| 1 |
efrain |
1 |
<?php
|
|
|
2 |
|
|
|
3 |
/**
|
|
|
4 |
* PHP lexer code snarfed from the CVS tree for the lamplib project at
|
|
|
5 |
* http://sourceforge.net/projects/lamplib
|
|
|
6 |
* This project is administered by Markus Baker, Harry Fuecks and Matt
|
|
|
7 |
* Mitchell, and the project code is in the public domain.
|
|
|
8 |
*
|
|
|
9 |
* Thanks, guys!
|
|
|
10 |
*
|
|
|
11 |
* @package moodlecore
|
|
|
12 |
* @copyright Markus Baker, Harry Fuecks and Matt Mitchell
|
|
|
13 |
* @license Public Domain {@link http://sourceforge.net/projects/lamplib}
|
|
|
14 |
*/
|
|
|
15 |
|
|
|
16 |
/** LEXER_ENTER = 1 */
|
|
|
17 |
define("LEXER_ENTER", 1);
|
|
|
18 |
/** LEXER_MATCHED = 2 */
|
|
|
19 |
define("LEXER_MATCHED", 2);
|
|
|
20 |
/** LEXER_UNMATCHED = 3 */
|
|
|
21 |
define("LEXER_UNMATCHED", 3);
|
|
|
22 |
/** LEXER_EXIT = 4 */
|
|
|
23 |
define("LEXER_EXIT", 4);
|
|
|
24 |
/** LEXER_SPECIAL = 5 */
|
|
|
25 |
define("LEXER_SPECIAL", 5);
|
|
|
26 |
|
|
|
27 |
/**
|
|
|
28 |
* Compounded regular expression. Any of
|
|
|
29 |
* the contained patterns could match and
|
|
|
30 |
* when one does it's label is returned.
|
|
|
31 |
* @package moodlecore
|
|
|
32 |
* @copyright Markus Baker, Harry Fuecks and Matt Mitchell
|
|
|
33 |
* @license Public Domain {@link http://sourceforge.net/projects/lamplib}
|
|
|
34 |
*/
|
|
|
35 |
class ParallelRegex {
|
|
|
36 |
var $_patterns;
|
|
|
37 |
var $_labels;
|
|
|
38 |
var $_regex;
|
|
|
39 |
var $_case;
|
|
|
40 |
|
|
|
41 |
/**
|
|
|
42 |
* Constructor. Starts with no patterns.
|
|
|
43 |
* @param bool $case True for case sensitive, false
|
|
|
44 |
* for insensitive.
|
|
|
45 |
* @access public
|
|
|
46 |
*/
|
|
|
47 |
public function __construct($case) {
|
|
|
48 |
$this->_case = $case;
|
|
|
49 |
$this->_patterns = array();
|
|
|
50 |
$this->_labels = array();
|
|
|
51 |
$this->_regex = null;
|
|
|
52 |
}
|
|
|
53 |
|
|
|
54 |
/**
|
|
|
55 |
* Old syntax of class constructor. Deprecated in PHP7.
|
|
|
56 |
*
|
|
|
57 |
* @deprecated since Moodle 3.1
|
|
|
58 |
*/
|
|
|
59 |
public function ParallelRegex($case) {
|
|
|
60 |
debugging('Use of class name as constructor is deprecated', DEBUG_DEVELOPER);
|
|
|
61 |
self::__construct($case);
|
|
|
62 |
}
|
|
|
63 |
|
|
|
64 |
/**
|
|
|
65 |
* Adds a pattern with an optional label.
|
|
|
66 |
* @param string $pattern Perl style regex, but ( and )
|
|
|
67 |
* lose the usual meaning.
|
|
|
68 |
* @param string $label Label of regex to be returned
|
|
|
69 |
* on a match.
|
|
|
70 |
* @access public
|
|
|
71 |
*/
|
|
|
72 |
function addPattern($pattern, $label = true) {
|
|
|
73 |
$count = count($this->_patterns);
|
|
|
74 |
$this->_patterns[$count] = $pattern;
|
|
|
75 |
$this->_labels[$count] = $label;
|
|
|
76 |
$this->_regex = null;
|
|
|
77 |
}
|
|
|
78 |
|
|
|
79 |
/**
|
|
|
80 |
* Attempts to match all patterns at once against
|
|
|
81 |
* a string.
|
|
|
82 |
* @param string $subject String to match against.
|
|
|
83 |
* @param string $match First matched portion of
|
|
|
84 |
* subject.
|
|
|
85 |
* @return bool True on success.
