forked from CloudWright/filbert
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathindex.html
1334 lines (1255 loc) · 309 KB
/
index.html
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
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
<!DOCTYPE html> <html> <head> <title>acorn.js</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> <link rel="stylesheet" media="all" href="docco.css" /> </head> <body> <div id="container"> <div id="background"></div> <table cellpadding="0" cellspacing="0"> <thead> <tr> <th class="docs"> <h1> acorn.js </h1> </th> <th class="code"> </th> </tr> </thead> <tbody> <tr id="section-1"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-1">¶</a> </div> <p>Acorn is a tiny, fast JavaScript parser written in JavaScript.</p>
<p>Acorn was written by Marijn Haverbeke and released under an MIT
license. The Unicode regexps (for identifiers and whitespace) were
taken from <a href="http://esprima.org">Esprima</a> by Ariya Hidayat.</p>
<p>Git repositories for Acorn are available at</p>
<pre><code>http://marijnhaverbeke.nl/git/acorn
https://github.com/marijnh/acorn.git
</code></pre>
<p>Please use the <a href="https://github.com/marijnh/acorn/issues">github bug tracker</a> to report issues.</p>
<p>This file defines the main parser interface. The library also comes
with a <a href="acorn_loose.js">error-tolerant parser</a> and an
<a href="util/walk.js">abstract syntax tree walker</a>, defined in other files.</p> </td> <td class="code"> <div class="highlight"><pre><span class="p">(</span><span class="kd">function</span><span class="p">(</span><span class="nx">root</span><span class="p">,</span> <span class="nx">mod</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="k">typeof</span> <span class="nx">exports</span> <span class="o">==</span> <span class="s2">"object"</span> <span class="o">&&</span> <span class="k">typeof</span> <span class="nx">module</span> <span class="o">==</span> <span class="s2">"object"</span><span class="p">)</span> <span class="k">return</span> <span class="nx">mod</span><span class="p">(</span><span class="nx">exports</span><span class="p">);</span> <span class="c1">// CommonJS</span>
<span class="k">if</span> <span class="p">(</span><span class="k">typeof</span> <span class="nx">define</span> <span class="o">==</span> <span class="s2">"function"</span> <span class="o">&&</span> <span class="nx">define</span><span class="p">.</span><span class="nx">amd</span><span class="p">)</span> <span class="k">return</span> <span class="nx">define</span><span class="p">([</span><span class="s2">"exports"</span><span class="p">],</span> <span class="nx">mod</span><span class="p">);</span> <span class="c1">// AMD</span>
<span class="nx">mod</span><span class="p">(</span><span class="nx">root</span><span class="p">.</span><span class="nx">acorn</span> <span class="o">||</span> <span class="p">(</span><span class="nx">root</span><span class="p">.</span><span class="nx">acorn</span> <span class="o">=</span> <span class="p">{}));</span> <span class="c1">// Plain browser env</span>
<span class="p">})(</span><span class="k">this</span><span class="p">,</span> <span class="kd">function</span><span class="p">(</span><span class="nx">exports</span><span class="p">)</span> <span class="p">{</span>
<span class="s2">"use strict"</span><span class="p">;</span>
<span class="nx">exports</span><span class="p">.</span><span class="nx">version</span> <span class="o">=</span> <span class="s2">"0.4.1"</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-2"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-2">¶</a> </div> <p>The main exported interface (under <code>self.acorn</code> when in the
browser) is a <code>parse</code> function that takes a code string and
returns an abstract syntax tree as specified by <a href="https://developer.mozilla.org/en-US/docs/SpiderMonkey/Parser_API">Mozilla parser
API</a>, with the caveat that the SpiderMonkey-specific syntax
(<code>let</code>, <code>yield</code>, inline XML, etc) is not recognized.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">options</span><span class="p">,</span> <span class="nx">input</span><span class="p">,</span> <span class="nx">inputLen</span><span class="p">,</span> <span class="nx">sourceFile</span><span class="p">;</span>
<span class="nx">exports</span><span class="p">.</span><span class="nx">parse</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">inpt</span><span class="p">,</span> <span class="nx">opts</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">input</span> <span class="o">=</span> <span class="nb">String</span><span class="p">(</span><span class="nx">inpt</span><span class="p">);</span> <span class="nx">inputLen</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<span class="nx">setOptions</span><span class="p">(</span><span class="nx">opts</span><span class="p">);</span>
<span class="nx">initTokenState</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">parseTopLevel</span><span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">program</span><span class="p">);</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-3"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-3">¶</a> </div> <p>A second optional argument can be given to further configure
the parser process. These options are recognized:</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">defaultOptions</span> <span class="o">=</span> <span class="nx">exports</span><span class="p">.</span><span class="nx">defaultOptions</span> <span class="o">=</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-4"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-4">¶</a> </div> <p><code>ecmaVersion</code> indicates the ECMAScript version to parse. Must
be either 3 or 5. This
influences support for strict mode, the set of reserved words, and
support for getters and setter.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">ecmaVersion</span><span class="o">:</span> <span class="mi">5</span><span class="p">,</span></pre></div> </td> </tr> <tr id="section-5"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-5">¶</a> </div> <p>Turn on <code>strictSemicolons</code> to prevent the parser from doing
automatic semicolon insertion.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">strictSemicolons</span><span class="o">:</span> <span class="kc">false</span><span class="p">,</span></pre></div> </td> </tr> <tr id="section-6"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-6">¶</a> </div> <p>When <code>allowTrailingCommas</code> is false, the parser will not allow
trailing commas in array and object literals.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">allowTrailingCommas</span><span class="o">:</span> <span class="kc">true</span><span class="p">,</span></pre></div> </td> </tr> <tr id="section-7"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-7">¶</a> </div> <p>By default, reserved words are not enforced. Enable
<code>forbidReserved</code> to enforce them.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">forbidReserved</span><span class="o">:</span> <span class="kc">false</span><span class="p">,</span></pre></div> </td> </tr> <tr id="section-8"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-8">¶</a> </div> <p>When enabled, a return at the top level is not considered an
error.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">allowReturnOutsideFunction</span><span class="o">:</span> <span class="kc">false</span><span class="p">,</span></pre></div> </td> </tr> <tr id="section-9"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-9">¶</a> </div> <p>When <code>locations</code> is on, <code>loc</code> properties holding objects with
<code>start</code> and <code>end</code> properties in <code>{line, column}</code> form (with
line being 1-based and column 0-based) will be attached to the
nodes.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">locations</span><span class="o">:</span> <span class="kc">false</span><span class="p">,</span></pre></div> </td> </tr> <tr id="section-10"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-10">¶</a> </div> <p>A function can be passed as <code>onComment</code> option, which will
cause Acorn to call that function with <code>(block, text, start,
end)</code> parameters whenever a comment is skipped. <code>block</code> is a
boolean indicating whether this is a block (<code>/* */</code>) comment,
<code>text</code> is the content of the comment, and <code>start</code> and <code>end</code> are
character offsets that denote the start and end of the comment.
When the <code>locations</code> option is on, two more parameters are
passed, the full <code>{line, column}</code> locations of the start and
end of the comments. Note that you are not allowed to call the
parser from the callback—that will corrupt its internal state.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">onComment</span><span class="o">:</span> <span class="kc">null</span><span class="p">,</span></pre></div> </td> </tr> <tr id="section-11"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-11">¶</a> </div> <p>Nodes have their start and end characters offsets recorded in
<code>start</code> and <code>end</code> properties (directly on the node, rather than
the <code>loc</code> object, which holds line/column data. To also add a
<a href="https://bugzilla.mozilla.org/show_bug.cgi?id=745678">semi-standardized</a> <code>range</code> property holding a <code>[start,
end]</code> array with the same numbers, set the <code>ranges</code> option to
<code>true</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">ranges</span><span class="o">:</span> <span class="kc">false</span><span class="p">,</span></pre></div> </td> </tr> <tr id="section-12"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-12">¶</a> </div> <p>It is possible to parse multiple files into a single AST by
passing the tree produced by parsing the first file as
<code>program</code> option in subsequent parses. This will add the
toplevel forms of the parsed file to the <code>Program</code> (top) node
of an existing parse tree.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">program</span><span class="o">:</span> <span class="kc">null</span><span class="p">,</span></pre></div> </td> </tr> <tr id="section-13"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-13">¶</a> </div> <p>When <code>locations</code> is on, you can pass this to record the source
file in every node's <code>loc</code> object.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">sourceFile</span><span class="o">:</span> <span class="kc">null</span><span class="p">,</span></pre></div> </td> </tr> <tr id="section-14"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-14">¶</a> </div> <p>This value, if given, is stored in every node, whether
<code>locations</code> is on or off.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">directSourceFile</span><span class="o">:</span> <span class="kc">null</span>
<span class="p">};</span>
<span class="kd">function</span> <span class="nx">setOptions</span><span class="p">(</span><span class="nx">opts</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">options</span> <span class="o">=</span> <span class="nx">opts</span> <span class="o">||</span> <span class="p">{};</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">opt</span> <span class="k">in</span> <span class="nx">defaultOptions</span><span class="p">)</span> <span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nb">Object</span><span class="p">.</span><span class="nx">prototype</span><span class="p">.</span><span class="nx">hasOwnProperty</span><span class="p">.</span><span class="nx">call</span><span class="p">(</span><span class="nx">options</span><span class="p">,</span> <span class="nx">opt</span><span class="p">))</span>
<span class="nx">options</span><span class="p">[</span><span class="nx">opt</span><span class="p">]</span> <span class="o">=</span> <span class="nx">defaultOptions</span><span class="p">[</span><span class="nx">opt</span><span class="p">];</span>
<span class="nx">sourceFile</span> <span class="o">=</span> <span class="nx">options</span><span class="p">.</span><span class="nx">sourceFile</span> <span class="o">||</span> <span class="kc">null</span><span class="p">;</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-15"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-15">¶</a> </div> <p>The <code>getLineInfo</code> function is mostly useful when the
<code>locations</code> option is off (for performance reasons) and you
want to find the line/column position for a given character
offset. <code>input</code> should be the code string that the offset refers
into.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">getLineInfo</span> <span class="o">=</span> <span class="nx">exports</span><span class="p">.</span><span class="nx">getLineInfo</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">input</span><span class="p">,</span> <span class="nx">offset</span><span class="p">)</span> <span class="p">{</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">line</span> <span class="o">=</span> <span class="mi">1</span><span class="p">,</span> <span class="nx">cur</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;;)</span> <span class="p">{</span>
<span class="nx">lineBreak</span><span class="p">.</span><span class="nx">lastIndex</span> <span class="o">=</span> <span class="nx">cur</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">match</span> <span class="o">=</span> <span class="nx">lineBreak</span><span class="p">.</span><span class="nx">exec</span><span class="p">(</span><span class="nx">input</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">match</span> <span class="o">&&</span> <span class="nx">match</span><span class="p">.</span><span class="nx">index</span> <span class="o"><</span> <span class="nx">offset</span><span class="p">)</span> <span class="p">{</span>
<span class="o">++</span><span class="nx">line</span><span class="p">;</span>
<span class="nx">cur</span> <span class="o">=</span> <span class="nx">match</span><span class="p">.</span><span class="nx">index</span> <span class="o">+</span> <span class="nx">match</span><span class="p">[</span><span class="mi">0</span><span class="p">].</span><span class="nx">length</span><span class="p">;</span>
<span class="p">}</span> <span class="k">else</span> <span class="k">break</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">return</span> <span class="p">{</span><span class="nx">line</span><span class="o">:</span> <span class="nx">line</span><span class="p">,</span> <span class="nx">column</span><span class="o">:</span> <span class="nx">offset</span> <span class="o">-</span> <span class="nx">cur</span><span class="p">};</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-16"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-16">¶</a> </div> <p>Acorn is organized as a tokenizer and a recursive-descent parser.
The <code>tokenize</code> export provides an interface to the tokenizer.
Because the tokenizer is optimized for being efficiently used by
the Acorn parser itself, this interface is somewhat crude and not
very modular. Performing another parse or call to <code>tokenize</code> will
reset the internal state, and invalidate existing tokenizers.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">exports</span><span class="p">.</span><span class="nx">tokenize</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">inpt</span><span class="p">,</span> <span class="nx">opts</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">input</span> <span class="o">=</span> <span class="nb">String</span><span class="p">(</span><span class="nx">inpt</span><span class="p">);</span> <span class="nx">inputLen</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span>
<span class="nx">setOptions</span><span class="p">(</span><span class="nx">opts</span><span class="p">);</span>
<span class="nx">initTokenState</span><span class="p">();</span>
<span class="kd">var</span> <span class="nx">t</span> <span class="o">=</span> <span class="p">{};</span>
<span class="kd">function</span> <span class="nx">getToken</span><span class="p">(</span><span class="nx">forceRegexp</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">lastEnd</span> <span class="o">=</span> <span class="nx">tokEnd</span><span class="p">;</span>
<span class="nx">readToken</span><span class="p">(</span><span class="nx">forceRegexp</span><span class="p">);</span>
<span class="nx">t</span><span class="p">.</span><span class="nx">start</span> <span class="o">=</span> <span class="nx">tokStart</span><span class="p">;</span> <span class="nx">t</span><span class="p">.</span><span class="nx">end</span> <span class="o">=</span> <span class="nx">tokEnd</span><span class="p">;</span>
<span class="nx">t</span><span class="p">.</span><span class="nx">startLoc</span> <span class="o">=</span> <span class="nx">tokStartLoc</span><span class="p">;</span> <span class="nx">t</span><span class="p">.</span><span class="nx">endLoc</span> <span class="o">=</span> <span class="nx">tokEndLoc</span><span class="p">;</span>
<span class="nx">t</span><span class="p">.</span><span class="nx">type</span> <span class="o">=</span> <span class="nx">tokType</span><span class="p">;</span> <span class="nx">t</span><span class="p">.</span><span class="nx">value</span> <span class="o">=</span> <span class="nx">tokVal</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">t</span><span class="p">;</span>
<span class="p">}</span>
<span class="nx">getToken</span><span class="p">.</span><span class="nx">jumpTo</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">pos</span><span class="p">,</span> <span class="nx">reAllowed</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">tokPos</span> <span class="o">=</span> <span class="nx">pos</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">locations</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">tokCurLine</span> <span class="o">=</span> <span class="mi">1</span><span class="p">;</span>
<span class="nx">tokLineStart</span> <span class="o">=</span> <span class="nx">lineBreak</span><span class="p">.</span><span class="nx">lastIndex</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">match</span><span class="p">;</span>
<span class="k">while</span> <span class="p">((</span><span class="nx">match</span> <span class="o">=</span> <span class="nx">lineBreak</span><span class="p">.</span><span class="nx">exec</span><span class="p">(</span><span class="nx">input</span><span class="p">))</span> <span class="o">&&</span> <span class="nx">match</span><span class="p">.</span><span class="nx">index</span> <span class="o"><</span> <span class="nx">pos</span><span class="p">)</span> <span class="p">{</span>
<span class="o">++</span><span class="nx">tokCurLine</span><span class="p">;</span>
<span class="nx">tokLineStart</span> <span class="o">=</span> <span class="nx">match</span><span class="p">.</span><span class="nx">index</span> <span class="o">+</span> <span class="nx">match</span><span class="p">[</span><span class="mi">0</span><span class="p">].</span><span class="nx">length</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="nx">tokRegexpAllowed</span> <span class="o">=</span> <span class="nx">reAllowed</span><span class="p">;</span>
<span class="nx">skipSpace</span><span class="p">();</span>
<span class="p">};</span>
<span class="k">return</span> <span class="nx">getToken</span><span class="p">;</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-17"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-17">¶</a> </div> <p>State is kept in (closure-)global variables. We already saw the
<code>options</code>, <code>input</code>, and <code>inputLen</code> variables above.</p> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-18"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-18">¶</a> </div> <p>The current position of the tokenizer in the input.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">tokPos</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-19"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-19">¶</a> </div> <p>The start and end offsets of the current token.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">tokStart</span><span class="p">,</span> <span class="nx">tokEnd</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-20"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-20">¶</a> </div> <p>When <code>options.locations</code> is true, these hold objects
containing the tokens start and end line/column pairs.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">tokStartLoc</span><span class="p">,</span> <span class="nx">tokEndLoc</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-21"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-21">¶</a> </div> <p>The type and value of the current token. Token types are objects,
named by variables against which they can be compared, and
holding properties that describe them (indicating, for example,
the precedence of an infix operator, and the original name of a
keyword token). The kind of value that's held in <code>tokVal</code> depends
on the type of the token. For literals, it is the literal value,
for operators, the operator name, and so on.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">tokType</span><span class="p">,</span> <span class="nx">tokVal</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-22"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-22">¶</a> </div> <p>Interal state for the tokenizer. To distinguish between division
operators and regular expressions, it remembers whether the last
token was one that is allowed to be followed by an expression.
