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| <div class="section"> |
| <div class="titlepage"><div><div><h5 class="title"> |
| <a name="spirit.karma.reference.generator_concepts.generator"></a><a class="link" href="generator.html" title="Generator">Generator</a> |
| </h5></div></div></div> |
| <a name="spirit.karma.reference.generator_concepts.generator.description"></a><h6> |
| <a name="id984547"></a> |
| <a class="link" href="generator.html#spirit.karma.reference.generator_concepts.generator.description">Description</a> |
| </h6> |
| <p> |
| The <span class="emphasis"><em>Generator</em></span> is the most fundamental concept. A |
| Generator has a member function, <code class="computeroutput"><span class="identifier">generate</span></code>, |
| that accepts an <code class="computeroutput"><span class="identifier">OutputIterator</span></code> |
| and returns bool as its result. The iterator receives the data being |
| generated. The Generator's <code class="computeroutput"><span class="identifier">generate</span></code> |
| member function returns <code class="computeroutput"><span class="keyword">true</span></code> |
| if the generator succeeds. Each Generator can represent a specific pattern |
| or algorithm, or it can be a more complex generator formed as a composition |
| of other Generators. |
| </p> |
| <div class="variablelist"> |
| <p class="title"><b>Notation</b></p> |
| <dl> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">g</span></code></span></dt> |
| <dd><p> |
| A <code class="computeroutput"><span class="identifier">Generator</span></code>. |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">G</span></code></span></dt> |
| <dd><p> |
| A <code class="computeroutput"><span class="identifier">Generator</span></code> type. |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">OutIter</span></code></span></dt> |
| <dd><p> |
| An <code class="computeroutput"><span class="identifier">OutputIterator</span></code> |
| type. |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">sink</span></code></span></dt> |
| <dd><p> |
| An <code class="computeroutput"><span class="identifier">OutputIterator</span></code> |
| instance. |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">Context</span></code></span></dt> |
| <dd><p> |
| The generator's Context type. |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">context</span></code></span></dt> |
| <dd><p> |
| The generator's Context, or <code class="computeroutput"><span class="identifier">unused</span></code>. |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">delimit</span></code></span></dt> |
| <dd><p> |
| A delimiter Generator, or <code class="computeroutput"><span class="identifier">unused</span></code>. |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">attrib</span></code></span></dt> |
| <dd><p> |
| A Compatible Attributes, or <code class="computeroutput"><span class="identifier">unused</span></code>. |
| </p></dd> |
| </dl> |
| </div> |
| <a name="spirit.karma.reference.generator_concepts.generator.valid_expressions"></a><h6> |
| <a name="id986517"></a> |
| <a class="link" href="generator.html#spirit.karma.reference.generator_concepts.generator.valid_expressions">Valid |
| Expressions</a> |
| </h6> |
| <p> |
| In the expressions below, the behavior of the generator, <code class="computeroutput"><span class="identifier">g</span></code>, as well as how <code class="computeroutput"><span class="identifier">delimit</span></code> |
| and <code class="computeroutput"><span class="identifier">attrib</span></code> are handled |
| by <code class="computeroutput"><span class="identifier">g</span></code>, are left unspecified |
| in the base <code class="computeroutput"><span class="identifier">Generator</span></code> |
| concept. These are specified in subsequent, more refined concepts and |
| by the actual models thereof. |
| </p> |
| <p> |
| For any Generator the following expressions must be valid: |
| </p> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Expression |
| </p> |
| </th> |
| <th> |
| <p> |
| Semantics |
| </p> |
| </th> |
| <th> |
| <p> |
| Return type |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| |
| </p> |
| <pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="identifier">g</span><span class="special">.</span><span class="identifier">generate</span><span class="special">(</span><span class="identifier">sink</span><span class="special">,</span> <span class="identifier">context</span><span class="special">,</span> <span class="identifier">delimit</span><span class="special">,</span> <span class="identifier">attrib</span><span class="special">)</span></pre> |
| <p> |
| </p> |
| </td> |
| <td> |
| <p> |
| Generate the output sequence by inserting the generated characters/tokens |
| into <code class="computeroutput"><span class="identifier">sink</span></code>. |
| Use the <code class="computeroutput"><span class="identifier">delimit</span></code> |