|
|
|
86 |
* @access public
|
|
|
87 |
*/
|
|
|
88 |
function match($subject, &$match) {
|
|
|
89 |
if (count($this->_patterns) == 0) {
|
|
|
90 |
return false;
|
|
|
91 |
}
|
|
|
92 |
if (!preg_match($this->_getCompoundedRegex(), $subject, $matches)) {
|
|
|
93 |
$match = "";
|
|
|
94 |
return false;
|
|
|
95 |
}
|
|
|
96 |
$match = $matches[0];
|
|
|
97 |
for ($i = 1; $i < count($matches); $i++) {
|
|
|
98 |
if ($matches[$i]) {
|
|
|
99 |
return $this->_labels[$i - 1];
|
|
|
100 |
}
|
|
|
101 |
}
|
|
|
102 |
return true;
|
|
|
103 |
}
|
|
|
104 |
|
|
|
105 |
/**
|
|
|
106 |
* Compounds the patterns into a single
|
|
|
107 |
* regular expression separated with the
|
|
|
108 |
* "or" operator. Caches the regex.
|
|
|
109 |
* Will automatically escape (, ) and / tokens.
|
|
|
110 |
* @access private
|
|
|
111 |
*/
|
|
|
112 |
function _getCompoundedRegex() {
|
|
|
113 |
if ($this->_regex == null) {
|
|
|
114 |
for ($i = 0; $i < count($this->_patterns); $i++) {
|
|
|
115 |
$this->_patterns[$i] = '(' . str_replace(
|
|
|
116 |
array('/', '(', ')'),
|
|
|
117 |
array('\/', '\(', '\)'),
|
|
|
118 |
$this->_patterns[$i]) . ')';
|
|
|
119 |
}
|
|
|
120 |
$this->_regex = "/" . implode("|", $this->_patterns) . "/" . $this->_getPerlMatchingFlags();
|
|
|
121 |
}
|
|
|
122 |
return $this->_regex;
|
|
|
123 |
}
|
|
|
124 |
|
|
|
125 |
/**
|
|
|
126 |
* Accessor for perl regex mode flags to use.
|
|
|
127 |
* @return string Flags as string.
|
|
|
128 |
* @access private
|
|
|
129 |
*/
|
|
|
130 |
function _getPerlMatchingFlags() {
|
|
|
131 |
return ($this->_case ? "msS" : "msSi");
|
|
|
132 |
}
|
|
|
133 |
}
|
|
|
134 |
|
|
|
135 |
/**
|
|
|
136 |
* States for a stack machine.
|
|
|
137 |
*
|
|
|
138 |
* @package moodlecore
|
|
|
139 |
* @copyright Markus Baker, Harry Fuecks and Matt Mitchell
|
|
|
140 |
* @license Public Domain {@link http://sourceforge.net/projects/lamplib}
|
|
|
141 |
*/
|
|
|
142 |
class StateStack {
|
|
|
143 |
var $_stack;
|
|
|
144 |
|
|
|
145 |
/**
|
|
|
146 |
* Constructor. Starts in named state.
|
|
|
147 |
* @param string $start Starting state name.
|
|
|
148 |
* @access public
|
|
|
149 |
*/
|
|
|
150 |
public function __construct($start) {
|
|
|
151 |
$this->_stack = array($start);
|
|
|
152 |
}
|
|
|
153 |
|
|
|
154 |
/**
|
|
|
155 |
* Old syntax of class constructor. Deprecated in PHP7.
|
|
|
156 |
*
|
|
|
157 |
* @deprecated since Moodle 3.1
|
|
|
158 |
*/
|
|
|
159 |
public function StateStack($start) {
|
|
|
160 |
debugging('Use of class name as constructor is deprecated', DEBUG_DEVELOPER);
|
|
|
161 |
self::__construct($start);
|
|
|
162 |
}
|
|
|
163 |
|
|
|
164 |
/**
|
|
|
165 |
* Accessor for current state.
|
|
|
166 |
* @return string State as string.
|
|
|
167 |
* @access public
|
|
|
168 |
*/
|
|
|
169 |
function getCurrent() {
|
|
|
170 |
return $this->_stack[count($this->_stack) - 1];
|
|
|
171 |
}
|
|
|
172 |
|
|
|
173 |
/**
|
|
|
174 |
* Adds a state to the stack and sets it
|
|
|
175 |
* to be the current state.
|
|
|
176 |
* @param string $state New state.
|
|
|
177 |
* @access public
|
|
|
178 |
*/
|
|
|
179 |
function enter($state) {
|
|
|
180 |
array_push($this->_stack, $state);
|
|
|
181 |
}
|
|
|
182 |
|
|
|
183 |
/**
|
|
|
184 |
* Leaves the current state and reverts
|
|
|
185 |
* to the previous one.
