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| <div class="section"> |
| <div class="titlepage"><div><div><h5 class="title"> |
| <a name="spirit.karma.reference.char.char_generator"></a><a class="link" href="char_generator.html" title="Character Generators (char_, lit)">Character |
| Generators (<code class="computeroutput"><span class="identifier">char_</span></code>, <code class="computeroutput"><span class="identifier">lit</span></code>)</a> |
| </h5></div></div></div> |
| <a name="spirit.karma.reference.char.char_generator.description"></a><h6> |
| <a name="id1025070"></a> |
| <a class="link" href="char_generator.html#spirit.karma.reference.char.char_generator.description">Description</a> |
| </h6> |
| <p> |
| The character generators described in this section are: |
| </p> |
| <p> |
| The <code class="computeroutput"><span class="identifier">char_</span></code> generator emits |
| single characters. The <code class="computeroutput"><span class="identifier">char_</span></code> |
| generator has an associated <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.character_encoding_namespace">Character |
| Encoding Namespace</a>. This is needed when doing basic operations |
| such as forcing lower or upper case and dealing with character ranges. |
| </p> |
| <p> |
| There are various forms of <code class="computeroutput"><span class="identifier">char_</span></code>. |
| </p> |
| <a name="spirit.karma.reference.char.char_generator.char_"></a><h6> |
| <a name="id1025120"></a> |
| <a class="link" href="char_generator.html#spirit.karma.reference.char.char_generator.char_">char_</a> |
| </h6> |
| <p> |
| The no argument form of <code class="computeroutput"><span class="identifier">char_</span></code> |
| emits any character in the associated <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.character_encoding_namespace">Character |
| Encoding Namespace</a>. |
| </p> |
| <pre class="programlisting"><span class="identifier">char_</span> <span class="comment">// emits any character as supplied by the attribute |
| </span></pre> |
| <a name="spirit.karma.reference.char.char_generator.char__ch_"></a><h6> |
| <a name="id1025161"></a> |
| <a class="link" href="char_generator.html#spirit.karma.reference.char.char_generator.char__ch_">char_(ch)</a> |
| </h6> |
| <p> |
| The single argument form of <code class="computeroutput"><span class="identifier">char_</span></code> |
| (with a character argument) emits the supplied character. |
| </p> |
| <pre class="programlisting"><span class="identifier">char_</span><span class="special">(</span><span class="char">'x'</span><span class="special">)</span> <span class="comment">// emits 'x' |
| </span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">L</span><span class="char">'x'</span><span class="special">)</span> <span class="comment">// emits L'x' |
| </span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span> <span class="comment">// emits x (a char) |
| </span></pre> |
| <a name="spirit.karma.reference.char.char_generator.char__first__last_"></a><h6> |
| <a name="id1025252"></a> |
| <a class="link" href="char_generator.html#spirit.karma.reference.char.char_generator.char__first__last_">char_(first, |
| last)</a> |
| </h6> |
| <p> |
| <code class="computeroutput"><span class="identifier">char_</span></code> with two arguments, |
| emits any character from a range of characters as supplied by the attribute. |
| </p> |
| <pre class="programlisting"><span class="identifier">char_</span><span class="special">(</span><span class="char">'a'</span><span class="special">,</span><span class="char">'z'</span><span class="special">)</span> <span class="comment">// alphabetic characters |
| </span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">L</span><span class="char">'0'</span><span class="special">,</span><span class="identifier">L</span><span class="char">'9'</span><span class="special">)</span> <span class="comment">// digits |
| </span></pre> |
| <p> |
| A range of characters is created from a low-high character pair. Such |
| a generator emits a single character that is in the range, including |
| both endpoints. Note, the first character must be <span class="emphasis"><em>before</em></span> |
| the second, according to the underlying <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.character_encoding_namespace">Character |
| Encoding Namespace</a>. |
| </p> |
| <p> |
| Character mapping is inherently platform dependent. It is not guaranteed |
| in the standard for example that <code class="computeroutput"><span class="char">'A'</span> |
| <span class="special"><</span> <span class="char">'Z'</span></code>, |
| that is why in Spirit2, we purposely attach a specific <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.character_encoding_namespace">Character |
