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| <div class="titlepage"><div><div><h5 class="title"> |
| <a name="spirit.karma.reference.string.string"></a><a class="link" href="string.html" title="String (string, lit)">String (<code class="computeroutput"><span class="identifier">string</span></code>, <code class="computeroutput"><span class="identifier">lit</span></code>)</a> |
| </h5></div></div></div> |
| <a name="spirit.karma.reference.string.string.description"></a><h6> |
| <a name="id1103935"></a> |
| <a class="link" href="string.html#spirit.karma.reference.string.string.description">Description</a> |
| </h6> |
| <p> |
| The string generators described in this section are: |
| </p> |
| <p> |
| The <code class="computeroutput"><span class="identifier">string</span></code> generator |
| emits a string of characters. The <code class="computeroutput"><span class="identifier">string</span></code> |
| generator is implicitly verbatim: the <code class="computeroutput"><span class="identifier">delimit</span></code> |
| parser is not applied in between characters of the string. The <code class="computeroutput"><span class="identifier">string</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. Examples: |
| </p> |
| <pre class="programlisting"><span class="identifier">string</span><span class="special">(</span><span class="string">"Hello"</span><span class="special">)</span> |
| <span class="identifier">string</span><span class="special">(</span><span class="identifier">L</span><span class="string">"Hello"</span><span class="special">)</span> |
| <span class="identifier">string</span><span class="special">(</span><span class="identifier">s</span><span class="special">)</span> <span class="comment">// s is a std::string |
| </span></pre> |
| <p> |
| <code class="computeroutput"><span class="identifier">lit</span></code>, like <code class="computeroutput"><span class="identifier">string</span></code>, also emits a string of characters. |
| The main difference is that <code class="computeroutput"><span class="identifier">lit</span></code> |
| does not consumes an attribute. A plain string like <code class="computeroutput"><span class="string">"hello"</span></code> |
| or a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span></code> is equivalent to a <code class="computeroutput"><span class="identifier">lit</span></code>. Examples: |
| </p> |
| <pre class="programlisting"><span class="string">"Hello"</span> |
| <span class="identifier">lit</span><span class="special">(</span><span class="string">"Hello"</span><span class="special">)</span> |
| <span class="identifier">lit</span><span class="special">(</span><span class="identifier">L</span><span class="string">"Hello"</span><span class="special">)</span> |
| <span class="identifier">lit</span><span class="special">(</span><span class="identifier">s</span><span class="special">)</span> <span class="comment">// s is a std::string |
| </span></pre> |
| <a name="spirit.karma.reference.string.string.header"></a><h6> |
| <a name="id1104716"></a> |
| <a class="link" href="string.html#spirit.karma.reference.string.string.header">Header</a> |
| </h6> |
| <pre class="programlisting"><span class="comment">// forwards to <boost/spirit/home/karma/string/lit.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_string</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.string.string.namespace"></a><h6> |
| <a name="id1104791"></a> |
| <a class="link" href="string.html#spirit.karma.reference.string.string.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">string</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> used by the corresponding string generator. |
| </p> |
| <a name="spirit.karma.reference.string.string.model_of"></a><h6> |
| <a name="id1104911"></a> |
| <a class="link" href="string.html#spirit.karma.reference.string.string.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">s</span></code></span></dt> |
| <dd><p> |
| Character-class specific 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-class specific string |
| value |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">S</span></code></span></dt> |
| <dd><p> |
| The type of a character-class specific string <code class="computeroutput"><span class="identifier">s</span></code>. |
| </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> |
| </dl> |
| </div> |
| <a name="spirit.karma.reference.string.string.expression_semantics"></a><h6> |
| <a name="id1105027"></a> |
| <a class="link" href="string.html#spirit.karma.reference.string.string.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">s</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the string literal <code class="computeroutput"><span class="identifier">s</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">s</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the string literal <code class="computeroutput"><span class="identifier">s</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">string</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the string 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">string</span><span class="special">(</span><span class="identifier">s</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the string <code class="computeroutput"><span class="identifier">s</span></code> |