|
|
|
186 |
* @return bool False if we drop off
|
|
|
187 |
* the bottom of the list.
|
|
|
188 |
* @access public
|
|
|
189 |
*/
|
|
|
190 |
function leave() {
|
|
|
191 |
if (count($this->_stack) == 1) {
|
|
|
192 |
return false;
|
|
|
193 |
}
|
|
|
194 |
array_pop($this->_stack);
|
|
|
195 |
return true;
|
|
|
196 |
}
|
|
|
197 |
}
|
|
|
198 |
|
|
|
199 |
/**
|
|
|
200 |
* Accepts text and breaks it into tokens.
|
|
|
201 |
* Some optimisation to make the sure the
|
|
|
202 |
* content is only scanned by the PHP regex
|
|
|
203 |
* parser once. Lexer modes must not start
|
|
|
204 |
* with leading underscores.
|
|
|
205 |
*
|
|
|
206 |
* @package moodlecore
|
|
|
207 |
* @copyright Markus Baker, Harry Fuecks and Matt Mitchell
|
|
|
208 |
* @license Public Domain {@link http://sourceforge.net/projects/lamplib}
|
|
|
209 |
*/
|
|
|
210 |
class Lexer {
|
|
|
211 |
var $_regexes;
|
|
|
212 |
var $_parser;
|
|
|
213 |
var $_mode;
|
|
|
214 |
var $_mode_handlers;
|
|
|
215 |
var $_case;
|
|
|
216 |
|
|
|
217 |
/**
|
|
|
218 |
* Sets up the lexer in case insensitive matching
|
|
|
219 |
* by default.
|
|
|
220 |
* @param object $parser Handling strategy by
|
|
|
221 |
* reference.
|
|
|
222 |
* @param string $start Starting handler.
|
|
|
223 |
* @param bool $case True for case sensitive.
|
|
|
224 |
* @access public
|
|
|
225 |
*/
|
|
|
226 |
public function __construct(&$parser, $start = "accept", $case = false) {
|
|
|
227 |
$this->_case = $case;
|
|
|
228 |
$this->_regexes = array();
|
|
|
229 |
$this->_parser = &$parser;
|
|
|
230 |
$this->_mode = new StateStack($start);
|
|
|
231 |
$this->_mode_handlers = array();
|
|
|
232 |
}
|
|
|
233 |
|
|
|
234 |
/**
|
|
|
235 |
* Old syntax of class constructor. Deprecated in PHP7.
|
|
|
236 |
*
|
|
|
237 |
* @deprecated since Moodle 3.1
|
|
|
238 |
*/
|
|
|
239 |
public function Lexer(&$parser, $start = "accept", $case = false) {
|
|
|
240 |
debugging('Use of class name as constructor is deprecated', DEBUG_DEVELOPER);
|
|
|
241 |
self::__construct($parser, $start, $case);
|
|
|
242 |
}
|
|
|
243 |
|
|
|
244 |
/**
|
|
|
245 |
* Adds a token search pattern for a particular
|
|
|
246 |
* parsing mode. The pattern does not change the
|
|
|
247 |
* current mode.
|
|
|
248 |
* @param string $pattern Perl style regex, but ( and )
|
|
|
249 |
* lose the usual meaning.
|
|
|
250 |
* @param string $mode Should only apply this
|
|
|
251 |
* pattern when dealing with
|
|
|
252 |
* this type of input.
|
|
|
253 |
* @access public
|
|
|
254 |
*/
|
|
|
255 |
function addPattern($pattern, $mode = "accept") {
|
|
|
256 |
if (!isset($this->_regexes[$mode])) {
|
|
|
257 |
$this->_regexes[$mode] = new ParallelRegex($this->_case);
|
|
|
258 |
}
|
|
|
259 |
$this->_regexes[$mode]->addPattern($pattern);
|
|
|
260 |
}
|
|
|
261 |
|
|
|
262 |
/**
|
|
|
263 |
* Adds a pattern that will enter a new parsing
|
|
|
264 |
* mode. Useful for entering parenthesis, strings,
|
|
|
265 |
* tags, etc.
|
|
|
266 |
* @param string $pattern Perl style regex, but ( and )
|
|
|
267 |
* lose the usual meaning.
|
|
|
268 |
* @param string $mode Should only apply this
|
|
|
269 |
* pattern when dealing with
|
|
|
270 |
* this type of input.
|
|
|
271 |
* @param string $new_mode Change parsing to this new
|
|
|
272 |
* nested mode.
