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| <div class="titlepage"><div><div><h5 class="title"> |
| <a name="spirit.qi.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.qi.reference.string.string.description"></a><h6> |
| <a name="id948149"></a> |
| <a class="link" href="string.html#spirit.qi.reference.string.string.description">Description</a> |
| </h6> |
| <p> |
| The <code class="computeroutput"><span class="identifier">string</span></code> parser matches |
| a string of characters. The <code class="computeroutput"><span class="identifier">string</span></code> |
| parser is an implicit lexeme: the <code class="computeroutput"><span class="identifier">skip</span></code> |
| parser is not applied in between characters of the string. The <code class="computeroutput"><span class="identifier">string</span></code> parser has an associated <a class="link" href="../basics.html#spirit.qi.reference.basics.character_encoding_namespace">Character |
| Encoding Namespace</a>. This is needed when doing basic operations |
| such as inhibiting case sensitivity. 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 matches a string of characters. |
| The main difference is that <code class="computeroutput"><span class="identifier">lit</span></code> |
| does not synthesize 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.qi.reference.string.string.header"></a><h6> |
| <a name="id948375"></a> |
| <a class="link" href="string.html#spirit.qi.reference.string.string.header">Header</a> |
| </h6> |
| <pre class="programlisting"><span class="comment">// forwards to <boost/spirit/home/qi/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">qi_lit</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| </pre> |
| <a name="spirit.qi.reference.string.string.namespace"></a><h6> |
| <a name="id948441"></a> |
| <a class="link" href="string.html#spirit.qi.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::qi::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="../basics.html#spirit.qi.reference.basics.character_encoding_namespace">Character |
| Encoding Namespace</a>. |
| </p> |
| <a name="spirit.qi.reference.string.string.model_of"></a><h6> |
| <a name="id948560"></a> |
| <a class="link" href="string.html#spirit.qi.reference.string.string.model_of">Model of</a> |
| </h6> |
| <div class="blockquote"><blockquote class="blockquote"><p> |
| <a class="link" href="../parser_concepts/primitiveparser.html" title="PrimitiveParser"><code class="computeroutput"><span class="identifier">PrimitiveParser</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> |
| A <a class="link" href="../basics.html#spirit.qi.reference.basics.string">String</a> |
| or a <a class="link" href="../basics.html#spirit.qi.reference.basics.lazy_argument">Lazy |
| Argument</a> that evaluates to a <a class="link" href="../basics.html#spirit.qi.reference.basics.string">String</a>. |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">ns</span></code></span></dt> |
| <dd><p> |
| A <a class="link" href="../basics.html#spirit.qi.reference.basics.character_encoding_namespace">Character |
| Encoding Namespace</a>. |
| </p></dd> |
| </dl> |
| </div> |
| <a name="spirit.qi.reference.string.string.expression_semantics"></a><h6> |
| <a name="id948654"></a> |
| <a class="link" href="string.html#spirit.qi.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="../parser_concepts/primitiveparser.html" title="PrimitiveParser"><code class="computeroutput"><span class="identifier">PrimitiveParser</span></code></a>. |
| </p> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Expression |
| </p> |
| </th> |
| <th> |
| <p> |
| Semantics |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">s</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Create string parser from a string, <code class="computeroutput"><span class="identifier">s</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> |
| Create a string parser from a string, <code class="computeroutput"><span class="identifier">s</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><span class="special">(</span><span class="identifier">s</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Create a string parser with <code class="computeroutput"><span class="identifier">ns</span></code> |
| encoding from a string, <code class="computeroutput"><span class="identifier">s</span></code>. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <a name="spirit.qi.reference.string.string.attributes"></a><h6> |
| <a name="id948851"></a> |
| <a class="link" href="string.html#spirit.qi.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><span class="special">(</span><span class="identifier">s</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| <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">T</span><span class="special">></span></code> |
| where <code class="computeroutput"><span class="identifier">T</span></code> is |
| the underlying character type of <code class="computeroutput"><span class="identifier">s</span></code>. |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <a name="spirit.qi.reference.string.string.complexity"></a><h6> |
| <a name="id949059"></a> |
| <a class="link" href="string.html#spirit.qi.reference.string.string.complexity">Complexity</a> |
| </h6> |
| <div class="blockquote"><blockquote class="blockquote"><p> |
| O(N) |
| </p></blockquote></div> |
| <p> |
| where <code class="computeroutput"><span class="identifier">N</span></code> is the number |
| of characters in the string to be parsed. |
| </p> |
| <a name="spirit.qi.reference.string.string.example"></a><h6> |
| <a name="id949090"></a> |
| <a class="link" href="string.html#spirit.qi.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="../basics.html#spirit.qi.reference.basics.examples">Basics Examples</a> |
| section. |
| </p></td></tr> |
| </table></div> |
| <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">qi</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 literals: |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="identifier">test_parser</span><span class="special">(</span><span class="string">"boost"</span><span class="special">,</span> <span class="string">"boost"</span><span class="special">);</span> <span class="comment">// plain literal |
| </span><span class="identifier">test_parser</span><span class="special">(</span><span class="string">"boost"</span><span class="special">,</span> <span class="identifier">lit</span><span class="special">(</span><span class="string">"boost"</span><span class="special">));</span> <span class="comment">// explicit literal |
| </span><span class="identifier">test_parser</span><span class="special">(</span><span class="string">"boost"</span><span class="special">,</span> <span class="identifier">string</span><span class="special">(</span><span class="string">"boost"</span><span class="special">));</span> <span class="comment">// ascii::string |
| </span></pre> |
| <p> |
| </p> |
| <p> |
| From a <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code> |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">s</span><span class="special">(</span><span class="string">"boost"</span><span class="special">);</span> |
| <span class="identifier">test_parser</span><span class="special">(</span><span class="string">"boost"</span><span class="special">,</span> <span class="identifier">s</span><span class="special">);</span> <span class="comment">// direct |
| </span><span class="identifier">test_parser</span><span class="special">(</span><span class="string">"boost"</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">// explicit |
| </span><span class="identifier">test_parser</span><span class="special">(</span><span class="string">"boost"</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">// ascii::string |
| </span></pre> |
| <p> |
| </p> |
| <p> |
| Lazy strings using <a href="../../../../../../phoenix/doc/html/index.html" target="_top">Phoenix</a> |
| </p> |
| <p> |
| |
| </p> |
| <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">phx</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">phoenix</span><span class="special">;</span> |
| <span class="identifier">test_parser</span><span class="special">(</span><span class="string">"boost"</span><span class="special">,</span> <span class="identifier">phx</span><span class="special">::</span><span class="identifier">val</span><span class="special">(</span><span class="string">"boost"</span><span class="special">));</span> <span class="comment">// direct |
| </span><span class="identifier">test_parser</span><span class="special">(</span><span class="string">"boost"</span><span class="special">,</span> <span class="identifier">lit</span><span class="special">(</span><span class="identifier">phx</span><span class="special">::</span><span class="identifier">val</span><span class="special">(</span><span class="string">"boost"</span><span class="special">)));</span> <span class="comment">// explicit |
| </span><span class="identifier">test_parser</span><span class="special">(</span><span class="string">"boost"</span><span class="special">,</span> <span class="identifier">string</span><span class="special">(</span><span class="identifier">phx</span><span class="special">::</span><span class="identifier">val</span><span class="special">(</span><span class="string">"boost"</span><span class="special">)));</span> <span class="comment">// ascii::string |
| </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> |
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