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
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
|
/* ____ ____ ____ ____ ______ *\
** / __// __ \/ __// __ \/ ____/ SOcos COmpiles Scala **
** __\_ \/ /_/ / /__/ /_/ /\_ \ (c) 2002, LAMP/EPFL **
** /_____/\____/\___/\____/____/ **
** **
** $Id$
\* */
package scalac.transformer.matching;
import ch.epfl.lamp.util.Position;
import scalac.*;
import scalac.ast.*;
import scalac.util.*;
import scalac.symtab.*;
import scalac.typechecker.*;
import PatternNode.*;
import Tree.*;
import scalac.transformer.TransMatch.Matcher ;
public class PatternMatcher {
public static final Name RESULT_N = Name.fromString("$result");
public static final Name SCALA_N = Name.fromString("scala");
public static final Name BOOLEAN_N = Name.fromString("Boolean");
public static final Name AND_N = Name.fromString("$amp$amp");
public static final Name OR_N = Name.fromString("$bar$bar");
public static final Name NOT_N = Name.fromString("$bang");
public static final Name EQUALS_N = Name.fromString("$eq$eq");
public static final Name SCALA_MATCHERROR_N = Name.fromString("scala.MatchError");
public static final Name MATCHERROR_N = Name.fromString("MatchError");
public static final Name FAIL_N = Name.fromString("fail");
public static final Name WILDCARD_N = Name.fromString("_");
public static final Name LENGTH_N = Name.fromString("length");
public static final Name AT_N = Name.fromString("at");
/** the current compilation unit
*/
Unit unit;
/** the global fresh name creator
*/
FreshNameCreator fresh;
/** the global tree factory
*/
TreeFactory make;
/** the global definitions component
*/
Definitions defs;
/** the global tree generation component
*/
TreeGen gen;
/** type inference engine
*/
Infer infer;
/** the owner of the pattern matching expression
*/
Symbol owner;
/** the selector expression
*/
Tree selector;
/** the root of the pattern node structure
*/
PatternNode root;
/** the symbol of the result variable
*/
Symbol resultVar;
/** the statics of class Boolean
*/
//Symbol statics;
/** container
*/
Matcher _m;
/** constructor
*/
public PatternMatcher(Unit unit, Infer infer/*, Symbol owner, Tree selector, Type tpe*/) {
this.unit = unit;
this.fresh = unit.global.freshNameCreator;
this.make = unit.global.make;
this.gen = unit.global.treeGen;
this.defs = unit.global.definitions;
/*
this.owner = owner;
this.selector = selector;
this.root = makeConstrPat(selector.pos,
selector.type.widen());
this.root.and = makeHeader(selector.pos,
selector.type.widen(),
make.Ident(selector.pos,
root.symbol().name)
.setType(selector.type.widen())
.setSymbol(root.symbol()));
this.resultVar = new TermSymbol(selector.pos,
RESULT_N,
owner,
Modifiers.MUTABLE);
this.resultVar.setType(tpe);
*/
//this.statics = defs.getModule(Names.scala_Boolean);
this.infer = infer;
}
/** constructs an algebraic pattern matcher from cases
*/
public void construct( Matcher m, Tree[] cases /*, boolean doBinding*/) {
//this.doBinding = doBinding;
this._m = m;
initialize();
for( int i = 0; i < cases.length; i++ ) {
enter( (CaseDef) cases[i]/*, i*/ );
}
_m.tree = toTree();
}
/** initializes this AlgebraicMatcher, see Matcher.initialize
*/
protected void initialize() {
//this.mk = new PatternNodeCreator( unit, infer, _m.owner/*_m.clazzOwner*/ );
//this.cf = new CodeFactory( unit, infer, _m.pos );
this.owner = _m.owner;
this.selector = _m.selector;
this.root = makeConstrPat/*mk.ConstrPat*/( _m.pos,
_m.selector.type.widen() );
this.root.and = makeHeader/*mk.Header*/( _m.pos,
