1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Sequence Parser (a >> b)</title> 5<link rel="stylesheet" href="../../../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../../index.html" title="Spirit 2.5.8"> 8<link rel="up" href="../operator.html" title="Parser Operators"> 9<link rel="prev" href="plus.html" title="Plus Parser (+a)"> 10<link rel="next" href="sequential_or.html" title="Sequential Or Parser (a || b)"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="plus.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../operator.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="sequential_or.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h5 class="title"> 27<a name="spirit.qi.reference.operator.sequence"></a><a class="link" href="sequence.html" title="Sequence Parser (a >> b)">Sequence Parser 28 (<code class="computeroutput"><span class="identifier">a</span> <span class="special">>></span> 29 <span class="identifier">b</span></code>)</a> 30</h5></div></div></div> 31<h6> 32<a name="spirit.qi.reference.operator.sequence.h0"></a> 33 <span class="phrase"><a name="spirit.qi.reference.operator.sequence.description"></a></span><a class="link" href="sequence.html#spirit.qi.reference.operator.sequence.description">Description</a> 34 </h6> 35<p> 36 The sequence operator, <code class="computeroutput"><span class="identifier">a</span> <span class="special">>></span> <span class="identifier">b</span></code>, 37 parses two or more operands (<code class="computeroutput"><span class="identifier">a</span></code>, 38 <code class="computeroutput"><span class="identifier">b</span></code>, ... etc.), in sequence: 39 </p> 40<pre class="programlisting"><span class="identifier">a</span> <span class="special">>></span> <span class="identifier">b</span> <span class="special">>></span> <span class="special">...</span> 41</pre> 42<h6> 43<a name="spirit.qi.reference.operator.sequence.h1"></a> 44 <span class="phrase"><a name="spirit.qi.reference.operator.sequence.header"></a></span><a class="link" href="sequence.html#spirit.qi.reference.operator.sequence.header">Header</a> 45 </h6> 46<pre class="programlisting"><span class="comment">// forwards to <boost/spirit/home/qi/operator/sequence.hpp></span> 47<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">qi_sequence</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 48</pre> 49<p> 50 Also, see <a class="link" href="../../../structure/include.html" title="Include">Include Structure</a>. 51 </p> 52<h6> 53<a name="spirit.qi.reference.operator.sequence.h2"></a> 54 <span class="phrase"><a name="spirit.qi.reference.operator.sequence.model_of"></a></span><a class="link" href="sequence.html#spirit.qi.reference.operator.sequence.model_of">Model 55 of</a> 56 </h6> 57<div class="blockquote"><blockquote class="blockquote"><p> 58 <a class="link" href="../parser_concepts/naryparser.html" title="NaryParser"><code class="computeroutput"><span class="identifier">NaryParser</span></code></a> 59 </p></blockquote></div> 60<div class="variablelist"> 61<p class="title"><b>Notation</b></p> 62<dl class="variablelist"> 63<dt><span class="term"><code class="computeroutput"><span class="identifier">a</span></code>, <code class="computeroutput"><span class="identifier">b</span></code></span></dt> 64<dd><p> 65 A <a class="link" href="../parser_concepts/parser.html" title="Parser"><code class="computeroutput"><span class="identifier">Parser</span></code></a> 66 </p></dd> 67</dl> 68</div> 69<h6> 70<a name="spirit.qi.reference.operator.sequence.h3"></a> 71 <span class="phrase"><a name="spirit.qi.reference.operator.sequence.expression_semantics"></a></span><a class="link" href="sequence.html#spirit.qi.reference.operator.sequence.expression_semantics">Expression 72 Semantics</a> 73 </h6> 74<p> 75 Semantics of an expression is defined only where it differs from, or 76 is not defined in <a class="link" href="../parser_concepts/naryparser.html" title="NaryParser"><code class="computeroutput"><span class="identifier">NaryParser</span></code></a>. 77 </p> 78<div class="informaltable"><table class="table"> 79<colgroup> 80<col> 81<col> 82</colgroup> 83<thead><tr> 84<th> 85 <p> 86 Expression 87 </p> 88 </th> 89<th> 90 <p> 91 Semantics 92 </p> 93 </th> 94</tr></thead> 95<tbody><tr> 96<td> 97 <p> 98 <code class="computeroutput"><span class="identifier">a</span> <span class="special">>></span> 99 <span class="identifier">b</span></code> 100 </p> 101 </td> 102<td> 103 <p> 104 Match <code class="computeroutput"><span class="identifier">a</span></code> followed 105 by <code class="computeroutput"><span class="identifier">b</span></code>. 106 </p> 107 </td> 108</tr></tbody> 109</table></div> 110<h6> 111<a name="spirit.qi.reference.operator.sequence.h4"></a> 112 <span class="phrase"><a name="spirit.qi.reference.operator.sequence.attributes"></a></span><a class="link" href="sequence.html#spirit.qi.reference.operator.sequence.attributes">Attributes</a> 113 </h6> 114<p> 115 See <a class="link" href="../../quick_reference/compound_attribute_rules.html#spirit.qi.quick_reference.compound_attribute_rules.notation">Compound 116 Attribute Notation</a>. 