(If it is, a slash is probably a regexp, if it isn't it's a
division operator. See the <code>parseStatement</code> function for a
caveat.)</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">tokRegexpAllowed</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-23"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-23">¶</a> </div> <p>When <code>options.locations</code> is true, these are used to keep
track of the current line, and know when a new line has been
entered.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">tokCurLine</span><span class="p">,</span> <span class="nx">tokLineStart</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-24"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-24">¶</a> </div> <p>These store the position of the previous token, which is useful
when finishing a node and assigning its <code>end</code> position.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">lastStart</span><span class="p">,</span> <span class="nx">lastEnd</span><span class="p">,</span> <span class="nx">lastEndLoc</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-25"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-25">¶</a> </div> <p>This is the parser's state. <code>inFunction</code> is used to reject
<code>return</code> statements outside of functions, <code>labels</code> to verify that
<code>break</code> and <code>continue</code> have somewhere to jump to, and <code>strict</code>
indicates whether strict mode is on.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">inFunction</span><span class="p">,</span> <span class="nx">labels</span><span class="p">,</span> <span class="nx">strict</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-26"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-26">¶</a> </div> <p>This function is used to raise exceptions on parse errors. It
takes an offset integer (into the current <code>input</code>) to indicate
the location of the error, attaches the position to the end
of the error message, and then raises a <code>SyntaxError</code> with that
message.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">pos</span><span class="p">,</span> <span class="nx">message</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">loc</span> <span class="o">=</span> <span class="nx">getLineInfo</span><span class="p">(</span><span class="nx">input</span><span class="p">,</span> <span class="nx">pos</span><span class="p">);</span>
<span class="nx">message</span> <span class="o">+=</span> <span class="s2">" ("</span> <span class="o">+</span> <span class="nx">loc</span><span class="p">.</span><span class="nx">line</span> <span class="o">+</span> <span class="s2">":"</span> <span class="o">+</span> <span class="nx">loc</span><span class="p">.</span><span class="nx">column</span> <span class="o">+</span> <span class="s2">")"</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">err</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">SyntaxError</span><span class="p">(</span><span class="nx">message</span><span class="p">);</span>
<span class="nx">err</span><span class="p">.</span><span class="nx">pos</span> <span class="o">=</span> <span class="nx">pos</span><span class="p">;</span> <span class="nx">err</span><span class="p">.</span><span class="nx">loc</span> <span class="o">=</span> <span class="nx">loc</span><span class="p">;</span> <span class="nx">err</span><span class="p">.</span><span class="nx">raisedAt</span> <span class="o">=</span> <span class="nx">tokPos</span><span class="p">;</span>
<span class="k">throw</span> <span class="nx">err</span><span class="p">;</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-27"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-27">¶</a> </div> <p>Reused empty array added for node fields that are always empty.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">empty</span> <span class="o">=</span> <span class="p">[];</span></pre></div> </td> </tr> <tr id="section-28"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-28">¶</a> </div> <h2>Token types</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-29"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-29">¶</a> </div> <p>The assignment of fine-grained, information-carrying type objects
allows the tokenizer to store the information it has about a
token in a way that is very cheap for the parser to look up.</p> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-30"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-30">¶</a> </div> <p>All token type variables start with an underscore, to make them
easy to recognize.</p> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-31"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-31">¶</a> </div> <p>These are the general types. The <code>type</code> property is only used to
make them recognizeable when debugging.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">_num</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">"num"</span><span class="p">},</span> <span class="nx">_regexp</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">"regexp"</span><span class="p">},</span> <span class="nx">_string</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">"string"</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_name</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">"name"</span><span class="p">},</span> <span class="nx">_eof</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">"eof"</span><span class="p">};</span></pre></div> </td> </tr> <tr id="section-32"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-32">¶</a> </div> <p>Keyword tokens. The <code>keyword</code> property (also used in keyword-like
operators) indicates that the token originated from an
identifier-like word, which is used when parsing property names.</p>
<p>The <code>beforeExpr</code> property is used to disambiguate between regular
expressions and divisions. It is set on all token types that can
be followed by an expression (thus, a slash after them would be a
regular expression).</p>
<p><code>isLoop</code> marks a keyword as starting a loop, which is important
to know when parsing a label, in order to allow or disallow
continue jumps to that label.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">_break</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"break"</span><span class="p">},</span> <span class="nx">_case</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"case"</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span> <span class="nx">_catch</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"catch"</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_continue</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"continue"</span><span class="p">},</span> <span class="nx">_debugger</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"debugger"</span><span class="p">},</span> <span class="nx">_default</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"default"</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_do</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"do"</span><span class="p">,</span> <span class="nx">isLoop</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span> <span class="nx">_else</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"else"</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_finally</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"finally"</span><span class="p">},</span> <span class="nx">_for</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"for"</span><span class="p">,</span> <span class="nx">isLoop</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span> <span class="nx">_function</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"function"</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_if</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"if"</span><span class="p">},</span> <span class="nx">_return</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"return"</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span> <span class="nx">_switch</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"switch"</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_throw</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"throw"</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span> <span class="nx">_try</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"try"</span><span class="p">},</span> <span class="nx">_var</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"var"</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_while</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"while"</span><span class="p">,</span> <span class="nx">isLoop</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span> <span class="nx">_with</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"with"</span><span class="p">},</span> <span class="nx">_new</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"new"</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_this</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"this"</span><span class="p">};</span></pre></div> </td> </tr> <tr id="section-33"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-33">¶</a> </div> <p>The keywords that denote values.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">_null</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"null"</span><span class="p">,</span> <span class="nx">atomValue</span><span class="o">:</span> <span class="kc">null</span><span class="p">},</span> <span class="nx">_true</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"true"</span><span class="p">,</span> <span class="nx">atomValue</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_false</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"false"</span><span class="p">,</span> <span class="nx">atomValue</span><span class="o">:</span> <span class="kc">false</span><span class="p">};</span></pre></div> </td> </tr> <tr id="section-34"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-34">¶</a> </div> <p>Some keywords are treated as regular operators. <code>in</code> sometimes
(when parsing <code>for</code>) needs to be tested against specifically, so
we assign a variable name to it for quick comparing.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">_in</span> <span class="o">=</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"in"</span><span class="p">,</span> <span class="nx">binop</span><span class="o">:</span> <span class="mi">7</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span></pre></div> </td> </tr> <tr id="section-35"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-35">¶</a> </div> <p>Map keyword names to token types.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">keywordTypes</span> <span class="o">=</span> <span class="p">{</span><span class="s2">"break"</span><span class="o">:</span> <span class="nx">_break</span><span class="p">,</span> <span class="s2">"case"</span><span class="o">:</span> <span class="nx">_case</span><span class="p">,</span> <span class="s2">"catch"</span><span class="o">:</span> <span class="nx">_catch</span><span class="p">,</span>
<span class="s2">"continue"</span><span class="o">:</span> <span class="nx">_continue</span><span class="p">,</span> <span class="s2">"debugger"</span><span class="o">:</span> <span class="nx">_debugger</span><span class="p">,</span> <span class="s2">"default"</span><span class="o">:</span> <span class="nx">_default</span><span class="p">,</span>
<span class="s2">"do"</span><span class="o">:</span> <span class="nx">_do</span><span class="p">,</span> <span class="s2">"else"</span><span class="o">:</span> <span class="nx">_else</span><span class="p">,</span> <span class="s2">"finally"</span><span class="o">:</span> <span class="nx">_finally</span><span class="p">,</span> <span class="s2">"for"</span><span class="o">:</span> <span class="nx">_for</span><span class="p">,</span>
<span class="s2">"function"</span><span class="o">:</span> <span class="nx">_function</span><span class="p">,</span> <span class="s2">"if"</span><span class="o">:</span> <span class="nx">_if</span><span class="p">,</span> <span class="s2">"return"</span><span class="o">:</span> <span class="nx">_return</span><span class="p">,</span> <span class="s2">"switch"</span><span class="o">:</span> <span class="nx">_switch</span><span class="p">,</span>
<span class="s2">"throw"</span><span class="o">:</span> <span class="nx">_throw</span><span class="p">,</span> <span class="s2">"try"</span><span class="o">:</span> <span class="nx">_try</span><span class="p">,</span> <span class="s2">"var"</span><span class="o">:</span> <span class="nx">_var</span><span class="p">,</span> <span class="s2">"while"</span><span class="o">:</span> <span class="nx">_while</span><span class="p">,</span> <span class="s2">"with"</span><span class="o">:</span> <span class="nx">_with</span><span class="p">,</span>
<span class="s2">"null"</span><span class="o">:</span> <span class="nx">_null</span><span class="p">,</span> <span class="s2">"true"</span><span class="o">:</span> <span class="nx">_true</span><span class="p">,</span> <span class="s2">"false"</span><span class="o">:</span> <span class="nx">_false</span><span class="p">,</span> <span class="s2">"new"</span><span class="o">:</span> <span class="nx">_new</span><span class="p">,</span> <span class="s2">"in"</span><span class="o">:</span> <span class="nx">_in</span><span class="p">,</span>
<span class="s2">"instanceof"</span><span class="o">:</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"instanceof"</span><span class="p">,</span> <span class="nx">binop</span><span class="o">:</span> <span class="mi">7</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span> <span class="s2">"this"</span><span class="o">:</span> <span class="nx">_this</span><span class="p">,</span>
<span class="s2">"typeof"</span><span class="o">:</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"typeof"</span><span class="p">,</span> <span class="nx">prefix</span><span class="o">:</span> <span class="kc">true</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span>
<span class="s2">"void"</span><span class="o">:</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"void"</span><span class="p">,</span> <span class="nx">prefix</span><span class="o">:</span> <span class="kc">true</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span>
<span class="s2">"delete"</span><span class="o">:</span> <span class="p">{</span><span class="nx">keyword</span><span class="o">:</span> <span class="s2">"delete"</span><span class="p">,</span> <span class="nx">prefix</span><span class="o">:</span> <span class="kc">true</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">}};</span></pre></div> </td> </tr> <tr id="section-36"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-36">¶</a> </div> <p>Punctuation token types. Again, the <code>type</code> property is purely for debugging.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">_bracketL</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">"["</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span> <span class="nx">_bracketR</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">"]"</span><span class="p">},</span> <span class="nx">_braceL</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">"{"</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_braceR</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">"}"</span><span class="p">},</span> <span class="nx">_parenL</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">"("</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span> <span class="nx">_parenR</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">")"</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_comma</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">","</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span> <span class="nx">_semi</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">";"</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_colon</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">":"</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span> <span class="nx">_dot</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">"."</span><span class="p">},</span> <span class="nx">_question</span> <span class="o">=</span> <span class="p">{</span><span class="nx">type</span><span class="o">:</span> <span class="s2">"?"</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span></pre></div> </td> </tr> <tr id="section-37"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-37">¶</a> </div> <p>Operators. These carry several kinds of properties to help the
parser use them properly (the presence of these properties is
what categorizes them as operators).</p>
<p><code>binop</code>, when present, specifies that this operator is a binary
operator, and will refer to its precedence.</p>
<p><code>prefix</code> and <code>postfix</code> mark the operator as a prefix or postfix
unary operator. <code>isUpdate</code> specifies that the node produced by
the operator should be of type UpdateExpression rather than
simply UnaryExpression (<code>++</code> and <code>--</code>).</p>
<p><code>isAssign</code> marks all of <code>=</code>, <code>+=</code>, <code>-=</code> etcetera, which act as
binary operators with a very low precedence, that should result
in AssignmentExpression nodes.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">_slash</span> <span class="o">=</span> <span class="p">{</span><span class="nx">binop</span><span class="o">:</span> <span class="mi">10</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span> <span class="nx">_eq</span> <span class="o">=</span> <span class="p">{</span><span class="nx">isAssign</span><span class="o">:</span> <span class="kc">true</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_assign</span> <span class="o">=</span> <span class="p">{</span><span class="nx">isAssign</span><span class="o">:</span> <span class="kc">true</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_incDec</span> <span class="o">=</span> <span class="p">{</span><span class="nx">postfix</span><span class="o">:</span> <span class="kc">true</span><span class="p">,</span> <span class="nx">prefix</span><span class="o">:</span> <span class="kc">true</span><span class="p">,</span> <span class="nx">isUpdate</span><span class="o">:</span> <span class="kc">true</span><span class="p">},</span> <span class="nx">_prefix</span> <span class="o">=</span> <span class="p">{</span><span class="nx">prefix</span><span class="o">:</span> <span class="kc">true</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_logicalOR</span> <span class="o">=</span> <span class="p">{</span><span class="nx">binop</span><span class="o">:</span> <span class="mi">1</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_logicalAND</span> <span class="o">=</span> <span class="p">{</span><span class="nx">binop</span><span class="o">:</span> <span class="mi">2</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_bitwiseOR</span> <span class="o">=</span> <span class="p">{</span><span class="nx">binop</span><span class="o">:</span> <span class="mi">3</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_bitwiseXOR</span> <span class="o">=</span> <span class="p">{</span><span class="nx">binop</span><span class="o">:</span> <span class="mi">4</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_bitwiseAND</span> <span class="o">=</span> <span class="p">{</span><span class="nx">binop</span><span class="o">:</span> <span class="mi">5</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_equality</span> <span class="o">=</span> <span class="p">{</span><span class="nx">binop</span><span class="o">:</span> <span class="mi">6</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_relational</span> <span class="o">=</span> <span class="p">{</span><span class="nx">binop</span><span class="o">:</span> <span class="mi">7</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_bitShift</span> <span class="o">=</span> <span class="p">{</span><span class="nx">binop</span><span class="o">:</span> <span class="mi">8</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_plusMin</span> <span class="o">=</span> <span class="p">{</span><span class="nx">binop</span><span class="o">:</span> <span class="mi">9</span><span class="p">,</span> <span class="nx">prefix</span><span class="o">:</span> <span class="kc">true</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span>
<span class="kd">var</span> <span class="nx">_multiplyModulo</span> <span class="o">=</span> <span class="p">{</span><span class="nx">binop</span><span class="o">:</span> <span class="mi">10</span><span class="p">,</span> <span class="nx">beforeExpr</span><span class="o">:</span> <span class="kc">true</span><span class="p">};</span></pre></div> </td> </tr> <tr id="section-38"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-38">¶</a> </div> <p>Provide access to the token types for external users of the
tokenizer.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">exports</span><span class="p">.</span><span class="nx">tokTypes</span> <span class="o">=</span> <span class="p">{</span><span class="nx">bracketL</span><span class="o">:</span> <span class="nx">_bracketL</span><span class="p">,</span> <span class="nx">bracketR</span><span class="o">:</span> <span class="nx">_bracketR</span><span class="p">,</span> <span class="nx">braceL</span><span class="o">:</span> <span class="nx">_braceL</span><span class="p">,</span> <span class="nx">braceR</span><span class="o">:</span> <span class="nx">_braceR</span><span class="p">,</span>
<span class="nx">parenL</span><span class="o">:</span> <span class="nx">_parenL</span><span class="p">,</span> <span class="nx">parenR</span><span class="o">:</span> <span class="nx">_parenR</span><span class="p">,</span> <span class="nx">comma</span><span class="o">:</span> <span class="nx">_comma</span><span class="p">,</span> <span class="nx">semi</span><span class="o">:</span> <span class="nx">_semi</span><span class="p">,</span> <span class="nx">colon</span><span class="o">:</span> <span class="nx">_colon</span><span class="p">,</span>
<span class="nx">dot</span><span class="o">:</span> <span class="nx">_dot</span><span class="p">,</span> <span class="nx">question</span><span class="o">:</span> <span class="nx">_question</span><span class="p">,</span> <span class="nx">slash</span><span class="o">:</span> <span class="nx">_slash</span><span class="p">,</span> <span class="nx">eq</span><span class="o">:</span> <span class="nx">_eq</span><span class="p">,</span> <span class="nx">name</span><span class="o">:</span> <span class="nx">_name</span><span class="p">,</span> <span class="nx">eof</span><span class="o">:</span> <span class="nx">_eof</span><span class="p">,</span>
<span class="nx">num</span><span class="o">:</span> <span class="nx">_num</span><span class="p">,</span> <span class="nx">regexp</span><span class="o">:</span> <span class="nx">_regexp</span><span class="p">,</span> <span class="nx">string</span><span class="o">:</span> <span class="nx">_string</span><span class="p">};</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">kw</span> <span class="k">in</span> <span class="nx">keywordTypes</span><span class="p">)</span> <span class="nx">exports</span><span class="p">.</span><span class="nx">tokTypes</span><span class="p">[</span><span class="s2">"_"</span> <span class="o">+</span> <span class="nx">kw</span><span class="p">]</span> <span class="o">=</span> <span class="nx">keywordTypes</span><span class="p">[</span><span class="nx">kw</span><span class="p">];</span></pre></div> </td> </tr> <tr id="section-39"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-39">¶</a> </div> <p>This is a trick taken from Esprima. It turns out that, on
non-Chrome browsers, to check whether a string is in a set, a
predicate containing a big ugly <code>switch</code> statement is faster than
a regular expression, and on Chrome the two are about on par.
