-
Notifications
You must be signed in to change notification settings - Fork 14
/
Lexer.php
409 lines (359 loc) · 8.4 KB
/
Lexer.php
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
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
<?php
/*
* This file is part of Spoon Library.
*
* (c) Davy Hellemans <davy@spoon-library.com>
*
* For the full copyright and license information, please view the license
* file that was distributed with this source code.
*/
namespace Spoon\Template;
/**
* Creates an array of token objects from source code.
*
* @author Davy Hellemans <davy@spoon-library.com>
*/
class Lexer
{
/**
* Regexes used for lexing the template source code.
*
* @var string
*/
const REGEX_NAME = '/\$?[A-Za-z_][A-Za-z0-9_]*/A';
const REGEX_NUMBER = '/[0-9]+(?:\.[0-9]+)?/A';
const REGEX_STRING = '/"([^"\\\\]*(?:\\\\.[^"\\\\]*)*)"|\'([^\'\\\\]*(?:\\\\.[^\'\\\\]*)*)\'/As';
/**
* List of punctuation characters.
*
* @var string
*/
const PUNCTUATION = '()[]{}?:.,|';
/**
* Lexing states, based on the template source code.
*
* @var string
*/
const STATE_BLOCK = 'block';
const STATE_DATA = 'data';
const STATE_VAR = 'var';
/**
* Keeps track of the opened/closed brackets in the source code.
*
* @var array
*/
protected $brackets;
/**
* Current cursor position.
*
* @var int
*/
protected $cursor;
/**
* Total number of characters in the source.
*
* @var int
*/
protected $end;
/**
* The template environment.
*
* @var \Spoon\Template\Environment
*/
protected $environment;
/**
* Optional filename for this source you want to tokenize.
*
* @var string
*/
protected $filename;
/**
* Current line number.
*
* @var int
*/
protected $line;
/**
* The template source code to lex.
*
* @var string
*/
protected $source;
/**
* The current lexing state.
*
* @var string
*/
protected $state;
/**
* The type of start/end tags used for lexing.
*
* @var array
*/
protected $tags = array(
'comment' => array('{*', '*}'),
'block' => array('{%', '%}'),
'variable' => array('{$', '}')
);
/**
* The list of all tokens found in the template source code.
*
* @var array
*/
protected $tokens;
/**
* @param \Spoon\Template\Environment $environment
*/
public function __construct(Environment $environment)
{
$this->environment = $environment;
}
/**
* Adds a new token to the list.
*
* @param string $type
* @param mixed[optional] $value
*/
protected function addToken($type, $value = null)
{
// text tokens must have a value
if($type == Token::TEXT && $value == '')
{
return;
}
$this->tokens[] = new Token($type, $value, $this->line);
}
/**
* Processes a block.
*/
protected function processBlock()
{
// matching end comment tag has been found
if(preg_match('/\s*\%\}\s*\n?/A', $this->source, $match, null, $this->cursor))
{
$this->addToken(Token::BLOCK_END);
$this->moveCursor($match[0]);
$this->state = self::STATE_DATA;
}
else $this->processExpression();
}
/**
* Processes a comment.
*/
protected function processComment()
{
if(!preg_match('/(?:\*\}\s*|\*\})\n?/s', $this->source, $match, PREG_OFFSET_CAPTURE, $this->cursor))
{
throw new SyntaxError('Unclosed comment', $this->line, $this->filename);
}
$this->moveCursor(
mb_substr(
$this->source, $this->cursor,
$match[0][1] - $this->cursor,
$this->environment->getCharset()
) . $match[0][0]
);
}
/**
* Processes data.
*/
protected function processData()
{
$position = $this->end;
// find comment, variable or block
foreach(array('comment', 'variable', 'block') as $type)
{
$tmpPosition = mb_strpos(
$this->source,
$this->tags[$type][0],
$this->cursor,
$this->environment->getCharset()
);
if($tmpPosition !== false && $tmpPosition < $position)
{
$position = $tmpPosition;
$token = $this->tags[$type][0];
}
}
// no matches found, return the rest of the template as text token
if($position === $this->end)
{
$this->addToken(
Token::TEXT,
mb_substr(
$this->source,
$this->cursor,
$this->end,
$this->environment->getCharset()
)
);
$this->cursor = $this->end;
return;
}
// push the template text first
$text = mb_substr(
$this->source,
$this->cursor,
$position - $this->cursor,
$this->environment->getCharset()
);
$this->addToken(Token::TEXT, $text);
$this->moveCursor($text . $token);
switch($token)
{
case '{*':
$this->processComment();
break;
case '{$':
$this->addToken(Token::VAR_START);
$this->state = self::STATE_VAR;
break;
case '{%':
$this->addToken(Token::BLOCK_START);
$this->state = self::STATE_BLOCK;
break;
}
}
/**
* Process an expression.