| Encoding Namespace</a> (such as ASCII, ISO-8859-1) to the <code class="computeroutput"><span class="identifier">char_</span></code> generator to eliminate such ambiguities. |
| </p> |
| <div class="note"><table border="0" summary="Note"> |
| <tr> |
| <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td> |
| <th align="left">Note</th> |
| </tr> |
| <tr><td align="left" valign="top"> |
| <p> |
| <span class="bold"><strong>Sparse bit vectors</strong></span> |
| </p> |
| <p> |
| To accommodate 16/32 and 64 bit characters, the char-set statically |
| switches from a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">bitset</span></code> |
| implementation when the character type is not greater than 8 bits, |
| to a sparse bit/boolean set which uses a sorted vector of disjoint |
| ranges (<code class="computeroutput"><span class="identifier">range_run</span></code>). |
| The set is constructed from ranges such that adjacent or overlapping |
| ranges are coalesced. |
| </p> |
| <p> |
| <code class="computeroutput"><span class="identifier">range_runs</span></code> are very |
| space-economical in situations where there are lots of ranges and a |
| few individual disjoint values. Searching is O(log n) where n is the |
| number of ranges. |
| </p> |
| </td></tr> |
| </table></div> |
| <a name="spirit.karma.reference.char.char_generator.char__def_"></a><h6> |
| <a name="id1025435"></a> |
| <a class="link" href="char_generator.html#spirit.karma.reference.char.char_generator.char__def_">char_(def)</a> |
| </h6> |
| <p> |
| Lastly, when given a string (a plain C string, a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span></code>, |
| etc.), the string is regarded as a char-set definition string following |
| a syntax that resembles posix style regular expression character sets |
| (except that double quotes delimit the set elements instead of square |
| brackets and there is no special negation ^ character). Examples: |
| </p> |
| <pre class="programlisting"><span class="identifier">char_</span><span class="special">(</span><span class="string">"a-zA-Z"</span><span class="special">)</span> <span class="comment">// alphabetic characters |
| </span><span class="identifier">char_</span><span class="special">(</span><span class="string">"0-9a-fA-F"</span><span class="special">)</span> <span class="comment">// hexadecimal characters |
| </span><span class="identifier">char_</span><span class="special">(</span><span class="string">"actgACTG"</span><span class="special">)</span> <span class="comment">// DNA identifiers |
| </span><span class="identifier">char_</span><span class="special">(</span><span class="string">"\x7f\x7e"</span><span class="special">)</span> <span class="comment">// Hexadecimal 0x7F and 0x7E |
| </span></pre> |
| <p> |
| These generators emit any character from a range of characters as supplied |
| by the attribute. |
| </p> |
| <a name="spirit.karma.reference.char.char_generator.lit_ch_"></a><h6> |
| <a name="id1025551"></a> |
| <a class="link" href="char_generator.html#spirit.karma.reference.char.char_generator.lit_ch_">lit(ch)</a> |
| </h6> |
| <p> |
| <code class="computeroutput"><span class="identifier">lit</span></code>, when passed a single |
| character, behaves like the single argument <code class="computeroutput"><span class="identifier">char_</span></code> |
| except that <code class="computeroutput"><span class="identifier">lit</span></code> does |
| not consume an attribute. A plain <code class="computeroutput"><span class="keyword">char</span></code> |
| or <code class="computeroutput"><span class="keyword">wchar_t</span></code> is equivalent |
| to a <code class="computeroutput"><span class="identifier">lit</span></code>. |
| </p> |
| <div class="note"><table border="0" summary="Note"> |
| <tr> |
| <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td> |
| <th align="left">Note</th> |
| </tr> |
| <tr><td align="left" valign="top"><p> |
| <code class="computeroutput"><span class="identifier">lit</span></code> is reused by the |
| <a class="link" href="../string.html" title="String">String Generators</a>, |
| the char generators, and the Numeric Generators (see <a class="link" href="../numeric/signed_int.html" title="Signed Integer Number Generators (int_, etc.)">signed |
| integer</a>, <a class="link" href="../numeric/unsigned_int.html" title="Unsigned Integer Number Generators (uint_, etc.)">unsigned |
| integer</a>, and <a class="link" href="../numeric/real_number.html" title="Real Number Generators (float_, double_, etc.)">real |
| number</a> generators). In general, a char generator is created |
| when you pass in a character, a string generator is created when you |
| pass in a string, and a numeric generator is created when you use a |
| numeric literal. The exception is when you pass a single element literal |
| string, e.g. <code class="computeroutput"><span class="identifier">lit</span><span class="special">(</span><span class="string">"x"</span><span class="special">)</span></code>. |
