<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>API for Automatic Parser Creation</title> <link rel="stylesheet" href="../../../../../../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.75.0"> <link rel="home" href="../../../../index.html" title="Spirit 2.4"> <link rel="up" href="../parse_api.html" title="Parser API"> <link rel="prev" href="stream_api.html" title="Stream Based Parser API"> <link rel="next" href="../action.html" title="Action"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../../boost.png"></td> <td align="center"><a href="../../../../../../../../index.html">Home</a></td> <td align="center"><a href="../../../../../../../../libs/libraries.htm">Libraries</a></td> <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> <td align="center"><a href="../../../../../../../../more/index.htm">More</a></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="stream_api.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../parse_api.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../action.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h5 class="title"> <a name="spirit.qi.reference.parse_api.create_parser"></a><a class="link" href="create_parser.html" title="API for Automatic Parser Creation"> API for Automatic Parser Creation</a> </h5></div></div></div> <a name="spirit.qi.reference.parse_api.create_parser.description"></a><h6> <a name="id898411"></a> <a class="link" href="create_parser.html#spirit.qi.reference.parse_api.create_parser.description">Description</a> </h6> <p> The library implements a special API returning a parser instance for a supplied attribute type. This function finds the best matching parser type for the attribute based on a set of simple matching rules (as outlined in the table below) applied recursively to the attribute type. The returned parser can be utilized to match input for the provided attribute. </p> <a name="spirit.qi.reference.parse_api.create_parser.header"></a><h6> <a name="id898428"></a> <a class="link" href="create_parser.html#spirit.qi.reference.parse_api.create_parser.header">Header</a> </h6> <pre class="programlisting"><span class="comment">// forwards to <boost/spirit/home/qi/auto.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_auto</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.qi.reference.parse_api.create_parser.namespace"></a><h6> <a name="id898502"></a> <a class="link" href="create_parser.html#spirit.qi.reference.parse_api.create_parser.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">qi</span><span class="special">::</span><span class="identifier">create_parser</span></code> </p> </td></tr> <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">traits</span><span class="special">::</span><span class="identifier">create_parser_exists</span></code> </p> </td></tr> </tbody> </table></div> <a name="spirit.qi.reference.parse_api.create_parser.synopsis"></a><h6> <a name="id898622"></a> <a class="link" href="create_parser.html#spirit.qi.reference.parse_api.create_parser.synopsis">Synopsis</a> </h6> <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">spirit</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">qi</span> <span class="special">{</span> <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Attr</span><span class="special">></span> <span class="keyword">inline</span> <span class="special"><</span><span class="identifier">unspecified</span><span class="special">></span> <span class="identifier">create_parser</span><span class="special">();</span> <span class="special">}}}</span> </pre> <p> The returned instance can be directly passed as the parser (or the skipping parser) to any of the <span class="emphasis"><em>Spirit.Qi</em></span> API functions. Additionally it can be assigned to a rule as the rules right hand side expression. This function will return a valid parser type only if the meta function <code class="computeroutput"><span class="identifier">traits</span><span class="special">::</span><span class="identifier">create_parser_exists</span></code> returns <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">true_</span></code>. Otherwise it will fail compiling. </p> <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">spirit</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">traits</span> <span class="special">{</span> <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Attr</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">create_parser_exists</span><span class="special">;</span> <span class="special">}}}</span> </pre> <p> The meta function evaluates to <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">true_</span></code> if <code class="computeroutput"><span class="identifier">create_parser</span></code> would return a valid parser for the given type <code class="computeroutput"><span class="identifier">Attr</span></code>. </p> <p> The following table outlines the mapping rules from the attribute type to the parser type. These rules are applied recursively to create the parser type which can be used to match input for the given attribute type. </p> <div class="informaltable"><table class="table"> <colgroup> <col> <col> </colgroup> <thead><tr> <th> <p> Attribute type </p> </th> <th> <p> Generator type </p> </th> </tr></thead> <tbody> <tr> <td> <p> <code class="computeroutput"><span class="keyword">char</span></code>, <code class="computeroutput"><span class="keyword">wchar_t</span></code> </p> </td> <td> <p> <code class="computeroutput"><span class="identifier">standard</span><span class="special">::</span><span