| generator for delimiting. Return <code class="computeroutput"><span class="keyword">true</span></code> |
| if successful, otherwise return <code class="computeroutput"><span class="keyword">false</span></code>. |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="keyword">bool</span></code> |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">g</span><span class="special">.</span><span class="identifier">what</span><span class="special">(</span><span class="identifier">context</span><span class="special">)</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Get information about a Generator. |
| </p> |
| </td> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">info</span></code> |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <a name="spirit.karma.reference.generator_concepts.generator.type_expressions"></a><h6> |
| <a name="id986786"></a> |
| <a class="link" href="generator.html#spirit.karma.reference.generator_concepts.generator.type_expressions">Type |
| Expressions</a> |
| </h6> |
| <div class="informaltable"><table class="table"> |
| <colgroup> |
| <col> |
| <col> |
| </colgroup> |
| <thead><tr> |
| <th> |
| <p> |
| Expression |
| </p> |
| </th> |
| <th> |
| <p> |
| Description |
| </p> |
| </th> |
| </tr></thead> |
| <tbody> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">G</span><span class="special">::</span><span class="keyword">template</span> <span class="identifier">attribute</span><span class="special"><</span><span class="identifier">Context</span><span class="special">>::</span><span class="identifier">type</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| The Generator's attribute. |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">traits</span><span class="special">::</span><span class="identifier">is_generator</span><span class="special"><</span><span class="identifier">G</span><span class="special">>::</span><span class="identifier">type</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| Metafunction that evaluates to <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">true_</span></code> |
| if a certain type, <code class="computeroutput"><span class="identifier">G</span></code> |
| is a Generator, <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">false_</span></code> |
| otherwise (See <a href="../../../../../../../../libs/mpl/doc/refmanual/integral-constant.html" target="_top">MPL |
| Boolean Constant</a>). |
| </p> |
| </td> |
| </tr> |
| <tr> |
| <td> |
| <p> |
| <code class="computeroutput"><span class="identifier">G</span><span class="special">::</span><span class="identifier">properties</span></code> |
| </p> |
| </td> |
| <td> |
| <p> |
| An <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">int_</span></code> (See <a href="../../../../../../../../libs/mpl/doc/refmanual/integral-constant.html" target="_top">MPL |
| Integral Constant</a>) holding a value from the <code class="computeroutput"><span class="identifier">karma</span><span class="special">::</span><span class="identifier">generator_properties</span></code> enumeration. |
| The default value is <code class="computeroutput"><span class="identifier">generator_properties</span><span class="special">::</span><span class="identifier">no_properties</span></code> |
| </p> |
| </td> |
| </tr> |
| </tbody> |
| </table></div> |
| <a name="spirit.karma.reference.generator_concepts.generator.postcondition"></a><h6> |
| <a name="id987057"></a> |
| <a class="link" href="generator.html#spirit.karma.reference.generator_concepts.generator.postcondition">Postcondition</a> |
| </h6> |
| <p> |
| Upon return from <code class="computeroutput"><span class="identifier">g</span><span class="special">.</span><span class="identifier">generate</span></code> the following post conditions |
| should hold: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| On successful generation, <code class="computeroutput"><span class="identifier">sink</span></code> |
| receives the generated characters/tokens sequence. |
| </li> |
| <li class="listitem"> |
| No pre-delimits: <code class="computeroutput"><span class="identifier">delimit</span></code> |
| characters/tokens will not be emitted in front of any other output. |
| </li> |
| <li class="listitem"> |
| The attribute <code class="computeroutput"><span class="identifier">attrib</span></code> |
| has not been modified. |
| </li> |
| </ul></div> |
| <a name="spirit.karma.reference.generator_concepts.generator.models"></a><h6> |
| <a name="id987138"></a> |
| <a class="link" href="generator.html#spirit.karma.reference.generator_concepts.generator.models">Models</a> |
| </h6> |
| <p> |
| All generators in <span class="emphasis"><em>Spirit.Karma</em></span> are models of the |
| <span class="emphasis"><em>Generator</em></span> concept. |
| </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> |
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