<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Not-Predicate (!a)</title> <link rel="stylesheet" href="../../../../../../../../doc/html/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.75.0"> <link rel="home" href="../../../../index.html" title="Spirit 2.2"> <link rel="up" href="../operator.html" title="Operator"> <link rel="prev" href="and_predicate.html" title="And-Predicate (&a)"> <link rel="next" href="../stream.html" title="Stream"> </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="../../../../../../../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="and_predicate.html"><img src="../../../../../../../../doc/html/images/prev.png" alt="Prev"></a><a accesskey="u" href="../operator.html"><img src="../../../../../../../../doc/html/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/html/images/home.png" alt="Home"></a><a accesskey="n" href="../stream.html"><img src="../../../../../../../../doc/html/images/next.png" alt="Next"></a> </div> <div class="section" title="Not-Predicate (!a)"> <div class="titlepage"><div><div><h5 class="title"> <a name="spirit.karma.reference.operator.not_predicate"></a><a class="link" href="not_predicate.html" title="Not-Predicate (!a)"> Not-Predicate (<code class="computeroutput"><span class="special">!</span><span class="identifier">a</span></code>)</a> </h5></div></div></div> <a name="spirit.karma.reference.operator.not_predicate.description"></a><h6> <a name="id914705"></a> <a class="link" href="not_predicate.html#spirit.karma.reference.operator.not_predicate.description">Description</a> </h6> <p> The not-predicate generator is used to test, whether the embedded generator fails, without generating any output. It succeeds if the embedded generator fails. </p> <a name="spirit.karma.reference.operator.not_predicate.header"></a><h6> <a name="id914724"></a> <a class="link" href="not_predicate.html#spirit.karma.reference.operator.not_predicate.header">Header</a> </h6> <pre class="programlisting"><span class="comment">// forwards to <boost/spirit/home/karma/operator/not_predicate.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">karma_not_predicate</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.karma.reference.operator.not_predicate.model_of"></a><h6> <a name="id914799"></a> <a class="link" href="not_predicate.html#spirit.karma.reference.operator.not_predicate.model_of">Model of</a> </h6> <div class="blockquote"><blockquote class="blockquote"> <p> </p> <p> <a class="link" href="../generator_concepts/unarygenerator.html" title="UnaryGenerator"><code class="computeroutput"><span class="identifier">UnaryGenerator</span></code></a> </p> <p> </p> </blockquote></div> <a name="spirit.karma.reference.operator.not_predicate.expression_semantics"></a><h6> <a name="id914835"></a> <a class="link" href="not_predicate.html#spirit.karma.reference.operator.not_predicate.expression_semantics">Expression Semantics</a> </h6> <p> Semantics of an expression is defined only where it differs from, or is not defined in <a class="link" href="../generator_concepts/unarygenerator.html" title="UnaryGenerator"><code class="computeroutput"><span class="identifier">UnaryGenerator</span></code></a>. </p> <div class="informaltable"><table class="table"> <colgroup> <col> <col> </colgroup> <thead><tr> <th> <p> Expression </p> </th> <th> <p> Semantics </p> </th> </tr></thead> <tbody><tr> <td> <p> <code class="computeroutput"><span class="special">!</span><span class="identifier">a</span></code> </p> </td> <td> <p> The generator <code class="computeroutput"><span class="identifier">a</span></code> is executed for the sole purpose of testing whether it succeeds. The not-predicate generator succeeds if its embedded generator fails (unless the underlying output stream reports an error). The not-predicate never produces any output. </p> </td> </tr></tbody> </table></div> <p> The not generator is implemented by redirecting all output produced by its embedded generator into a discarding device. </p> <a name="spirit.karma.reference.operator.not_predicate.attributes"></a><h6> <a name="id914938"></a> <a class="link" href="not_predicate.html#spirit.karma.reference.operator.not_predicate.attributes">Attributes</a> </h6> <p> See <a class="link" href="../../quick_reference/compound_attribute_rules.html#spirit.karma.quick_reference.compound_attribute_rules.notation">Compound Attribute Notation</a>. </p> <div class="informaltable"><table class="table"> <colgroup> <col> <col> </colgroup> <thead><tr> <th> <p> Expression </p> </th> <th> <p> Attribute </p> </th> </tr></thead> <tbody><tr> <td> <p> <code class="computeroutput"><span class="special">!</span><span class="identifier">a</span></code> (not-predicate, unary <code class="computeroutput"><span class="special">!</span></code>) </p> </td> <td> <p> <code class="computeroutput"><span class="identifier">a</span><span class="special">:</span> <span class="identifier">A</span> <span class="special">--></span> <span class="special">!