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authorSergio Medeiros <sqmedeiros@gmail.com>2015-03-23 15:22:24 -0300
committerSergio Medeiros <sqmedeiros@gmail.com>2015-03-23 15:22:24 -0300
commita8b6ece30a54901084394f040f7d8a1d8f01d0b0 (patch)
tree30457373875fdf6f1e382f2a663d0d74faa041e6 /lpeglabel.html
parentf124b2d4449a13ac21af9581a44b4455d89eaddb (diff)
downloadlpeglabel-0.12.2.tar.gz
lpeglabel-0.12.2.tar.bz2
lpeglabel-0.12.2.zip
Small update of lpeg.htmlv0.12.2
Diffstat (limited to 'lpeglabel.html')
-rw-r--r--lpeglabel.html72
1 files changed, 38 insertions, 34 deletions
diff --git a/lpeglabel.html b/lpeglabel.html
index b38e900..30e6636 100644
--- a/lpeglabel.html
+++ b/lpeglabel.html
@@ -10,14 +10,12 @@
10</head> 10</head>
11<body> 11<body>
12 12
13<!-- $Id: lpeg.html,v 1.71 2013/04/11 19:17:41 roberto Exp $ -->
14
15<div id="container"> 13<div id="container">
16 14
17<div id="product"> 15<div id="product">
18 <div id="product_logo"> 16 <div id="product_logo">
19 <a href="https://github.com/sqmedeiros/lpeglabel"> 17 <a href="https://github.com/sqmedeiros/lpeglabel">
20 <img alt="LPeg logo" src="lpeg-128.gif"/></a> 18 <img alt="LPegLabel logo" src="lpeglabel-logo.gif" width="128"/></a>
21 19
22 </div> 20 </div>
23 <div id="product_name"><big><strong>LPegLabel</strong></big></div> 21 <div id="product_name"><big><strong>LPegLabel</strong></big></div>
@@ -86,14 +84,13 @@ provided by LpegLabel:
86 if the matching of <code>p1</code> gives one of l<sub>1</sub>, ..., l<sub>n</sub> 84 if the matching of <code>p1</code> gives one of l<sub>1</sub>, ..., l<sub>n</sub>
87 </td></tr> 85 </td></tr>
88<tr><td><a href="#re-t"><code>%{l<sub>1</sub>, ..., l<sub>n</sub>}</code></a></td> 86<tr><td><a href="#re-t"><code>%{l<sub>1</sub>, ..., l<sub>n</sub>}</code></a></td>
89 <td>Syntax of <em>re</em> module. Equivalent to <code>lpeg.T(l<sub>1</sub>, ..., l<sub>n</sub>)</code> 87 <td>Syntax of <em>relabel</em> module. Equivalent to <code>lpeg.T(l<sub>1</sub>, ..., l<sub>n</sub>)</code>
90 </td></tr> 88 </td></tr>
91<tr><td><a href="#re-lc"><code>p1 /{l<sub>1</sub>, ..., l<sub>n</sub>} p2</code></a></td> 89<tr><td><a href="#re-lc"><code>p1 /{l<sub>1</sub>, ..., l<sub>n</sub>} p2</code></a></td>
92 <td>Syntax of <em>re</em> module. Equivalent to <code>lpeg.Lc(p1, p2, l<sub>1</sub>, ..., l<sub>n</sub>)</code> 90 <td>Syntax of <em>relabel</em> module. Equivalent to <code>lpeg.Lc(p1, p2, l<sub>1</sub>, ..., l<sub>n</sub>)</code>
93 </td></tr> 91 </td></tr>
94<tr><td><a href="#re-setl"><code>re.setlabels (tlabel)</code></a></td> 92<tr><td><a href="#re-setl"><code>relabel.setlabels (tlabel)</code></a></td>
95 <td>Allows to specicify a table with labels. They keys of 93 <td>Allows to specicify a table with mnemonic labels.
96 <code>tlabel</code> must be integers, and the associated values usually are strings.
97 </td></tr> 94 </td></tr>
98</tbody></table> 95</tbody></table>
99 96
@@ -136,13 +133,13 @@ labeled ordered choice pattern.