| as provided by the immediate literal value the generator is |
| initialized from. If this generator has an associated attribute |
| it succeeds only if 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> |
| </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> |
| The generators <code class="computeroutput"><span class="identifier">lit</span><span class="special">(</span><span class="identifier">s</span><span class="special">)</span></code> and <code class="computeroutput"><span class="identifier">string</span><span class="special">(</span><span class="identifier">s</span><span class="special">)</span></code> can be initialized either using a |
| string literal value (i.e. <code class="computeroutput"><span class="string">"abc"</span></code>), |
| or using a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">basic_string</span><span class="special"><</span><span class="identifier">char_type</span><span class="special">,</span> |
| <span class="special">...></span></code>, where <code class="computeroutput"><span class="identifier">char_type</span></code> is the required value type |
| of the underlying character sequence. |
| </p></td></tr> |
| </table></div> |
| <a name="spirit.karma.reference.string.string.attributes"></a><h6> |
| <a name="id1105346"></a> |
| <a class="link" href="string.html#spirit.karma.reference.string.string.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">s</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">s</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">string</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">S</span></code>, attribute |
| is mandatory (otherwise compilation will fail) |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">ns</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="identifier">s</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">S</span></code>, attribute |
| is optional, if it is supplied, the generator compares the |
| attribute with <code class="computeroutput"><span class="identifier">s</span></code> |
| and succeeds only if both are equal, failing otherwise |
| </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">S</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">S</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">S</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.string.string.complexity"></a><h6> |
| <a name="id1105652"></a> |
| <a class="link" href="string.html#spirit.karma.reference.string.string.complexity">Complexity</a> |
| </h6> |
| <div class="blockquote"><blockquote class="blockquote"><p> |
| O(N), where N is the number of characters emitted by the string generator |
| </p></blockquote></div> |
| <a name="spirit.karma.reference.string.string.example"></a><h6> |
| <a name="id1105673"></a> |
| <a class="link" href="string.html#spirit.karma.reference.string.string.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">string</span><span class="special">;</span> |
| </pre> |
| <p> |
| </p> |
| <p> |
| Basic usage of <code class="computeroutput"><span class="identifier">string</span></code> |
| generators: |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="identifier">test_generator</span><span class="special">(</span><span class="string">"abc"</span><span class="special">,</span> <span class="string">"abc"</span><span class="special">);</span> |
| <span class="identifier">test_generator</span><span class="special">(</span><span class="string">"abc"</span><span class="special">,</span> <span class="identifier">lit</span><span class="special">(</span><span class="string">"abc"</span><span class="special">));</span> |
| <span class="identifier">test_generator</span><span class="special">(</span><span class="string">"abc"</span><span class="special">,</span> <span class="identifier">lit</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">"abc"</span><span class="special">)));</span> |
| |
| <span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">"abc"</span><span class="special">,</span> <span class="identifier">string</span><span class="special">,</span> <span class="string">"abc"</span><span class="special">);</span> |
| <span class="identifier">test_generator</span><span class="special">(</span><span class="string">"abc"</span><span class="special">,</span> <span class="identifier">string</span><span class="special">(</span><span class="string">"abc"</span><span class="special">));</span> |
| <span class="identifier">test_generator</span><span class="special">(</span><span class="string">"abc"</span><span class="special">,</span> <span class="identifier">string</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">"abc"</span><span class="special">)));</span> |
| |
| <span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">"abc"</span><span class="special">,</span> <span class="identifier">string</span><span class="special">(</span><span class="string">"abc"</span><span class="special">),</span> <span class="string">"abc"</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">string</span><span class="special">(</span><span class="string">"abc"</span><span class="special">),</span> <span class="string">"cba"</span><span class="special">);</span> <span class="comment">// fails (as "abc" != "cba") |
| </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> |
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