| In this case, we optimize this to create a char generator instead of |
| a string generator. |
| </p></td></tr> |
| </table></div> |
| <p> |
| Examples: |
| </p> |
| <pre class="programlisting"><span class="char">'x'</span> |
| <span class="identifier">lit</span><span class="special">(</span><span class="char">'x'</span><span class="special">)</span> |
| <span class="identifier">lit</span><span class="special">(</span><span class="identifier">L</span><span class="char">'x'</span><span class="special">)</span> |
| <span class="identifier">lit</span><span class="special">(</span><span class="identifier">c</span><span class="special">)</span> <span class="comment">// c is a char |
| </span></pre> |
| <a name="spirit.karma.reference.char.char_generator.header"></a><h6> |
| <a name="id1025729"></a> |
| <a class="link" href="char_generator.html#spirit.karma.reference.char.char_generator.header">Header</a> |
| </h6> |
| <pre class="programlisting"><span class="comment">// forwards to <boost/spirit/home/karma/char/char.hpp> |
| </span><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">karma_char_</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| </pre> |
| <p> |
| Also, see <a class="link" href="../../../structure/include.html" title="Include">Include Structure</a>. |
| </p> |
| <a name="spirit.karma.reference.char.char_generator.namespace"></a><h6> |
| <a name="id1025803"></a> |
| <a class="link" href="char_generator.html#spirit.karma.reference.char.char_generator.namespace">Namespace</a> |
| </h6> |
| <div class="informaltable"><table class="table"> |
| <colgroup><col></colgroup> |
| <thead><tr><th> |
| <p> |
| Name |
| </p> |
| </th></tr></thead> |
| <tbody> |
| <tr><td> |
| <p> |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">lit</span> <span class="comment">// alias: |
| boost::spirit::karma::lit</span></code> |
| </p> |
| </td></tr> |
| <tr><td> |
| <p> |
| <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span></code> |
| </p> |
| </td></tr> |
| </tbody> |
| </table></div> |
| <p> |
| In the table above, <code class="computeroutput"><span class="identifier">ns</span></code> |
| represents a <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.character_encoding_namespace">Character |
| Encoding Namespace</a>. |
| </p> |
| <a name="spirit.karma.reference.char.char_generator.model_of"></a><h6> |
| <a name="id1025923"></a> |
| <a class="link" href="char_generator.html#spirit.karma.reference.char.char_generator.model_of">Model |
| of</a> |
| </h6> |
| <div class="blockquote"><blockquote class="blockquote"><p> |
| <a class="link" href="../generator_concepts/primitivegenerator.html" title="PrimitiveGenerator"><code class="computeroutput"><span class="identifier">PrimitiveGenerator</span></code></a> |
| </p></blockquote></div> |
| <div class="variablelist"> |
| <p class="title"><b>Notation</b></p> |
| <dl> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">ch</span></code>, <code class="computeroutput"><span class="identifier">ch1</span></code>, <code class="computeroutput"><span class="identifier">ch2</span></code></span></dt> |
| <dd><p> |
| Character-class specific character (See Character Class Types), |
| or a <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.lazy_argument">Lazy |
| Argument</a> that evaluates to a character-class specific character |
| value |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">cs</span></code></span></dt> |
| <dd><p> |
| Character-set specifier string (See Character Class Types), or |
| a <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.lazy_argument">Lazy |
| Argument</a> that evaluates to a character-set specifier string, |
| or a pointer/reference to a null-terminated array of characters. |
| This string specifies a char-set definition string following a |
| syntax that resembles posix style regular expression character |
| sets (except the square brackets and the negation <code class="computeroutput"><span class="special">^</span></code> character). |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">ns</span></code></span></dt> |
| <dd><p> |
| A <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.character_encoding_namespace">Character |
| Encoding Namespace</a>. |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">cg</span></code></span></dt> |
| <dd><p> |
| A char generator, a char range generator, or a char set generator. |
| </p></dd> |
| </dl> |
| </div> |
| <a name="spirit.karma.reference.char.char_generator.expression_semantics"></a><h6> |
| <a name="id1026078"></a> |
| <a class="link" href="char_generator.html#spirit.karma.reference.char.char_generator.expression_semantics">Expression |
| Semantics</a> |
| </h6> |
| <p> |
| Semantics of an expression is defined only where it differs from, or |