136 133
137<h3><a name="re-t"></a><code>%{l<sub>1</sub>, ..., l<sub>n</sub>}</code></h3> 134<h3><a name="re-t"></a><code>%{l<sub>1</sub>, ..., l<sub>n</sub>}</code></h3>
138<p> 135<p>
139Syntax of <em>re</em> module. Equivalent to <code>lpeg.T(l<sub>1</sub>, ..., l<sub>n</sub>)</code>. 136Syntax of <em>relabel</em> module. Equivalent to <code>lpeg.T(l<sub>1</sub>, ..., l<sub>n</sub>)</code>.
140</p> 137</p>
141 138
142 139
143<h3><a name="re-lc"></a><code>p1 /{l<sub>1</sub>, ..., l<sub>n</sub>} p2</code></h3> 140<h3><a name="re-lc"></a><code>p1 /{l<sub>1</sub>, ..., l<sub>n</sub>} p2</code></h3>
144<p> 141<p>
145Syntax of <em>re</em> module. Equivalent to <code>lpeg.Lc(p1, p2, l<sub>1</sub>, ..., l<sub>n</sub>)</code>. 142Syntax of <em>relabel</em> module. Equivalent to <code>lpeg.Lc(p1, p2, l<sub>1</sub>, ..., l<sub>n</sub>)</code>.
146</p> 143</p>
147 144
148<p> 145<p>
@@ -152,11 +149,19 @@ The <code>/{}</code> operator is left-associative.
152<p> 149<p>
153A grammar can use both choice operators (<code>/</code> and <code>/{}</code>), 150A grammar can use both choice operators (<code>/</code> and <code>/{}</code>),
154but a single choice can not mix them. That is, the parser 151but a single choice can not mix them. That is, the parser
155of <code>re</code> module will not recognize a pattern as 152of <code>relabel</code> module will not recognize a pattern as
156<code>p1 / p2 /{l<sub>1</sub>} p3</code>. 153<code>p1 / p2 /{l<sub>1</sub>} p3</code>.
157</p> 154</p>
158 155
159 156
157<h3><a name="re-setl"></a><code>relabel.setlabels (tlabel)</code></h3>
158
159<p>Allows to specicify a table with labels. They keys of
160<code>tlabel</code> must be integers between <code>0</code> and <code>31</code>,
161and the associated values should be strings.
162</p>
163
164
160 165
161<h2><a name="ex">Some Examples</a></h2> 166<h2><a name="ex">Some Examples</a></h2>
162 167
@@ -181,11 +186,11 @@ function mymatch (g, s)
181 local r, e = g:match(s) 186 local r, e = g:match(s)
182 if not r then 187 if not r then
183 if e == 1 then 188 if e == 1 then
184 return r, "Error: expecting an identifier" 189 return "Error: expecting an identifier"
185 elseif e == 2 then 190 elseif e == 2 then
186 return r, "Error: expecting ','" 191 return "Error: expecting ','"
187 else 192 else
188 return r, "Error" 193 return "Error"
189 end 194 end
190 end 195 end
191 return r 196 return r
@@ -201,9 +206,8 @@ In this example we could think about writing rule <em>List</em> as follows:
201List = m.P(("," + m.T(2)) * m.V"Id")^0 206List = m.P(("," + m.T(2)) * m.V"Id")^0
202</pre> 207</pre>
203but this would give us an expression that when matching 208but this would give us an expression that when matching
204the end of input would result in a failure with a label 209the end of input would result in a failure whose associated
205different from 0, that is equivalent to the regular failure, 210label would be <em>2</em>.
206and the result of the repetition would be this label.
