1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Generator Grammar</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="../nonterminal.html" title="Nonterminal Generators"> 9<link rel="prev" href="rule.html" title="Generator Rule"> 10<link rel="next" href="../numeric.html" title="Numeric 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 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29</h5></div></div></div> 30<h6> 31<a name="spirit.karma.reference.nonterminal.grammar.h0"></a> 32 <span class="phrase"><a name="spirit.karma.reference.nonterminal.grammar.description"></a></span><a class="link" href="grammar.html#spirit.karma.reference.nonterminal.grammar.description">Description</a> 33 </h6> 34<p> 35 The grammar encapsulates a set of <a class="link" href="rule.html" title="Generator Rule">rules</a> 36 (as well as primitive generators (<a class="link" href="../generator_concepts/primitivegenerator.html" title="PrimitiveGenerator"><code class="computeroutput"><span class="identifier">PrimitiveGenerator</span></code></a>) and sub-grammars). 37 The grammar is the main mechanism for modularization and composition. 38 Grammars can be composed to form more complex grammars. 39 </p> 40<h6> 41<a name="spirit.karma.reference.nonterminal.grammar.h1"></a> 42 <span class="phrase"><a name="spirit.karma.reference.nonterminal.grammar.header"></a></span><a class="link" href="grammar.html#spirit.karma.reference.nonterminal.grammar.header">Header</a> 43 </h6> 44<pre class="programlisting"><span class="comment">// forwards to <boost/spirit/home/karma/nonterminal/grammar.hpp></span> 45<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_grammar</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 46</pre> 47<p> 48 Also, see <a class="link" href="../../../structure/include.html" title="Include">Include Structure</a>. 49 </p> 50<h6> 51<a name="spirit.karma.reference.nonterminal.grammar.h2"></a> 52 <span class="phrase"><a name="spirit.karma.reference.nonterminal.grammar.namespace"></a></span><a class="link" href="grammar.html#spirit.karma.reference.nonterminal.grammar.namespace">Namespace</a> 53 </h6> 54<div class="informaltable"><table class="table"> 55<colgroup><col></colgroup> 56<thead><tr><th> 57 <p> 58 Name 59 </p> 60 </th></tr></thead> 61<tbody><tr><td> 62 <p> 63 <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">grammar</span></code> 64 </p> 65 </td></tr></tbody> 66</table></div> 67<h6> 68<a name="spirit.karma.reference.nonterminal.grammar.h3"></a> 69 <span class="phrase"><a name="spirit.karma.reference.nonterminal.grammar.synopsis"></a></span><a class="link" href="grammar.html#spirit.karma.reference.nonterminal.grammar.synopsis">Synopsis</a> 70 </h6> 71<pre class="programlisting"><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">A1</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">A2</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">A3</span><span class="special">></span> 72<span class="keyword">struct</span> <span class="identifier">grammar</span><span class="special">;</span> 73</pre> 74<h6> 75<a name="spirit.karma.reference.nonterminal.grammar.h4"></a> 76 <span class="phrase"><a name="spirit.karma.reference.nonterminal.grammar.template_parameters"></a></span><a class="link" href="grammar.html#spirit.karma.reference.nonterminal.grammar.template_parameters">Template 77 parameters</a> 78 </h6> 79<div class="informaltable"><table class="table"> 80<colgroup> 81<col> 82<col> 83<col> 84</colgroup> 85<thead><tr> 86<th> 87 <p> 88 Parameter 89 </p> 90 </th> 91<th> 92 <p> 93 Description 94 </p> 95 </th> 96<th> 97 <p> 98 Default 99 </p> 100 </th> 101</tr></thead> 102<tbody> 103<tr> 104<td> 105 <p> 106 <code class="computeroutput"><span class="identifier">OutputIterator</span></code> 107 </p> 108 </td> 109<td> 110 <p> 111 The underlying output iterator type that the rule is expected 112 to work on. 113 </p> 114 </td> 115<td> 116 <p> 117 none 118 </p> 119 </td> 120</tr> 121<tr> 122<td> 123 <p> 124 <code class="computeroutput"><span class="identifier">A1</span></code>, <code class="computeroutput"><span class="identifier">A2</span></code>, <code class="computeroutput"><span class="identifier">A3</span></code> 125 </p> 126 </td> 127<td> 128 <p> 129 Either <code class="computeroutput"><span class="identifier">Signature</span></code>, 130 <code class="computeroutput"><span class="identifier">Delimiter</span></code> or 131 <code class="computeroutput"><span class="identifier">Locals</span></code> in any 132 order. See table below. 