This function uses <code>eval</code> (non-lexical) to produce such a
predicate from a space-separated string of words.</p>
<p>It starts by sorting the words by length.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">makePredicate</span><span class="p">(</span><span class="nx">words</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">words</span> <span class="o">=</span> <span class="nx">words</span><span class="p">.</span><span class="nx">split</span><span class="p">(</span><span class="s2">" "</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">f</span> <span class="o">=</span> <span class="s2">""</span><span class="p">,</span> <span class="nx">cats</span> <span class="o">=</span> <span class="p">[];</span>
<span class="nx">out</span><span class="o">:</span> <span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="nx">i</span> <span class="o"><</span> <span class="nx">words</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span> <span class="o">++</span><span class="nx">i</span><span class="p">)</span> <span class="p">{</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">j</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="nx">j</span> <span class="o"><</span> <span class="nx">cats</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span> <span class="o">++</span><span class="nx">j</span><span class="p">)</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">cats</span><span class="p">[</span><span class="nx">j</span><span class="p">][</span><span class="mi">0</span><span class="p">].</span><span class="nx">length</span> <span class="o">==</span> <span class="nx">words</span><span class="p">[</span><span class="nx">i</span><span class="p">].</span><span class="nx">length</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">cats</span><span class="p">[</span><span class="nx">j</span><span class="p">].</span><span class="nx">push</span><span class="p">(</span><span class="nx">words</span><span class="p">[</span><span class="nx">i</span><span class="p">]);</span>
<span class="k">continue</span> <span class="nx">out</span><span class="p">;</span>
<span class="p">}</span>
<span class="nx">cats</span><span class="p">.</span><span class="nx">push</span><span class="p">([</span><span class="nx">words</span><span class="p">[</span><span class="nx">i</span><span class="p">]]);</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">compareTo</span><span class="p">(</span><span class="nx">arr</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">arr</span><span class="p">.</span><span class="nx">length</span> <span class="o">==</span> <span class="mi">1</span><span class="p">)</span> <span class="k">return</span> <span class="nx">f</span> <span class="o">+=</span> <span class="s2">"return str === "</span> <span class="o">+</span> <span class="nx">JSON</span><span class="p">.</span><span class="nx">stringify</span><span class="p">(</span><span class="nx">arr</span><span class="p">[</span><span class="mi">0</span><span class="p">])</span> <span class="o">+</span> <span class="s2">";"</span><span class="p">;</span>
<span class="nx">f</span> <span class="o">+=</span> <span class="s2">"switch(str){"</span><span class="p">;</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="nx">i</span> <span class="o"><</span> <span class="nx">arr</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span> <span class="o">++</span><span class="nx">i</span><span class="p">)</span> <span class="nx">f</span> <span class="o">+=</span> <span class="s2">"case "</span> <span class="o">+</span> <span class="nx">JSON</span><span class="p">.</span><span class="nx">stringify</span><span class="p">(</span><span class="nx">arr</span><span class="p">[</span><span class="nx">i</span><span class="p">])</span> <span class="o">+</span> <span class="s2">":"</span><span class="p">;</span>
<span class="nx">f</span> <span class="o">+=</span> <span class="s2">"return true}return false;"</span><span class="p">;</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-40"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-40">¶</a> </div> <p>When there are more than three length categories, an outer
switch first dispatches on the lengths, to save on comparisons.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="nx">cats</span><span class="p">.</span><span class="nx">length</span> <span class="o">></span> <span class="mi">3</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">cats</span><span class="p">.</span><span class="nx">sort</span><span class="p">(</span><span class="kd">function</span><span class="p">(</span><span class="nx">a</span><span class="p">,</span> <span class="nx">b</span><span class="p">)</span> <span class="p">{</span><span class="k">return</span> <span class="nx">b</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="nx">a</span><span class="p">.</span><span class="nx">length</span><span class="p">;});</span>
<span class="nx">f</span> <span class="o">+=</span> <span class="s2">"switch(str.length){"</span><span class="p">;</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="nx">i</span> <span class="o"><</span> <span class="nx">cats</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span> <span class="o">++</span><span class="nx">i</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">cat</span> <span class="o">=</span> <span class="nx">cats</span><span class="p">[</span><span class="nx">i</span><span class="p">];</span>
<span class="nx">f</span> <span class="o">+=</span> <span class="s2">"case "</span> <span class="o">+</span> <span class="nx">cat</span><span class="p">[</span><span class="mi">0</span><span class="p">].</span><span class="nx">length</span> <span class="o">+</span> <span class="s2">":"</span><span class="p">;</span>
<span class="nx">compareTo</span><span class="p">(</span><span class="nx">cat</span><span class="p">);</span>
<span class="p">}</span>
<span class="nx">f</span> <span class="o">+=</span> <span class="s2">"}"</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-41"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-41">¶</a> </div> <p>Otherwise, simply generate a flat <code>switch</code> statement.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
<span class="nx">compareTo</span><span class="p">(</span><span class="nx">words</span><span class="p">);</span>
<span class="p">}</span>
<span class="k">return</span> <span class="k">new</span> <span class="nb">Function</span><span class="p">(</span><span class="s2">"str"</span><span class="p">,</span> <span class="nx">f</span><span class="p">);</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-42"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-42">¶</a> </div> <p>The ECMAScript 3 reserved word list.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">isReservedWord3</span> <span class="o">=</span> <span class="nx">makePredicate</span><span class="p">(</span><span class="s2">"abstract boolean byte char class double enum export extends final float goto implements import int interface long native package private protected public short static super synchronized throws transient volatile"</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-43"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-43">¶</a> </div> <p>ECMAScript 5 reserved words.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">isReservedWord5</span> <span class="o">=</span> <span class="nx">makePredicate</span><span class="p">(</span><span class="s2">"class enum extends super const export import"</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-44"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-44">¶</a> </div> <p>The additional reserved words in strict mode.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">isStrictReservedWord</span> <span class="o">=</span> <span class="nx">makePredicate</span><span class="p">(</span><span class="s2">"implements interface let package private protected public static yield"</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-45"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-45">¶</a> </div> <p>The forbidden variable names in strict mode.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">isStrictBadIdWord</span> <span class="o">=</span> <span class="nx">makePredicate</span><span class="p">(</span><span class="s2">"eval arguments"</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-46"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-46">¶</a> </div> <p>And the keywords.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">isKeyword</span> <span class="o">=</span> <span class="nx">makePredicate</span><span class="p">(</span><span class="s2">"break case catch continue debugger default do else finally for function if return switch throw try var while with null true false instanceof typeof void delete new in this"</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-47"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-47">¶</a> </div> <h2>Character categories</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-48"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-48">¶</a> </div> <p>Big ugly regular expressions that match characters in the
whitespace, identifier, and identifier-start categories. These
are only applied when a character is found to actually have a
code point above 128.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">nonASCIIwhitespace</span> <span class="o">=</span> <span class="sr">/[\u1680\u180e\u2000-\u200a\u202f\u205f\u3000\ufeff]/</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">nonASCIIidentifierStartChars</span> <span class="o">=</span> <span class="s2">"\xaa\xb5\xba\xc0-\xd6\xd8-\xf6\xf8-\u02c1\u02c6-\u02d1\u02e0-\u02e4\u02ec\u02ee\u0370-\u0374\u0376\u0377\u037a-\u037d\u0386\u0388-\u038a\u038c\u038e-\u03a1\u03a3-\u03f5\u03f7-\u0481\u048a-\u0527\u0531-\u0556\u0559\u0561-\u0587\u05d0-\u05ea\u05f0-\u05f2\u0620-\u064a\u066e\u066f\u0671-\u06d3\u06d5\u06e5\u06e6\u06ee\u06ef\u06fa-\u06fc\u06ff\u0710\u0712-\u072f\u074d-\u07a5\u07b1\u07ca-\u07ea\u07f4\u07f5\u07fa\u0800-\u0815\u081a\u0824\u0828\u0840-\u0858\u08a0\u08a2-\u08ac\u0904-\u0939\u093d\u0950\u0958-\u0961\u0971-\u0977\u0979-\u097f\u0985-\u098c\u098f\u0990\u0993-\u09a8\u09aa-\u09b0\u09b2\u09b6-\u09b9\u09bd\u09ce\u09dc\u09dd\u09df-\u09e1\u09f0\u09f1\u0a05-\u0a0a\u0a0f\u0a10\u0a13-\u0a28\u0a2a-\u0a30\u0a32\u0a33\u0a35\u0a36\u0a38\u0a39\u0a59-\u0a5c\u0a5e\u0a72-\u0a74\u0a85-\u0a8d\u0a8f-\u0a91\u0a93-\u0aa8\u0aaa-\u0ab0\u0ab2\u0ab3\u0ab5-\u0ab9\u0abd\u0ad0\u0ae0\u0ae1\u0b05-\u0b0c\u0b0f\u0b10\u0b13-\u0b28\u0b2a-\u0b30\u0b32\u0b33\u0b35-\u0b39\u0b3d\u0b5c\u0b5d\u0b5f-\u0b61\u0b71\u0b83\u0b85-\u0b8a\u0b8e-\u0b90\u0b92-\u0b95\u0b99\u0b9a\u0b9c\u0b9e\u0b9f\u0ba3\u0ba4\u0ba8-\u0baa\u0bae-\u0bb9\u0bd0\u0c05-\u0c0c\u0c0e-\u0c10\u0c12-\u0c28\u0c2a-\u0c33\u0c35-\u0c39\u0c3d\u0c58\u0c59\u0c60\u0c61\u0c85-\u0c8c\u0c8e-\u0c90\u0c92-\u0ca8\u0caa-\u0cb3\u0cb5-\u0cb9\u0cbd\u0cde\u0ce0\u0ce1\u0cf1\u0cf2\u0d05-\u0d0c\u0d0e-\u0d10\u0d12-\u0d3a\u0d3d\u0d4e\u0d60\u0d61\u0d7a-\u0d7f\u0d85-\u0d96\u0d9a-\u0db1\u0db3-\u0dbb\u0dbd\u0dc0-\u0dc6\u0e01-\u0e30\u0e32\u0e33\u0e40-\u0e46\u0e81\u0e82\u0e84\u0e87\u0e88\u0e8a\u0e8d\u0e94-\u0e97\u0e99-\u0e9f\u0ea1-\u0ea3\u0ea5\u0ea7\u0eaa\u0eab\u0ead-\u0eb0\u0eb2\u0eb3\u0ebd\u0ec0-\u0ec4\u0ec6\u0edc-\u0edf\u0f00\u0f40-\u0f47\u0f49-\u0f6c\u0f88-\u0f8c\u1000-\u102a\u103f\u1050-\u1055\u105a-\u105d\u1061\u1065\u1066\u106e-\u1070\u1075-\u1081\u108e\u10a0-\u10c5\u10c7\u10cd\u10d0-\u10fa\u10fc-\u1248\u124a-\u124d\u1250-\u1256\u1258\u125a-\u125d\u1260-\u1288\u128a-\u128d\u1290-\u12b0\u12b2-\u12b5\u12b8-\u12be\u12c0\u12c2-\u12c5\u12c8-\u12d6\u12d8-\u1310\u1312-\u1315\u1318-\u135a\u1380-\u138f\u13a0-\u13f4\u1401-\u166c\u166f-\u167f\u1681-\u169a\u16a0-\u16ea\u16ee-\u16f0\u1700-\u170c\u170e-\u1711\u1720-\u1731\u1740-\u1751\u1760-\u176c\u176e-\u1770\u1780-\u17b3\u17d7\u17dc\u1820-\u1877\u1880-\u18a8\u18aa\u18b0-\u18f5\u1900-\u191c\u1950-\u196d\u1970-\u1974\u1980-\u19ab\u19c1-\u19c7\u1a00-\u1a16\u1a20-\u1a54\u1aa7\u1b05-\u1b33\u1b45-\u1b4b\u1b83-\u1ba0\u1bae\u1baf\u1bba-\u1be5\u1c00-\u1c23\u1c4d-\u1c4f\u1c5a-\u1c7d\u1ce9-\u1cec\u1cee-\u1cf1\u1cf5\u1cf6\u1d00-\u1dbf\u1e00-\u1f15\u1f18-\u1f1d\u1f20-\u1f45\u1f48-\u1f4d\u1f50-\u1f57\u1f59\u1f5b\u1f5d\u1f5f-\u1f7d\u1f80-\u1fb4\u1fb6-\u1fbc\u1fbe\u1fc2-\u1fc4\u1fc6-\u1fcc\u1fd0-\u1fd3\u1fd6-\u1fdb\u1fe0-\u1fec\u1ff2-\u1ff4\u1ff6-\u1ffc\u2071\u207f\u2090-\u209c\u2102\u2107\u210a-\u2113\u2115\u2119-\u211d\u2124\u2126\u2128\u212a-\u212d\u212f-\u2139\u213c-\u213f\u2145-\u2149\u214e\u2160-\u2188\u2c00-\u2c2e\u2c30-\u2c5e\u2c60-\u2ce4\u2ceb-\u2cee\u2cf2\u2cf3\u2d00-\u2d25\u2d27\u2d2d\u2d30-\u2d67\u2d6f\u2d80-\u2d96\u2da0-\u2da6\u2da8-\u2dae\u2db0-\u2db6\u2db8-\u2dbe\u2dc0-\u2dc6\u2dc8-\u2dce\u2dd0-\u2dd6\u2dd8-\u2dde\u2e2f\u3005-\u3007\u3021-\u3029\u3031-\u3035\u3038-\u303c\u3041-\u3096\u309d-\u309f\u30a1-\u30fa\u30fc-\u30ff\u3105-\u312d\u3131-\u318e\u31a0-\u31ba\u31f0-\u31ff\u3400-\u4db5\u4e00-\u9fcc\ua000-\ua48c\ua4d0-\ua4fd\ua500-\ua60c\ua610-\ua61f\ua62a\ua62b\ua640-\ua66e\ua67f-\ua697\ua6a0-\ua6ef\ua717-\ua71f\ua722-\ua788\ua78b-\ua78e\ua790-\ua793\ua7a0-\ua7aa\ua7f8-\ua801\ua803-\ua805\ua807-\ua80a\ua80c-\ua822\ua840-\ua873\ua882-\ua8b3\ua8f2-\ua8f7\ua8fb\ua90a-\ua925\ua930-\ua946\ua960-\ua97c\ua984-\ua9b2\ua9cf\uaa00-\uaa28\uaa40-\uaa42\uaa44-\uaa4b\uaa60-\uaa76\uaa7a\uaa80-\uaaaf\uaab1\uaab5\uaab6\uaab9-\uaabd\uaac0\uaac2\uaadb-\uaadd\uaae0-\uaaea\uaaf2-\uaaf4\uab01-\uab06\uab09-\uab0e\uab11-\uab16\uab20-\uab26\uab28-\uab2e\uabc0-\uabe2\uac00-\ud7a3\ud7b0-\ud7c6\ud7cb-\ud7fb\uf900-\ufa6d\ufa70-\ufad9\ufb00-\ufb06\ufb13-\ufb17\ufb1d\ufb1f-\ufb28\ufb2a-\ufb36\ufb38-\ufb3c\ufb3e\ufb40\ufb41\ufb43\ufb44\ufb46-\ufbb1\ufbd3-\ufd3d\ufd50-\ufd8f\ufd92-\ufdc7\ufdf0-\ufdfb\ufe70-\ufe74\ufe76-\ufefc\uff21-\uff3a\uff41-\uff5a\uff66-\uffbe\uffc2-\uffc7\uffca-\uffcf\uffd2-\uffd7\uffda-\uffdc"</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">nonASCIIidentifierChars</span> <span class="o">=</span> <span class="s2">"\u0300-\u036f\u0483-\u0487\u0591-\u05bd\u05bf\u05c1\u05c2\u05c4\u05c5\u05c7\u0610-\u061a\u0620-\u0649\u0672-\u06d3\u06e7-\u06e8\u06fb-\u06fc\u0730-\u074a\u0800-\u0814\u081b-\u0823\u0825-\u0827\u0829-\u082d\u0840-\u0857\u08e4-\u08fe\u0900-\u0903\u093a-\u093c\u093e-\u094f\u0951-\u0957\u0962-\u0963\u0966-\u096f\u0981-\u0983\u09bc\u09be-\u09c4\u09c7\u09c8\u09d7\u09df-\u09e0\u0a01-\u0a03\u0a3c\u0a3e-\u0a42\u0a47\u0a48\u0a4b-\u0a4d\u0a51\u0a66-\u0a71\u0a75\u0a81-\u0a83\u0abc\u0abe-\u0ac5\u0ac7-\u0ac9\u0acb-\u0acd\u0ae2-\u0ae3\u0ae6-\u0aef\u0b01-\u0b03\u0b3c\u0b3e-\u0b44\u0b47\u0b48\u0b4b-\u0b4d\u0b56\u0b57\u0b5f-\u0b60\u0b66-\u0b6f\u0b82\u0bbe-\u0bc2\u0bc6-\u0bc8\u0bca-\u0bcd\u0bd7\u0be6-\u0bef\u0c01-\u0c03\u0c46-\u0c48\u0c4a-\u0c4d\u0c55\u0c56\u0c62-\u0c63\u0c66-\u0c6f\u0c82\u0c83\u0cbc\u0cbe-\u0cc4\u0cc6-\u0cc8\u0cca-\u0ccd\u0cd5\u0cd6\u0ce2-\u0ce3\u0ce6-\u0cef\u0d02\u0d03\u0d46-\u0d48\u0d57\u0d62-\u0d63\u0d66-\u0d6f\u0d82\u0d83\u0dca\u0dcf-\u0dd4\u0dd6\u0dd8-\u0ddf\u0df2\u0df3\u0e34-\u0e3a\u0e40-\u0e45\u0e50-\u0e59\u0eb4-\u0eb9\u0ec8-\u0ecd\u0ed0-\u0ed9\u0f18\u0f19\u0f20-\u0f29\u0f35\u0f37\u0f39\u0f41-\u0f47\u0f71-\u0f84\u0f86-\u0f87\u0f8d-\u0f97\u0f99-\u0fbc\u0fc6\u1000-\u1029\u1040-\u1049\u1067-\u106d\u1071-\u1074\u1082-\u108d\u108f-\u109d\u135d-\u135f\u170e-\u1710\u1720-\u1730\u1740-\u1750\u1772\u1773\u1780-\u17b2\u17dd\u17e0-\u17e9\u180b-\u180d\u1810-\u1819\u1920-\u192b\u1930-\u193b\u1951-\u196d\u19b0-\u19c0\u19c8-\u19c9\u19d0-\u19d9\u1a00-\u1a15\u1a20-\u1a53\u1a60-\u1a7c\u1a7f-\u1a89\u1a90-\u1a99\u1b46-\u1b4b\u1b50-\u1b59\u1b6b-\u1b73\u1bb0-\u1bb9\u1be6-\u1bf3\u1c00-\u1c22\u1c40-\u1c49\u1c5b-\u1c7d\u1cd0-\u1cd2\u1d00-\u1dbe\u1e01-\u1f15\u200c\u200d\u203f\u2040\u2054\u20d0-\u20dc\u20e1\u20e5-\u20f0\u2d81-\u2d96\u2de0-\u2dff\u3021-\u3028\u3099\u309a\ua640-\ua66d\ua674-\ua67d\ua69f\ua6f0-\ua6f1\ua7f8-\ua800\ua806\ua80b\ua823-\ua827\ua880-\ua881\ua8b4-\ua8c4\ua8d0-\ua8d9\ua8f3-\ua8f7\ua900-\ua909\ua926-\ua92d\ua930-\ua945\ua980-\ua983\ua9b3-\ua9c0\uaa00-\uaa27\uaa40-\uaa41\uaa4c-\uaa4d\uaa50-\uaa59\uaa7b\uaae0-\uaae9\uaaf2-\uaaf3\uabc0-\uabe1\uabec\uabed\uabf0-\uabf9\ufb20-\ufb28\ufe00-\ufe0f\ufe20-\ufe26\ufe33\ufe34\ufe4d-\ufe4f\uff10-\uff19\uff3f"</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">nonASCIIidentifierStart</span> <span class="o">=</span> <span class="k">new</span> <span class="nb">RegExp</span><span class="p">(</span><span class="s2">"["</span> <span class="o">+</span> <span class="nx">nonASCIIidentifierStartChars</span> <span class="o">+</span> <span class="s2">"]"</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">nonASCIIidentifier</span> <span class="o">=</span> <span class="k">new</span> <span class="nb">RegExp</span><span class="p">(</span><span class="s2">"["</span> <span class="o">+</span> <span class="nx">nonASCIIidentifierStartChars</span> <span class="o">+</span> <span class="nx">nonASCIIidentifierChars</span> <span class="o">+</span> <span class="s2">"]"</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-49"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-49">¶</a> </div> <p>Whether a single character denotes a newline.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">newline</span> <span class="o">=</span> <span class="sr">/[\n\r\u2028\u2029]/</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-50"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-50">¶</a> </div> <p>Matches a whole line break (where CRLF is considered a single
line break). Used to count lines.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">lineBreak</span> <span class="o">=</span> <span class="sr">/\r\n|[\n\r\u2028\u2029]/g</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-51"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-51">¶</a> </div> <p>Test whether a given character code starts an identifier.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">isIdentifierStart</span> <span class="o">=</span> <span class="nx">exports</span><span class="p">.</span><span class="nx">isIdentifierStart</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">code</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">code</span> <span class="o"><</span> <span class="mi">65</span><span class="p">)</span> <span class="k">return</span> <span class="nx">code</span> <span class="o">===</span> <span class="mi">36</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">code</span> <span class="o"><</span> <span class="mi">91</span><span class="p">)</span> <span class="k">return</span> <span class="kc">true</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">code</span> <span class="o"><</span> <span class="mi">97</span><span class="p">)</span> <span class="k">return</span> <span class="nx">code</span> <span class="o">===</span> <span class="mi">95</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">code</span> <span class="o"><</span> <span class="mi">123</span><span class="p">)</span><span class="k">return</span> <span class="kc">true</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">code</span> <span class="o">>=</span> <span class="mh">0xaa</span> <span class="o">&&</span> <span class="nx">nonASCIIidentifierStart</span><span class="p">.</span><span class="nx">test</span><span class="p">(</span><span class="nb">String</span><span class="p">.</span><span class="nx">fromCharCode</span><span class="p">(</span><span class="nx">code</span><span class="p">));</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-52"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-52">¶</a> </div> <p>Test whether a given character is part of an identifier.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">isIdentifierChar</span> <span class="o">=</span> <span class="nx">exports</span><span class="p">.</span><span class="nx">isIdentifierChar</span> <span class="o">=</span> <span class="kd">function</span><span class="p">(</span><span class="nx">code</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">code</span> <span class="o"><</span> <span class="mi">48</span><span class="p">)</span> <span class="k">return</span> <span class="nx">code</span> <span class="o">===</span> <span class="mi">36</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">code</span> <span class="o"><</span> <span class="mi">58</span><span class="p">)</span> <span class="k">return</span> <span class="kc">true</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">code</span> <span class="o"><</span> <span class="mi">65</span><span class="p">)</span> <span class="k">return</span> <span class="kc">false</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">code</span> <span class="o"><</span> <span class="mi">91</span><span class="p">)</span> <span class="k">return</span> <span class="kc">true</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">code</span> <span class="o"><</span> <span class="mi">97</span><span class="p">)</span> <span class="k">return</span> <span class="nx">code</span> <span class="o">===</span> <span class="mi">95</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">code</span> <span class="o"><</span> <span class="mi">123</span><span class="p">)</span><span class="k">return</span> <span class="kc">true</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">code</span> <span class="o">>=</span> <span class="mh">0xaa</span> <span class="o">&&</span> <span class="nx">nonASCIIidentifier</span><span class="p">.</span><span class="nx">test</span><span class="p">(</span><span class="nb">String</span><span class="p">.</span><span class="nx">fromCharCode</span><span class="p">(</span><span class="nx">code</span><span class="p">));</span>
<span class="p">};</span></pre></div> </td> </tr> <tr id="section-53"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-53">¶</a> </div> <h2>Tokenizer</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-54"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-54">¶</a> </div> <p>These are used when <code>options.locations</code> is on, for the
<code>tokStartLoc</code> and <code>tokEndLoc</code> properties.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">line_loc_t</span><span class="p">()</span> <span class="p">{</span>
<span class="k">this</span><span class="p">.</span><span class="nx">line</span> <span class="o">=</span> <span class="nx">tokCurLine</span><span class="p">;</span>