117 </p> 118<div class="informaltable"><table class="table"> 119<colgroup> 120<col> 121<col> 122</colgroup> 123<thead><tr> 124<th> 125 <p> 126 Expression 127 </p> 128 </th> 129<th> 130 <p> 131 Attribute 132 </p> 133 </th> 134</tr></thead> 135<tbody><tr> 136<td> 137 <p> 138 <code class="computeroutput"><span class="identifier">a</span> <span class="special">>></span> 139 <span class="identifier">b</span></code> 140 </p> 141 </td> 142<td> 143 <p> 144</p> 145<pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="identifier">a</span><span class="special">:</span> <span class="identifier">A</span><span class="special">,</span> <span class="identifier">b</span><span class="special">:</span> <span class="identifier">B</span> <span class="special">--></span> <span class="special">(</span><span class="identifier">a</span> <span class="special">>></span> <span class="identifier">b</span><span class="special">):</span> <span class="identifier">tuple</span><span class="special"><</span><span class="identifier">A</span><span class="special">,</span> <span class="identifier">B</span><span class="special">></span> 146<span class="identifier">a</span><span class="special">:</span> <span class="identifier">A</span><span class="special">,</span> <span class="identifier">b</span><span class="special">:</span> <span class="identifier">Unused</span> <span class="special">--></span> <span class="special">(</span><span class="identifier">a</span> <span class="special">>></span> <span class="identifier">b</span><span class="special">):</span> <span class="identifier">A</span> 147<span class="identifier">a</span><span class="special">:</span> <span class="identifier">Unused</span><span class="special">,</span> <span class="identifier">b</span><span class="special">:</span> <span class="identifier">B</span> <span class="special">--></span> <span class="special">(</span><span class="identifier">a</span> <span class="special">>></span> <span class="identifier">b</span><span class="special">):</span> <span class="identifier">B</span> 148<span class="identifier">a</span><span class="special">:</span> <span class="identifier">Unused</span><span class="special">,</span> <span class="identifier">b</span><span class="special">:</span> <span class="identifier">Unused</span> <span class="special">--></span> <span class="special">(</span><span class="identifier">a</span> <span class="special">>></span> <span class="identifier">b</span><span class="special">):</span> <span class="identifier">Unused</span> 149 150<span class="identifier">a</span><span class="special">:</span> <span class="identifier">A</span><span class="special">,</span> <span class="identifier">b</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">b</span><span class="special">):</span> <span class="identifier">vector</span><span class="special"><</span><span class="identifier">A</span><span class="special">></span> 151<span class="identifier">a</span><span class="special">:</span> <span class="identifier">vector</span><span class="special"><</span><span class="identifier">A</span><span class="special">>,</span> <span class="identifier">b</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">b</span><span class="special">):</span> <span class="identifier">vector</span><span class="special"><</span><span class="identifier">A</span><span class="special">></span> 152<span class="identifier">a</span><span class="special">:</span> <span class="identifier">A</span><span class="special">,</span> <span class="identifier">b</span><span class="special">:</span> <span class="identifier">vector</span><span class="special"><</span><span class="identifier">A</span><span class="special">></span> <span class="special">--></span> <span class="special">(</span><span class="identifier">a</span> <span class="special">>></span> <span class="identifier">b</span><span class="special">):</span> <span class="identifier">vector</span><span class="special"><</span><span class="identifier">A</span><span class="special">></span> 153<span class="identifier">a</span><span class="special">:</span> <span class="identifier">vector</span><span class="special"><</span><span class="identifier">A</span><span class="special">>,</span> <span class="identifier">b</span><span class="special">:</span> <span class="identifier">vector</span><span class="special"><</span><span class="identifier">A</span><span class="special">></span> <span class="special">--></span> <span class="special">(</span><span class="identifier">a</span> <span class="special">>></span> <span class="identifier">b</span><span class="special">):</span> <span class="identifier">vector</span><span class="special"><</span><span class="identifier">A</span><span class="special">></span></pre> 154<p> 155 </p> 156 </td> 157</tr></tbody> 158</table></div> 159<h6> 160<a name="spirit.qi.reference.operator.sequence.h5"></a> 161 <span class="phrase"><a name="spirit.qi.reference.operator.sequence.complexity"></a></span><a class="link" href="sequence.html#spirit.qi.reference.operator.sequence.complexity">Complexity</a> 162 </h6> 163<div class="blockquote"><blockquote class="blockquote"><p> 164 The overall complexity of the sequence parser is defined by the sum 165 of the complexities of its elements. The complexity of the sequence 166 itself is O(N), where N is the number of elements in the sequence. 