133 </p> 134 </td> 135<td> 136 <p> 137 See table below. 138 </p> 139 </td> 140</tr> 141</tbody> 142</table></div> 143<p> 144 Here is more information about the template parameters: 145 </p> 146<div class="informaltable"><table class="table"> 147<colgroup> 148<col> 149<col> 150<col> 151</colgroup> 152<thead><tr> 153<th> 154 <p> 155 Parameter 156 </p> 157 </th> 158<th> 159 <p> 160 Description 161 </p> 162 </th> 163<th> 164 <p> 165 Default 166 </p> 167 </th> 168</tr></thead> 169<tbody> 170<tr> 171<td> 172 <p> 173 <code class="computeroutput"><span class="identifier">Signature</span></code> 174 </p> 175 </td> 176<td> 177 <p> 178 Specifies the grammar's synthesized (return value) and inherited 179 attributes (arguments). More on this here: <a class="link" href="../generator_concepts/nonterminal.html" title="Nonterminal"><code class="computeroutput"><span class="identifier">Nonterminal</span></code></a>. 180 </p> 181 </td> 182<td> 183 <p> 184 <code class="computeroutput"><span class="identifier">unused_type</span></code>. 185 When <code class="computeroutput"><span class="identifier">Signature</span></code> 186 defaults to <code class="computeroutput"><span class="identifier">unused_type</span></code>, 187 the effect is the same as specifying a signature of <code class="computeroutput"><span class="keyword">void</span><span class="special">()</span></code> 188 which is also equivalent to <code class="computeroutput"><span class="identifier">unused_type</span><span class="special">()</span></code> 189 </p> 190 </td> 191</tr> 192<tr> 193<td> 194 <p> 195 <code class="computeroutput"><span class="identifier">Delimiter</span></code> 196 </p> 197 </td> 198<td> 199 <p> 200 Specifies the grammar's delimiter generator. Specify this if 201 you want the grammar to delimit the generated output. 202 </p> 203 </td> 204<td> 205 <p> 206 <code class="computeroutput"><span class="identifier">unused_type</span></code> 207 </p> 208 </td> 209</tr> 210<tr> 211<td> 212 <p> 213 <code class="computeroutput"><span class="identifier">Locals</span></code> 214 </p> 215 </td> 216<td> 217 <p> 218 Specifies the grammar's local variables. See <a class="link" href="../generator_concepts/nonterminal.html" title="Nonterminal"><code class="computeroutput"><span class="identifier">Nonterminal</span></code></a>. 219 </p> 220 </td> 221<td> 222 <p> 223 <code class="computeroutput"><span class="identifier">unused_type</span></code> 224 </p> 225 </td> 226</tr> 227</tbody> 228</table></div> 229<h6> 230<a name="spirit.karma.reference.nonterminal.grammar.h5"></a> 231 <span class="phrase"><a name="spirit.karma.reference.nonterminal.grammar.model_of"></a></span><a class="link" href="grammar.html#spirit.karma.reference.nonterminal.grammar.model_of">Model of</a> 232 </h6> 233<div class="blockquote"><blockquote class="blockquote"><p> 234 <a class="link" href="../generator_concepts/nonterminal.html" title="Nonterminal"><code class="computeroutput"><span class="identifier">Nonterminal</span></code></a> 235 </p></blockquote></div> 236<div class="variablelist"> 237<p class="title"><b>Notation</b></p> 238<dl class="variablelist"> 239<dt><span class="term"><code class="computeroutput"><span class="identifier">g</span></code></span></dt> 240<dd><p> 241 A grammar 242 </p></dd> 243</dl> 244</div> 245<h6> 246<a name="spirit.karma.reference.nonterminal.grammar.h6"></a> 247 <span class="phrase"><a name="spirit.karma.reference.nonterminal.grammar.expression_semantics"></a></span><a class="link" href="grammar.html#spirit.karma.reference.nonterminal.grammar.expression_semantics">Expression 248 Semantics</a> 249 </h6> 250<p> 251 Semantics of an expression is defined only where it differs from, or 252 is not defined in <a class="link" href="../generator_concepts/nonterminal.html" title="Nonterminal"><code class="computeroutput"><span class="identifier">Nonterminal</span></code></a>. 