<span class="k">this</span><span class="p">.</span><span class="nx">column</span> <span class="o">=</span> <span class="nx">tokPos</span> <span class="o">-</span> <span class="nx">tokLineStart</span><span class="p">;</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-55"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-55">¶</a> </div> <p>Reset the token state. Used at the start of a parse.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">initTokenState</span><span class="p">()</span> <span class="p">{</span>
<span class="nx">tokCurLine</span> <span class="o">=</span> <span class="mi">1</span><span class="p">;</span>
<span class="nx">tokPos</span> <span class="o">=</span> <span class="nx">tokLineStart</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
<span class="nx">tokRegexpAllowed</span> <span class="o">=</span> <span class="kc">true</span><span class="p">;</span>
<span class="nx">skipSpace</span><span class="p">();</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-56"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-56">¶</a> </div> <p>Called at the end of every token. Sets <code>tokEnd</code>, <code>tokVal</code>, and
<code>tokRegexpAllowed</code>, and skips the space after the token, so that
the next one's <code>tokStart</code> will point at the right position.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">type</span><span class="p">,</span> <span class="nx">val</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">tokEnd</span> <span class="o">=</span> <span class="nx">tokPos</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">locations</span><span class="p">)</span> <span class="nx">tokEndLoc</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">line_loc_t</span><span class="p">;</span>
<span class="nx">tokType</span> <span class="o">=</span> <span class="nx">type</span><span class="p">;</span>
<span class="nx">skipSpace</span><span class="p">();</span>
<span class="nx">tokVal</span> <span class="o">=</span> <span class="nx">val</span><span class="p">;</span>
<span class="nx">tokRegexpAllowed</span> <span class="o">=</span> <span class="nx">type</span><span class="p">.</span><span class="nx">beforeExpr</span><span class="p">;</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">skipBlockComment</span><span class="p">()</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">startLoc</span> <span class="o">=</span> <span class="nx">options</span><span class="p">.</span><span class="nx">onComment</span> <span class="o">&&</span> <span class="nx">options</span><span class="p">.</span><span class="nx">locations</span> <span class="o">&&</span> <span class="k">new</span> <span class="nx">line_loc_t</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">start</span> <span class="o">=</span> <span class="nx">tokPos</span><span class="p">,</span> <span class="nx">end</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">indexOf</span><span class="p">(</span><span class="s2">"*/"</span><span class="p">,</span> <span class="nx">tokPos</span> <span class="o">+=</span> <span class="mi">2</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">end</span> <span class="o">===</span> <span class="o">-</span><span class="mi">1</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">-</span> <span class="mi">2</span><span class="p">,</span> <span class="s2">"Unterminated comment"</span><span class="p">);</span>
<span class="nx">tokPos</span> <span class="o">=</span> <span class="nx">end</span> <span class="o">+</span> <span class="mi">2</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">locations</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">lineBreak</span><span class="p">.</span><span class="nx">lastIndex</span> <span class="o">=</span> <span class="nx">start</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">match</span><span class="p">;</span>
<span class="k">while</span> <span class="p">((</span><span class="nx">match</span> <span class="o">=</span> <span class="nx">lineBreak</span><span class="p">.</span><span class="nx">exec</span><span class="p">(</span><span class="nx">input</span><span class="p">))</span> <span class="o">&&</span> <span class="nx">match</span><span class="p">.</span><span class="nx">index</span> <span class="o"><</span> <span class="nx">tokPos</span><span class="p">)</span> <span class="p">{</span>
<span class="o">++</span><span class="nx">tokCurLine</span><span class="p">;</span>
<span class="nx">tokLineStart</span> <span class="o">=</span> <span class="nx">match</span><span class="p">.</span><span class="nx">index</span> <span class="o">+</span> <span class="nx">match</span><span class="p">[</span><span class="mi">0</span><span class="p">].</span><span class="nx">length</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">onComment</span><span class="p">)</span>
<span class="nx">options</span><span class="p">.</span><span class="nx">onComment</span><span class="p">(</span><span class="kc">true</span><span class="p">,</span> <span class="nx">input</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="nx">start</span> <span class="o">+</span> <span class="mi">2</span><span class="p">,</span> <span class="nx">end</span><span class="p">),</span> <span class="nx">start</span><span class="p">,</span> <span class="nx">tokPos</span><span class="p">,</span>
<span class="nx">startLoc</span><span class="p">,</span> <span class="nx">options</span><span class="p">.</span><span class="nx">locations</span> <span class="o">&&</span> <span class="k">new</span> <span class="nx">line_loc_t</span><span class="p">);</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">skipLineComment</span><span class="p">()</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">start</span> <span class="o">=</span> <span class="nx">tokPos</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">startLoc</span> <span class="o">=</span> <span class="nx">options</span><span class="p">.</span><span class="nx">onComment</span> <span class="o">&&</span> <span class="nx">options</span><span class="p">.</span><span class="nx">locations</span> <span class="o">&&</span> <span class="k">new</span> <span class="nx">line_loc_t</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">ch</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="o">+=</span><span class="mi">2</span><span class="p">);</span>
<span class="k">while</span> <span class="p">(</span><span class="nx">tokPos</span> <span class="o"><</span> <span class="nx">inputLen</span> <span class="o">&&</span> <span class="nx">ch</span> <span class="o">!==</span> <span class="mi">10</span> <span class="o">&&</span> <span class="nx">ch</span> <span class="o">!==</span> <span class="mi">13</span> <span class="o">&&</span> <span class="nx">ch</span> <span class="o">!==</span> <span class="mi">8232</span> <span class="o">&&</span> <span class="nx">ch</span> <span class="o">!==</span> <span class="mi">8233</span><span class="p">)</span> <span class="p">{</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="nx">ch</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">);</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">onComment</span><span class="p">)</span>
<span class="nx">options</span><span class="p">.</span><span class="nx">onComment</span><span class="p">(</span><span class="kc">false</span><span class="p">,</span> <span class="nx">input</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="nx">start</span> <span class="o">+</span> <span class="mi">2</span><span class="p">,</span> <span class="nx">tokPos</span><span class="p">),</span> <span class="nx">start</span><span class="p">,</span> <span class="nx">tokPos</span><span class="p">,</span>
<span class="nx">startLoc</span><span class="p">,</span> <span class="nx">options</span><span class="p">.</span><span class="nx">locations</span> <span class="o">&&</span> <span class="k">new</span> <span class="nx">line_loc_t</span><span class="p">);</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-57"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-57">¶</a> </div> <p>Called at the start of the parse and after every token. Skips
whitespace and comments, and.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">skipSpace</span><span class="p">()</span> <span class="p">{</span>
<span class="k">while</span> <span class="p">(</span><span class="nx">tokPos</span> <span class="o"><</span> <span class="nx">inputLen</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">ch</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">===</span> <span class="mi">32</span><span class="p">)</span> <span class="p">{</span> <span class="c1">// ' '</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="p">}</span> <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">===</span> <span class="mi">13</span><span class="p">)</span> <span class="p">{</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">next</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="mi">10</span><span class="p">)</span> <span class="p">{</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">locations</span><span class="p">)</span> <span class="p">{</span>
<span class="o">++</span><span class="nx">tokCurLine</span><span class="p">;</span>
<span class="nx">tokLineStart</span> <span class="o">=</span> <span class="nx">tokPos</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span> <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">===</span> <span class="mi">10</span> <span class="o">||</span> <span class="nx">ch</span> <span class="o">===</span> <span class="mi">8232</span> <span class="o">||</span> <span class="nx">ch</span> <span class="o">===</span> <span class="mi">8233</span><span class="p">)</span> <span class="p">{</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">locations</span><span class="p">)</span> <span class="p">{</span>
<span class="o">++</span><span class="nx">tokCurLine</span><span class="p">;</span>
<span class="nx">tokLineStart</span> <span class="o">=</span> <span class="nx">tokPos</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span> <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">></span> <span class="mi">8</span> <span class="o">&&</span> <span class="nx">ch</span> <span class="o"><</span> <span class="mi">14</span><span class="p">)</span> <span class="p">{</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="p">}</span> <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">===</span> <span class="mi">47</span><span class="p">)</span> <span class="p">{</span> <span class="c1">// '/'</span>
<span class="kd">var</span> <span class="nx">next</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">1</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="mi">42</span><span class="p">)</span> <span class="p">{</span> <span class="c1">// '*'</span>
<span class="nx">skipBlockComment</span><span class="p">();</span>
<span class="p">}</span> <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="mi">47</span><span class="p">)</span> <span class="p">{</span> <span class="c1">// '/'</span>
<span class="nx">skipLineComment</span><span class="p">();</span>
<span class="p">}</span> <span class="k">else</span> <span class="k">break</span><span class="p">;</span>
<span class="p">}</span> <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">===</span> <span class="mi">160</span><span class="p">)</span> <span class="p">{</span> <span class="c1">// '\xa0'</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="p">}</span> <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">>=</span> <span class="mi">5760</span> <span class="o">&&</span> <span class="nx">nonASCIIwhitespace</span><span class="p">.</span><span class="nx">test</span><span class="p">(</span><span class="nb">String</span><span class="p">.</span><span class="nx">fromCharCode</span><span class="p">(</span><span class="nx">ch</span><span class="p">)))</span> <span class="p">{</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
<span class="k">break</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-58"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-58">¶</a> </div> <h3>Token reading</h3> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-59"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-59">¶</a> </div> <p>This is the function that is called to fetch the next token. It
is somewhat obscure, because it works in character codes rather
than characters, and because operator parsing has been inlined
into it.</p>
<p>All in the name of speed.</p>
<p>The <code>forceRegexp</code> parameter is used in the one case where the
<code>tokRegexpAllowed</code> trick does not work. See <code>parseStatement</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">readToken_dot</span><span class="p">()</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">next</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">1</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">>=</span> <span class="mi">48</span> <span class="o">&&</span> <span class="nx">next</span> <span class="o"><=</span> <span class="mi">57</span><span class="p">)</span> <span class="k">return</span> <span class="nx">readNumber</span><span class="p">(</span><span class="kc">true</span><span class="p">);</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_dot</span><span class="p">);</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">readToken_slash</span><span class="p">()</span> <span class="p">{</span> <span class="c1">// '/'</span>
<span class="kd">var</span> <span class="nx">next</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">1</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">tokRegexpAllowed</span><span class="p">)</span> <span class="p">{</span><span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span> <span class="k">return</span> <span class="nx">readRegexp</span><span class="p">();}</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="mi">61</span><span class="p">)</span> <span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_assign</span><span class="p">,</span> <span class="mi">2</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_slash</span><span class="p">,</span> <span class="mi">1</span><span class="p">);</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">readToken_mult_modulo</span><span class="p">()</span> <span class="p">{</span> <span class="c1">// '%*'</span>
<span class="kd">var</span> <span class="nx">next</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">1</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="mi">61</span><span class="p">)</span> <span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_assign</span><span class="p">,</span> <span class="mi">2</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_multiplyModulo</span><span class="p">,</span> <span class="mi">1</span><span class="p">);</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">readToken_pipe_amp</span><span class="p">(</span><span class="nx">code</span><span class="p">)</span> <span class="p">{</span> <span class="c1">// '|&'</span>
<span class="kd">var</span> <span class="nx">next</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">1</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="nx">code</span><span class="p">)</span> <span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">code</span> <span class="o">===</span> <span class="mi">124</span> <span class="o">?</span> <span class="nx">_logicalOR</span> <span class="o">:</span> <span class="nx">_logicalAND</span><span class="p">,</span> <span class="mi">2</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="mi">61</span><span class="p">)</span> <span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_assign</span><span class="p">,</span> <span class="mi">2</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">code</span> <span class="o">===</span> <span class="mi">124</span> <span class="o">?</span> <span class="nx">_bitwiseOR</span> <span class="o">:</span> <span class="nx">_bitwiseAND</span><span class="p">,</span> <span class="mi">1</span><span class="p">);</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">readToken_caret</span><span class="p">()</span> <span class="p">{</span> <span class="c1">// '^'</span>
<span class="kd">var</span> <span class="nx">next</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">1</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="mi">61</span><span class="p">)</span> <span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_assign</span><span class="p">,</span> <span class="mi">2</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_bitwiseXOR</span><span class="p">,</span> <span class="mi">1</span><span class="p">);</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">readToken_plus_min</span><span class="p">(</span><span class="nx">code</span><span class="p">)</span> <span class="p">{</span> <span class="c1">// '+-'</span>
<span class="kd">var</span> <span class="nx">next</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">1</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="nx">code</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">==</span> <span class="mi">45</span> <span class="o">&&</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">2</span><span class="p">)</span> <span class="o">==</span> <span class="mi">62</span> <span class="o">&&</span>
<span class="nx">newline</span><span class="p">.</span><span class="nx">test</span><span class="p">(</span><span class="nx">input</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="nx">lastEnd</span><span class="p">,</span> <span class="nx">tokPos</span><span class="p">)))</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-60"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-60">¶</a> </div> <p>A <code>--></code> line comment</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">tokPos</span> <span class="o">+=</span> <span class="mi">3</span><span class="p">;</span>
<span class="nx">skipLineComment</span><span class="p">();</span>
<span class="nx">skipSpace</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">readToken</span><span class="p">();</span>
<span class="p">}</span>
<span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_incDec</span><span class="p">,</span> <span class="mi">2</span><span class="p">);</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="mi">61</span><span class="p">)</span> <span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_assign</span><span class="p">,</span> <span class="mi">2</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_plusMin</span><span class="p">,</span> <span class="mi">1</span><span class="p">);</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">readToken_lt_gt</span><span class="p">(</span><span class="nx">code</span><span class="p">)</span> <span class="p">{</span> <span class="c1">// '<>'</span>
<span class="kd">var</span> <span class="nx">next</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">1</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">size</span> <span class="o">=</span> <span class="mi">1</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="nx">code</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">size</span> <span class="o">=</span> <span class="nx">code</span> <span class="o">===</span> <span class="mi">62</span> <span class="o">&&</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">2</span><span class="p">)</span> <span class="o">===</span> <span class="mi">62</span> <span class="o">?</span> <span class="mi">3</span> <span class="o">:</span> <span class="mi">2</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="nx">size</span><span class="p">)</span> <span class="o">===</span> <span class="mi">61</span><span class="p">)</span> <span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_assign</span><span class="p">,</span> <span class="nx">size</span> <span class="o">+</span> <span class="mi">1</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_bitShift</span><span class="p">,</span> <span class="nx">size</span><span class="p">);</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">==</span> <span class="mi">33</span> <span class="o">&&</span> <span class="nx">code</span> <span class="o">==</span> <span class="mi">60</span> <span class="o">&&</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">2</span><span class="p">)</span> <span class="o">==</span> <span class="mi">45</span> <span class="o">&&</span>
<span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">3</span><span class="p">)</span> <span class="o">==</span> <span class="mi">45</span><span class="p">)</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-61"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-61">¶</a> </div> <p><code><!--</code>, an XML-style comment that should be interpreted as a line comment</p> </td> <td class="code"> <div class="highlight"><pre> <span class="nx">tokPos</span> <span class="o">+=</span> <span class="mi">4</span><span class="p">;</span>
<span class="nx">skipLineComment</span><span class="p">();</span>
<span class="nx">skipSpace</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">readToken</span><span class="p">();</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="mi">61</span><span class="p">)</span>
<span class="nx">size</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">2</span><span class="p">)</span> <span class="o">===</span> <span class="mi">61</span> <span class="o">?</span> <span class="mi">3</span> <span class="o">:</span> <span class="mi">2</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_relational</span><span class="p">,</span> <span class="nx">size</span><span class="p">);</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">readToken_eq_excl</span><span class="p">(</span><span class="nx">code</span><span class="p">)</span> <span class="p">{</span> <span class="c1">// '=!'</span>
<span class="kd">var</span> <span class="nx">next</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">1</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="mi">61</span><span class="p">)</span> <span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_equality</span><span class="p">,</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">2</span><span class="p">)</span> <span class="o">===</span> <span class="mi">61</span> <span class="o">?</span> <span class="mi">3</span> <span class="o">:</span> <span class="mi">2</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">code</span> <span class="o">===</span> <span class="mi">61</span> <span class="o">?</span> <span class="nx">_eq</span> <span class="o">:</span> <span class="nx">_prefix</span><span class="p">,</span> <span class="mi">1</span><span class="p">);</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">getTokenFromCode</span><span class="p">(</span><span class="nx">code</span><span class="p">)</span> <span class="p">{</span>
