1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Iterator Based Generator API</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="../generate_api.html" title="Generator API"> 9<link rel="prev" href="../generate_api.html" title="Generator API"> 10<link rel="next" href="stream_api.html" title="Stream Based Generator API"> 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="../generate_api.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../generate_api.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="stream_api.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.karma.reference.generate_api.iterator_api"></a><a class="link" href="iterator_api.html" title="Iterator Based Generator API">Iterator 28 Based Generator API</a> 29</h5></div></div></div> 30<h6> 31<a name="spirit.karma.reference.generate_api.iterator_api.h0"></a> 32 <span class="phrase"><a name="spirit.karma.reference.generate_api.iterator_api.description"></a></span><a class="link" href="iterator_api.html#spirit.karma.reference.generate_api.iterator_api.description">Description</a> 33 </h6> 34<p> 35 The library provides a couple of free functions to make generating a 36 snap. These generator functions have two forms. The first form, <code class="computeroutput"><span class="identifier">generate</span></code>, concatenates the output generated 37 by the involved components without inserting any output in between. The 38 second <code class="computeroutput"><span class="identifier">generate_delimited</span></code> 39 intersperses the output generated by the involved components using the 40 given delimiter generator. Both versions can take in attributes by (constant) 41 reference that hold the attribute values to output. 42 </p> 43<h6> 44<a name="spirit.karma.reference.generate_api.iterator_api.h1"></a> 45 <span class="phrase"><a name="spirit.karma.reference.generate_api.iterator_api.header"></a></span><a class="link" href="iterator_api.html#spirit.karma.reference.generate_api.iterator_api.header">Header</a> 46 </h6> 47<pre class="programlisting"><span class="comment">// forwards to <boost/spirit/home/karma/generate.hpp></span> 48<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_generate</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 49</pre> 50<p> 51 For variadic attributes: 52 </p> 53<pre class="programlisting"><span class="comment">// forwards to <boost/spirit/home/karma/generate_attr.hpp></span> 54<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_generate_attr</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 55</pre> 56<p> 57 The variadic attributes version of the API allows one or more attributes 58 to be passed into the <code class="computeroutput"><span class="identifier">generate</span></code> 59 functions. The functions taking two or more attributes are usable when 60 the generator expression is a <a class="link" href="../operator/sequence.html" title="Sequence Generator (a << b)">Sequence 61 (<code class="computeroutput"><span class="special"><<</span></code>)</a> only. 62 In this case each of the attributes passed have to match the corresponding 63 part of the sequence. 64 </p> 65<p> 66 For the API functions deducing the correct (matching) generator type 67 from the supplied attribute type: 68 </p> 69<pre class="programlisting"><span class="comment">// forwards to <boost/spirit/home/karma/detail/generate_auto.hpp></span> 70<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_generate_auto</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 71</pre> 72<p> 73 Also, see <a class="link" href="../../../structure/include.html" title="Include">Include Structure</a>. 74 </p> 75<h6> 76<a name="spirit.karma.reference.generate_api.iterator_api.h2"></a> 77 <span class="phrase"><a name="spirit.karma.reference.generate_api.iterator_api.namespace"></a></span><a class="link" href="iterator_api.html#spirit.karma.reference.generate_api.iterator_api.namespace">Namespace</a> 78 </h6> 79<div class="informaltable"><table class="table"> 80<colgroup><col></colgroup> 81<thead><tr><th> 82 <p> 83 Name 84 </p> 85 </th></tr></thead> 86<tbody> 87<tr><td> 88 <p> 89 <code class="computeroutput"><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">generate</span></code> 90 </p> 91 </td></tr> 92<tr><td> 93 <p> 94 <code class="computeroutput"><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">generate_delimited</span></code> 95 </p> 96 </td></tr> 97<tr><td> 98 <p> 99 <code class="computeroutput"><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">delimit_flag</span><span class="special">::</span><span class="identifier">predelimit</span></code> 100 </p> 101 </td></tr> 102<tr><td> 103 <p> 104 <code class="computeroutput"><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">delimit_flag</span><span class="special">::</span><span class="identifier">dont_predelimit</span></code> 