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diff --git a/doc/html/boost/xpressive/let.html b/doc/html/boost/xpressive/let.html index ab4c6bcf5b..15b31da16c 100644 --- a/doc/html/boost/xpressive/let.html +++ b/doc/html/boost/xpressive/let.html @@ -1,13 +1,13 @@ <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> -<title>Global let</title> +<title>Function template let</title> <link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> -<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<meta name="generator" content="DocBook XSL Stylesheets V1.78.1"> <link rel="home" href="../../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> <link rel="up" href="../../xpressive/reference.html#header.boost.xpressive.regex_actions_hpp" title="Header <boost/xpressive/regex_actions.hpp>"> -<link rel="prev" href="check.html" title="Global check"> -<link rel="next" href="as_id1893681.html" title="Function template as"> +<link rel="prev" href="check.html" title="Function template check"> +<link rel="next" href="construct_idp355727504.html" title="Function template construct"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> @@ -20,21 +20,77 @@ </tr></table> <hr> <div class="spirit-nav"> -<a accesskey="p" href="check.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../xpressive/reference.html#header.boost.xpressive.regex_actions_hpp"><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="as_id1893681.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> +<a accesskey="p" href="check.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../xpressive/reference.html#header.boost.xpressive.regex_actions_hpp"><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="construct_idp355727504.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="refentry"> <a name="boost.xpressive.let"></a><div class="titlepage"></div> <div class="refnamediv"> -<h2><span class="refentrytitle">Global let</span></h2> -<p>boost::xpressive::let</p> +<h2><span class="refentrytitle">Function template let</span></h2> +<p>boost::xpressive::let — For binding local variables to placeholders in semantic actions when constructing a <code class="computeroutput"><a class="link" href="regex_iterator.html" title="Struct template regex_iterator">regex_iterator</a></code> or a <code class="computeroutput"><a class="link" href="regex_token_iterator.html" title="Struct template regex_token_iterator">regex_token_iterator</a></code>. </p> </div> <h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> <div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../xpressive/reference.html#header.boost.xpressive.regex_actions_hpp" title="Header <boost/xpressive/regex_actions.hpp>">boost/xpressive/regex_actions.hpp</a>> -</span><span class="emphasis"><em><span class="identifier">unspecified</span></em></span> let<span class="special">;</span></pre></div> +</span> +<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span><span class="special">...</span> ArgBindings<span class="special">></span> <span class="emphasis"><em><span class="identifier">unspecified</span></em></span> <span class="identifier">let</span><span class="special">(</span><span class="identifier">ArgBindings</span> <span class="keyword">const</span> <span class="special">&</span><span class="special">...</span> args<span class="special">)</span><span class="special">;</span></pre></div> <div class="refsect1"> -<a name="id3893825"></a><h2>Description</h2> -<p>let(), for binding references to non-local variables </p> +<a name="idp534686464"></a><h2>Description</h2> +<p> +<code class="computeroutput">xpressive::let()</code> serves the same purpose as <code class="computeroutput">match_results::let()</code>; that is, it binds a placeholder to a local value. The purpose is to allow a regex with semantic actions to be defined that refers to objects that do not yet exist. Rather than referring directly to an object, a semantic action can refer to a placeholder, and the value of the placeholder can be specified later with a <span class="emphasis"><em>let expression</em></span>. The <span class="emphasis"><em>let expression</em></span> created with <code class="computeroutput">let()</code> is passed to the constructor of either <code class="computeroutput"><code class="computeroutput"><a class="link" href="regex_iterator.html" title="Struct template regex_iterator">regex_iterator</a></code></code> or <code class="computeroutput"><code class="computeroutput"><a class="link" href="regex_token_iterator.html" title="Struct template regex_token_iterator">regex_token_iterator</a></code></code>.</p> +<p>See the section <a class="link" href="../../xpressive/user_s_guide.html#boost_xpressive.user_s_guide.semantic_actions_and_user_defined_assertions.referring_to_non_local_variables"> "Referring to Non-Local Variables"</a> in the Users' Guide for more discussion.