207</p> 211</p>
208 212
209<p> 213<p>
@@ -235,7 +239,7 @@ local g = m.P{
235function mymatch (g, s) 239function mymatch (g, s)
236 local r, e = g:match(s) 240 local r, e = g:match(s)
237 if not r then 241 if not r then
238 return r, terror[e] 242 return terror[e]
239 end 243 end
240 return r 244 return r
241end 245end
@@ -245,14 +249,14 @@ print(mymatch(g, "a b"))
245print(mymatch(g, ", b")) 249print(mymatch(g, ", b"))
246</pre> 250</pre>
247 251
248<h3>Throwing a label using the <em>re</em> module</h3> 252<h3>Throwing a label using the <em>relabel</em> module</h3>
249 253
250<p> 254<p>
251We can also rewrite the previous example using the <em>re</em> module 255We can also rewrite the previous example using the <em>relabel</em> module
252as follows: 256as follows:
253</p> 257</p>
254<pre class="example"> 258<pre class="example">
255local re = require 're' 259local re = require 'relabel'
256 260
257local g = re.compile[[ 261local g = re.compile[[
258 S <- Id List 262 S <- Id List
@@ -264,11 +268,11 @@ function mymatch (g, s)
264 local r, e = g:match(s) 268 local r, e = g:match(s)
265 if not r then 269 if not r then
266 if e == 1 then 270 if e == 1 then
267 return r, "Error: expecting an identifier" 271 return "Error: expecting an identifier"
268 elseif e == 2 then 272 elseif e == 2 then
269 return r, "Error: expecting ','" 273 return "Error: expecting ','"
270 else 274 else
271 return r, "Error" 275 return "Error"
272 end 276 end
273 end 277 end
274 return r 278 return r
@@ -280,12 +284,12 @@ print(mymatch(g, ", b"))
280</pre> 284</pre>
281 285
282<p> 286<p>
283Another way to describe the previous example using the <em>re</em> module 287Another way to describe the previous example using the <em>relabel</em> module
284is by using a table with the description the errors (<em>terror</em>) and 288is by using a table with the description of the errors (<em>terror</em>) and
285another table that associates a name to a given label (<em>tlabel</em>): 289another table that associates a name to a given label (<em>tlabels</em>):
286</p> 290</p>
287<pre class="example"> 291<pre class="example">
288local re = require 're' 292local re = require 'relabel'
289 293
290local errUndef, errId, errComma = 0, 1, 2 294local errUndef, errId, errComma = 0, 1, 2
291 295
@@ -310,7 +314,7 @@ local g = re.compile[[
310function mymatch (g, s) 314function mymatch (g, s)
311 local r, e = g:match(s) 315 local r, e = g:match(s)
312 if not r then 316 if not r then
313 return r, terror[e] 317 return terror[e]
314 end 318 end
315 return r 319 return r
316end 320end
@@ -369,7 +373,7 @@ a left-associative order as we did in the previous example that
369used <code>Lc</code>: 373used <code>Lc</code>:
370</p> 374</p>
371<pre class="example"> 375<pre class="example">
372local re = require're' 376local re = require'relabel'
373 377
374local terror = {} 378local terror = {}
375 379
@@ -409,11 +413,11 @@ print(p:match(",b"))
409As a more complex example, below we have the grammar 413As a more complex example, below we have the grammar
410for the Tiny language, as described in 414for the Tiny language, as described in
411<a href="http://arxiv.org/abs/1405.6646">this</a> paper. 415<a href="http://arxiv.org/abs/1405.6646">this</a> paper.
412The example below can also how the line where the syntactic 416The example below can also show the line where the syntactic
413error probably happened. 417error probably happened.
414</p> 418</p>
415<pre class="example"> 419<pre class="example">
416local re = require 're' 420local re = require 'relabel'
417 421
418local terror = {} 422local terror = {}
419 423
@@ -523,8 +527,8 @@ local g = re.compile([[
523 527
524<h2><a name="download"></a>Download</h2> 528<h2><a name="download"></a>Download</h2>
525 529
526<p>LPeg 530<p>LPegLabel
527<a href="http://www.inf.puc-rio.br/~roberto/lpeg/lpeg-0.12.tar.gz">source code</a>.</p> 531<a href="https://github.com/sqmedeiros/lpeglabel/archive/master.zip">source code</a>.</p>
528 532
529 533
530<h2><a name="license">License</a></h2> 534<h2><a name="license">License</a></h2>
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