_m.selector.type.widen(),
gen.Ident( _m.pos, root.symbol() )
.setType(_m.selector.type.widen()));
this.resultVar = new TermSymbol(_m.pos,
/*cf.*/fresh.newName( RESULT_N ),
_m.owner,
Modifiers.MUTABLE );
//this.resultType = resultType;
this.resultVar.setType( _m.resultType );
//System.out.println(" constructed matcherDefs ");
}
/** return the analyzed type
*/
public Type typeOf(Symbol sym) {
return sym.type();
//return sym.typeAt(unit.global.ANALYZER_PHASE.id);
}
/** return the analyzed type
*/
public Type typeOf0(Symbol sym) {
return sym.typeAt(unit.global.PHASE.ANALYZER.id);
}
/** factories
*/
public Header makeHeader(int pos, Type type, Tree selector) {
Header node = new Header(selector, null);
node.pos = pos;
node.type = type;
return node;
}
public Body makeBody(int pos, ValDef[] bound, Tree guard, Tree body) {
Body node = new Body(new ValDef[][]{bound}, new Tree[]{guard}, new Tree[]{body});
node.pos = pos;
return node;
}
public void updateBody(Body tree, ValDef[] bound, Tree guard, Tree body) {
if (tree.guard[tree.guard.length - 1] == Tree.Empty)
unit.error(body.pos, "unreachable code");
ValDef[][] bd = new ValDef[tree.bound.length + 1][];
Tree[] ng = new Tree[tree.guard.length + 1];
Tree[] nb = new Tree[tree.body.length + 1];
System.arraycopy(tree.bound, 0, bd, 0, tree.bound.length);
System.arraycopy(tree.guard, 0, ng, 0, tree.guard.length);
System.arraycopy(tree.body, 0, nb, 0, tree.body.length);
bd[bd.length - 1] = bound;
ng[ng.length - 1] = guard;
nb[nb.length - 1] = body;
tree.bound = bd;
tree.guard = ng;
tree.body = nb;
}
public DefaultPat makeDefaultPat(int pos, Type type) {
DefaultPat node = new DefaultPat();
node.pos = pos;
node.type = type;
return node;
}
public ConstrPat makeConstrPat(int pos, Type type) {
//System.out.println("making constructor pattern for " + type);
ConstrPat node = new ConstrPat(newVar(pos, type));
node.pos = pos;
node.type = type;
return node;
}
public SequencePat makeSequencePat(int pos, Type type, int len) {
Symbol sym = newVar(Position.NOPOS, type);
SequencePat node = new SequencePat(sym, len);
node.pos = pos;
node.type = type;
return node;
}
public ConstantPat makeConstantPat(int pos, Type type, Object value) {
//System.out.println("making constant pattern for " + type + " of value " + value);
ConstantPat node = new ConstantPat(value);
node.pos = pos;
node.type = type;
return node;
}
public VariablePat makeVariablePat(int pos, Tree tree) {
//System.out.println("making variable pattern for " + tree.type);
VariablePat node = new VariablePat(tree);
node.pos = pos;
node.type = tree.type;
return node;
}
public TermSymbol newVar(int pos, Name name, Type type) {
TermSymbol sym = new TermSymbol(pos, name, owner, 0);
sym.setType(type);
return sym;
}
public TermSymbol newVar(int pos, Type type) {
return newVar(pos, fresh.newName("temp"), type);
}
public Tree copy(Tree tree) {
return tree; // insert copy function here
}
/** pretty printer
*/
public void print() {
print(root.and, "");
}
public void print(PatternNode patNode, String indent) {
if (patNode == null)
System.out.println(indent + "NULL");
else
switch (patNode) {
case Header(Tree selector, Header next):
System.out.println(indent + "HEADER(" + patNode.type +
", " + selector + ")");
print(patNode.or, indent + "|");
if (next != null)
print(next, indent);
break;
case ConstrPat(Symbol casted):
String s = "-- " + patNode.type.symbol().name +
"(" + patNode.type + ", " + casted + ") -> ";
String ind = indent;
indent = (patNode.or != null) ?