|
|
|
273 |
* @access public
|
|
|
274 |
*/
|
|
|
275 |
function addEntryPattern($pattern, $mode, $new_mode) {
|
|
|
276 |
if (!isset($this->_regexes[$mode])) {
|
|
|
277 |
$this->_regexes[$mode] = new ParallelRegex($this->_case);
|
|
|
278 |
}
|
|
|
279 |
$this->_regexes[$mode]->addPattern($pattern, $new_mode);
|
|
|
280 |
}
|
|
|
281 |
|
|
|
282 |
/**
|
|
|
283 |
* Adds a pattern that will exit the current mode
|
|
|
284 |
* and re-enter the previous one.
|
|
|
285 |
* @param string $pattern Perl style regex, but ( and )
|
|
|
286 |
* lose the usual meaning.
|
|
|
287 |
* @param string $mode Mode to leave.
|
|
|
288 |
* @access public
|
|
|
289 |
*/
|
|
|
290 |
function addExitPattern($pattern, $mode) {
|
|
|
291 |
if (!isset($this->_regexes[$mode])) {
|
|
|
292 |
$this->_regexes[$mode] = new ParallelRegex($this->_case);
|
|
|
293 |
}
|
|
|
294 |
$this->_regexes[$mode]->addPattern($pattern, "__exit");
|
|
|
295 |
}
|
|
|
296 |
|
|
|
297 |
/**
|
|
|
298 |
* Adds a pattern that has a special mode.
|
|
|
299 |
* Acts as an entry and exit pattern in one go.
|
|
|
300 |
* @param string $pattern Perl style regex, but ( and )
|
|
|
301 |
* lose the usual meaning.
|
|
|
302 |
* @param string $mode Should only apply this
|
|
|
303 |
* pattern when dealing with
|
|
|
304 |
* this type of input.
|
|
|
305 |
* @param string $special Use this mode for this one token.
|
|
|
306 |
* @access public
|
|
|
307 |
*/
|
|
|
308 |
function addSpecialPattern($pattern, $mode, $special) {
|
|
|
309 |
if (!isset($this->_regexes[$mode])) {
|
|
|
310 |
$this->_regexes[$mode] = new ParallelRegex($this->_case);
|
|
|
311 |
}
|
|
|
312 |
$this->_regexes[$mode]->addPattern($pattern, "_$special");
|
|
|
313 |
}
|
|
|
314 |
|
|
|
315 |
/**
|
|
|
316 |
* Adds a mapping from a mode to another handler.
|
|
|
317 |
* @param string $mode Mode to be remapped.
|
|
|
318 |
* @param string $handler New target handler.
|
|
|
319 |
* @access public
|
|
|
320 |
*/
|
|
|
321 |
function mapHandler($mode, $handler) {
|
|
|
322 |
$this->_mode_handlers[$mode] = $handler;
|
|
|
323 |
}
|
|
|
324 |
|
|
|
325 |
/**
|
|
|
326 |
* Splits the page text into tokens. Will fail
|
|
|
327 |
* if the handlers report an error or if no
|
|
|
328 |
* content is consumed. If successful then each
|
|
|
329 |
* unparsed and parsed token invokes a call to the
|
|
|
330 |
* held listener.
|
|
|
331 |
* @param string $raw Raw HTML text.
|
|
|
332 |
* @return bool True on success, else false.
|
|
|
333 |
* @access public
|
|
|
334 |
*/
|
|
|
335 |
function parse($raw) {
|
|
|
336 |
if (!isset($this->_parser)) {
|
|
|
337 |
return false;
|
|
|
338 |
}
|
|
|
339 |
$length = strlen($raw);
|
|
|
340 |
while (is_array($parsed = $this->_reduce($raw))) {
|
|
|
341 |
list($unmatched, $matched, $mode) = $parsed;
|
|
|
342 |
if (!$this->_dispatchTokens($unmatched, $matched, $mode)) {
|
|
|
343 |
return false;
|
|
|
344 |
}
|
|
|
345 |
if (strlen($raw) == $length) {
|
|
|
346 |
return false;
|
|
|
347 |
}
|
|
|
348 |
$length = strlen($raw);
|
|
|
349 |
}
|
|
|
350 |
if (!$parsed) {
|
|
|
351 |
return false;
|
|
|
352 |
}
|
|
|
353 |
return $this->_invokeParser($raw, LEXER_UNMATCHED);
|
|
|
354 |
}
|
|
|
355 |
|
|
|
356 |
/**
|
|
|
357 |
* Sends the matched token and any leading unmatched
|
|
|
358 |
* text to the parser changing the lexer to a new
|
|
|
359 |
* mode if one is listed.