</p> +<p><span class="emphasis"><em>Example:</em></span> </p> +<pre class="programlisting"><span class="comment">// Define a placeholder for a map object:</span> +<span class="identifier">placeholder</span><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">map</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="keyword">int</span><span class="special">></span> <span class="special">></span> <span class="identifier">_map</span><span class="special">;</span> + +<span class="comment">// Match a word and an integer, separated by =>,</span> +<span class="comment">// and then stuff the result into a std::map<></span> +<span class="identifier">sregex</span> <span class="identifier">pair</span> <span class="special">=</span> <span class="special">(</span> <span class="special">(</span><span class="identifier">s1</span><span class="special">=</span> <span class="special">+</span><span class="identifier">_w</span><span class="special">)</span> <span class="special">>></span> <span class="string">"=>"</span> <span class="special">>></span> <span class="special">(</span><span class="identifier">s2</span><span class="special">=</span> <span class="special">+</span><span class="identifier">_d</span><span class="special">)</span> <span class="special">)</span> + <span class="special">[</span> <span class="identifier">_map</span><span class="special">[</span><span class="identifier">s1</span><span class="special">]</span> <span class="special">=</span> <span class="identifier">as</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span><span class="special">(</span><span class="identifier">s2</span><span class="special">)</span> <span class="special">]</span><span class="special">;</span> + +<span class="comment">// The string to parse</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">str</span><span class="special">(</span><span class="string">"aaa=>1 bbb=>23 ccc=>456"</span><span class="special">)</span><span class="special">;</span> + +<span class="comment">// Here is the actual map to fill in:</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">map</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="keyword">int</span><span class="special">></span> <span class="identifier">result</span><span class="special">;</span> + +<span class="comment">// Create a regex_iterator to find all the matches</span> +<span class="identifier">sregex_iterator</span> <span class="identifier">it</span><span class="special">(</span><span class="identifier">str</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(</span><span class="special">)</span><span class="special">,</span> <span class="identifier">str</span><span class="special">.</span><span class="identifier">end</span><span class="special">(</span><span class="special">)</span><span class="special">,</span> <span class="identifier">pair</span><span class="special">,</span> <span class="identifier">let</span><span class="special">(</span><span class="identifier">_map</span><span class="special">=</span><span class="identifier">result</span><span class="special">)</span><span class="special">)</span><span class="special">;</span> +<span class="identifier">sregex_iterator</span> <span class="identifier">end</span><span class="special">;</span> + +<span class="comment">// step through all the matches, and fill in</span> +<span class="comment">// the result map</span> +<span class="keyword">while</span><span class="special">(</span><span class="identifier">it</span> <span class="special">!=</span> <span class="identifier">end</span><span class="special">)</span> + <span class="special">++</span><span class="identifier">it</span><span class="special">;</span> + +<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">result</span><span class="special">[</span><span class="string">"aaa"</span><span class="special">]</span> <span class="special"><<</span> <span class="char">'\n'</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">result</span><span class="special">[</span><span class="string">"bbb"</span><span class="special">]</span> <span class="special"><<</span> <span class="char">'\n'</span><span class="special">;</span> +<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">result</span><span class="special">[</span><span class="string">"ccc"</span><span class="special">]</span> <span class="special"><<</span> <span class="char">'\n'</span><span class="special">;</span> +</pre> +<p> The above code displays:</p> +<pre class="programlisting"><span class="number">1</span> +<span class="number">23</span> +<span class="number">456</span> +</pre> +<p> </p> +<div class="variablelist"><table border="0" class="variablelist compact"> +<colgroup> +<col align="left" valign="top"> +<col> +</colgroup> +<tbody><tr> +<td><p><span class="term">Parameters:</span></p></td> +<td><div class="variablelist"><table border="0" class="variablelist compact"> +<colgroup> +<col align="left" valign="top"> +<col> +</colgroup> +<tbody><tr> +<td><p><span class="term"><code class="computeroutput">args</code></span></p></td> +<td><p>A set of argument bindings, where each argument binding is an assignment expression, the left hand side of which must be an instance of <code class="computeroutput">placeholder<X></code> for some <code class="computeroutput">X</code>, and the right hand side is an lvalue of type <code class="computeroutput">X</code>.</p></td> +</tr></tbody> +</table></div></td> +</tr></tbody> +</table></div> </div> </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> @@ -47,7 +103,7 @@ </tr></table> <hr> <div class="spirit-nav"> -<a accesskey="p" href="check.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../xpressive/reference.html#header.boost.xpressive.regex_actions_hpp"><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="as_id1893681.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> +<a accesskey="p" href="check.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" 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