indent :
indent.substring(0, indent.length() - 1) + " ";
for (int i = 0; i < s.length(); i++)
indent += " ";
System.out.println(ind + s);
print(patNode.and, indent);
if (patNode.or != null)
print(patNode.or, ind);
break;
case SequencePat(Symbol casted, int plen):
String s = "-- " + patNode.type.symbol().name + "(" + patNode.type +
", " + casted + ", " + plen + ") -> ";
String ind = indent;
indent = (patNode.or != null) ?
indent :
indent.substring(0, indent.length() - 1) + " ";
for (int i = 0; i < s.length(); i++)
indent += " ";
System.out.println(ind + s);
print(patNode.and, indent);
if (patNode.or != null)
print(patNode.or, ind);
break;
case DefaultPat():
System.out.println(indent + "-- _ -> ");
print(patNode.and, indent.substring(0, indent.length() - 1) +
" ");
if (patNode.or != null)
print(patNode.or, indent);
break;
case ConstantPat(Object value):
String s = "-- CONST(" + value + ") -> ";
String ind = indent;
indent = (patNode.or != null) ?
indent :
indent.substring(0, indent.length() - 1) + " ";
for (int i = 0; i < s.length(); i++)
indent += " ";
System.out.println(ind + s);
print(patNode.and, indent);
if (patNode.or != null)
print(patNode.or, ind);
break;
case VariablePat(Tree tree):
String s = "-- STABLEID(" + tree + ": " + patNode.type + ") -> ";
String ind = indent;
indent = (patNode.or != null) ?
indent :
indent.substring(0, indent.length() - 1) + " ";
for (int i = 0; i < s.length(); i++)
indent += " ";
System.out.println(ind + s);
print(patNode.and, indent);
if (patNode.or != null)
print(patNode.or, ind);
break;
case Body(_, _, Tree[] stats):
System.out.println(indent + "BODY(" + stats.length + ")");
break;
}
}
public void enter(CaseDef tree) {
enter(tree.pos, tree.pat, tree.guard, tree.body);
}
protected CaseEnv enter(int pos, Tree pat, Tree guard, Tree body) {
CaseEnv env = new CaseEnv();
//PatternNode matched = match(pat, root);
PatternNode target = enter1(pat, -1, root, root.symbol(), env);
//if (target.and != null)
// unit.error(pat.pos, "duplicate case");
if (target.and == null)
target.and = makeBody(pos, env.boundVars(), guard, body);
else if (target.and instanceof Body)
updateBody((Body)target.and, env.boundVars(), guard, body);
else
unit.error(pat.pos, "duplicate case");
return env;
}
public PatternNode match(Tree pat, PatternNode target) {
// advance one step in pattern
PatternNode next = target.and;
// we are done (no match yet)
if (next == null)
return null;
// check if matched
switch (next) {
case Body(_, _, _):
return next;
case Header(_, _):
Header header = (Header)next;
// get pattern arguments
Tree[] patArgs = patternArgs(pat);
// get next pattern node
PatternNode patNode = patternNode(pat, header, null);
do {
next = header;
while ((next = next.or) != null)
if (superPat(next, patNode) &&
((target = match(patArgs, next)) != null))
return target;
else if (isDefaultPat(next))
return next.and;
} while ((header = header.next) != null);
return null;
default:
throw new ApplicationError();
}
}
public PatternNode match(Tree[] pats, PatternNode target) {
for (int i = 0; i < pats.length; i++)
if ((target = match(pats[i], target)) == null)
return null;
return target;
}
protected Tree[] patternArgs(Tree tree) {
switch (tree) {
case Apply(_, Tree[] args):
if (args.length == 1 && (tree.type.symbol().flags & Modifiers.CASE) == 0)
switch (args[0]) {
case Sequence(Tree[] ts):
return ts;
}
return args;
case Sequence(Tree[] ts):
return ts;
default:
return Tree.EMPTY_ARRAY;
}
}
protected Type getConstrType(Type tpe) {
return tpe;
/*
switch (tpe) {
case ConstructorType(Type result):
return result;
default:
return tpe;
} */
}
protected Type getHeaderType(Type tpe) {
switch (tpe) {
case PolyType(_, Type res):
return res;
default:
return tpe;
}
}
protected PatternNode patternNode(Tree tree, Header header, CaseEnv env) {
switch (tree) {
case Apply(Tree fn, Tree[] args): // pattern with args
if (args.length == 1 && (tree.type.symbol().flags & Modifiers.CASE) == 0)
switch (args[0]) {
case Sequence(Tree[] ts):
return makeSequencePat(tree.pos, tree.type, ts.length);
}
return makeConstrPat(tree.pos, getConstrType(tree.type));
case Typed(Ident(Name name), Tree tpe): // variable pattern
PatternNode node =
(header.type.isSubType(getConstrType(tpe.type))) ?