| is not defined in <a class="link" href="../generator_concepts/primitivegenerator.html" title="PrimitiveGenerator"><code class="computeroutput"><span class="identifier">PrimitiveGenerator</span></code></a>. |
| </p> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Expression |
| </p> |
| </th> |
| <th> |
| <p> |
| Description |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">ch</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the character literal <code class="computeroutput"><span class="identifier">ch</span></code>. |
| This generator never fails (unless the underlying output stream |
| reports an error). |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">lit</span><span class="special">(</span><span class="identifier">ch</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the character literal <code class="computeroutput"><span class="identifier">ch</span></code>. |
| This generator never fails (unless the underlying output stream |
| reports an error). |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the character provided by a mandatory attribute interpreted |
| in the character set defined by <code class="computeroutput"><span class="identifier">ns</span></code>. |
| This generator never fails (unless the underlying output stream |
| reports an error). |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">ch</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the character <code class="computeroutput"><span class="identifier">ch</span></code> |
| as provided by the immediate literal value the generator is |
| initialized from. If this generator has an associated attribute |
| it succeeds only as long as the attribute is equal to the immediate |
| literal (unless the underlying output stream reports an error). |
| Otherwise this generator fails and does not generate any output. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="string">"c"</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the character <code class="computeroutput"><span class="identifier">c</span></code> |
| as provided by the immediate literal value the generator is |
| initialized from. If this generator has an associated attribute |
| it succeeds only as long as the attribute is equal to the immediate |
| literal (unless the underlying output stream reports an error). |
| Otherwise this generator fails and does not generate any output. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">ch1</span><span class="special">,</span> |
| <span class="identifier">ch2</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the character provided by a mandatory attribute interpreted |
| in the character set defined by <code class="computeroutput"><span class="identifier">ns</span></code>. |
| The generator succeeds as long as the attribute belongs to |
| the character range <code class="computeroutput"><span class="special">[</span><span class="identifier">ch1</span><span class="special">,</span> |
| <span class="identifier">ch2</span><span class="special">]</span></code> |
| (unless the underlying output stream reports an error). Otherwise |
| this generator fails and does not generate any output. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">cs</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the character provided by a mandatory attribute interpreted |
| in the character set defined by <code class="computeroutput"><span class="identifier">ns</span></code>. |
| The generator succeeds as long as the attribute belongs to |
| the character set <code class="computeroutput"><span class="identifier">cs</span></code> |
| (unless the underlying output stream reports an error). Otherwise |
| this generator fails and does not generate any output. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">~</span><span class="identifier">cg</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Negate <code class="computeroutput"><span class="identifier">cg</span></code>. |
| The result is a negated char generator that inverts the test |
| condition of the character generator it is attached to. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <p> |
| A character <code class="computeroutput"><span class="identifier">ch</span></code> is assumed |
| to belong to the character range defined by <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">ch1</span><span class="special">,</span> <span class="identifier">ch2</span><span class="special">)</span></code> if its character value (binary representation) |
| interpreted in the character set defined by <code class="computeroutput"><span class="identifier">ns</span></code> |
| is not smaller than the character value of <code class="computeroutput"><span class="identifier">ch1</span></code> |
| and not larger then the character value of <code class="computeroutput"><span class="identifier">ch2</span></code> |
| (i.e. <code class="computeroutput"><span class="identifier">ch1</span> <span class="special"><=</span> |
