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
------------------------------------------------------------------