regjsgen.js
10.9 KB
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
/*!
* regjsgen 0.5.2
* Copyright 2014-2020 Benjamin Tan <https://ofcr.se/>
* Available under the MIT license <https://github.com/bnjmnt4n/regjsgen/blob/master/LICENSE-MIT.txt>
*/
;(function() {
'use strict';
// Used to determine if values are of the language type `Object`.
var objectTypes = {
'function': true,
'object': true
};
// Used as a reference to the global object.
var root = (objectTypes[typeof window] && window) || this;
// Detect free variable `exports`.
var freeExports = objectTypes[typeof exports] && exports && !exports.nodeType && exports;
// Detect free variable `module`.
var hasFreeModule = objectTypes[typeof module] && module && !module.nodeType;
// Detect free variable `global` from Node.js or Browserified code and use it as `root`.
var freeGlobal = freeExports && hasFreeModule && typeof global == 'object' && global;
if (freeGlobal && (freeGlobal.global === freeGlobal || freeGlobal.window === freeGlobal || freeGlobal.self === freeGlobal)) {
root = freeGlobal;
}
// Used to check objects for own properties.
var hasOwnProperty = Object.prototype.hasOwnProperty;
/*--------------------------------------------------------------------------*/
// Generates a string based on the given code point.
// Based on https://mths.be/fromcodepoint by @mathias.
function fromCodePoint() {
var codePoint = Number(arguments[0]);
if (
!isFinite(codePoint) || // `NaN`, `+Infinity`, or `-Infinity`
codePoint < 0 || // not a valid Unicode code point
codePoint > 0x10FFFF || // not a valid Unicode code point
Math.floor(codePoint) != codePoint // not an integer
) {
throw RangeError('Invalid code point: ' + codePoint);
}
if (codePoint <= 0xFFFF) {
// BMP code point
return String.fromCharCode(codePoint);
} else {
// Astral code point; split in surrogate halves
// http://mathiasbynens.be/notes/javascript-encoding#surrogate-formulae
codePoint -= 0x10000;
var highSurrogate = (codePoint >> 10) + 0xD800;
var lowSurrogate = (codePoint % 0x400) + 0xDC00;
return String.fromCharCode(highSurrogate, lowSurrogate);
}
}
/*--------------------------------------------------------------------------*/
// Ensures that nodes have the correct types.
var assertTypeRegexMap = {};
function assertType(type, expected) {
if (expected.indexOf('|') == -1) {
if (type == expected) {
return;
}
throw Error('Invalid node type: ' + type + '; expected type: ' + expected);
}
expected = hasOwnProperty.call(assertTypeRegexMap, expected)
? assertTypeRegexMap[expected]
: (assertTypeRegexMap[expected] = RegExp('^(?:' + expected + ')$'));
if (expected.test(type)) {
return;
}
throw Error('Invalid node type: ' + type + '; expected types: ' + expected);
}
/*--------------------------------------------------------------------------*/
// Generates a regular expression string based on an AST.
function generate(node) {
var type = node.type;
if (hasOwnProperty.call(generators, type)) {
return generators[type](node);
}
throw Error('Invalid node type: ' + type);
}
// Constructs a string by concatentating the output of each term.
function generateSequence(generator, terms) {
var i = -1,
length = terms.length,
result = '',
term;
while (++i < length) {
term = terms[i];
// Ensure that `\0` null escapes followed by number symbols are not
// treated as backreferences.
if (
i + 1 < length &&
terms[i].type == 'value' &&
terms[i].kind == 'null' &&
terms[i + 1].type == 'value' &&
terms[i + 1].kind == 'symbol' &&
terms[i + 1].codePoint >= 48 &&
terms[i + 1].codePoint <= 57
) {
result += '\\000';
continue;
}
result += generator(term);
}
return result;
}
/*--------------------------------------------------------------------------*/
function generateAlternative(node) {
assertType(node.type, 'alternative');
return generateSequence(generateTerm, node.body);
}
function generateAnchor(node) {
assertType(node.type, 'anchor');
switch (node.kind) {
case 'start':
return '^';
case 'end':
return '$';
case 'boundary':
return '\\b';
case 'not-boundary':
return '\\B';
default:
throw Error('Invalid assertion');
}
}
function generateAtom(node) {
assertType(node.type, 'anchor|characterClass|characterClassEscape|dot|group|reference|value');
return generate(node);
}
function generateCharacterClass(node) {
assertType(node.type, 'characterClass');
return '[' +
(node.negative ? '^' : '') +
generateSequence(generateClassAtom, node.body) +
']';
}
function generateCharacterClassEscape(node) {
assertType(node.type, 'characterClassEscape');
return '\\' + node.value;
}
function generateCharacterClassRange(node) {
assertType(node.type, 'characterClassRange');
var min = node.min,
max = node.max;
if (min.type == 'characterClassRange' || max.type == 'characterClassRange') {
throw Error('Invalid character class range');