167 </p></blockquote></div> 168<h6> 169<a name="spirit.qi.reference.operator.sequence.h6"></a> 170 <span class="phrase"><a name="spirit.qi.reference.operator.sequence.example"></a></span><a class="link" href="sequence.html#spirit.qi.reference.operator.sequence.example">Example</a> 171 </h6> 172<p> 173 Some using declarations: 174 </p> 175<p> 176</p> 177<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">ascii</span><span class="special">::</span><span class="identifier">char_</span><span class="special">;</span> 178<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">qi</span><span class="special">::</span><span class="identifier">_1</span><span class="special">;</span> 179<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">qi</span><span class="special">::</span><span class="identifier">_2</span><span class="special">;</span> 180<span class="keyword">namespace</span> <span class="identifier">bf</span> <span class="special">=</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">fusion</span><span class="special">;</span> 181</pre> 182<p> 183 </p> 184<div class="note"><table border="0" summary="Note"> 185<tr> 186<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td> 187<th align="left">Note</th> 188</tr> 189<tr><td align="left" valign="top"><p> 190 The test harness for the example(s) below is presented in the <a class="link" href="../basics.html#spirit.qi.reference.basics.examples">Basics Examples</a> 191 section. 192 </p></td></tr> 193</table></div> 194<p> 195 Simple usage: 196 </p> 197<p> 198</p> 199<pre class="programlisting"><span class="identifier">test_parser</span><span class="special">(</span><span class="string">"xy"</span><span class="special">,</span> <span class="identifier">char_</span> <span class="special">>></span> <span class="identifier">char_</span><span class="special">);</span> 200</pre> 201<p> 202 </p> 203<p> 204 Extracting the attribute tuple (using <a href="../../../../../../../../libs/fusion/doc/html/index.html" target="_top">Boost.Fusion</a>): 205 </p> 206<p> 207</p> 208<pre class="programlisting"><span class="identifier">bf</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="keyword">char</span><span class="special">,</span> <span class="keyword">char</span><span class="special">></span> <span class="identifier">attr</span><span class="special">;</span> 209<span class="identifier">test_parser_attr</span><span class="special">(</span><span class="string">"xy"</span><span class="special">,</span> <span class="identifier">char_</span> <span class="special">>></span> <span class="identifier">char_</span><span class="special">,</span> <span class="identifier">attr</span><span class="special">);</span> 210<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">bf</span><span class="special">::</span><span class="identifier">at_c</span><span class="special"><</span><span class="number">0</span><span class="special">>(</span><span class="identifier">attr</span><span class="special">)</span> <span class="special"><<</span> <span class="char">','</span> <span class="special"><<</span> <span class="identifier">bf</span><span class="special">::</span><span class="identifier">at_c</span><span class="special"><</span><span class="number">1</span><span class="special">>(</span><span class="identifier">attr</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> 211</pre> 212<p> 213 </p> 214<p> 215 Extracting the attribute vector (using <a href="https://en.wikipedia.org/wiki/Standard_Template_Library" target="_top">STL</a>): 216 </p> 217<p> 218</p> 219<pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="keyword">char</span><span class="special">></span> <span class="identifier">vec</span><span class="special">;</span> 220<span class="identifier">test_parser_attr</span><span class="special">(</span><span class="string">"xy"</span><span class="special">,</span> <span class="identifier">char_</span> <span class="special">>></span> <span class="identifier">char_</span><span class="special">,</span> <span class="identifier">vec</span><span class="special">);</span> 221<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">vec</span><span class="special">[</span><span class="number">0</span><span class="special">]</span> <span class="special"><<</span> <span class="char">','</span> <span class="special"><<</span> <span class="identifier">vec</span><span class="special">[</span><span class="number">1</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> 222</pre> 223<p> 224 </p> 225<p> 226 Extracting the attributes using Semantic Actions (using <a href="../../../../../../../../libs/phoenix/doc/html/index.html" target="_top">Boost.Phoenix</a>): 227 </p> 228<p> 229</p> 230<pre class="programlisting"><span class="identifier">test_parser</span><span class="special">(</span><span class="string">"xy"</span><span class="special">,</span> <span class="special">(</span><span class="identifier">char_</span> <span class="special">>></span> <span class="identifier">char_</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">_1</span> <span class="special"><<</span> <span class="char">','</span> <span class="special"><<</span> <span class="identifier">_2</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</span><span class="special">]);</span> 231</pre> 232<p> 233 </p> 234</div> 235<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 236<td align="left"></td> 237<td align="right"><div class="copyright-footer">Copyright © 2001-2011 Joel de Guzman, Hartmut Kaiser<p> 238 Distributed under the Boost Software License, Version 1.0. (See accompanying 239 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>) 240 </p> 241</div></td> 242</tr></table> 243<hr> 244<div class="spirit-nav"> 245<a accesskey="p" href="plus.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../operator.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="sequential_or.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 246</div> 247</body> 248</html> 249
