<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Karma Confix Generator</title> <link rel="stylesheet" href="../../../../../../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> <link rel="home" href="../../../index.html" title="Spirit Repository 0.1"> <link rel="up" href="../directives.html" title="Karma Generator Directives"> <link rel="prev" href="../directives.html" title="Karma Generator Directives"> <link rel="next" href="../nonterminal.html" title="Karma Generator Non-terminals"> </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="../directives.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../directives.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="../nonterminal.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h4 class="title"> <a name="spirit_repository.karma_components.directives.karma_confix_generator"></a><a class="link" href="karma_confix_generator.html" title="Karma Confix Generator">Karma Confix Generator</a> </h4></div></div></div> <a name="spirit_repository.karma_components.directives.karma_confix_generator.description"></a><h6> <a name="id771856"></a> <a class="link" href="karma_confix_generator.html#spirit_repository.karma_components.directives.karma_confix_generator.description">Description</a> </h6> <p> The <span class="emphasis"><em>Spirit.Karma</em></span> <code class="computeroutput"><span class="identifier">confix</span></code> generator is a generator directive component allowing to embed any generated ouput inside an opening (a prefix) and a closing (a suffix). A simple example is a C comment: <code class="computeroutput"><span class="comment">/* This is a C comment */</span></code> which can be generated using the <code class="computeroutput"><span class="identifier">confix</span></code> generator as: <code class="computeroutput"><span class="identifier">confix</span><span class="special">(</span><span class="string">"/*"</span><span class="special">,</span> <span class="string">"*/"</span><span class="special">)[</span><span class="string">"This is a C comment"</span><span class="special">]</span></code>. The general syntax for using the <code class="computeroutput"><span class="identifier">confix</span></code> is: </p> <pre class="programlisting"><span class="identifier">confix</span><span class="special">(</span><span class="identifier">prefix</span><span class="special">,</span> <span class="identifier">suffix</span><span class="special">)[</span><span class="identifier">subject</span><span class="special">]</span> </pre> <p> which results in generating a sequence equivalent to </p> <pre class="programlisting"><span class="identifier">prefix</span> <span class="special"><<</span> <span class="identifier">subject</span> <span class="special"><<</span> <span class="identifier">suffix</span> </pre> <p> Using the <code class="computeroutput"><span class="identifier">confix</span></code> component instead of the explicit sequence has the advantage of being able to encapsulate the prefix and the suffix into a separate generator construct. The following code snippet illustrates the idea: </p> <pre class="programlisting"><span class="comment">// Define a metafunction allowing to compute the type of the confix() </span><span class="comment">// construct </span><span class="keyword">namespace</span> <span class="identifier">traits</span> <span class="special">{</span> <span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">;</span> <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Prefix</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Suffix</span> <span class="special">=</span> <span class="identifier">Prefix</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">confix_spec</span> <span class="special">:</span> <span class="identifier">spirit</span><span class="special">::</span><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">terminal</span><span class="special"><</span><span class="identifier">repository</span><span class="special">::</span><span class="identifier">tag</span><span class="special">::</span><span class="identifier">confix</span><span class="special">(</span><span class="identifier">Prefix</span><span class="special">,</span> <span class="identifier">Suffix</span><span class="special">)></span> <span class="special">{};</span> <span class="special">};</span> <span class="comment">// Define a helper function allowing to create a confix() construct from </span><span class="comment">// arbitrary prefix and suffix generators </span><span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Prefix</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Suffix</span><span class="special">></span> <span class="keyword">typename</span> <span class="identifier">traits</span><span class="special">::</span><span class="identifier">confix_spec</span><span class="special"><</span><span class="identifier">Prefix</span><span class="special">,</span> <span class="identifier">Suffix</span><span class="special">>::</span><span class="identifier">type</span> <span class="identifier">confix_spec</span><span class="special">(</span><span class="identifier">Prefix</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">prefix</span><span class="special">,</span> <span class="identifier">Suffix</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">suffix</span><span class="special">)</span> <span class="special">{</span> <span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">;</span> <span class="keyword">return</span> <span class="identifier">repository</span><span class="special">::</span><span class="identifier">confix</span><span class="special">(</span><span class="identifier">prefix</span><span class="special">,</span> <span class="identifier">suffix</span><span class="special">);</span> <span class="special">}</span> <span class="comment">// Define a helper function to construct a HTML tag from the tag name </span><span class="keyword">inline</span> <span class="keyword">typename</span> <span class="identifier">traits</span><span class="special">::</span><span class="identifier">confix_spec</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="identifier">type</span> <span class="identifier">tag</span> <span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">tagname</span><span class="special">)</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">confix_spec</span><span class="special">(</span><span class="string">"<"</span> <span class="special">+</span> <span class="identifier">tagname</span> <span class="special">+</span> <span class="string">">"</span><span class="special">,</span> <span class="string">"</"</span> <span class="special">+</span> <span class="identifier">tagname</span> <span class="special">+</span> <span class="string">">"</span><span class="special">);</span> <span class="special">}</span> <span class="comment">// Define generators for different HTML tags the HTML tag </span><span class="keyword">typedef</span> <span class="identifier">traits</span><span class="special">::</span><span class="identifier">confix_spec</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="identifier">type</span> <span class="identifier">ol</span> <span class="special">=</span> <span class="identifier">tag</span><span class="special">(</span><span class="string">"ol"</span><span class="special">);</span> <span class="comment">// <ol>...