|
|
|
360 |
* @param string $unmatched Unmatched leading portion.
|
|
|
361 |
* @param string $matched Actual token match.
|
|
|
362 |
* @param string $mode Mode after match. The "_exit"
|
|
|
363 |
* mode causes a stack pop. An
|
|
|
364 |
* false mode causes no change.
|
|
|
365 |
* @return bool False if there was any error
|
|
|
366 |
* from the parser.
|
|
|
367 |
* @access private
|
|
|
368 |
*/
|
|
|
369 |
function _dispatchTokens($unmatched, $matched, $mode = false) {
|
|
|
370 |
if (!$this->_invokeParser($unmatched, LEXER_UNMATCHED)) {
|
|
|
371 |
return false;
|
|
|
372 |
}
|
|
|
373 |
if ($mode === "__exit") {
|
|
|
374 |
if (!$this->_invokeParser($matched, LEXER_EXIT)) {
|
|
|
375 |
return false;
|
|
|
376 |
}
|
|
|
377 |
return $this->_mode->leave();
|
|
|
378 |
}
|
|
|
379 |
if (strncmp($mode, "_", 1) == 0) {
|
|
|
380 |
$mode = substr($mode, 1);
|
|
|
381 |
$this->_mode->enter($mode);
|
|
|
382 |
if (!$this->_invokeParser($matched, LEXER_SPECIAL)) {
|
|
|
383 |
return false;
|
|
|
384 |
}
|
|
|
385 |
return $this->_mode->leave();
|
|
|
386 |
}
|
|
|
387 |
if (is_string($mode)) {
|
|
|
388 |
$this->_mode->enter($mode);
|
|
|
389 |
return $this->_invokeParser($matched, LEXER_ENTER);
|
|
|
390 |
}
|
|
|
391 |
return $this->_invokeParser($matched, LEXER_MATCHED);
|
|
|
392 |
}
|
|
|
393 |
|
|
|
394 |
/**
|
|
|
395 |
* Calls the parser method named after the current
|
|
|
396 |
* mode. Empty content will be ignored.
|
|
|
397 |
* @param string $content Text parsed.
|
|
|
398 |
* @param string $is_match Token is recognised rather
|
|
|
399 |
* than unparsed data.
|
|
|
400 |
* @access private
|
|
|
401 |
*/
|
|
|
402 |
function _invokeParser($content, $is_match) {
|
|
|
403 |
if (($content === "") || ($content === false)) {
|
|
|
404 |
return true;
|
|
|
405 |
}
|
|
|
406 |
$handler = $this->_mode->getCurrent();
|
|
|
407 |
if (isset($this->_mode_handlers[$handler])) {
|
|
|
408 |
$handler = $this->_mode_handlers[$handler];
|
|
|
409 |
}
|
|
|
410 |
return $this->_parser->$handler($content, $is_match);
|
|
|
411 |
}
|
|
|
412 |
|
|
|
413 |
/**
|
|
|
414 |
* Tries to match a chunk of text and if successful
|
|
|
415 |
* removes the recognised chunk and any leading
|
|
|
416 |
* unparsed data. Empty strings will not be matched.
|
|
|
417 |
* @param string $raw The subject to parse. This is the
|
|
|
418 |
* content that will be eaten.
|
|
|
419 |
* @return bool|array Three item list of unparsed
|
|
|
420 |
* content followed by the
|
|
|
421 |
* recognised token and finally the
|
|
|
422 |
* action the parser is to take.
|
|
|
423 |
* True if no match, false if there
|
|
|
424 |
* is a parsing error.
|
|
|
425 |
* @access private
|
|
|
426 |
*/
|
|
|
427 |
function _reduce(&$raw) {
|
|
|
428 |
if (!isset($this->_regexes[$this->_mode->getCurrent()])) {
|
|
|
429 |
return false;
|
|
|
430 |
}
|
|
|
431 |
if ($raw === "") {
|
|
|
432 |
return true;
|
|
|
433 |
}
|
|
|
434 |
if ($action = $this->_regexes[$this->_mode->getCurrent()]->match($raw, $match)) {
|
|
|
435 |
$count = strpos($raw, $match);
|
|
|
436 |
$unparsed = substr($raw, 0, $count);
|
|
|
437 |
$raw = substr($raw, $count + strlen($match));
|
|
|
438 |
return array($unparsed, $match, $action);
|
|
|
439 |
}
|
|
|
440 |
return true;
|
|
|
441 |
}
|
|
|
442 |
}
|
|
|
443 |
?>
|