*/
protected function processExpression()
{
// used to ignore spaces at stupid places
if(preg_match('/\s+/A', $this->source, $match, null, $this->cursor))
{
$this->moveCursor($match[0]);
// we still expect something, but the source seems to end
if($this->cursor >= $this->end)
{
throw new SyntaxError(
sprintf('Unexpected end of file: Unclosed "%s"',
$this->state === self::STATE_BLOCK ? 'block' : 'variable'
),
$this->line,
$this->filename
);
}
}
/*
* Expression regex pattern for:
* or, and, not, ==, !=, <, >, >=, <=, +, -, *, /, %, ~
*/
$pattern = '/and(?=[ ()])|\>\=|\<\=|\!\=|\=\=|not|or(?=[ ()])|%|\+|\-|\/|\>|\<|~|\*/A';
// operators
if(preg_match($pattern, $this->source, $match, null, $this->cursor))
{
$this->addToken(Token::OPERATOR, $match[0]);
$this->moveCursor($match[0]);
}
// names
elseif(preg_match(self::REGEX_NAME, $this->source, $match, null, $this->cursor))
{
$this->addToken(Token::NAME, $match[0]);
$this->moveCursor($match[0]);
}
// numbers
elseif(preg_match(self::REGEX_NUMBER, $this->source, $match, null, $this->cursor))
{
$this->addToken(Token::NUMBER, ctype_digit($match[0]) ? (int) $match[0] : (float) $match[0]);
$this->moveCursor($match[0]);
}
// punctuation
elseif(strpos(self::PUNCTUATION, $this->source[$this->cursor]) !== false)
{
// opening bracket
if(strpos('([{', $this->source[$this->cursor]) !== false)
{
$this->brackets[] = array($this->source[$this->cursor], $this->line);
}
// closing bracket
elseif(strpos(')]}', $this->source[$this->cursor]) !== false)
{
if(empty($this->brackets))
{
throw new SyntaxError(
sprintf('Unexpected "%s"', $this->source[$this->cursor]), $this->line, $this->filename
);
}
list($expect, $line) = array_pop($this->brackets);
if($this->source[$this->cursor] != strtr($expect, '([{', ')]}'))
{
throw new SyntaxError(
sprintf('Unclosed "%s"', $expect), $this->line, $this->filename
);
}
}
$this->addToken(Token::PUNCTUATION, $this->source[$this->cursor]);
++$this->cursor;
}
// strings
elseif(preg_match(self::REGEX_STRING, $this->source, $match, null, $this->cursor))
{
$this->addToken(Token::STRING, stripcslashes(substr($match[0], 1, -1)));
$this->moveCursor($match[0]);
}
// unlexable
else
{
throw new SyntaxError('The source can not be lexed.');
}
}
/**
* Process variable.
*/
protected function processVariable()
{
if(preg_match('/\}/A', $this->source, $match, null, $this->cursor))
{
$this->addToken(Token::VAR_END);
$this->moveCursor($match[0]);
$this->state = self::STATE_DATA;
}
else $this->processExpression();
}
/**
* Moves the cursor forward based on the string length of the first argument.
*
* @param string $text
*/
protected function moveCursor($text)
{
$this->cursor += mb_strlen($text, $this->environment->getCharset());
$this->line += mb_substr_count($text, "\n", $this->environment->getCharset());
}
/**
* Returns a stream of tokens found in the source.
*
* @param string $source
* @param string[optional] $filename
* @return \Spoon\Template\TokenStream
*/
public function tokenize($source, $filename = null)
{
$this->source = str_replace(array("\r\n", "\r"), "\n", $source);
$this->cursor = 0;
$this->line = 1;
$this->end = mb_strlen($this->source, $this->environment->getCharset());
$this->tokens = array();
$this->state = self::STATE_DATA;
$this->brackets = array();
$this->filename = $filename;
while($this->cursor < $this->end)
{
switch($this->state)
{
case self::STATE_DATA:
$this->processData();
break;
case self::STATE_BLOCK:
$this->processBlock();
break;
case self::STATE_VAR:
$this->processVariable();
break;
}
}
$this->addToken(Token::EOF);
return new TokenStream($this->tokens, $filename);
}
}