</ol> </span><span class="keyword">typedef</span> <span class="identifier">traits</span><span class="special">::</span><span class="identifier">confix_spec</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="identifier">type</span> <span class="identifier">li</span> <span class="special">=</span> <span class="identifier">tag</span><span class="special">(</span><span class="string">"li"</span><span class="special">);</span> <span class="comment">// <li>...</li> </span></pre> <p> Now, for instance, the above definitions allow to generate the HTML 'ol' tag using a simple: <code class="computeroutput"><span class="identifier">ol</span><span class="special">[</span><span class="string">"Some text"</span><span class="special">]</span></code> (which results in <code class="computeroutput"><span class="special"><</span><span class="identifier">ol</span><span class="special">></span><span class="identifier">Some</span> <span class="identifier">text</span><span class="special"></</span><span class="identifier">ol</span><span class="special">></span></code>). </p> <a name="spirit_repository.karma_components.directives.karma_confix_generator.header"></a><h6> <a name="id772961"></a> <a class="link" href="karma_confix_generator.html#spirit_repository.karma_components.directives.karma_confix_generator.header">Header</a> </h6> <pre class="programlisting"><span class="comment">// forwards to <boost/spirit/repository/home/karma/directive/confix.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">repository</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">karma_confix</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> </pre> <a name="spirit_repository.karma_components.directives.karma_confix_generator.synopsis"></a><h6> <a name="id773061"></a> <a class="link" href="karma_confix_generator.html#spirit_repository.karma_components.directives.karma_confix_generator.synopsis">Synopsis</a> </h6> <pre class="programlisting"><span class="identifier">confix</span><span class="special">(</span><span class="identifier">prefix</span><span class="special">,</span> <span class="identifier">suffix</span><span class="special">)[</span><span class="identifier">subject</span><span class="special">]</span> </pre> <a name="spirit_repository.karma_components.directives.karma_confix_generator.parameters"></a><h6> <a name="id773128"></a> <a class="link" href="karma_confix_generator.html#spirit_repository.karma_components.directives.karma_confix_generator.parameters">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">prefix</span></code> </p> </td> <td> <p> The generator construct to use to format the opening (the prefix). The prefix is the part generated <span class="emphasis"><em>before</em></span> any output as generated by the <code class="computeroutput"><span class="identifier">subject</span></code>. </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">suffix</span></code> </p> </td> <td> <p> The generator construct to use to format the ending (the suffix). The suffix is the part generated <span class="emphasis"><em>after</em></span> any output as generated by the <code class="computeroutput"><span class="identifier">subject</span></code>. </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">subject</span></code> </p> </td> <td> <p> The generator construct to use to format the actual output in between the <code class="computeroutput"><span class="identifier">prefix</span></code> and <code class="computeroutput"><span class="identifier">suffix</span></code> parts. </p> </td> </tr> </tbody> </table></div> <p> All three parameters can be arbitrary complex generators themselves. </p> <a name="spirit_repository.karma_components.directives.karma_confix_generator.attribute"></a><h6> <a name="id773327"></a> <a class="link" href="karma_confix_generator.html#spirit_repository.karma_components.directives.karma_confix_generator.attribute">Attribute</a> </h6> <p> The <code class="computeroutput"><span class="identifier">confix</span></code> component exposes the attribute type of its subject as its own attribute type. If the <code class="computeroutput"><span class="identifier">subject</span></code> does not expose any attribute (the type is <code class="computeroutput"><span class="identifier">unused_type</span></code>), then the <code class="computeroutput"><span class="identifier">confix</span></code> does not expose any attribute either. </p> <pre class="programlisting"><span class="identifier">a</span><span class="special">:</span> <span class="identifier">A</span> <span class="special">--></span> <span class="identifier">confix</span><span class="special">(</span><span class="identifier">p</span><span class="special">,</span> <span class="identifier">s</span><span class="special">)[</span><span class="identifier">a</span><span class="special">]:</span> <span class="identifier">A</span> </pre> <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> This notation is used all over the Spirit documentation and reads as: Given, <code class="computeroutput"><span class="identifier">a</span></code> is generator, and <code class="computeroutput"><span class="identifier">A</span></code> is the type of the attribute of generator <code class="computeroutput"><span class="identifier">a</span></code>, then the type of the attribute exposed by <code class="computeroutput"><span class="identifier">confix</span><span class="special">(</span><span class="identifier">p</span><span class="special">,</span> <span class="identifier">s</span><span class="special">)[</span><span class="identifier">a</span><span class="special">]</span></code> will be <code class="computeroutput"><span class="identifier">A</span></code> as well. </p></td></tr> </table></div> <a name="spirit_repository.karma_components.directives.karma_confix_generator.example"></a><h6> <a name="id773559"></a> <a class="link" href="karma_confix_generator.html#spirit_repository.karma_components.directives.karma_confix_generator.example">Example</a> </h6> <p> The following example shows simple use cases of the <code class="computeroutput"><span class="identifier">confix</span></code> generator. We