<span class="k">switch</span><span class="p">(</span><span class="nx">code</span><span class="p">)</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-62"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-62">¶</a> </div> <p>The interpretation of a dot depends on whether it is followed
by a digit.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">case</span> <span class="mi">46</span><span class="o">:</span> <span class="c1">// '.'</span>
<span class="k">return</span> <span class="nx">readToken_dot</span><span class="p">();</span></pre></div> </td> </tr> <tr id="section-63"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-63">¶</a> </div> <p>Punctuation tokens.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">case</span> <span class="mi">40</span><span class="o">:</span> <span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span> <span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_parenL</span><span class="p">);</span>
<span class="k">case</span> <span class="mi">41</span><span class="o">:</span> <span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span> <span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_parenR</span><span class="p">);</span>
<span class="k">case</span> <span class="mi">59</span><span class="o">:</span> <span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span> <span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_semi</span><span class="p">);</span>
<span class="k">case</span> <span class="mi">44</span><span class="o">:</span> <span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span> <span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_comma</span><span class="p">);</span>
<span class="k">case</span> <span class="mi">91</span><span class="o">:</span> <span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span> <span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_bracketL</span><span class="p">);</span>
<span class="k">case</span> <span class="mi">93</span><span class="o">:</span> <span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span> <span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_bracketR</span><span class="p">);</span>
<span class="k">case</span> <span class="mi">123</span><span class="o">:</span> <span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span> <span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_braceL</span><span class="p">);</span>
<span class="k">case</span> <span class="mi">125</span><span class="o">:</span> <span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span> <span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_braceR</span><span class="p">);</span>
<span class="k">case</span> <span class="mi">58</span><span class="o">:</span> <span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span> <span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_colon</span><span class="p">);</span>
<span class="k">case</span> <span class="mi">63</span><span class="o">:</span> <span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span> <span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_question</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-64"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-64">¶</a> </div> <p>'0x' is a hexadecimal number.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">case</span> <span class="mi">48</span><span class="o">:</span> <span class="c1">// '0'</span>
<span class="kd">var</span> <span class="nx">next</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">1</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="mi">120</span> <span class="o">||</span> <span class="nx">next</span> <span class="o">===</span> <span class="mi">88</span><span class="p">)</span> <span class="k">return</span> <span class="nx">readHexNumber</span><span class="p">();</span></pre></div> </td> </tr> <tr id="section-65"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-65">¶</a> </div> <p>Anything else beginning with a digit is an integer, octal
number, or float.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">case</span> <span class="mi">49</span><span class="o">:</span> <span class="k">case</span> <span class="mi">50</span><span class="o">:</span> <span class="k">case</span> <span class="mi">51</span><span class="o">:</span> <span class="k">case</span> <span class="mi">52</span><span class="o">:</span> <span class="k">case</span> <span class="mi">53</span><span class="o">:</span> <span class="k">case</span> <span class="mi">54</span><span class="o">:</span> <span class="k">case</span> <span class="mi">55</span><span class="o">:</span> <span class="k">case</span> <span class="mi">56</span><span class="o">:</span> <span class="k">case</span> <span class="mi">57</span><span class="o">:</span> <span class="c1">// 1-9</span>
<span class="k">return</span> <span class="nx">readNumber</span><span class="p">(</span><span class="kc">false</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-66"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-66">¶</a> </div> <p>Quotes produce strings.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">case</span> <span class="mi">34</span><span class="o">:</span> <span class="k">case</span> <span class="mi">39</span><span class="o">:</span> <span class="c1">// '"', "'"</span>
<span class="k">return</span> <span class="nx">readString</span><span class="p">(</span><span class="nx">code</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-67"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-67">¶</a> </div> <p>Operators are parsed inline in tiny state machines. '=' (61) is
often referred to. <code>finishOp</code> simply skips the amount of
characters it is given as second argument, and returns a token
of the type given by its first argument.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">case</span> <span class="mi">47</span><span class="o">:</span> <span class="c1">// '/'</span>
<span class="k">return</span> <span class="nx">readToken_slash</span><span class="p">(</span><span class="nx">code</span><span class="p">);</span>
<span class="k">case</span> <span class="mi">37</span><span class="o">:</span> <span class="k">case</span> <span class="mi">42</span><span class="o">:</span> <span class="c1">// '%*'</span>
<span class="k">return</span> <span class="nx">readToken_mult_modulo</span><span class="p">();</span>
<span class="k">case</span> <span class="mi">124</span><span class="o">:</span> <span class="k">case</span> <span class="mi">38</span><span class="o">:</span> <span class="c1">// '|&'</span>
<span class="k">return</span> <span class="nx">readToken_pipe_amp</span><span class="p">(</span><span class="nx">code</span><span class="p">);</span>
<span class="k">case</span> <span class="mi">94</span><span class="o">:</span> <span class="c1">// '^'</span>
<span class="k">return</span> <span class="nx">readToken_caret</span><span class="p">();</span>
<span class="k">case</span> <span class="mi">43</span><span class="o">:</span> <span class="k">case</span> <span class="mi">45</span><span class="o">:</span> <span class="c1">// '+-'</span>
<span class="k">return</span> <span class="nx">readToken_plus_min</span><span class="p">(</span><span class="nx">code</span><span class="p">);</span>
<span class="k">case</span> <span class="mi">60</span><span class="o">:</span> <span class="k">case</span> <span class="mi">62</span><span class="o">:</span> <span class="c1">// '<>'</span>
<span class="k">return</span> <span class="nx">readToken_lt_gt</span><span class="p">(</span><span class="nx">code</span><span class="p">);</span>
<span class="k">case</span> <span class="mi">61</span><span class="o">:</span> <span class="k">case</span> <span class="mi">33</span><span class="o">:</span> <span class="c1">// '=!'</span>
<span class="k">return</span> <span class="nx">readToken_eq_excl</span><span class="p">(</span><span class="nx">code</span><span class="p">);</span>
<span class="k">case</span> <span class="mi">126</span><span class="o">:</span> <span class="c1">// '~'</span>
<span class="k">return</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">_prefix</span><span class="p">,</span> <span class="mi">1</span><span class="p">);</span>
<span class="p">}</span>
<span class="k">return</span> <span class="kc">false</span><span class="p">;</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">readToken</span><span class="p">(</span><span class="nx">forceRegexp</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">forceRegexp</span><span class="p">)</span> <span class="nx">tokStart</span> <span class="o">=</span> <span class="nx">tokPos</span><span class="p">;</span>
<span class="k">else</span> <span class="nx">tokPos</span> <span class="o">=</span> <span class="nx">tokStart</span> <span class="o">+</span> <span class="mi">1</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">locations</span><span class="p">)</span> <span class="nx">tokStartLoc</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">line_loc_t</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">forceRegexp</span><span class="p">)</span> <span class="k">return</span> <span class="nx">readRegexp</span><span class="p">();</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">tokPos</span> <span class="o">>=</span> <span class="nx">inputLen</span><span class="p">)</span> <span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_eof</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">code</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-68"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-68">¶</a> </div> <p>Identifier or keyword. '\uXXXX' sequences are allowed in
identifiers, so '\' also dispatches to that.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="nx">isIdentifierStart</span><span class="p">(</span><span class="nx">code</span><span class="p">)</span> <span class="o">||</span> <span class="nx">code</span> <span class="o">===</span> <span class="mi">92</span> <span class="cm">/* '\' */</span><span class="p">)</span> <span class="k">return</span> <span class="nx">readWord</span><span class="p">();</span>
<span class="kd">var</span> <span class="nx">tok</span> <span class="o">=</span> <span class="nx">getTokenFromCode</span><span class="p">(</span><span class="nx">code</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">tok</span> <span class="o">===</span> <span class="kc">false</span><span class="p">)</span> <span class="p">{</span></pre></div> </td> </tr> <tr id="section-69"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-69">¶</a> </div> <p>If we are here, we either found a non-ASCII identifier
character, or something that's entirely disallowed.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">ch</span> <span class="o">=</span> <span class="nb">String</span><span class="p">.</span><span class="nx">fromCharCode</span><span class="p">(</span><span class="nx">code</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">===</span> <span class="s2">"\\"</span> <span class="o">||</span> <span class="nx">nonASCIIidentifierStart</span><span class="p">.</span><span class="nx">test</span><span class="p">(</span><span class="nx">ch</span><span class="p">))</span> <span class="k">return</span> <span class="nx">readWord</span><span class="p">();</span>
<span class="nx">raise</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">,</span> <span class="s2">"Unexpected character '"</span> <span class="o">+</span> <span class="nx">ch</span> <span class="o">+</span> <span class="s2">"'"</span><span class="p">);</span>
<span class="p">}</span>
<span class="k">return</span> <span class="nx">tok</span><span class="p">;</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">finishOp</span><span class="p">(</span><span class="nx">type</span><span class="p">,</span> <span class="nx">size</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">str</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">,</span> <span class="nx">tokPos</span> <span class="o">+</span> <span class="nx">size</span><span class="p">);</span>
<span class="nx">tokPos</span> <span class="o">+=</span> <span class="nx">size</span><span class="p">;</span>
<span class="nx">finishToken</span><span class="p">(</span><span class="nx">type</span><span class="p">,</span> <span class="nx">str</span><span class="p">);</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-70"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-70">¶</a> </div> <p>Parse a regular expression. Some context-awareness is necessary,
since a '/' inside a '[]' set does not end the expression.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">readRegexp</span><span class="p">()</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">content</span> <span class="o">=</span> <span class="s2">""</span><span class="p">,</span> <span class="nx">escaped</span><span class="p">,</span> <span class="nx">inClass</span><span class="p">,</span> <span class="nx">start</span> <span class="o">=</span> <span class="nx">tokPos</span><span class="p">;</span>
<span class="k">for</span> <span class="p">(;;)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">tokPos</span> <span class="o">>=</span> <span class="nx">inputLen</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="s2">"Unterminated regular expression"</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">ch</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">newline</span><span class="p">.</span><span class="nx">test</span><span class="p">(</span><span class="nx">ch</span><span class="p">))</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="s2">"Unterminated regular expression"</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">escaped</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">===</span> <span class="s2">"["</span><span class="p">)</span> <span class="nx">inClass</span> <span class="o">=</span> <span class="kc">true</span><span class="p">;</span>
<span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">===</span> <span class="s2">"]"</span> <span class="o">&&</span> <span class="nx">inClass</span><span class="p">)</span> <span class="nx">inClass</span> <span class="o">=</span> <span class="kc">false</span><span class="p">;</span>
<span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">===</span> <span class="s2">"/"</span> <span class="o">&&</span> <span class="o">!</span><span class="nx">inClass</span><span class="p">)</span> <span class="k">break</span><span class="p">;</span>
<span class="nx">escaped</span> <span class="o">=</span> <span class="nx">ch</span> <span class="o">===</span> <span class="s2">"\\"</span><span class="p">;</span>
<span class="p">}</span> <span class="k">else</span> <span class="nx">escaped</span> <span class="o">=</span> <span class="kc">false</span><span class="p">;</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="p">}</span>
<span class="kd">var</span> <span class="nx">content</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="nx">tokPos</span><span class="p">);</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-71"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-71">¶</a> </div> <p>Need to use <code>readWord1</code> because '\uXXXX' sequences are allowed
here (don't ask).</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">mods</span> <span class="o">=</span> <span class="nx">readWord1</span><span class="p">();</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">mods</span> <span class="o">&&</span> <span class="o">!</span><span class="sr">/^[gmsiy]*$/</span><span class="p">.</span><span class="nx">test</span><span class="p">(</span><span class="nx">mods</span><span class="p">))</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="s2">"Invalid regexp flag"</span><span class="p">);</span>
<span class="k">try</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">value</span> <span class="o">=</span> <span class="k">new</span> <span class="nb">RegExp</span><span class="p">(</span><span class="nx">content</span><span class="p">,</span> <span class="nx">mods</span><span class="p">);</span>
<span class="p">}</span> <span class="k">catch</span> <span class="p">(</span><span class="nx">e</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">e</span> <span class="k">instanceof</span> <span class="nx">SyntaxError</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="nx">e</span><span class="p">.</span><span class="nx">message</span><span class="p">);</span>
<span class="nx">raise</span><span class="p">(</span><span class="nx">e</span><span class="p">);</span>
<span class="p">}</span>
<span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_regexp</span><span class="p">,</span> <span class="nx">value</span><span class="p">);</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-72"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-72">¶</a> </div> <p>Read an integer in the given radix. Return null if zero digits
were read, the integer value otherwise. When <code>len</code> is given, this
will return <code>null</code> unless the integer has exactly <code>len</code> digits.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">readInt</span><span class="p">(</span><span class="nx">radix</span><span class="p">,</span> <span class="nx">len</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">start</span> <span class="o">=</span> <span class="nx">tokPos</span><span class="p">,</span> <span class="nx">total</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">,</span> <span class="nx">e</span> <span class="o">=</span> <span class="nx">len</span> <span class="o">==</span> <span class="kc">null</span> <span class="o">?</span> <span class="kc">Infinity</span> <span class="o">:</span> <span class="nx">len</span><span class="p">;</span> <span class="nx">i</span> <span class="o"><</span> <span class="nx">e</span><span class="p">;</span> <span class="o">++</span><span class="nx">i</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">code</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">),</span> <span class="nx">val</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">code</span> <span class="o">>=</span> <span class="mi">97</span><span class="p">)</span> <span class="nx">val</span> <span class="o">=</span> <span class="nx">code</span> <span class="o">-</span> <span class="mi">97</span> <span class="o">+</span> <span class="mi">10</span><span class="p">;</span> <span class="c1">// a</span>
<span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">code</span> <span class="o">>=</span> <span class="mi">65</span><span class="p">)</span> <span class="nx">val</span> <span class="o">=</span> <span class="nx">code</span> <span class="o">-</span> <span class="mi">65</span> <span class="o">+</span> <span class="mi">10</span><span class="p">;</span> <span class="c1">// A</span>
<span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">code</span> <span class="o">>=</span> <span class="mi">48</span> <span class="o">&&</span> <span class="nx">code</span> <span class="o"><=</span> <span class="mi">57</span><span class="p">)</span> <span class="nx">val</span> <span class="o">=</span> <span class="nx">code</span> <span class="o">-</span> <span class="mi">48</span><span class="p">;</span> <span class="c1">// 0-9</span>
<span class="k">else</span> <span class="nx">val</span> <span class="o">=</span> <span class="kc">Infinity</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">val</span> <span class="o">>=</span> <span class="nx">radix</span><span class="p">)</span> <span class="k">break</span><span class="p">;</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="nx">total</span> <span class="o">=</span> <span class="nx">total</span> <span class="o">*</span> <span class="nx">radix</span> <span class="o">+</span> <span class="nx">val</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">tokPos</span> <span class="o">===</span> <span class="nx">start</span> <span class="o">||</span> <span class="nx">len</span> <span class="o">!=</span> <span class="kc">null</span> <span class="o">&&</span> <span class="nx">tokPos</span> <span class="o">-</span> <span class="nx">start</span> <span class="o">!==</span> <span class="nx">len</span><span class="p">)</span> <span class="k">return</span> <span class="kc">null</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">total</span><span class="p">;</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">readHexNumber</span><span class="p">()</span> <span class="p">{</span>
<span class="nx">tokPos</span> <span class="o">+=</span> <span class="mi">2</span><span class="p">;</span> <span class="c1">// 0x</span>
<span class="kd">var</span> <span class="nx">val</span> <span class="o">=</span> <span class="nx">readInt</span><span class="p">(</span><span class="mi">16</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">val</span> <span class="o">==</span> <span class="kc">null</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">tokStart</span> <span class="o">+</span> <span class="mi">2</span><span class="p">,</span> <span class="s2">"Expected hexadecimal number"</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">isIdentifierStart</span><span class="p">(</span><span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">)))</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">,</span> <span class="s2">"Identifier directly after number"</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_num</span><span class="p">,</span> <span class="nx">val</span><span class="p">);</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-73"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-73">¶</a> </div> <p>Read an integer, octal integer, or floating-point number.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">readNumber</span><span class="p">(</span><span class="nx">startsWithDot</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">start</span> <span class="o">=</span> <span class="nx">tokPos</span><span class="p">,</span> <span class="nx">isFloat</span> <span class="o">=</span> <span class="kc">false</span><span class="p">,</span> <span class="nx">octal</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">)</span> <span class="o">===</span> <span class="mi">48</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">startsWithDot</span> <span class="o">&&</span> <span class="nx">readInt</span><span class="p">(</span><span class="mi">10</span><span class="p">)</span> <span class="o">===</span> <span class="kc">null</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="s2">"Invalid number"</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">)</span> <span class="o">===</span> <span class="mi">46</span><span class="p">)</span> <span class="p">{</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="nx">readInt</span><span class="p">(</span><span class="mi">10</span><span class="p">);</span>