105 </p> 106 </td></tr> 107</tbody> 108</table></div> 109<h6> 110<a name="spirit.karma.reference.generate_api.iterator_api.h3"></a> 111 <span class="phrase"><a name="spirit.karma.reference.generate_api.iterator_api.synopsis"></a></span><a class="link" href="iterator_api.html#spirit.karma.reference.generate_api.iterator_api.synopsis">Synopsis</a> 112 </h6> 113<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">spirit</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">karma</span> 114<span class="special">{</span> 115 <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Expr</span><span class="special">></span> 116 <span class="keyword">inline</span> <span class="keyword">bool</span> 117 <span class="identifier">generate</span><span class="special">(</span> 118 <span class="identifier">OutputIterator</span><span class="special">&</span> <span class="identifier">sink</span> 119 <span class="special">,</span> <span class="identifier">Expr</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">expr</span><span class="special">);</span> 120 121 <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Expr</span> 122 <span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Attr1</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Attr2</span><span class="special">,</span> <span class="special">...,</span> <span class="keyword">typename</span> <span class="identifier">AttrN</span><span class="special">></span> 123 <span class="keyword">inline</span> <span class="keyword">bool</span> 124 <span class="identifier">generate</span><span class="special">(</span> 125 <span class="identifier">OutputIterator</span><span class="special">&</span> <span class="identifier">sink</span> 126 <span class="special">,</span> <span class="identifier">Expr</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">expr</span> 127 <span class="special">,</span> <span class="identifier">Attr1</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">attr1</span><span class="special">,</span> <span class="identifier">Attr2</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">attr2</span><span class="special">,</span> <span class="special">...,</span> <span class="identifier">AttrN</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">attrN</span><span class="special">);</span> 128 129 <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Expr</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Delimiter</span><span class="special">></span> 130 <span class="keyword">inline</span> <span class="keyword">bool</span> 131 <span class="identifier">generate_delimited</span><span class="special">(</span> 132 <span class="identifier">OutputIterator</span><span class="special">&</span> <span class="identifier">sink</span> 133 <span class="special">,</span> <span class="identifier">Expr</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">expr</span> 134 <span class="special">,</span> <span class="identifier">Delimiter</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">delimiter</span> 135 <span class="special">,</span> <span class="identifier">BOOST_SCOPED_ENUM</span><span class="special">(</span><span class="identifier">delimit_flag</span><span class="special">)</span> <span class="identifier">pre_delimit</span> <span class="special">=</span> <span class="identifier">delimit_flag</span><span class="special">::</span><span class="identifier">dont_predelimit</span><span class="special">);</span> 136 137 <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Expr</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Delimiter</span> 138 <span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Attr1</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Attr2</span><span class="special">,</span> <span class="special">...,</span> <span class="keyword">typename</span> <span class="identifier">AttrN</span><span class="special">></span> 139 <span class="keyword">inline</span> <span class="keyword">bool</span> 140 <span class="identifier">generate_delimited</span><span class="special">(</span> 141 <span class="identifier">OutputIterator</span><span class="special">&</span> <span class="identifier">sink</span> 142 <span class="special">,</span> <span class="identifier">Expr</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">expr</span> 143 <span class="special">,</span> <span class="identifier">Delimiter</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">delimiter</span> 144 <span class="special">,</span> <span class="identifier">Attr1</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">attr1</span><span class="special">,</span> <span class="identifier">Attr2</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">attr2</span><span class="special">,</span> <span class="special">...,</span> <span class="identifier">AttrN</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">attrN</span><span