| <span class="identifier">ch</span> <span class="special"><=</span> |
| <span class="identifier">ch2</span></code>). |
| </p> |
| <p> |
| The <code class="computeroutput"><span class="identifier">charset</span></code> parameter |
| passed to <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">charset</span><span class="special">)</span></code> |
| must be a string containing more than one character. Every single character |
| in this string is assumed to belong to the character set defined by this |
| expression. An exception to this is the <code class="computeroutput"><span class="char">'-'</span></code> |
| character which has a special meaning if it is not specified as the first |
| and not the last character in <code class="computeroutput"><span class="identifier">charset</span></code>. |
| If the <code class="computeroutput"><span class="char">'-'</span></code> is used in between |
| to characters it is interpreted as spanning a character range. A character |
| <code class="computeroutput"><span class="identifier">ch</span></code> is considered to belong |
| to the defined character set <code class="computeroutput"><span class="identifier">charset</span></code> |
| if it matches one of the characters as specified by the string parameter |
| described above. For example |
| </p> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Example |
| </p> |
| </th> |
| <th> |
| <p> |
| Description |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">char_</span><span class="special">(</span><span class="string">"abc"</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| 'a', 'b', and 'c' |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">char_</span><span class="special">(</span><span class="string">"a-z"</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| all characters (and including) from 'a' to 'z' |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">char_</span><span class="special">(</span><span class="string">"a-zA-Z"</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| all characters (and including) from 'a' to 'z' and 'A' and |
| 'Z' |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">char_</span><span class="special">(</span><span class="string">"-1-9"</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| '-' and all characters (and including) from '1' to '9' |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <a name="spirit.karma.reference.char.char_generator.attributes"></a><h6> |
| <a name="id1026882"></a> |
| <a class="link" href="char_generator.html#spirit.karma.reference.char.char_generator.attributes">Attributes</a> |
| </h6> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Expression |
| </p> |
| </th> |
| <th> |
| <p> |
| Attribute |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">ch</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">unused</span></code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">lit</span><span class="special">(</span><span class="identifier">ch</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">unused</span></code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Ch</span></code>, attribute |
| is mandatory (otherwise compilation will fail). <code class="computeroutput"><span class="identifier">Ch</span></code> is the character type |
| of the <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.character_encoding_namespace">Character |
| Encoding Namespace</a>, <code class="computeroutput"><span class="identifier">ns</span></code>. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">ch</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Ch</span></code>, attribute |
| is optional, if it is supplied, the generator compares the |
| attribute with <code class="computeroutput"><span class="identifier">ch</span></code> |
| and succeeds only if both are equal, failing otherwise. <code class="computeroutput"><span class="identifier">Ch</span></code> is the character type |
| of the <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.character_encoding_namespace">Character |
| Encoding Namespace</a>, <code class="computeroutput"><span class="identifier">ns</span></code>. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="string">"c"</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Ch</span></code>, attribute |
| is optional, if it is supplied, the generator compares the |
| attribute with <code class="computeroutput"><span class="identifier">c</span></code> |
| and succeeds only if both are equal, failing otherwise. <code class="computeroutput"><span class="identifier">Ch</span></code> is the character type |
| of the <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.character_encoding_namespace">Character |
| Encoding Namespace</a>, <code class="computeroutput"><span class="identifier">ns</span></code>. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">ch1</span><span class="special">,</span> |
