1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>API for Automatic Generator Creation</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="stream_api.html" title="Stream Based Generator API"> 10<link rel="next" href="../action.html" title="Semantic Actions with Generators"> 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="stream_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="../action.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.create_generator"></a><a class="link" href="create_generator.html" title="API for Automatic Generator Creation">API 28 for Automatic Generator Creation</a> 29</h5></div></div></div> 30<h6> 31<a name="spirit.karma.reference.generate_api.create_generator.h0"></a> 32 <span class="phrase"><a name="spirit.karma.reference.generate_api.create_generator.description"></a></span><a class="link" href="create_generator.html#spirit.karma.reference.generate_api.create_generator.description">Description</a> 33 </h6> 34<p> 35 The library implements a special API returning a generator instance for 36 a supplied attribute type. This function finds the best matching generator 37 type for the attribute based on a set of simple matching rules (as outlined 38 in the table below) applied recursively to the attribute type. The returned 39 generator can be utilized to emit output for the provided attribute. 40 </p> 41<h6> 42<a name="spirit.karma.reference.generate_api.create_generator.h1"></a> 43 <span class="phrase"><a name="spirit.karma.reference.generate_api.create_generator.header"></a></span><a class="link" href="create_generator.html#spirit.karma.reference.generate_api.create_generator.header">Header</a> 44 </h6> 45<pre class="programlisting"><span class="comment">// forwards to <boost/spirit/home/karma/auto.hpp></span> 46<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_auto</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 47</pre> 48<p> 49 Also, see <a class="link" href="../../../structure/include.html" title="Include">Include Structure</a>. 50 </p> 51<h6> 52<a name="spirit.karma.reference.generate_api.create_generator.h2"></a> 53 <span class="phrase"><a name="spirit.karma.reference.generate_api.create_generator.namespace"></a></span><a class="link" href="create_generator.html#spirit.karma.reference.generate_api.create_generator.namespace">Namespace</a> 54 </h6> 55<div class="informaltable"><table class="table"> 56<colgroup><col></colgroup> 57<thead><tr><th> 58 <p> 59 Name 60 </p> 61 </th></tr></thead> 62<tbody> 63<tr><td> 64 <p> 65 <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">create_generator</span></code> 66 </p> 67 </td></tr> 68<tr><td> 69 <p> 70 <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">spirit</span><span class="special">::</span><span class="identifier">traits</span><span class="special">::</span><span class="identifier">create_generator_exists</span></code> 71 </p> 72 </td></tr> 73</tbody> 74</table></div> 75<h6> 76<a name="spirit.karma.reference.generate_api.create_generator.h3"></a> 77 <span class="phrase"><a name="spirit.karma.reference.generate_api.create_generator.synopsis"></a></span><a class="link" href="create_generator.html#spirit.karma.reference.generate_api.create_generator.synopsis">Synopsis</a> 78 </h6> 79<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> 80<span class="special">{</span> 81 <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Attr</span><span class="special">></span> 82 <span class="keyword">inline</span> <span class="special"><</span><span class="identifier">unspecified</span><span class="special">></span> 83 <span class="identifier">create_generator</span><span class="special">();</span> 84<span class="special">}}}</span> 85</pre> 86<p> 87 The returned instance can be directly passed as the generator (or the 88 delimiting generator) to any of the <span class="emphasis"><em>Spirit.Karma</em></span> 89 API functions. Additionally it can be assigned to a rule as the rules 90 right hand side expression. This function will return a valid generator 91 type only if the meta function <code class="computeroutput"><span class="identifier">traits</span><span class="special">::</span><span class="identifier">create_generator_exists</span></code> 92 returns <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">true_</span></code>. Otherwise it will fail compiling. 