class="special">);</span> 145 146 <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Expr</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Delimiter</span> 147 <span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Attr1</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Attr2</span><span class="special">,</span> <span class="special">...,</span> <span class="keyword">typename</span> <span class="identifier">AttrN</span><span class="special">></span> 148 <span class="keyword">inline</span> <span class="keyword">bool</span> 149 <span class="identifier">generate_delimited</span><span class="special">(</span> 150 <span class="identifier">OutputIterator</span><span class="special">&</span> <span class="identifier">sink</span> 151 <span class="special">,</span> <span class="identifier">Expr</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">expr</span> 152 <span class="special">,</span> <span class="identifier">Delimiter</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">delimiter</span> 153 <span class="special">,</span> <span class="identifier">BOOST_SCOPED_ENUM</span><span class="special">(</span><span class="identifier">delimit_flag</span><span class="special">)</span> <span class="identifier">pre_delimit</span> 154 <span class="special">,</span> <span class="identifier">Attr1</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">attr1</span><span class="special">,</span> <span class="identifier">Attr2</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">attr2</span><span class="special">,</span> <span class="special">...,</span> <span class="identifier">AttrN</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">attrN</span><span class="special">);</span> 155<span class="special">}}}</span> 156</pre> 157<div class="note"><table border="0" summary="Note"> 158<tr> 159<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td> 160<th align="left">Note</th> 161</tr> 162<tr><td align="left" valign="top"><p> 163 Starting with <a href="http://boost-spirit.com" target="_top">Spirit</a> V2.5 164 (distributed with Boost V1.47) the placeholder <code class="computeroutput"><span class="identifier">_val</span></code> 165 can be used in semantic actions attached to top level generator components. 166 In this case <code class="computeroutput"><span class="identifier">_val</span></code> refers 167 to the supplied attribute as a whole. For API functions taking more 168 than one attribute argument <code class="computeroutput"><span class="identifier">_val</span></code> 169 will refer to a Fusion vector or references to the attributes. 170 </p></td></tr> 171</table></div> 172<p> 173 <span class="emphasis"><em>Spirit.Karma</em></span> generator API functions based on the 174 automatic creation of the matching generator type: 175 </p> 176<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">spirit</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">karma</span> 177<span class="special">{</span> 178 <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Attr</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Delimiter</span><span class="special">></span> 179 <span class="keyword">inline</span> <span class="keyword">bool</span> 180 <span class="identifier">generate_delimited</span><span class="special">(</span> 181 <span class="identifier">OutputIterator</span><span class="special">&</span> <span class="identifier">sink</span> 182 <span class="special">,</span> <span class="identifier">Attr</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">attr</span> 183 <span class="special">,</span> <span class="identifier">Delimiter</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">delimiter</span> 184 <span class="special">,</span> <span class="identifier">BOOST_SCOPED_ENUM</span><span class="special">(</span><span class="identifier">delimit_flag</span><span class="special">)</span> <span class="identifier">pre_delimit</span> <span class="special">=</span> <span class="identifier">delimit_flag</span><span class="special">::</span><span class="identifier">dont_predelimit</span><span class="special">);</span> 185 186 <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">OutputIterator</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Attr</span><span class="special">></span> 187 <span class="keyword">inline</span> <span class="keyword">bool</span> 188 <span class="identifier">generate</span><span class="special">(</span> 189 <span class="identifier">OutputIterator</span><span class="special">&</span> <span class="identifier">sink</span> 190 <span class="special">,</span> <span class="identifier">Attr</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">attr</span><span class="special">);</span> 191<span class="special">}}}</span> 192</pre> 193<p> 194 All functions above return <code class="computeroutput"><span class="keyword">true</span></code> 195 if none of the involved generator components failed, and <code class="computeroutput"><span class="keyword">false</span></code> otherwise. If during the process 196 of the output generation the underlying output stream reports an error, 197 the return value will be <code class="computeroutput"><span class="keyword">false</span></code> 198 as well. 199 </p> 200<p> 201 The maximum number of supported arguments is limited by the preprocessor 202 constant <code class="computeroutput"><span class="identifier">SPIRIT_ARGUMENTS_LIMIT</span></code>. 