| <span class="identifier">ch2</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Ch</span></code>, attribute |
| is mandatory (otherwise compilation will fail), the generator |
| succeeds if the attribute belongs to the character range <code class="computeroutput"><span class="special">[</span><span class="identifier">ch1</span><span class="special">,</span> <span class="identifier">ch2</span><span class="special">]</span></code> interpreted in the character |
| set defined by <code class="computeroutput"><span class="identifier">ns</span></code>. |
| <code class="computeroutput"><span class="identifier">Ch</span></code> is the character |
| type of the <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.character_encoding_namespace">Character |
| Encoding Namespace</a>, <code class="computeroutput"><span class="identifier">ns</span></code>. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">cs</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">Ch</span></code>, attribute |
| is mandatory (otherwise compilation will fail), the generator |
| succeeds if the attribute belongs to the character set <code class="computeroutput"><span class="identifier">cs</span></code>, interpreted in the character |
| set defined by <code class="computeroutput"><span class="identifier">ns</span></code>. |
| <code class="computeroutput"><span class="identifier">Ch</span></code> is the character |
| type of the <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.character_encoding_namespace">Character |
| Encoding Namespace</a>, <code class="computeroutput"><span class="identifier">ns</span></code>. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="special">~</span><span class="identifier">cg</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Attribute of <code class="computeroutput"><span class="identifier">cg</span></code> |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <div class="note"><table border="0" summary="Note"> |
| <tr> |
| <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td> |
| <th align="left">Note</th> |
| </tr> |
| <tr><td align="left" valign="top"><p> |
| In addition to their usual attribute of type <code class="computeroutput"><span class="identifier">Ch</span></code> |
| all listed generators accept an instance of a <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special"><</span><span class="identifier">Ch</span><span class="special">></span></code> as well. If the <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special"><></span></code> is initialized (holds a value) |
| the generators behave as if their attribute was an instance of <code class="computeroutput"><span class="identifier">Ch</span></code> and emit the value stored in the |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special"><></span></code>. |
| Otherwise the generators will fail. |
| </p></td></tr> |
| </table></div> |
| <a name="spirit.karma.reference.char.char_generator.complexity"></a><h6> |
| <a name="id1028642"></a> |
| <a class="link" href="char_generator.html#spirit.karma.reference.char.char_generator.complexity">Complexity</a> |
| </h6> |
| <div class="blockquote"><blockquote class="blockquote"><p> |
| O(1) |
| </p></blockquote></div> |
| <p> |
| The complexity of <code class="computeroutput"><span class="identifier">ch</span></code>, |
| <code class="computeroutput"><span class="identifier">lit</span><span class="special">(</span><span class="identifier">ch</span><span class="special">)</span></code>, |
| <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span></code>, <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">ch</span><span class="special">)</span></code>, and <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="string">"c"</span><span class="special">)</span></code> is constant as all generators emit exactly |
| one character per invocation. |
| </p> |
| <p> |
| The character range generator (<code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">ch1</span><span class="special">,</span> <span class="identifier">ch2</span><span class="special">)</span></code>) additionally requires constant lookup |
| time for the verification whether the attribute belongs to the character |
| range. |
| </p> |
| <p> |
| The character set generator (<code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">char_</span><span class="special">(</span><span class="identifier">cs</span><span class="special">)</span></code>) additionally requires O(log N) lookup |
| time for the verification whether the attribute belongs to the character |
| set, where N is the number of characters in the character set. |
| </p> |
| <a name="spirit.karma.reference.char.char_generator.example"></a><h6> |
| <a name="id1028822"></a> |
| <a class="link" href="char_generator.html#spirit.karma.reference.char.char_generator.example">Example</a> |
| </h6> |
| <div class="note"><table border="0" summary="Note"> |
