail=11000000000
** Invalid value in 'callout_fail=11000000000'
    \=callout_fail=1:11000000000
** Invalid value in 'callout_fail=1:11000000000'
    \=callout_data=11000000000 
** Invalid value in 'callout_data=11000000000'
    \=callout_data=-11000000000 
** Invalid value in 'callout_data=-11000000000'
    \=offset_limit=1100000000000000000000 
** Invalid value in 'offset_limit=1100000000000000000000'
    \=copy=11000000000 
** Invalid value in 'copy=11000000000'

/(*MARK:A\x00b)/mark
    abc
 0: 
MK: A\x00b

/(*MARK:A\x00b)/mark,alt_verbnames
    abc
 0: 
MK: A\x00b

# /(*MARK:A\x00b)/
/28 2a 4d 41 52 4b 3a 41 00 62 29/mark,hex
    abc
 0: 
MK: A\x00b

# /(*MARK:A\x00b)/
/28 2a 4d 41 52 4b 3a 41 00 62 29/mark,hex,alt_verbnames
    abc
 0: 
MK: A\x00b

# End of testinput2