1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
|
<?php
/**
* PHP_ParserGenerator, a php 5 parser generator.
*
* This is a direct port of the Lemon parser generator, found at
* {@link http://www.hwaci.com/sw/lemon/}
*
* PHP version 5
*
* LICENSE:
*
* Copyright (c) 2006, Gregory Beaver <cellog@php.net>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the distribution.
* * Neither the name of the PHP_ParserGenerator nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
* IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* @category php
* @package PHP_ParserGenerator
* @author Gregory Beaver <cellog@php.net>
* @copyright 2006 Gregory Beaver
* @license http://www.opensource.org/licenses/bsd-license.php New BSD License
* @version CVS: $Id: ActionTable.php,v 1.1 2006/07/18 00:53:10 cellog Exp $
* @since File available since Release 0.1.0
*/
/**
* The state of the yy_action table under construction is an instance of
* the following structure
* @package PHP_ParserGenerator
* @author Gregory Beaver <cellog@php.net>
* @copyright 2006 Gregory Beaver
* @license http://www.opensource.org/licenses/bsd-license.php New BSD License
* @version 0.1.5
* @since Class available since Release 0.1.0
*/
class PHP_ParserGenerator_ActionTable
{
/**
* Number of used slots in {@link $aAction}
* @var int
*/
public $nAction = 0;
/**
* The $yy_action table under construction.
*
* Each entry is of format:
* <code>
* array(
* 'lookahead' => -1, // Value of the lookahead token (symbol index)
* 'action' => -1 // Action to take on the given lookahead (action index)
* );
* </code>
* @see PHP_ParserGenerator_Data::compute_action()
* @var array
*/
public $aAction =
array(array(
'lookahead' => -1,
'action' => -1
));
/**
* A single new transaction set.
*
* @see $aAction format of the internal array is described here
* @var array
*/
public $aLookahead =
array(array(
'lookahead' => 0,
'action' => 0
));
/**
* The smallest (minimum) value of any lookahead token in {@link $aLookahead}
*
* The lowest non-terminal is always introduced earlier in the parser file,
* and is therefore a more significant token.
* @var int
*/
public $mnLookahead = 0;
/**
* The action associated with the smallest lookahead token.
* @see $mnLookahead
* @var int
*/
public $mnAction = 0;
/**
* The largest (maximum) value of any lookahead token in {@link $aLookahead}
* @var int
*/
public $mxLookahead = 0;
/**
* The number of slots used in {@link $aLookahead}.
*
* This is the same as count($aLookahead), but there was no pressing reason
* to change this when porting from C.
* @see $mnLookahead
* @var int
*/
public $nLookahead = 0;
/**
* Add a new action to the current transaction set
* @param int
* @param int
*/
public function acttab_action($lookahead, $action)
{
if ($this->nLookahead === 0) {
$this->aLookahead = array();
$this->mxLookahead = $lookahead;
$this->mnLookahead = $lookahead;
$this->mnAction = $action;
} else {
if ($this->mxLookahead < $lookahead) {
$this->mxLookahead = $lookahead;
}
if ($this->mnLookahead > $lookahead) {
$this->mnLookahead = $lookahead;
$this->mnAction = $action;
}
}
$this->aLookahead[$this->nLookahead] = array(
'lookahead' => $lookahead,
'action' => $action);
$this->nLookahead++;
}
/**
* Add the transaction set built up with prior calls to acttab_action()
* into the current action table. Then reset the transaction set back
* to an empty set in preparation for a new round of acttab_action() calls.
*
* Return the offset into the action table of the new transaction.
* @return int Return the offset that should be added to the lookahead in
* order to get the index into $yy_action of the action. This will be used
* in generation of $yy_ofst tables (reduce and shift)
* @throws Exception
*/
public function acttab_insert()
{
if ($this->nLookahead <= 0) {
throw new Exception('nLookahead is not set up?');
}
/* Scan the existing action table looking for an offset where we can
** insert the current transaction set. Fall out of the loop when that
** offset is found. In the worst case, we fall out of the loop when
** i reaches $this->nAction, which means we append the new transaction set.
**
** i is the index in $this->aAction[] where $this->mnLookahead is inserted.
*/
for ($i = 0; $i < $this->nAction + $this->mnLookahead; $i++) {
if (!isset($this->aAction[$i])) {
$this->aAction[$i] = array(
'lookahead' => -1,
'action' => -1,
);
}
if ($this->aAction[$i]['lookahead'] < 0) {
for ($j = 0; $j < $this->nLookahead; $j++) {
if (!isset($this->aLookahead[$j])) {
$this->aLookahead[$j] = array(
'lookahead' => 0,
'action' => 0,
);
}
$k = $this->aLookahead[$j]['lookahead'] -
$this->mnLookahead + $i;
if ($k < 0) {
break;
}
if (!isset($this->aAction[$k])) {
$this->aAction[$k] = array(
'lookahead' => -1,
'action' => -1,
);
}
if ($this->aAction[$k]['lookahead'] >= 0) {
break;
}
}
if ($j < $this->nLookahead) {
continue;
}
for ($j = 0; $j < $this->nAction; $j++) {
if (!isset($this->aAction[$j])) {
$this->aAction[$j] = array(
'lookahead' => -1,
'action' => -1,
);
}
if ($this->aAction[$j]['lookahead'] == $j +
$this->mnLookahead - $i) {
break;
}
}
if ($j == $this->nAction) {
break; /* Fits in empty slots */
}
} elseif ($this->aAction[$i]['lookahead'] == $this->mnLookahead) {
if ($this->aAction[$i]['action'] != $this->mnAction) {
continue;
}
for ($j = 0; $j < $this->nLookahead; $j++) {
$k = $this->aLookahead[$j]['lookahead'] -
$this->mnLookahead + $i;
if ($k < 0 || $k >= $this->nAction) {
break;
}
if (!isset($this->aAction[$k])) {
$this->aAction[$k] = array(
'lookahead' => -1,
'action' => -1,
);
}
if ($this->aLookahead[$j]['lookahead'] !=
$this->aAction[$k]['lookahead']) {
break;
}
if ($this->aLookahead[$j]['action'] !=
$this->aAction[$k]['action']) {
break;
}
}
if ($j < $this->nLookahead) {
continue;
}
$n = 0;
for ($j = 0; $j < $this->nAction; $j++) {
if (!isset($this->aAction[$j])) {
$this->aAction[$j] = array(
'lookahead' => -1,
'action' => -1,
);
}
if ($this->aAction[$j]['lookahead'] < 0) {
continue;
}
if ($this->aAction[$j]['lookahead'] == $j +
$this->mnLookahead - $i) {
$n++;
}
}
if ($n == $this->nLookahead) {
break; /* Same as a prior transaction set */
}
}
}
/* Insert transaction set at index i. */
for ($j = 0; $j < $this->nLookahead; $j++) {
if (!isset($this->aLookahead[$j])) {
$this->aLookahead[$j] = array(
'lookahead' => 0,
'action' => 0,
);
}
$k = $this->aLookahead[$j]['lookahead'] - $this->mnLookahead + $i;
$this->aAction[$k] = $this->aLookahead[$j];
if ($k >= $this->nAction) {
$this->nAction = $k + 1;
}
}
$this->nLookahead = 0;
$this->aLookahead = array();
/* Return the offset that is added to the lookahead in order to get the
** index into yy_action of the action */
return $i - $this->mnLookahead;
}
}
|