| <tr> |
| <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td> |
| <th align="left">Note</th> |
| </tr> |
| <tr><td align="left" valign="top"><p> |
| The test harness for the example(s) below is presented in the <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.examples">Basics Examples</a> |
| section. |
| </p></td></tr> |
| </table></div> |
| <p> |
| Some includes: |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">karma</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">phoenix_core</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">spirit</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">phoenix_operator</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">std_pair</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">string</span><span class="special">></span> |
| </pre> |
| <p> |
| </p> |
| <p> |
| Some using declarations: |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">karma</span><span class="special">::</span><span class="identifier">lit</span><span class="special">;</span> |
| <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">ascii</span><span class="special">::</span><span class="identifier">char_</span><span class="special">;</span> |
| </pre> |
| <p> |
| </p> |
| <p> |
| Basic usage of <code class="computeroutput"><span class="identifier">char_</span></code> |
| generators: |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="identifier">test_generator</span><span class="special">(</span><span class="string">"A"</span><span class="special">,</span> <span class="char">'A'</span><span class="special">);</span> |
| <span class="identifier">test_generator</span><span class="special">(</span><span class="string">"A"</span><span class="special">,</span> <span class="identifier">lit</span><span class="special">(</span><span class="char">'A'</span><span class="special">));</span> |
| |
| <span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">"a"</span><span class="special">,</span> <span class="identifier">char_</span><span class="special">,</span> <span class="char">'a'</span><span class="special">);</span> |
| <span class="identifier">test_generator</span><span class="special">(</span><span class="string">"A"</span><span class="special">,</span> <span class="identifier">char_</span><span class="special">(</span><span class="char">'A'</span><span class="special">));</span> |
| <span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">"A"</span><span class="special">,</span> <span class="identifier">char_</span><span class="special">(</span><span class="char">'A'</span><span class="special">),</span> <span class="char">'A'</span><span class="special">);</span> |
| <span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">""</span><span class="special">,</span> <span class="identifier">char_</span><span class="special">(</span><span class="char">'A'</span><span class="special">),</span> <span class="char">'B'</span><span class="special">);</span> <span class="comment">// fails (as 'A' != 'B') |
| </span> |
| <span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">"A"</span><span class="special">,</span> <span class="identifier">char_</span><span class="special">(</span><span class="char">'A'</span><span class="special">,</span> <span class="char">'Z'</span><span class="special">),</span> <span class="char">'A'</span><span class="special">);</span> |
| <span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">""</span><span class="special">,</span> <span class="identifier">char_</span><span class="special">(</span><span class="char">'A'</span><span class="special">,</span> <span class="char">'Z'</span><span class="special">),</span> <span class="char">'a'</span><span class="special">);</span> <span class="comment">// fails (as 'a' does not belong to 'A'...'Z') |
| </span> |
| <span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">"k"</span><span class="special">,</span> <span class="identifier">char_</span><span class="special">(</span><span class="string">"a-z0-9"</span><span class="special">),</span> <span class="char">'k'</span><span class="special">);</span> |
| <span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">""</span><span class="special">,</span> <span class="identifier">char_</span><span class="special">(</span><span class="string">"a-z0-9"</span><span class="special">),</span> <span class="char">'A'</span><span class="special">);</span> <span class="comment">// fails (as 'A' does not belong to "a-z0-9") |
| </span></pre> |
| <p> |
| </p> |
| </div> |
| <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> |
| <td align="left"></td> |
| <td align="right"><div class="copyright-footer">Copyright © 2001-2010 Joel de Guzman, Hartmut Kaiser<p> |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) |
| </p> |
| </div></td> |
| </tr></table> |
| <hr> |
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