}
return generateClassAtom(min) + '-' + generateClassAtom(max);
}
function generateClassAtom(node) {
assertType(node.type, 'anchor|characterClassEscape|characterClassRange|dot|value');
return generate(node);
}
function generateDisjunction(node) {
assertType(node.type, 'disjunction');
var body = node.body,
i = -1,
length = body.length,
result = '';
while (++i < length) {
if (i != 0) {
result += '|';
}
result += generate(body[i]);
}
return result;
}
function generateDot(node) {
assertType(node.type, 'dot');
return '.';
}
function generateGroup(node) {
assertType(node.type, 'group');
var result = '';
switch (node.behavior) {
case 'normal':
if (node.name) {
result += '?<' + generateIdentifier(node.name) + '>';
}
break;
case 'ignore':
result += '?:';
break;
case 'lookahead':
result += '?=';
break;
case 'negativeLookahead':
result += '?!';
break;
case 'lookbehind':
result += '?<=';
break;
case 'negativeLookbehind':
result += '?<!';
break;
default:
throw Error('Invalid behaviour: ' + node.behaviour);
}
result += generateSequence(generate, node.body);
return '(' + result + ')';
}
function generateIdentifier(node) {
assertType(node.type, 'identifier');
return node.value;
}
function generateQuantifier(node) {
assertType(node.type, 'quantifier');
var quantifier = '',
min = node.min,
max = node.max;
if (max == null) {
if (min == 0) {
quantifier = '*';
} else if (min == 1) {
quantifier = '+';
} else {
quantifier = '{' + min + ',}';
}
} else if (min == max) {
quantifier = '{' + min + '}';
} else if (min == 0 && max == 1) {
quantifier = '?';
} else {
quantifier = '{' + min + ',' + max + '}';
}
if (!node.greedy) {
quantifier += '?';
}
return generateAtom(node.body[0]) + quantifier;
}
function generateReference(node) {
assertType(node.type, 'reference');
if (node.matchIndex) {
return '\\' + node.matchIndex;
}
if (node.name) {
return '\\k<' + generateIdentifier(node.name) + '>';
}
throw new Error('Unknown reference type');
}
function generateTerm(node) {
assertType(node.type, 'anchor|characterClass|characterClassEscape|empty|group|quantifier|reference|unicodePropertyEscape|value|dot');
return generate(node);
}
function generateUnicodePropertyEscape(node) {
assertType(node.type, 'unicodePropertyEscape');
return '\\' + (node.negative ? 'P' : 'p') + '{' + node.value + '}';
}
function generateValue(node) {
assertType(node.type, 'value');
var kind = node.kind,
codePoint = node.codePoint;
if (typeof codePoint != 'number') {
throw new Error('Invalid code point: ' + codePoint);
}
switch (kind) {
case 'controlLetter':
return '\\c' + fromCodePoint(codePoint + 64);
case 'hexadecimalEscape':
return '\\x' + ('00' + codePoint.toString(16).toUpperCase()).slice(-2);
case 'identifier':
return '\\' + fromCodePoint(codePoint);
case 'null':
return '\\' + codePoint;
case 'octal':
return '\\' + ('000' + codePoint.toString(8)).slice(-3);
case 'singleEscape':
switch (codePoint) {
case 0x0008:
return '\\b';
case 0x0009:
return '\\t';
case 0x000A:
return '\\n';
case 0x000B:
return '\\v';
case 0x000C:
return '\\f';
case 0x000D:
return '\\r';
case 0x002D:
return '\\-';
default:
throw Error('Invalid code point: ' + codePoint);
}
case 'symbol':
return fromCodePoint(codePoint);
case 'unicodeEscape':
return '\\u' + ('0000' + codePoint.toString(16).toUpperCase()).slice(-4);
case 'unicodeCodePointEscape':
return '\\u{' + codePoint.toString(16).toUpperCase() + '}';
default:
throw Error('Unsupported node kind: ' + kind);
}
}
/*--------------------------------------------------------------------------*/
// Used to generate strings for each node type.
var generators = {
'alternative': generateAlternative,
'anchor': generateAnchor,
'characterClass': generateCharacterClass,
'characterClassEscape': generateCharacterClassEscape,
'characterClassRange': generateCharacterClassRange,
'disjunction': generateDisjunction,
'dot': generateDot,
'group': generateGroup,
'quantifier': generateQuantifier,
'reference': generateReference,
'unicodePropertyEscape': generateUnicodePropertyEscape,
'value': generateValue
};
/*--------------------------------------------------------------------------*/
// Export regjsgen.
var regjsgen = {
'generate': generate
};
// Some AMD build optimizers, like r.js, check for condition patterns like the following:
if (typeof define == 'function' && typeof define.amd == 'object' && define.amd) {
// Define as an anonymous module so it can be aliased through path mapping.
define(function() {
return regjsgen;
});
root.regjsgen = regjsgen;
}
// Check for `exports` after `define` in case a build optimizer adds an `exports` object.
else if (freeExports && hasFreeModule) {
// Export for CommonJS support.
freeExports.generate = generate;
}
else {
// Export to the global object.
root.regjsgen = regjsgen;
}
}.call(this));