<span class="nx">isFloat</span> <span class="o">=</span> <span class="kc">true</span><span class="p">;</span>
<span class="p">}</span>
<span class="kd">var</span> <span class="nx">next</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="mi">69</span> <span class="o">||</span> <span class="nx">next</span> <span class="o">===</span> <span class="mi">101</span><span class="p">)</span> <span class="p">{</span> <span class="c1">// 'eE'</span>
<span class="nx">next</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="o">++</span><span class="nx">tokPos</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">next</span> <span class="o">===</span> <span class="mi">43</span> <span class="o">||</span> <span class="nx">next</span> <span class="o">===</span> <span class="mi">45</span><span class="p">)</span> <span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span> <span class="c1">// '+-'</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">readInt</span><span class="p">(</span><span class="mi">10</span><span class="p">)</span> <span class="o">===</span> <span class="kc">null</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="s2">"Invalid number"</span><span class="p">);</span>
<span class="nx">isFloat</span> <span class="o">=</span> <span class="kc">true</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">isIdentifierStart</span><span class="p">(</span><span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">)))</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">,</span> <span class="s2">"Identifier directly after number"</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">str</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="nx">tokPos</span><span class="p">),</span> <span class="nx">val</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">isFloat</span><span class="p">)</span> <span class="nx">val</span> <span class="o">=</span> <span class="nb">parseFloat</span><span class="p">(</span><span class="nx">str</span><span class="p">);</span>
<span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">octal</span> <span class="o">||</span> <span class="nx">str</span><span class="p">.</span><span class="nx">length</span> <span class="o">===</span> <span class="mi">1</span><span class="p">)</span> <span class="nx">val</span> <span class="o">=</span> <span class="nb">parseInt</span><span class="p">(</span><span class="nx">str</span><span class="p">,</span> <span class="mi">10</span><span class="p">);</span>
<span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="sr">/[89]/</span><span class="p">.</span><span class="nx">test</span><span class="p">(</span><span class="nx">str</span><span class="p">)</span> <span class="o">||</span> <span class="nx">strict</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="s2">"Invalid number"</span><span class="p">);</span>
<span class="k">else</span> <span class="nx">val</span> <span class="o">=</span> <span class="nb">parseInt</span><span class="p">(</span><span class="nx">str</span><span class="p">,</span> <span class="mi">8</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_num</span><span class="p">,</span> <span class="nx">val</span><span class="p">);</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-74"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-74">¶</a> </div> <p>Read a string value, interpreting backslash-escapes.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">readString</span><span class="p">(</span><span class="nx">quote</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">tokPos</span><span class="o">++</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">out</span> <span class="o">=</span> <span class="s2">""</span><span class="p">;</span>
<span class="k">for</span> <span class="p">(;;)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">tokPos</span> <span class="o">>=</span> <span class="nx">inputLen</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">tokStart</span><span class="p">,</span> <span class="s2">"Unterminated string constant"</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">ch</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">===</span> <span class="nx">quote</span><span class="p">)</span> <span class="p">{</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">_string</span><span class="p">,</span> <span class="nx">out</span><span class="p">);</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">===</span> <span class="mi">92</span><span class="p">)</span> <span class="p">{</span> <span class="c1">// '\'</span>
<span class="nx">ch</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="o">++</span><span class="nx">tokPos</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">octal</span> <span class="o">=</span> <span class="sr">/^[0-7]+/</span><span class="p">.</span><span class="nx">exec</span><span class="p">(</span><span class="nx">input</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">,</span> <span class="nx">tokPos</span> <span class="o">+</span> <span class="mi">3</span><span class="p">));</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">octal</span><span class="p">)</span> <span class="nx">octal</span> <span class="o">=</span> <span class="nx">octal</span><span class="p">[</span><span class="mi">0</span><span class="p">];</span>
<span class="k">while</span> <span class="p">(</span><span class="nx">octal</span> <span class="o">&&</span> <span class="nb">parseInt</span><span class="p">(</span><span class="nx">octal</span><span class="p">,</span> <span class="mi">8</span><span class="p">)</span> <span class="o">></span> <span class="mi">255</span><span class="p">)</span> <span class="nx">octal</span> <span class="o">=</span> <span class="nx">octal</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="mi">0</span><span class="p">,</span> <span class="o">-</span><span class="mi">1</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">octal</span> <span class="o">===</span> <span class="s2">"0"</span><span class="p">)</span> <span class="nx">octal</span> <span class="o">=</span> <span class="kc">null</span><span class="p">;</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">octal</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">strict</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">-</span> <span class="mi">2</span><span class="p">,</span> <span class="s2">"Octal literal in strict mode"</span><span class="p">);</span>
<span class="nx">out</span> <span class="o">+=</span> <span class="nb">String</span><span class="p">.</span><span class="nx">fromCharCode</span><span class="p">(</span><span class="nb">parseInt</span><span class="p">(</span><span class="nx">octal</span><span class="p">,</span> <span class="mi">8</span><span class="p">));</span>
<span class="nx">tokPos</span> <span class="o">+=</span> <span class="nx">octal</span><span class="p">.</span><span class="nx">length</span> <span class="o">-</span> <span class="mi">1</span><span class="p">;</span>
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
<span class="k">switch</span> <span class="p">(</span><span class="nx">ch</span><span class="p">)</span> <span class="p">{</span>
<span class="k">case</span> <span class="mi">110</span><span class="o">:</span> <span class="nx">out</span> <span class="o">+=</span> <span class="s2">"\n"</span><span class="p">;</span> <span class="k">break</span><span class="p">;</span> <span class="c1">// 'n' -> '\n'</span>
<span class="k">case</span> <span class="mi">114</span><span class="o">:</span> <span class="nx">out</span> <span class="o">+=</span> <span class="s2">"\r"</span><span class="p">;</span> <span class="k">break</span><span class="p">;</span> <span class="c1">// 'r' -> '\r'</span>
<span class="k">case</span> <span class="mi">120</span><span class="o">:</span> <span class="nx">out</span> <span class="o">+=</span> <span class="nb">String</span><span class="p">.</span><span class="nx">fromCharCode</span><span class="p">(</span><span class="nx">readHexChar</span><span class="p">(</span><span class="mi">2</span><span class="p">));</span> <span class="k">break</span><span class="p">;</span> <span class="c1">// 'x'</span>
<span class="k">case</span> <span class="mi">117</span><span class="o">:</span> <span class="nx">out</span> <span class="o">+=</span> <span class="nb">String</span><span class="p">.</span><span class="nx">fromCharCode</span><span class="p">(</span><span class="nx">readHexChar</span><span class="p">(</span><span class="mi">4</span><span class="p">));</span> <span class="k">break</span><span class="p">;</span> <span class="c1">// 'u'</span>
<span class="k">case</span> <span class="mi">85</span><span class="o">:</span> <span class="nx">out</span> <span class="o">+=</span> <span class="nb">String</span><span class="p">.</span><span class="nx">fromCharCode</span><span class="p">(</span><span class="nx">readHexChar</span><span class="p">(</span><span class="mi">8</span><span class="p">));</span> <span class="k">break</span><span class="p">;</span> <span class="c1">// 'U'</span>
<span class="k">case</span> <span class="mi">116</span><span class="o">:</span> <span class="nx">out</span> <span class="o">+=</span> <span class="s2">"\t"</span><span class="p">;</span> <span class="k">break</span><span class="p">;</span> <span class="c1">// 't' -> '\t'</span>
<span class="k">case</span> <span class="mi">98</span><span class="o">:</span> <span class="nx">out</span> <span class="o">+=</span> <span class="s2">"\b"</span><span class="p">;</span> <span class="k">break</span><span class="p">;</span> <span class="c1">// 'b' -> '\b'</span>
<span class="k">case</span> <span class="mi">118</span><span class="o">:</span> <span class="nx">out</span> <span class="o">+=</span> <span class="s2">"\u000b"</span><span class="p">;</span> <span class="k">break</span><span class="p">;</span> <span class="c1">// 'v' -> '\u000b'</span>
<span class="k">case</span> <span class="mi">102</span><span class="o">:</span> <span class="nx">out</span> <span class="o">+=</span> <span class="s2">"\f"</span><span class="p">;</span> <span class="k">break</span><span class="p">;</span> <span class="c1">// 'f' -> '\f'</span>
<span class="k">case</span> <span class="mi">48</span><span class="o">:</span> <span class="nx">out</span> <span class="o">+=</span> <span class="s2">"\0"</span><span class="p">;</span> <span class="k">break</span><span class="p">;</span> <span class="c1">// 0 -> '\0'</span>
<span class="k">case</span> <span class="mi">13</span><span class="o">:</span> <span class="k">if</span> <span class="p">(</span><span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">)</span> <span class="o">===</span> <span class="mi">10</span><span class="p">)</span> <span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span> <span class="c1">// '\r\n'</span>
<span class="k">case</span> <span class="mi">10</span><span class="o">:</span> <span class="c1">// ' \n'</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">locations</span><span class="p">)</span> <span class="p">{</span> <span class="nx">tokLineStart</span> <span class="o">=</span> <span class="nx">tokPos</span><span class="p">;</span> <span class="o">++</span><span class="nx">tokCurLine</span><span class="p">;</span> <span class="p">}</span>
<span class="k">break</span><span class="p">;</span>
<span class="k">default</span><span class="o">:</span> <span class="nx">out</span> <span class="o">+=</span> <span class="nb">String</span><span class="p">.</span><span class="nx">fromCharCode</span><span class="p">(</span><span class="nx">ch</span><span class="p">);</span> <span class="k">break</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">===</span> <span class="mi">13</span> <span class="o">||</span> <span class="nx">ch</span> <span class="o">===</span> <span class="mi">10</span> <span class="o">||</span> <span class="nx">ch</span> <span class="o">===</span> <span class="mi">8232</span> <span class="o">||</span> <span class="nx">ch</span> <span class="o">===</span> <span class="mi">8233</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">tokStart</span><span class="p">,</span> <span class="s2">"Unterminated string constant"</span><span class="p">);</span>
<span class="nx">out</span> <span class="o">+=</span> <span class="nb">String</span><span class="p">.</span><span class="nx">fromCharCode</span><span class="p">(</span><span class="nx">ch</span><span class="p">);</span> <span class="c1">// '\'</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-75"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-75">¶</a> </div> <p>Used to read character escape sequences ('\x', '\u', '\U').</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">readHexChar</span><span class="p">(</span><span class="nx">len</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">n</span> <span class="o">=</span> <span class="nx">readInt</span><span class="p">(</span><span class="mi">16</span><span class="p">,</span> <span class="nx">len</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">n</span> <span class="o">===</span> <span class="kc">null</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">tokStart</span><span class="p">,</span> <span class="s2">"Bad character escape sequence"</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">n</span><span class="p">;</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-76"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-76">¶</a> </div> <p>Used to signal to callers of <code>readWord1</code> whether the word
contained any escape sequences. This is needed because words with
escape sequences must not be interpreted as keywords.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">var</span> <span class="nx">containsEsc</span><span class="p">;</span></pre></div> </td> </tr> <tr id="section-77"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-77">¶</a> </div> <p>Read an identifier, and return it as a string. Sets <code>containsEsc</code>
to whether the word contained a '\u' escape.</p>
<p>Only builds up the word character-by-character when it actually
containeds an escape, as a micro-optimization.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">readWord1</span><span class="p">()</span> <span class="p">{</span>
<span class="nx">containsEsc</span> <span class="o">=</span> <span class="kc">false</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">word</span><span class="p">,</span> <span class="nx">first</span> <span class="o">=</span> <span class="kc">true</span><span class="p">,</span> <span class="nx">start</span> <span class="o">=</span> <span class="nx">tokPos</span><span class="p">;</span>
<span class="k">for</span> <span class="p">(;;)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">ch</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">isIdentifierChar</span><span class="p">(</span><span class="nx">ch</span><span class="p">))</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">containsEsc</span><span class="p">)</span> <span class="nx">word</span> <span class="o">+=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">charAt</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">);</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="p">}</span> <span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">ch</span> <span class="o">===</span> <span class="mi">92</span><span class="p">)</span> <span class="p">{</span> <span class="c1">// "\"</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">containsEsc</span><span class="p">)</span> <span class="nx">word</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="nx">tokPos</span><span class="p">);</span>
<span class="nx">containsEsc</span> <span class="o">=</span> <span class="kc">true</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">input</span><span class="p">.</span><span class="nx">charCodeAt</span><span class="p">(</span><span class="o">++</span><span class="nx">tokPos</span><span class="p">)</span> <span class="o">!=</span> <span class="mi">117</span><span class="p">)</span> <span class="c1">// "u"</span>
<span class="nx">raise</span><span class="p">(</span><span class="nx">tokPos</span><span class="p">,</span> <span class="s2">"Expecting Unicode escape sequence \\uXXXX"</span><span class="p">);</span>
<span class="o">++</span><span class="nx">tokPos</span><span class="p">;</span>
<span class="kd">var</span> <span class="nx">esc</span> <span class="o">=</span> <span class="nx">readHexChar</span><span class="p">(</span><span class="mi">4</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">escStr</span> <span class="o">=</span> <span class="nb">String</span><span class="p">.</span><span class="nx">fromCharCode</span><span class="p">(</span><span class="nx">esc</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">escStr</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">-</span> <span class="mi">1</span><span class="p">,</span> <span class="s2">"Invalid Unicode escape"</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="p">(</span><span class="nx">first</span> <span class="o">?</span> <span class="nx">isIdentifierStart</span><span class="p">(</span><span class="nx">esc</span><span class="p">)</span> <span class="o">:</span> <span class="nx">isIdentifierChar</span><span class="p">(</span><span class="nx">esc</span><span class="p">)))</span>
<span class="nx">raise</span><span class="p">(</span><span class="nx">tokPos</span> <span class="o">-</span> <span class="mi">4</span><span class="p">,</span> <span class="s2">"Invalid Unicode escape"</span><span class="p">);</span>
<span class="nx">word</span> <span class="o">+=</span> <span class="nx">escStr</span><span class="p">;</span>
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
<span class="k">break</span><span class="p">;</span>
<span class="p">}</span>
<span class="nx">first</span> <span class="o">=</span> <span class="kc">false</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">return</span> <span class="nx">containsEsc</span> <span class="o">?</span> <span class="nx">word</span> <span class="o">:</span> <span class="nx">input</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="nx">start</span><span class="p">,</span> <span class="nx">tokPos</span><span class="p">);</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-78"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-78">¶</a> </div> <p>Read an identifier or keyword token. Will check for reserved
words when necessary.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">readWord</span><span class="p">()</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">word</span> <span class="o">=</span> <span class="nx">readWord1</span><span class="p">();</span>
<span class="kd">var</span> <span class="nx">type</span> <span class="o">=</span> <span class="nx">_name</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">containsEsc</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">isKeyword</span><span class="p">(</span><span class="nx">word</span><span class="p">))</span> <span class="nx">type</span> <span class="o">=</span> <span class="nx">keywordTypes</span><span class="p">[</span><span class="nx">word</span><span class="p">];</span>
<span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">forbidReserved</span> <span class="o">&&</span>
<span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">ecmaVersion</span> <span class="o">===</span> <span class="mi">3</span> <span class="o">?</span> <span class="nx">isReservedWord3</span> <span class="o">:</span> <span class="nx">isReservedWord5</span><span class="p">)(</span><span class="nx">word</span><span class="p">)</span> <span class="o">||</span>
<span class="nx">strict</span> <span class="o">&&</span> <span class="nx">isStrictReservedWord</span><span class="p">(</span><span class="nx">word</span><span class="p">))</span>
<span class="nx">raise</span><span class="p">(</span><span class="nx">tokStart</span><span class="p">,</span> <span class="s2">"The keyword '"</span> <span class="o">+</span> <span class="nx">word</span> <span class="o">+</span> <span class="s2">"' is reserved"</span><span class="p">);</span>
<span class="p">}</span>
<span class="k">return</span> <span class="nx">finishToken</span><span class="p">(</span><span class="nx">type</span><span class="p">,</span> <span class="nx">word</span><span class="p">);</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-79"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-79">¶</a> </div> <h2>Parser</h2> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-80"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-80">¶</a> </div> <p>A recursive descent parser operates by defining functions for all
syntactic elements, and recursively calling those, each function
advancing the input stream and returning an AST node. Precedence
of constructs (for example, the fact that <code>!x[1]</code> means <code>!(x[1])</code>
instead of <code>(!x)[1]</code> is handled by the fact that the parser
function that parses unary prefix operators is called first, and
in turn calls the function that parses <code>[]</code> subscripts — that
way, it'll receive the node for <code>x[1]</code> already parsed, and wraps
<em>that</em> in the unary operator node.</p>
<p>Acorn uses an <a href="http://en.wikipedia.org/wiki/Operator-precedence_parser">operator precedence parser</a> to handle binary
operator precedence, because it is much more compact than using
the technique outlined above, which uses different, nesting
functions to specify precedence, for all of the ten binary
precedence levels that JavaScript defines.</p> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-81"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-81">¶</a> </div> <h3>Parser utilities</h3> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-82"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-82">¶</a> </div> <p>Continue to the next token.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">next</span><span class="p">()</span> <span class="p">{</span>