203 This constant defaults to the value defined by the preprocessor constant 204 <code class="computeroutput"><span class="identifier">PHOENIX_LIMIT</span></code> (which 205 in turn defaults to <code class="computeroutput"><span class="number">10</span></code>). 206 </p> 207<div class="note"><table border="0" summary="Note"> 208<tr> 209<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td> 210<th align="left">Note</th> 211</tr> 212<tr><td align="left" valign="top"><p> 213 The variadic functions with two or more attributes internally combine 214 (constant) references to all passed attributes into a <code class="computeroutput"><span class="identifier">fusion</span><span class="special">::</span><span class="identifier">vector</span></code> and forward this as a combined 215 attribute to the corresponding function taking one attribute. 216 </p></td></tr> 217</table></div> 218<p> 219 The <code class="computeroutput"><span class="identifier">generate_delimited</span></code> 220 functions not taking an explicit <code class="computeroutput"><span class="identifier">delimit_flag</span></code> 221 as one of their arguments don't invoke the passed delimiter before starting 222 to generate output from the generator expression. This can be enabled 223 by using the other version of that function while passing <code class="computeroutput"><span class="identifier">delimit_flag</span><span class="special">::</span><span class="identifier">predelimit</span></code> to the corresponding argument. 224 </p> 225<h6> 226<a name="spirit.karma.reference.generate_api.iterator_api.h4"></a> 227 <span class="phrase"><a name="spirit.karma.reference.generate_api.iterator_api.template_parameters"></a></span><a class="link" href="iterator_api.html#spirit.karma.reference.generate_api.iterator_api.template_parameters">Template 228 parameters</a> 229 </h6> 230<div class="informaltable"><table class="table"> 231<colgroup> 232<col> 233<col> 234</colgroup> 235<thead><tr> 236<th> 237 <p> 238 Parameter 239 </p> 240 </th> 241<th> 242 <p> 243 Description 244 </p> 245 </th> 246</tr></thead> 247<tbody> 248<tr> 249<td> 250 <p> 251 <code class="computeroutput"><span class="identifier">OutputIterator</span></code> 252 </p> 253 </td> 254<td> 255 <p> 256 <a href="http://en.cppreference.com/w/cpp/named_req/OutputIterator" target="_top"><code class="computeroutput"><span class="identifier">OutputIterator</span></code></a> receiving 257 the generated output. 258 </p> 259 </td> 260</tr> 261<tr> 262<td> 263 <p> 264 <code class="computeroutput"><span class="identifier">Expr</span></code> 265 </p> 266 </td> 267<td> 268 <p> 269 An expression that can be converted to a Karma generator. 270 </p> 271 </td> 272</tr> 273<tr> 274<td> 275 <p> 276 <code class="computeroutput"><span class="identifier">Delimiter</span></code> 277 </p> 278 </td> 279<td> 280 <p> 281 Generator used to delimit the output of the expression components. 282 </p> 283 </td> 284</tr> 285<tr> 286<td> 287 <p> 288 <code class="computeroutput"><span class="identifier">Attr</span></code> 289 </p> 290 </td> 291<td> 292 <p> 293 An attribute type utilized to create the corresponding generator 294 type from. 295 </p> 296 </td> 297</tr> 298<tr> 299<td> 300 <p> 301 <code class="computeroutput"><span class="identifier">Attr1</span></code>, <code class="computeroutput"><span class="identifier">Attr2</span></code>, ..., <code class="computeroutput"><span class="identifier">AttrN</span></code> 302 </p> 303 </td> 304<td> 305 <p> 306 One or more attributes. 307 </p> 308 </td> 309</tr> 310</tbody> 311</table></div> 312</div> 313<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 314<td align="left"></td> 315<td align="right"><div class="copyright-footer">Copyright © 2001-2011 Joel de Guzman, Hartmut Kaiser<p> 316 Distributed under the Boost Software License, Version 1.0. (See accompanying 317 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>) 318 </p> 319</div></td> 320</tr></table> 321<hr> 322<div class="spirit-nav"> 323<a accesskey="p" href="../generate_api.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../generate_api.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="stream_api.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 324</div> 325</body> 326</html> 327