253 </p> 254<div class="informaltable"><table class="table"> 255<colgroup> 256<col> 257<col> 258</colgroup> 259<thead><tr> 260<th> 261 <p> 262 Expression 263 </p> 264 </th> 265<th> 266 <p> 267 Semantics 268 </p> 269 </th> 270</tr></thead> 271<tbody><tr> 272<td> 273 <p> 274</p> 275<pre xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="table-programlisting"><span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">OutputIterator</span><span class="special">></span> 276<span class="keyword">struct</span> <span class="identifier">my_grammar</span> <span class="special">:</span> <span class="identifier">grammar</span><span class="special"><</span><span class="identifier">OutputIterator</span><span class="special">,</span> <span class="identifier">A1</span><span class="special">,</span> <span class="identifier">A2</span><span class="special">,</span> <span class="identifier">A3</span><span class="special">></span> 277<span class="special">{</span> 278 <span class="identifier">my_grammar</span><span class="special">()</span> <span class="special">:</span> <span class="identifier">my_grammar</span><span class="special">::</span><span class="identifier">base_type</span><span class="special">(</span><span class="identifier">start</span><span class="special">,</span> <span class="identifier">name</span><span class="special">)</span> 279 <span class="special">{</span> 280 <span class="comment">// Rule definitions</span> 281 <span class="identifier">start</span> <span class="special">=</span> <span class="comment">/* ... */</span><span class="special">;</span> 282 <span class="special">}</span> 283 284 <span class="identifier">rule</span><span class="special"><</span><span class="identifier">OutputIterator</span><span class="special">,</span> <span class="identifier">A1</span><span class="special">,</span> <span class="identifier">A2</span><span class="special">,</span> <span class="identifier">A3</span><span class="special">></span> <span class="identifier">start</span><span class="special">;</span> 285 <span class="comment">// more rule declarations...</span> 286<span class="special">};</span> 287</pre> 288<p> 289 </p> 290 </td> 291<td> 292 <p> 293 Grammar definition. <code class="computeroutput"><span class="identifier">name</span></code> 294 is an optional string that gives the grammar its name, useful 295 for debugging. 296 </p> 297 </td> 298</tr></tbody> 299</table></div> 300<div class="note"><table border="0" summary="Note"> 301<tr> 302<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td> 303<th align="left">Note</th> 304</tr> 305<tr><td align="left" valign="top"><p> 306 The template parameters of a grammar and its start rule (the rule passed 307 to the grammar's base class constructor) must match, otherwise you 308 will see compilation errors. 309 </p></td></tr> 310</table></div> 311<h6> 312<a name="spirit.karma.reference.nonterminal.grammar.h7"></a> 313 <span class="phrase"><a name="spirit.karma.reference.nonterminal.grammar.attributes"></a></span><a class="link" href="grammar.html#spirit.karma.reference.nonterminal.grammar.attributes">Attributes</a> 314 </h6> 315<div class="blockquote"><blockquote class="blockquote"><p> 316 The generator attribute of the grammar is <code class="computeroutput"><span class="identifier">RT</span></code>, 317 its consumed attribute. See <a class="link" href="../generator_concepts/nonterminal.html#spirit.karma.reference.generator_concepts.nonterminal.attributes"><code class="computeroutput"><span class="identifier">Attribute</span></code></a> 318 </p></blockquote></div> 319<h6> 320<a name="spirit.karma.reference.nonterminal.grammar.h8"></a> 321 <span class="phrase"><a name="spirit.karma.reference.nonterminal.grammar.complexity"></a></span><a class="link" href="grammar.html#spirit.karma.reference.nonterminal.grammar.complexity">Complexity</a> 322 </h6> 323<div class="blockquote"><blockquote class="blockquote"><p> 324 The complexity is defined by the complexity of the its definition. 325 </p></blockquote></div> 326<h6> 327<a name="spirit.karma.reference.nonterminal.grammar.h9"></a> 328 <span class="phrase"><a name="spirit.karma.reference.nonterminal.grammar.example"></a></span><a class="link" href="grammar.html#spirit.karma.reference.nonterminal.grammar.example">Example</a> 329 </h6> 330<div class="note"><table border="0" summary="Note"> 331<tr> 332<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../images/note.png"></td> 333<th align="left">Note</th> 334</tr> 335<tr><td align="left" valign="top"><p> 336 The test harness for the example(s) below is presented in the <a class="link" href="../basics.html#spirit.karma.reference.basics.examples">Basics Examples</a> 337 section. 