will illustrate its usage by generating different comment styles and a function prototype (for the full example code see here: <a href="../../../../../example/karma/confix.cpp" target="_top">confix.cpp</a>) </p> <a name="spirit_repository.karma_components.directives.karma_confix_generator.prerequisites"></a><h6> <a name="id773606"></a> <a class="link" href="karma_confix_generator.html#spirit_repository.karma_components.directives.karma_confix_generator.prerequisites">Prerequisites</a> </h6> <p> In addition to the main header file needed to include the core components implemented in <span class="emphasis"><em>Spirit.Karma</em></span> we add the header file needed for the new <code class="computeroutput"><span class="identifier">confix</span></code> generator. </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">repository</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">karma_confix</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> </pre> <p> </p> <p> To make all the code below more readable we introduce the following namespaces. </p> <p> </p> <pre class="programlisting"><span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">;</span> <span class="keyword">using</span> <span class="keyword">namespace</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="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">repository</span><span class="special">::</span><span class="identifier">confix</span><span class="special">;</span> </pre> <p> </p> <a name="spirit_repository.karma_components.directives.karma_confix_generator.generating_different_comment_styles"></a><h6> <a name="id773903"></a> <a class="link" href="karma_confix_generator.html#spirit_repository.karma_components.directives.karma_confix_generator.generating_different_comment_styles">Generating Different Comment Styles</a> </h6> <p> We will show how to generate different comment styles. First we will generate a C++ comment: </p> <p> </p> <pre class="programlisting"><span class="comment">// C++ comment </span><span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">karma</span><span class="special">::</span><span class="identifier">format_delimited</span><span class="special">(</span> <span class="identifier">confix</span><span class="special">(</span><span class="string">"//"</span><span class="special">,</span> <span class="identifier">eol</span><span class="special">)[</span><span class="identifier">string</span><span class="special">],</span> <span class="comment">// format description </span> <span class="identifier">space</span><span class="special">,</span> <span class="comment">// delimiter </span> <span class="string">"This is a comment"</span> <span class="comment">// data </span> <span class="special">)</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> </pre> <p> </p> <p> This code snippet will obviouly generate <code class="computeroutput"><span class="comment">// This is a comment \n </span></code>. Similarily generating a 'C'-style comment proves to be straightforward: </p> <p> </p> <pre class="programlisting"><span class="comment">// C comment </span><span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">karma</span><span class="special">::</span><span class="identifier">format_delimited</span><span class="special">(</span> <span class="identifier">confix</span><span class="special">(</span><span class="string">"/*"</span><span class="special">,</span> <span class="string">"*/"</span><span class="special">)[</span><span class="identifier">string</span><span class="special">],</span> <span class="comment">// format description </span> <span class="identifier">space</span><span class="special">,</span> <span class="comment">// delimiter </span> <span class="string">"This is a comment"</span> <span class="comment">// data </span> <span class="special">)</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> </pre> <p> </p> <p> which again will generate <code class="computeroutput"><span class="comment">/* This is a comment */</span> </code>. </p> <a name="spirit_repository.karma_components.directives.karma_confix_generator.generating_a_function_prototype"></a><h6> <a name="id774271"></a> <a class="link" href="karma_confix_generator.html#spirit_repository.karma_components.directives.karma_confix_generator.generating_a_function_prototype">Generating a Function Prototype</a> </h6> <p> Generating a function prototype given a function name a vector or parameter names is simple as well: </p> <p> </p> <pre class="programlisting"><span class="comment">// Generate a function call with an arbitrary parameter list </span><span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</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="identifier">parameters</span><span class="special">;</span> <span class="identifier">parameters</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="string">"par1"</span><span class="special">);</span> <span class="identifier">parameters</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="string">"par2"</span><span class="special">);</span> <span class="identifier">parameters</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="string">"par3"</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">karma</span><span class="special">::</span><span class="identifier">format</span><span class="special">(</span> <span class="identifier">string</span> <span class="special"><<</span> <span class="identifier">confix</span><span class="special">(</span><span class="char">'('</span><span class="special">,</span> <span class="char">')'</span><span class="special">)[</span><span class="identifier">string</span> <span class="special">%</span> <span class="char">','</span><span class="special">],</span> <span class="comment">// format description </span> <span class="string">"func"</span><span class="special">,</span> <span class="comment">// function name </span> <span class="identifier">parameters</span> <span class="comment">// parameter names </span> <span class="special">)</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">;</span> </pre> <p> </p> <p> which generates the expected output: <code class="computeroutput"><span class="identifier">func</span><span class="special">(</span><span class="identifier">par1</span><span class="special">,</span><span class="identifier">par2</span><span class="special">,</span><span class="identifier">par3</span><span class="special">)</span></code>. </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> <div class="spirit-nav"> <a accesskey="p" href="../directives.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../directives.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="../nonterminal.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>