<span class="nx">lastStart</span> <span class="o">=</span> <span class="nx">tokStart</span><span class="p">;</span>
<span class="nx">lastEnd</span> <span class="o">=</span> <span class="nx">tokEnd</span><span class="p">;</span>
<span class="nx">lastEndLoc</span> <span class="o">=</span> <span class="nx">tokEndLoc</span><span class="p">;</span>
<span class="nx">readToken</span><span class="p">();</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-83"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-83">¶</a> </div> <p>Enter strict mode. Re-reads the next token to please pedantic
tests ("use strict"; 010; -- should fail).</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">setStrict</span><span class="p">(</span><span class="nx">strct</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">strict</span> <span class="o">=</span> <span class="nx">strct</span><span class="p">;</span>
<span class="nx">tokPos</span> <span class="o">=</span> <span class="nx">tokStart</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">locations</span><span class="p">)</span> <span class="p">{</span>
<span class="k">while</span> <span class="p">(</span><span class="nx">tokPos</span> <span class="o"><</span> <span class="nx">tokLineStart</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">tokLineStart</span> <span class="o">=</span> <span class="nx">input</span><span class="p">.</span><span class="nx">lastIndexOf</span><span class="p">(</span><span class="s2">"\n"</span><span class="p">,</span> <span class="nx">tokLineStart</span> <span class="o">-</span> <span class="mi">2</span><span class="p">)</span> <span class="o">+</span> <span class="mi">1</span><span class="p">;</span>
<span class="o">--</span><span class="nx">tokCurLine</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="nx">skipSpace</span><span class="p">();</span>
<span class="nx">readToken</span><span class="p">();</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-84"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-84">¶</a> </div> <p>Start an AST node, attaching a start offset.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">node_t</span><span class="p">()</span> <span class="p">{</span>
<span class="k">this</span><span class="p">.</span><span class="nx">type</span> <span class="o">=</span> <span class="kc">null</span><span class="p">;</span>
<span class="k">this</span><span class="p">.</span><span class="nx">start</span> <span class="o">=</span> <span class="nx">tokStart</span><span class="p">;</span>
<span class="k">this</span><span class="p">.</span><span class="nx">end</span> <span class="o">=</span> <span class="kc">null</span><span class="p">;</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">node_loc_t</span><span class="p">()</span> <span class="p">{</span>
<span class="k">this</span><span class="p">.</span><span class="nx">start</span> <span class="o">=</span> <span class="nx">tokStartLoc</span><span class="p">;</span>
<span class="k">this</span><span class="p">.</span><span class="nx">end</span> <span class="o">=</span> <span class="kc">null</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">sourceFile</span> <span class="o">!==</span> <span class="kc">null</span><span class="p">)</span> <span class="k">this</span><span class="p">.</span><span class="nx">source</span> <span class="o">=</span> <span class="nx">sourceFile</span><span class="p">;</span>
<span class="p">}</span>
<span class="kd">function</span> <span class="nx">startNode</span><span class="p">()</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">node</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">node_t</span><span class="p">();</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">locations</span><span class="p">)</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">loc</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">node_loc_t</span><span class="p">();</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">directSourceFile</span><span class="p">)</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">sourceFile</span> <span class="o">=</span> <span class="nx">options</span><span class="p">.</span><span class="nx">directSourceFile</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">ranges</span><span class="p">)</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">range</span> <span class="o">=</span> <span class="p">[</span><span class="nx">tokStart</span><span class="p">,</span> <span class="mi">0</span><span class="p">];</span>
<span class="k">return</span> <span class="nx">node</span><span class="p">;</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-85"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-85">¶</a> </div> <p>Start a node whose start offset information should be based on
the start of another node. For example, a binary operator node is
only started after its left-hand side has already been parsed.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">startNodeFrom</span><span class="p">(</span><span class="nx">other</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">node</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">node_t</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">start</span> <span class="o">=</span> <span class="nx">other</span><span class="p">.</span><span class="nx">start</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">locations</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">loc</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">node_loc_t</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">loc</span><span class="p">.</span><span class="nx">start</span> <span class="o">=</span> <span class="nx">other</span><span class="p">.</span><span class="nx">loc</span><span class="p">.</span><span class="nx">start</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">ranges</span><span class="p">)</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">range</span> <span class="o">=</span> <span class="p">[</span><span class="nx">other</span><span class="p">.</span><span class="nx">range</span><span class="p">[</span><span class="mi">0</span><span class="p">],</span> <span class="mi">0</span><span class="p">];</span>
<span class="k">return</span> <span class="nx">node</span><span class="p">;</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-86"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-86">¶</a> </div> <p>Finish an AST node, adding <code>type</code> and <code>end</code> properties.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="nx">type</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">type</span> <span class="o">=</span> <span class="nx">type</span><span class="p">;</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">end</span> <span class="o">=</span> <span class="nx">lastEnd</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">locations</span><span class="p">)</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">loc</span><span class="p">.</span><span class="nx">end</span> <span class="o">=</span> <span class="nx">lastEndLoc</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">ranges</span><span class="p">)</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">range</span><span class="p">[</span><span class="mi">1</span><span class="p">]</span> <span class="o">=</span> <span class="nx">lastEnd</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">node</span><span class="p">;</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-87"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-87">¶</a> </div> <p>Test whether a statement node is the string literal <code>"use strict"</code>.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">isUseStrict</span><span class="p">(</span><span class="nx">stmt</span><span class="p">)</span> <span class="p">{</span>
<span class="k">return</span> <span class="nx">options</span><span class="p">.</span><span class="nx">ecmaVersion</span> <span class="o">>=</span> <span class="mi">5</span> <span class="o">&&</span> <span class="nx">stmt</span><span class="p">.</span><span class="nx">type</span> <span class="o">===</span> <span class="s2">"ExpressionStatement"</span> <span class="o">&&</span>
<span class="nx">stmt</span><span class="p">.</span><span class="nx">expression</span><span class="p">.</span><span class="nx">type</span> <span class="o">===</span> <span class="s2">"Literal"</span> <span class="o">&&</span> <span class="nx">stmt</span><span class="p">.</span><span class="nx">expression</span><span class="p">.</span><span class="nx">value</span> <span class="o">===</span> <span class="s2">"use strict"</span><span class="p">;</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-88"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-88">¶</a> </div> <p>Predicate that tests whether the next token is of the given
type, and if yes, consumes it as a side effect.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">eat</span><span class="p">(</span><span class="nx">type</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">tokType</span> <span class="o">===</span> <span class="nx">type</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">next</span><span class="p">();</span>
<span class="k">return</span> <span class="kc">true</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-89"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-89">¶</a> </div> <p>Test whether a semicolon can be inserted at the current position.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">canInsertSemicolon</span><span class="p">()</span> <span class="p">{</span>
<span class="k">return</span> <span class="o">!</span><span class="nx">options</span><span class="p">.</span><span class="nx">strictSemicolons</span> <span class="o">&&</span>
<span class="p">(</span><span class="nx">tokType</span> <span class="o">===</span> <span class="nx">_eof</span> <span class="o">||</span> <span class="nx">tokType</span> <span class="o">===</span> <span class="nx">_braceR</span> <span class="o">||</span> <span class="nx">newline</span><span class="p">.</span><span class="nx">test</span><span class="p">(</span><span class="nx">input</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="nx">lastEnd</span><span class="p">,</span> <span class="nx">tokStart</span><span class="p">)));</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-90"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-90">¶</a> </div> <p>Consume a semicolon, or, failing that, see if we are allowed to
pretend that there is a semicolon at this position.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">semicolon</span><span class="p">()</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">eat</span><span class="p">(</span><span class="nx">_semi</span><span class="p">)</span> <span class="o">&&</span> <span class="o">!</span><span class="nx">canInsertSemicolon</span><span class="p">())</span> <span class="nx">unexpected</span><span class="p">();</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-91"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-91">¶</a> </div> <p>Expect a token of a given type. If found, consume it, otherwise,
raise an unexpected token error.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">expect</span><span class="p">(</span><span class="nx">type</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">tokType</span> <span class="o">===</span> <span class="nx">type</span><span class="p">)</span> <span class="nx">next</span><span class="p">();</span>
<span class="k">else</span> <span class="nx">unexpected</span><span class="p">();</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-92"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-92">¶</a> </div> <p>Raise an unexpected token error.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">unexpected</span><span class="p">()</span> <span class="p">{</span>
<span class="nx">raise</span><span class="p">(</span><span class="nx">tokStart</span><span class="p">,</span> <span class="s2">"Unexpected token"</span><span class="p">);</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-93"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-93">¶</a> </div> <p>Verify that a node is an lval — something that can be assigned
to.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">checkLVal</span><span class="p">(</span><span class="nx">expr</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">expr</span><span class="p">.</span><span class="nx">type</span> <span class="o">!==</span> <span class="s2">"Identifier"</span> <span class="o">&&</span> <span class="nx">expr</span><span class="p">.</span><span class="nx">type</span> <span class="o">!==</span> <span class="s2">"MemberExpression"</span><span class="p">)</span>
<span class="nx">raise</span><span class="p">(</span><span class="nx">expr</span><span class="p">.</span><span class="nx">start</span><span class="p">,</span> <span class="s2">"Assigning to rvalue"</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">strict</span> <span class="o">&&</span> <span class="nx">expr</span><span class="p">.</span><span class="nx">type</span> <span class="o">===</span> <span class="s2">"Identifier"</span> <span class="o">&&</span> <span class="nx">isStrictBadIdWord</span><span class="p">(</span><span class="nx">expr</span><span class="p">.</span><span class="nx">name</span><span class="p">))</span>
<span class="nx">raise</span><span class="p">(</span><span class="nx">expr</span><span class="p">.</span><span class="nx">start</span><span class="p">,</span> <span class="s2">"Assigning to "</span> <span class="o">+</span> <span class="nx">expr</span><span class="p">.</span><span class="nx">name</span> <span class="o">+</span> <span class="s2">" in strict mode"</span><span class="p">);</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-94"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-94">¶</a> </div> <h3>Statement parsing</h3> </td> <td class="code"> <div class="highlight"><pre></pre></div> </td> </tr> <tr id="section-95"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-95">¶</a> </div> <p>Parse a program. Initializes the parser, reads any number of
statements, and wraps them in a Program node. Optionally takes a
<code>program</code> argument. If present, the statements will be appended
to its body instead of creating a new node.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">parseTopLevel</span><span class="p">(</span><span class="nx">program</span><span class="p">)</span> <span class="p">{</span>
<span class="nx">lastStart</span> <span class="o">=</span> <span class="nx">lastEnd</span> <span class="o">=</span> <span class="nx">tokPos</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">options</span><span class="p">.</span><span class="nx">locations</span><span class="p">)</span> <span class="nx">lastEndLoc</span> <span class="o">=</span> <span class="k">new</span> <span class="nx">line_loc_t</span><span class="p">;</span>
<span class="nx">inFunction</span> <span class="o">=</span> <span class="nx">strict</span> <span class="o">=</span> <span class="kc">null</span><span class="p">;</span>
<span class="nx">labels</span> <span class="o">=</span> <span class="p">[];</span>
<span class="nx">readToken</span><span class="p">();</span>
<span class="kd">var</span> <span class="nx">node</span> <span class="o">=</span> <span class="nx">program</span> <span class="o">||</span> <span class="nx">startNode</span><span class="p">(),</span> <span class="nx">first</span> <span class="o">=</span> <span class="kc">true</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">program</span><span class="p">)</span> <span class="nx">node</span><span class="p">.</span><span class="nx">body</span> <span class="o">=</span> <span class="p">[];</span>
<span class="k">while</span> <span class="p">(</span><span class="nx">tokType</span> <span class="o">!==</span> <span class="nx">_eof</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">stmt</span> <span class="o">=</span> <span class="nx">parseStatement</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">body</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">stmt</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">first</span> <span class="o">&&</span> <span class="nx">isUseStrict</span><span class="p">(</span><span class="nx">stmt</span><span class="p">))</span> <span class="nx">setStrict</span><span class="p">(</span><span class="kc">true</span><span class="p">);</span>
<span class="nx">first</span> <span class="o">=</span> <span class="kc">false</span><span class="p">;</span>
<span class="p">}</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">"Program"</span><span class="p">);</span>
<span class="p">}</span>
<span class="kd">var</span> <span class="nx">loopLabel</span> <span class="o">=</span> <span class="p">{</span><span class="nx">kind</span><span class="o">:</span> <span class="s2">"loop"</span><span class="p">},</span> <span class="nx">switchLabel</span> <span class="o">=</span> <span class="p">{</span><span class="nx">kind</span><span class="o">:</span> <span class="s2">"switch"</span><span class="p">};</span></pre></div> </td> </tr> <tr id="section-96"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-96">¶</a> </div> <p>Parse a single statement.</p>
<p>If expecting a statement and finding a slash operator, parse a
regular expression literal. This is to handle cases like
<code>if (foo) /blah/.exec(foo);</code>, where looking at the previous token
does not help.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="kd">function</span> <span class="nx">parseStatement</span><span class="p">()</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">tokType</span> <span class="o">===</span> <span class="nx">_slash</span> <span class="o">||</span> <span class="nx">tokType</span> <span class="o">===</span> <span class="nx">_assign</span> <span class="o">&&</span> <span class="nx">tokVal</span> <span class="o">==</span> <span class="s2">"/="</span><span class="p">)</span>
<span class="nx">readToken</span><span class="p">(</span><span class="kc">true</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">starttype</span> <span class="o">=</span> <span class="nx">tokType</span><span class="p">,</span> <span class="nx">node</span> <span class="o">=</span> <span class="nx">startNode</span><span class="p">();</span></pre></div> </td> </tr> <tr id="section-97"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-97">¶</a> </div> <p>Most types of statements are recognized by the keyword they
start with. Many are trivial to parse, some require a bit of
complexity.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">switch</span> <span class="p">(</span><span class="nx">starttype</span><span class="p">)</span> <span class="p">{</span>
<span class="k">case</span> <span class="nx">_break</span><span class="o">:</span> <span class="k">case</span> <span class="nx">_continue</span><span class="o">:</span>
<span class="nx">next</span><span class="p">();</span>
<span class="kd">var</span> <span class="nx">isBreak</span> <span class="o">=</span> <span class="nx">starttype</span> <span class="o">===</span> <span class="nx">_break</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">eat</span><span class="p">(</span><span class="nx">_semi</span><span class="p">)</span> <span class="o">||</span> <span class="nx">canInsertSemicolon</span><span class="p">())</span> <span class="nx">node</span><span class="p">.</span><span class="nx">label</span> <span class="o">=</span> <span class="kc">null</span><span class="p">;</span>
<span class="k">else</span> <span class="k">if</span> <span class="p">(</span><span class="nx">tokType</span> <span class="o">!==</span> <span class="nx">_name</span><span class="p">)</span> <span class="nx">unexpected</span><span class="p">();</span>
<span class="k">else</span> <span class="p">{</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">label</span> <span class="o">=</span> <span class="nx">parseIdent</span><span class="p">();</span>
<span class="nx">semicolon</span><span class="p">();</span>
<span class="p">}</span></pre></div> </td> </tr> <tr id="section-98"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-98">¶</a> </div> <p>Verify that there is an actual destination to break or
continue to.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="nx">i</span> <span class="o"><</span> <span class="nx">labels</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span> <span class="o">++</span><span class="nx">i</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">lab</span> <span class="o">=</span> <span class="nx">labels</span><span class="p">[</span><span class="nx">i</span><span class="p">];</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">node</span><span class="p">.</span><span class="nx">label</span> <span class="o">==</span> <span class="kc">null</span> <span class="o">||</span> <span class="nx">lab</span><span class="p">.</span><span class="nx">name</span> <span class="o">===</span> <span class="nx">node</span><span class="p">.</span><span class="nx">label</span><span class="p">.</span><span class="nx">name</span><span class="p">)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">lab</span><span class="p">.</span><span class="nx">kind</span> <span class="o">!=</span> <span class="kc">null</span> <span class="o">&&</span> <span class="p">(</span><span class="nx">isBreak</span> <span class="o">||</span> <span class="nx">lab</span><span class="p">.</span><span class="nx">kind</span> <span class="o">===</span> <span class="s2">"loop"</span><span class="p">))</span> <span class="k">break</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">node</span><span class="p">.</span><span class="nx">label</span> <span class="o">&&</span> <span class="nx">isBreak</span><span class="p">)</span> <span class="k">break</span><span class="p">;</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">i</span> <span class="o">===</span> <span class="nx">labels</span><span class="p">.</span><span class="nx">length</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">node</span><span class="p">.</span><span class="nx">start</span><span class="p">,</span> <span class="s2">"Unsyntactic "</span> <span class="o">+</span> <span class="nx">starttype</span><span class="p">.</span><span class="nx">keyword</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="nx">isBreak</span> <span class="o">?</span> <span class="s2">"BreakStatement"</span> <span class="o">:</span> <span class="s2">"ContinueStatement"</span><span class="p">);</span>