</span><span class="identifier">a</span><span class="special">:</span> <span class="identifier">A</span></code> </p> </td> </tr></tbody> </table></div> <div class="note" title="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> The attribute of the not-predicate is not always <code class="computeroutput"><span class="identifier">unused_type</span></code>, which is different from Qi's not-predicate. This is necessary as the generator the and-predicate is attached to most of the time needs an attribute. </p></td></tr> </table></div> <a name="spirit.karma.reference.operator.not_predicate.complexity"></a><h6> <a name="id915304"></a> <a class="link" href="not_predicate.html#spirit.karma.reference.operator.not_predicate.complexity">Complexity</a> </h6> <div class="blockquote"><blockquote class="blockquote"> <p> </p> <p> The overall complexity of the not-predicate generator is defined by the complexity of its embedded generator. The complexity of the not-predicate generator itself is O(1). </p> <p> </p> </blockquote></div> <a name="spirit.karma.reference.operator.not_predicate.example"></a><h6> <a name="id915330"></a> <a class="link" href="not_predicate.html#spirit.karma.reference.operator.not_predicate.example">Example</a> </h6> <div class="note" title="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> The test harness for the example(s) below is presented in the <a class="link" href="../karma_basics.html#spirit.karma.reference.karma_basics.examples">Basics Examples</a> section. </p></td></tr> </table></div> <p> Some includes: </p> <p> </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">include</span><span class="special">/</span><span class="identifier">phoenix_core</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">include</span><span class="special">/</span><span class="identifier">phoenix_operator</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">fusion</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">std_pair</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">iostream</span><span class="special">></span> <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">string</span><span class="special">></span> </pre> <p> </p> <p> </p> <p> Some using declarations: </p> <p> </p> <p> </p> <pre class="programlisting"><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">karma</span><span class="special">::</span><span class="identifier">double_</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">karma</span><span class="special">::</span><span class="identifier">ascii</span><span class="special">::</span><span class="identifier">char_</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">karma</span><span class="special">::</span><span class="identifier">ascii</span><span class="special">::</span><span class="identifier">string</span><span class="special">;</span> <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">phoenix</span><span class="special">::</span><span class="identifier">ref</span><span class="special">;</span> </pre> <p> </p> <p> </p> <p> Basic usage of a not predicate generator: </p> <p> </p> <p> </p> <pre class="programlisting"><span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">"c"</span><span class="special">,</span> <span class="special">!</span><span class="identifier">char_</span><span class="special">(</span><span class="char">'a'</span><span class="special">)</span> <span class="special"><<</span> <span class="char">'b'</span> <span class="special">|</span> <span class="char">'c'</span><span class="special">,</span> <span class="char">'a'</span><span class="special">);</span> <span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">"b"</span><span class="special">,</span> <span class="special">!</span><span class="identifier">char_</span><span class="special">(</span><span class="char">'a'</span><span class="special">)</span> <span class="special"><<</span> <span class="char">'b'</span> <span class="special">|</span> <span class="char">'c'</span><span class="special">,</span> <span class="char">'x'</span><span class="special">);</span> <span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">"def"</span><span class="special">,</span> <span class="special">!</span><span class="identifier">string</span><span class="special">(</span><span class="string">"123"</span><span class="special">)</span> <span class="special"><<</span> <span class="string">"abc"</span> <span class="special">|</span> <span class="string">"def"</span><span class="special">,</span> <span class="string">"123"</span><span class="special">);</span> <span class="identifier">test_generator_attr</span><span class="special">(</span><span class="string">"abc"</span><span class="special">,</span> <span class="special">!</span><span class="identifier">string</span><span class="special">(</span><span class="string">"123"</span><span class="special">)</span> <span class="special"><<</span> <span class="string">"abc"</span> <span class="special">|</span> <span class="string">"def"</span><span class="special">,</span> <span class="string">"456"</span><span class="special">);</span> </pre> <p> </p> <p> </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="and_predicate.html"><img src="../../../../../../../../doc/html/images/prev.png" alt="Prev"></a><a accesskey="u" href="../operator.html"><img src="../../../../../../../../doc/html/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/html/images/home.png" alt="Home"></a><a accesskey="n" href="../stream.html"><img src="../../../../../../../../doc/html/images/next.png" alt="Next"></a> </div> </body> </html>