338 </p></td></tr> 339</table></div> 340<p> 341 Some using declarations: 342 </p> 343<p> 344</p> 345<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">space_type</span><span class="special">;</span> 346<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">space</span><span class="special">;</span> 347<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">int_</span><span class="special">;</span> 348<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">grammar</span><span class="special">;</span> 349<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">rule</span><span class="special">;</span> 350</pre> 351<p> 352 </p> 353<p> 354 Basic grammar usage: 355 </p> 356<p> 357</p> 358<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">num_list</span> <span class="special">:</span> <span class="identifier">grammar</span><span class="special"><</span><span class="identifier">output_iterator_type</span><span class="special">,</span> <span class="identifier">space_type</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="keyword">int</span><span class="special">>()></span> 359<span class="special">{</span> 360 <span class="identifier">num_list</span><span class="special">()</span> <span class="special">:</span> <span class="identifier">base_type</span><span class="special">(</span><span class="identifier">start</span><span class="special">)</span> 361 <span class="special">{</span> 362 <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">int_</span><span class="special">;</span> 363 <span class="identifier">num</span> <span class="special">=</span> <span class="identifier">int_</span><span class="special">;</span> 364 <span class="identifier">start</span> <span class="special">=</span> <span class="identifier">num</span> <span class="special"><<</span> <span class="special">*(</span><span class="char">','</span> <span class="special"><<</span> <span class="identifier">num</span><span class="special">);</span> 365 <span class="special">}</span> 366 367 <span class="identifier">rule</span><span class="special"><</span><span class="identifier">output_iterator_type</span><span class="special">,</span> <span class="identifier">space_type</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="keyword">int</span><span class="special">>()></span> <span class="identifier">start</span><span class="special">;</span> 368 <span class="identifier">rule</span><span class="special"><</span><span class="identifier">output_iterator_type</span><span class="special">,</span> <span class="identifier">space_type</span><span class="special">,</span> <span class="keyword">int</span><span class="special">()></span> <span class="identifier">num</span><span class="special">;</span> 369<span class="special">};</span> 370</pre> 371<p> 372 </p> 373<p> 374 How to use the example grammar: 375 </p> 376<p> 377</p> 378<pre class="programlisting"><span class="identifier">num_list</span> <span class="identifier">nlist</span><span class="special">;</span> 379<span class="identifier">std</span><span class="special">::</span><span class="identifier">vector</span><span class="special"><</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">v</span><span class="special">;</span> 380<span class="identifier">v</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="number">123</span><span class="special">);</span> 381<span class="identifier">v</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="number">456</span><span class="special">);</span> 382<span class="identifier">v</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="number">789</span><span class="special">);</span> 383<span class="identifier">test_generator_attr_delim</span><span class="special">(</span><span class="string">"123 , 456 , 789"</span><span class="special">,</span> <span class="identifier">nlist</span><span class="special">,</span> <span class="identifier">space</span><span class="special">,</span> <span class="identifier">v</span><span class="special">);</span> 384</pre> 385<p> 386 </p> 387</div> 388<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 389<td align="left"></td> 390<td align="right"><div class="copyright-footer">Copyright © 2001-2011 Joel de Guzman, Hartmut Kaiser<p> 391 Distributed under the Boost Software License, Version 1.0. (See accompanying 392 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>) 393 </p> 394</div></td> 395</tr></table> 396<hr> 397<div class="spirit-nav"> 398<a accesskey="p" href="rule.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../nonterminal.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="../numeric.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 399</div> 400</body> 401</html> 402