<span class="k">case</span> <span class="nx">_debugger</span><span class="o">:</span>
<span class="nx">next</span><span class="p">();</span>
<span class="nx">semicolon</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">"DebuggerStatement"</span><span class="p">);</span>
<span class="k">case</span> <span class="nx">_do</span><span class="o">:</span>
<span class="nx">next</span><span class="p">();</span>
<span class="nx">labels</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">loopLabel</span><span class="p">);</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">body</span> <span class="o">=</span> <span class="nx">parseStatement</span><span class="p">();</span>
<span class="nx">labels</span><span class="p">.</span><span class="nx">pop</span><span class="p">();</span>
<span class="nx">expect</span><span class="p">(</span><span class="nx">_while</span><span class="p">);</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">test</span> <span class="o">=</span> <span class="nx">parseParenExpression</span><span class="p">();</span>
<span class="nx">semicolon</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">"DoWhileStatement"</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-99"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-99">¶</a> </div> <p>Disambiguating between a <code>for</code> and a <code>for</code>/<code>in</code> loop is
non-trivial. Basically, we have to parse the init <code>var</code>
statement or expression, disallowing the <code>in</code> operator (see
the second parameter to <code>parseExpression</code>), and then check
whether the next token is <code>in</code>. When there is no init part
(semicolon immediately after the opening parenthesis), it is
a regular <code>for</code> loop.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">case</span> <span class="nx">_for</span><span class="o">:</span>
<span class="nx">next</span><span class="p">();</span>
<span class="nx">labels</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">loopLabel</span><span class="p">);</span>
<span class="nx">expect</span><span class="p">(</span><span class="nx">_parenL</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">tokType</span> <span class="o">===</span> <span class="nx">_semi</span><span class="p">)</span> <span class="k">return</span> <span class="nx">parseFor</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="kc">null</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">tokType</span> <span class="o">===</span> <span class="nx">_var</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">init</span> <span class="o">=</span> <span class="nx">startNode</span><span class="p">();</span>
<span class="nx">next</span><span class="p">();</span>
<span class="nx">parseVar</span><span class="p">(</span><span class="nx">init</span><span class="p">,</span> <span class="kc">true</span><span class="p">);</span>
<span class="nx">finishNode</span><span class="p">(</span><span class="nx">init</span><span class="p">,</span> <span class="s2">"VariableDeclaration"</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">init</span><span class="p">.</span><span class="nx">declarations</span><span class="p">.</span><span class="nx">length</span> <span class="o">===</span> <span class="mi">1</span> <span class="o">&&</span> <span class="nx">eat</span><span class="p">(</span><span class="nx">_in</span><span class="p">))</span>
<span class="k">return</span> <span class="nx">parseForIn</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="nx">init</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">parseFor</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="nx">init</span><span class="p">);</span>
<span class="p">}</span>
<span class="kd">var</span> <span class="nx">init</span> <span class="o">=</span> <span class="nx">parseExpression</span><span class="p">(</span><span class="kc">false</span><span class="p">,</span> <span class="kc">true</span><span class="p">);</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">eat</span><span class="p">(</span><span class="nx">_in</span><span class="p">))</span> <span class="p">{</span><span class="nx">checkLVal</span><span class="p">(</span><span class="nx">init</span><span class="p">);</span> <span class="k">return</span> <span class="nx">parseForIn</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="nx">init</span><span class="p">);}</span>
<span class="k">return</span> <span class="nx">parseFor</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="nx">init</span><span class="p">);</span>
<span class="k">case</span> <span class="nx">_function</span><span class="o">:</span>
<span class="nx">next</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">parseFunction</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="kc">true</span><span class="p">);</span>
<span class="k">case</span> <span class="nx">_if</span><span class="o">:</span>
<span class="nx">next</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">test</span> <span class="o">=</span> <span class="nx">parseParenExpression</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">consequent</span> <span class="o">=</span> <span class="nx">parseStatement</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">alternate</span> <span class="o">=</span> <span class="nx">eat</span><span class="p">(</span><span class="nx">_else</span><span class="p">)</span> <span class="o">?</span> <span class="nx">parseStatement</span><span class="p">()</span> <span class="o">:</span> <span class="kc">null</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">"IfStatement"</span><span class="p">);</span>
<span class="k">case</span> <span class="nx">_return</span><span class="o">:</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">inFunction</span> <span class="o">&&</span> <span class="o">!</span><span class="nx">options</span><span class="p">.</span><span class="nx">allowReturnOutsideFunction</span><span class="p">)</span>
<span class="nx">raise</span><span class="p">(</span><span class="nx">tokStart</span><span class="p">,</span> <span class="s2">"'return' outside of function"</span><span class="p">);</span>
<span class="nx">next</span><span class="p">();</span></pre></div> </td> </tr> <tr id="section-100"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-100">¶</a> </div> <p>In <code>return</code> (and <code>break</code>/<code>continue</code>), the keywords with
optional arguments, we eagerly look for a semicolon or the
possibility to insert one.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">if</span> <span class="p">(</span><span class="nx">eat</span><span class="p">(</span><span class="nx">_semi</span><span class="p">)</span> <span class="o">||</span> <span class="nx">canInsertSemicolon</span><span class="p">())</span> <span class="nx">node</span><span class="p">.</span><span class="nx">argument</span> <span class="o">=</span> <span class="kc">null</span><span class="p">;</span>
<span class="k">else</span> <span class="p">{</span> <span class="nx">node</span><span class="p">.</span><span class="nx">argument</span> <span class="o">=</span> <span class="nx">parseExpression</span><span class="p">();</span> <span class="nx">semicolon</span><span class="p">();</span> <span class="p">}</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">"ReturnStatement"</span><span class="p">);</span>
<span class="k">case</span> <span class="nx">_switch</span><span class="o">:</span>
<span class="nx">next</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">discriminant</span> <span class="o">=</span> <span class="nx">parseParenExpression</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">cases</span> <span class="o">=</span> <span class="p">[];</span>
<span class="nx">expect</span><span class="p">(</span><span class="nx">_braceL</span><span class="p">);</span>
<span class="nx">labels</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">switchLabel</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-101"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-101">¶</a> </div> <p>Statements under must be grouped (by label) in SwitchCase
nodes. <code>cur</code> is used to keep the node that we are currently
adding statements to.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">cur</span><span class="p">,</span> <span class="nx">sawDefault</span><span class="p">;</span> <span class="nx">tokType</span> <span class="o">!=</span> <span class="nx">_braceR</span><span class="p">;)</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">tokType</span> <span class="o">===</span> <span class="nx">_case</span> <span class="o">||</span> <span class="nx">tokType</span> <span class="o">===</span> <span class="nx">_default</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">isCase</span> <span class="o">=</span> <span class="nx">tokType</span> <span class="o">===</span> <span class="nx">_case</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">cur</span><span class="p">)</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">cur</span><span class="p">,</span> <span class="s2">"SwitchCase"</span><span class="p">);</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">cases</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">cur</span> <span class="o">=</span> <span class="nx">startNode</span><span class="p">());</span>
<span class="nx">cur</span><span class="p">.</span><span class="nx">consequent</span> <span class="o">=</span> <span class="p">[];</span>
<span class="nx">next</span><span class="p">();</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">isCase</span><span class="p">)</span> <span class="nx">cur</span><span class="p">.</span><span class="nx">test</span> <span class="o">=</span> <span class="nx">parseExpression</span><span class="p">();</span>
<span class="k">else</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">sawDefault</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">lastStart</span><span class="p">,</span> <span class="s2">"Multiple default clauses"</span><span class="p">);</span> <span class="nx">sawDefault</span> <span class="o">=</span> <span class="kc">true</span><span class="p">;</span>
<span class="nx">cur</span><span class="p">.</span><span class="nx">test</span> <span class="o">=</span> <span class="kc">null</span><span class="p">;</span>
<span class="p">}</span>
<span class="nx">expect</span><span class="p">(</span><span class="nx">_colon</span><span class="p">);</span>
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">cur</span><span class="p">)</span> <span class="nx">unexpected</span><span class="p">();</span>
<span class="nx">cur</span><span class="p">.</span><span class="nx">consequent</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">parseStatement</span><span class="p">());</span>
<span class="p">}</span>
<span class="p">}</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">cur</span><span class="p">)</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">cur</span><span class="p">,</span> <span class="s2">"SwitchCase"</span><span class="p">);</span>
<span class="nx">next</span><span class="p">();</span> <span class="c1">// Closing brace</span>
<span class="nx">labels</span><span class="p">.</span><span class="nx">pop</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">"SwitchStatement"</span><span class="p">);</span>
<span class="k">case</span> <span class="nx">_throw</span><span class="o">:</span>
<span class="nx">next</span><span class="p">();</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">newline</span><span class="p">.</span><span class="nx">test</span><span class="p">(</span><span class="nx">input</span><span class="p">.</span><span class="nx">slice</span><span class="p">(</span><span class="nx">lastEnd</span><span class="p">,</span> <span class="nx">tokStart</span><span class="p">)))</span>
<span class="nx">raise</span><span class="p">(</span><span class="nx">lastEnd</span><span class="p">,</span> <span class="s2">"Illegal newline after throw"</span><span class="p">);</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">argument</span> <span class="o">=</span> <span class="nx">parseExpression</span><span class="p">();</span>
<span class="nx">semicolon</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">"ThrowStatement"</span><span class="p">);</span>
<span class="k">case</span> <span class="nx">_try</span><span class="o">:</span>
<span class="nx">next</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">block</span> <span class="o">=</span> <span class="nx">parseBlock</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">handler</span> <span class="o">=</span> <span class="kc">null</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">tokType</span> <span class="o">===</span> <span class="nx">_catch</span><span class="p">)</span> <span class="p">{</span>
<span class="kd">var</span> <span class="nx">clause</span> <span class="o">=</span> <span class="nx">startNode</span><span class="p">();</span>
<span class="nx">next</span><span class="p">();</span>
<span class="nx">expect</span><span class="p">(</span><span class="nx">_parenL</span><span class="p">);</span>
<span class="nx">clause</span><span class="p">.</span><span class="nx">param</span> <span class="o">=</span> <span class="nx">parseIdent</span><span class="p">();</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">strict</span> <span class="o">&&</span> <span class="nx">isStrictBadIdWord</span><span class="p">(</span><span class="nx">clause</span><span class="p">.</span><span class="nx">param</span><span class="p">.</span><span class="nx">name</span><span class="p">))</span>
<span class="nx">raise</span><span class="p">(</span><span class="nx">clause</span><span class="p">.</span><span class="nx">param</span><span class="p">.</span><span class="nx">start</span><span class="p">,</span> <span class="s2">"Binding "</span> <span class="o">+</span> <span class="nx">clause</span><span class="p">.</span><span class="nx">param</span><span class="p">.</span><span class="nx">name</span> <span class="o">+</span> <span class="s2">" in strict mode"</span><span class="p">);</span>
<span class="nx">expect</span><span class="p">(</span><span class="nx">_parenR</span><span class="p">);</span>
<span class="nx">clause</span><span class="p">.</span><span class="nx">guard</span> <span class="o">=</span> <span class="kc">null</span><span class="p">;</span>
<span class="nx">clause</span><span class="p">.</span><span class="nx">body</span> <span class="o">=</span> <span class="nx">parseBlock</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">handler</span> <span class="o">=</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">clause</span><span class="p">,</span> <span class="s2">"CatchClause"</span><span class="p">);</span>
<span class="p">}</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">guardedHandlers</span> <span class="o">=</span> <span class="nx">empty</span><span class="p">;</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">finalizer</span> <span class="o">=</span> <span class="nx">eat</span><span class="p">(</span><span class="nx">_finally</span><span class="p">)</span> <span class="o">?</span> <span class="nx">parseBlock</span><span class="p">()</span> <span class="o">:</span> <span class="kc">null</span><span class="p">;</span>
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">node</span><span class="p">.</span><span class="nx">handler</span> <span class="o">&&</span> <span class="o">!</span><span class="nx">node</span><span class="p">.</span><span class="nx">finalizer</span><span class="p">)</span>
<span class="nx">raise</span><span class="p">(</span><span class="nx">node</span><span class="p">.</span><span class="nx">start</span><span class="p">,</span> <span class="s2">"Missing catch or finally clause"</span><span class="p">);</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">"TryStatement"</span><span class="p">);</span>
<span class="k">case</span> <span class="nx">_var</span><span class="o">:</span>
<span class="nx">next</span><span class="p">();</span>
<span class="nx">parseVar</span><span class="p">(</span><span class="nx">node</span><span class="p">);</span>
<span class="nx">semicolon</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">"VariableDeclaration"</span><span class="p">);</span>
<span class="k">case</span> <span class="nx">_while</span><span class="o">:</span>
<span class="nx">next</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">test</span> <span class="o">=</span> <span class="nx">parseParenExpression</span><span class="p">();</span>
<span class="nx">labels</span><span class="p">.</span><span class="nx">push</span><span class="p">(</span><span class="nx">loopLabel</span><span class="p">);</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">body</span> <span class="o">=</span> <span class="nx">parseStatement</span><span class="p">();</span>
<span class="nx">labels</span><span class="p">.</span><span class="nx">pop</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">"WhileStatement"</span><span class="p">);</span>
<span class="k">case</span> <span class="nx">_with</span><span class="o">:</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">strict</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">tokStart</span><span class="p">,</span> <span class="s2">"'with' in strict mode"</span><span class="p">);</span>
<span class="nx">next</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">object</span> <span class="o">=</span> <span class="nx">parseParenExpression</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">body</span> <span class="o">=</span> <span class="nx">parseStatement</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">"WithStatement"</span><span class="p">);</span>
<span class="k">case</span> <span class="nx">_braceL</span><span class="o">:</span>
<span class="k">return</span> <span class="nx">parseBlock</span><span class="p">();</span>
<span class="k">case</span> <span class="nx">_semi</span><span class="o">:</span>
<span class="nx">next</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">"EmptyStatement"</span><span class="p">);</span></pre></div> </td> </tr> <tr id="section-102"> <td class="docs"> <div class="pilwrap"> <a class="pilcrow" href="#section-102">¶</a> </div> <p>If the statement does not start with a statement keyword or a
brace, it's an ExpressionStatement or LabeledStatement. We
simply start parsing an expression, and afterwards, if the
next token is a colon and the expression was a simple
Identifier node, we switch to interpreting it as a label.</p> </td> <td class="code"> <div class="highlight"><pre> <span class="k">default</span><span class="o">:</span>
<span class="kd">var</span> <span class="nx">maybeName</span> <span class="o">=</span> <span class="nx">tokVal</span><span class="p">,</span> <span class="nx">expr</span> <span class="o">=</span> <span class="nx">parseExpression</span><span class="p">();</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">starttype</span> <span class="o">===</span> <span class="nx">_name</span> <span class="o">&&</span> <span class="nx">expr</span><span class="p">.</span><span class="nx">type</span> <span class="o">===</span> <span class="s2">"Identifier"</span> <span class="o">&&</span> <span class="nx">eat</span><span class="p">(</span><span class="nx">_colon</span><span class="p">))</span> <span class="p">{</span>
<span class="k">for</span> <span class="p">(</span><span class="kd">var</span> <span class="nx">i</span> <span class="o">=</span> <span class="mi">0</span><span class="p">;</span> <span class="nx">i</span> <span class="o"><</span> <span class="nx">labels</span><span class="p">.</span><span class="nx">length</span><span class="p">;</span> <span class="o">++</span><span class="nx">i</span><span class="p">)</span>
<span class="k">if</span> <span class="p">(</span><span class="nx">labels</span><span class="p">[</span><span class="nx">i</span><span class="p">].</span><span class="nx">name</span> <span class="o">===</span> <span class="nx">maybeName</span><span class="p">)</span> <span class="nx">raise</span><span class="p">(</span><span class="nx">expr</span><span class="p">.</span><span class="nx">start</span><span class="p">,</span> <span class="s2">"Label '"</span> <span class="o">+</span> <span class="nx">maybeName</span> <span class="o">+</span> <span class="s2">"' is already declared"</span><span class="p">);</span>
<span class="kd">var</span> <span class="nx">kind</span> <span class="o">=</span> <span class="nx">tokType</span><span class="p">.</span><span class="nx">isLoop</span> <span class="o">?</span> <span class="s2">"loop"</span> <span class="o">:</span> <span class="nx">tokType</span> <span class="o">===</span> <span class="nx">_switch</span> <span class="o">?</span> <span class="s2">"switch"</span> <span class="o">:</span> <span class="kc">null</span><span class="p">;</span>
<span class="nx">labels</span><span class="p">.</span><span class="nx">push</span><span class="p">({</span><span class="nx">name</span><span class="o">:</span> <span class="nx">maybeName</span><span class="p">,</span> <span class="nx">kind</span><span class="o">:</span> <span class="nx">kind</span><span class="p">});</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">body</span> <span class="o">=</span> <span class="nx">parseStatement</span><span class="p">();</span>
<span class="nx">labels</span><span class="p">.</span><span class="nx">pop</span><span class="p">();</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">label</span> <span class="o">=</span> <span class="nx">expr</span><span class="p">;</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">"LabeledStatement"</span><span class="p">);</span>
<span class="p">}</span> <span class="k">else</span> <span class="p">{</span>
<span class="nx">node</span><span class="p">.</span><span class="nx">expression</span> <span class="o">=</span> <span class="nx">expr</span><span class="p">;</span>
<span class="nx">semicolon</span><span class="p">();</span>
<span class="k">return</span> <span class="nx">finishNode</span><span class="p">(</span><span class="nx">node</span><span class="p">,</span> <span class="s2">"ExpressionStatement"</span><span class="p">);</span>