93 </p> 94<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">traits</span> 95<span class="special">{</span> 96 <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Attr</span><span class="special">></span> 97 <span class="keyword">struct</span> <span class="identifier">create_generator_exists</span><span class="special">;</span> 98<span class="special">}}}</span> 99</pre> 100<p> 101 The meta function evaluates to <code class="computeroutput"><span class="identifier">mpl</span><span class="special">::</span><span class="identifier">true_</span></code> 102 if <code class="computeroutput"><span class="identifier">create_generator</span></code> would 103 return a valid generator for the given type <code class="computeroutput"><span class="identifier">Attr</span></code>. 104 </p> 105<p> 106 The following table outlines the mapping rules from the attribute type 107 to the generator type. These rules are applied recursively to create 108 the generator type which can be used to generate output from the given 109 attribute type. 110 </p> 111<div class="informaltable"><table class="table"> 112<colgroup> 113<col> 114<col> 115</colgroup> 116<thead><tr> 117<th> 118 <p> 119 Attribute type 120 </p> 121 </th> 122<th> 123 <p> 124 Generator type 125 </p> 126 </th> 127</tr></thead> 128<tbody> 129<tr> 130<td> 131 <p> 132 <code class="computeroutput"><span class="keyword">char</span></code>, <code class="computeroutput"><span class="keyword">wchar_t</span></code> 133 </p> 134 </td> 135<td> 136 <p> 137 <code class="computeroutput"><span class="identifier">standard</span><span class="special">::</span><span class="identifier">char_</span></code>, <code class="computeroutput"><span class="identifier">standard_wide</span><span class="special">::</span><span class="identifier">char_</span></code> 138 </p> 139 </td> 140</tr> 141<tr> 142<td> 143 <p> 144 <code class="computeroutput"><span class="keyword">short</span></code>, <code class="computeroutput"><span class="keyword">int</span></code>, <code class="computeroutput"><span class="keyword">long</span></code> 145 </p> 146 </td> 147<td> 148 <p> 149 <code class="computeroutput"><span class="identifier">short_</span></code>, <code class="computeroutput"><span class="identifier">int_</span></code>, <code class="computeroutput"><span class="identifier">long_</span></code> 150 </p> 151 </td> 152</tr> 153<tr> 154<td> 155 <p> 156 <code class="computeroutput"><span class="keyword">unsigned</span> <span class="keyword">short</span></code>, 157 <code class="computeroutput"><span class="keyword">unsigned</span> <span class="keyword">int</span></code>, 158 <code class="computeroutput"><span class="keyword">unsigned</span> <span class="keyword">long</span></code> 159 </p> 160 </td> 161<td> 162 <p> 163 <code class="computeroutput"><span class="identifier">ushort_</span></code>, <code class="computeroutput"><span class="identifier">uint_</span></code>, <code class="computeroutput"><span class="identifier">ulong_</span></code> 164 </p> 165 </td> 166</tr> 167<tr> 168<td> 169 <p> 170 <code class="computeroutput"><span class="keyword">float</span></code>, <code class="computeroutput"><span class="keyword">double</span></code>, <code class="computeroutput"><span class="keyword">long</span> 171 <span class="keyword">double</span></code> 172 </p> 173 </td> 174<td> 175 <p> 176 <code class="computeroutput"><span class="identifier">float_</span></code>, <code class="computeroutput"><span class="identifier">double_</span></code>, <code class="computeroutput"><span class="identifier">long_double</span></code> 177 </p> 178 </td> 179</tr> 180<tr> 181<td> 182 <p> 183 <code class="computeroutput"><span class="keyword">short</span></code>, <code class="computeroutput"><span class="keyword">int</span></code>, <code class="computeroutput"><span class="keyword">long</span></code> 184 </p> 185 </td> 186<td> 187 <p> 188 <code class="computeroutput"><span class="identifier">short_</span></code>, <code class="computeroutput"><span class="identifier">int_</span></code>, <code class="computeroutput"><span class="identifier">long_</span></code> 189 </p> 190 </td> 191</tr> 192<tr> 193<td> 194 <p> 195 <code class="computeroutput"><span class="keyword">long</span> <span class="keyword">long</span></code>, 196 <code class="computeroutput"><span class="keyword">unsigned</span> <span class="keyword">long</span> 197 <span class="keyword">long</span></code> 198 </p> 