class="identifier">char_</span></code>, <code class="computeroutput"><span class="identifier">standard_wide</span><span class="special">::</span><span class="identifier">char_</span></code> </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="keyword">short</span></code>, <code class="computeroutput"><span class="keyword">int</span></code>, <code class="computeroutput"><span class="keyword">long</span></code> </p> </td> <td> <p> <code class="computeroutput"><span class="identifier">short_</span></code>, <code class="computeroutput"><span class="identifier">int_</span></code>, <code class="computeroutput"><span class="identifier">long_</span></code> </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="keyword">unsigned</span> <span class="keyword">short</span></code>, <code class="computeroutput"><span class="keyword">unsigned</span> <span class="keyword">int</span></code>, <code class="computeroutput"><span class="keyword">unsigned</span> <span class="keyword">long</span></code> </p> </td> <td> <p> <code class="computeroutput"><span class="identifier">ushort_</span></code>, <code class="computeroutput"><span class="identifier">uint_</span></code>, <code class="computeroutput"><span class="identifier">ulong_</span></code> </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="keyword">float</span></code>, <code class="computeroutput"><span class="keyword">double</span></code>, <code class="computeroutput"><span class="keyword">long</span> <span class="keyword">double</span></code> </p> </td> <td> <p> <code class="computeroutput"><span class="identifier">float_</span></code>, <code class="computeroutput"><span class="identifier">double_</span></code>, <code class="computeroutput"><span class="identifier">long_double</span></code> </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="keyword">short</span></code>, <code class="computeroutput"><span class="keyword">int</span></code>, <code class="computeroutput"><span class="keyword">long</span></code> </p> </td> <td> <p> <code class="computeroutput"><span class="identifier">short_</span></code>, <code class="computeroutput"><span class="identifier">int_</span></code>, <code class="computeroutput"><span class="identifier">long_</span></code> </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="keyword">long</span> <span class="keyword">long</span></code>, <code class="computeroutput"><span class="keyword">unsigned</span> <span class="keyword">long</span> <span class="keyword">long</span></code> </p> </td> <td> <p> <code class="computeroutput"><span class="identifier">long_long</span></code>, <code class="computeroutput"><span class="identifier">ulong_long</span></code> </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="keyword">bool</span></code> </p> </td> <td> <p> <code class="computeroutput"><span class="identifier">bool_</span></code> </p> </td> </tr> <tr> <td> <p> Any (STL) container </p> </td> <td> <p> Kleene Star (unary <code class="computeroutput"><span class="char">'*'</span></code>) </p> </td> </tr> <tr> <td> <p> Any Fusion sequence </p> </td> <td> <p> Sequence operator (<code class="computeroutput"><span class="char">'<<'</span></code>) </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special"><></span></code> </p> </td> <td> <p> Optional operator (unary <code class="computeroutput"><span class="char">'-'</span></code>) </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">variant</span><span class="special"><></span></code> </p> </td> <td> <p> Alternative operator (<code class="computeroutput"><span class="char">'|'</span></code>) </p> </td> </tr> </tbody> </table></div> <div class="important"><table border="0" summary="Important"> <tr> <td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="../../../../images/important.png"></td> <th align="left">Important</th> </tr> <tr><td align="left" valign="top"><p> The mapping for the parsers <code class="computeroutput"><span class="identifier">long_long</span></code> and <code class="computeroutput"><span class="identifier">ulong_long</span></code> are only available on platforms where the preprocessor constant <code class="computeroutput"><span class="identifier">BOOST_HAS_LONG_LONG</span></code> is defined (i.e. on platforms having native support for <code class="computeroutput"><span class="keyword">long</span> <span class="keyword">long</span></code> and <code class="computeroutput"><span class="keyword">unsigned</span> <span class="keyword">long</span> <span class="keyword">long</span></code> (64 bit) signed and unsigned integer types). </p></td></tr> </table></div> <a name="spirit.qi.reference.parse_api.create_parser.template_parameters"></a><h6> <a name="id900646"></a> <a class="link" href="create_parser.html#spirit.qi.reference.parse_api.create_parser.template_parameters">Template parameters</a> </h6> <div class="informaltable"><table class="table"> <colgroup> <col> <col> </colgroup> <thead><tr> <th> <p> Parameter </p> </th> <th> <p> Description </p> </th> </tr></thead> <tbody><tr> <td> <p> <code class="computeroutput"><span class="identifier">Attr</span></code> </p> </td> <td> <p> An attribute type utilized to create the corresponding parser type from. </p> </td> </tr></tbody> </table></div> </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> <div class="spirit-nav"> <a accesskey="p" href="stream_api.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../parse_api.html"><img src="../../../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="../action.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>