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| <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> |
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| <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> |
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