199 </td> 200<td> 201 <p> 202 <code class="computeroutput"><span class="identifier">long_long</span></code>, 203 <code class="computeroutput"><span class="identifier">ulong_long</span></code> 204 </p> 205 </td> 206</tr> 207<tr> 208<td> 209 <p> 210 <code class="computeroutput"><span class="keyword">bool</span></code> 211 </p> 212 </td> 213<td> 214 <p> 215 <code class="computeroutput"><span class="identifier">bool_</span></code> 216 </p> 217 </td> 218</tr> 219<tr> 220<td> 221 <p> 222 Any string (<code class="computeroutput"><span class="keyword">char</span> <span class="keyword">const</span><span class="special">*</span></code>, 223 <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code>, etc.) 224 </p> 225 </td> 226<td> 227 <p> 228 <code class="computeroutput"><span class="identifier">string</span></code> 229 </p> 230 </td> 231</tr> 232<tr> 233<td> 234 <p> 235 Any (STL) container 236 </p> 237 </td> 238<td> 239 <p> 240 Kleene Star (unary <code class="computeroutput"><span class="char">'*'</span></code>) 241 </p> 242 </td> 243</tr> 244<tr> 245<td> 246 <p> 247 Any Fusion sequence 248 </p> 249 </td> 250<td> 251 <p> 252 Sequence operator (<code class="computeroutput"><span class="char">'<<'</span></code>) 253 </p> 254 </td> 255</tr> 256<tr> 257<td> 258 <p> 259 <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">optional</span><span class="special"><></span></code> 260 </p> 261 </td> 262<td> 263 <p> 264 Optional operator (unary <code class="computeroutput"><span class="char">'-'</span></code>) 265 </p> 266 </td> 267</tr> 268<tr> 269<td> 270 <p> 271 <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">variant</span><span class="special"><></span></code> 272 </p> 273 </td> 274<td> 275 <p> 276 Alternative operator (<code class="computeroutput"><span class="char">'|'</span></code>) 277 </p> 278 </td> 279</tr> 280</tbody> 281</table></div> 282<div class="important"><table border="0" summary="Important"> 283<tr> 284<td rowspan="2" align="center" valign="top" width="25"><img alt="[Important]" src="../../../../images/important.png"></td> 285<th align="left">Important</th> 286</tr> 287<tr><td align="left" valign="top"><p> 288 The mapping for the generators <code class="computeroutput"><span class="identifier">long_long</span></code> 289 and <code class="computeroutput"><span class="identifier">ulong_long</span></code> are 290 only available on platforms where the preprocessor constant <code class="computeroutput"><span class="identifier">BOOST_HAS_LONG_LONG</span></code> is defined (i.e. 291 on platforms having native support for <code class="computeroutput"><span class="keyword">long</span> 292 <span class="keyword">long</span></code> and <code class="computeroutput"><span class="keyword">unsigned</span> 293 <span class="keyword">long</span> <span class="keyword">long</span></code> 294 (64 bit) signed and unsigned integer types). 295 </p></td></tr> 296</table></div> 297<h6> 298<a name="spirit.karma.reference.generate_api.create_generator.h4"></a> 299 <span class="phrase"><a name="spirit.karma.reference.generate_api.create_generator.template_parameters"></a></span><a class="link" href="create_generator.html#spirit.karma.reference.generate_api.create_generator.template_parameters">Template 300 parameters</a> 301 </h6> 302<div class="informaltable"><table class="table"> 303<colgroup> 304<col> 305<col> 306</colgroup> 307<thead><tr> 308<th> 309 <p> 310 Parameter 311 </p> 312 </th> 313<th> 314 <p> 315 Description 316 </p> 317 </th> 318</tr></thead> 319<tbody><tr> 320<td> 321 <p> 322 <code class="computeroutput"><span class="identifier">Attr</span></code> 323 </p> 324 </td> 325<td> 326 <p> 327 An attribute type utilized to create the corresponding generator 328 type from. 329 </p> 330 </td> 331</tr></tbody> 332</table></div> 333</div> 334<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 335<td align="left"></td> 336<td align="right"><div class="copyright-footer">Copyright © 2001-2011 Joel de Guzman, Hartmut Kaiser<p> 337 Distributed under the Boost Software License, Version 1.0. (See accompanying 338 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>) 339 </p> 340</div></td> 341</tr></table> 342<hr> 343<div class="spirit-nav"> 344<a accesskey="p" href="stream_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="../action.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 345</div> 346</body> 347</html> 348