makeDefaultPat(tree.pos, getConstrType(tpe.type))
: makeConstrPat(tree.pos, getConstrType(tpe.type));
if ((env != null) && (name != WILDCARD_N))
switch (node) {
case ConstrPat(Symbol casted):
env.newBoundVar(
tree.pos,
((Tree.Typed)tree).expr.symbol(),
getConstrType(tpe.type),
make.Ident(tree.pos, casted.name).
setType(typeOf(casted)).
setSymbol(casted));
break;
default:
env.newBoundVar(
tree.pos,
((Tree.Typed)tree).expr.symbol(),
getConstrType(tpe.type),
header.selector);
}
return node;
case Ident(Name name): // pattern without args or variable
if (tree.symbol().isPrimaryConstructor())
return makeConstrPat(tree.pos, getConstrType(tree.type));
else if (name.isVariable()) {
if ((env != null) && (name != WILDCARD_N))
env.newBoundVar(
tree.pos,
tree.symbol(),
getConstrType(tree.type),
header.selector);
return makeDefaultPat(tree.pos, getConstrType(header.type));
} else
return makeVariablePat(tree.pos, tree);
case Select(_, Name name): // variable
if (tree.symbol().isPrimaryConstructor())
return makeConstrPat(tree.pos, getConstrType(tree.type));
else
return makeVariablePat(tree.pos, tree);
case Literal(Object value):
return makeConstantPat(tree.pos, getConstrType(tree.type), value);
case Sequence(Tree[] ts):
return makeSequencePat(tree.pos, tree.type, ts.length);
default:
new scalac.ast.printer.TextTreePrinter().print(tree).flush();
throw new ApplicationError(tree);
}
}
protected boolean superPat(PatternNode p, PatternNode q) {
switch (p) {
case DefaultPat():
switch (q) {
case DefaultPat():
return true;
//case ConstantPat(_, _):
// return q.type.isSubType(p.type);
}
return false;
case ConstrPat(_):
switch (q) {
case ConstrPat(_):
return q.type.isSubType(p.type);
}
return false;
case SequencePat(_, int plen):
switch (q) {
case SequencePat(_, int qlen):
return (plen == qlen) && q.type.isSubType(p.type);
}
return false;
case ConstantPat(Object pval):
switch (q) {
case ConstantPat(Object qval):
return pval.equals(qval);
}
return false;
case VariablePat(Tree tree):
switch (q) {
case VariablePat(Tree other):
return (tree.symbol() != null) &&
(tree.symbol().kind != Kinds.NONE) &&
(tree.symbol().kind != Kinds.ERROR) &&
(tree.symbol() == other.symbol());
}
return false;
}
return false;
}
protected boolean isDefaultPat(PatternNode p) {
switch (p) {
case DefaultPat():
return true;
default:
return false;
}
}
public PatternNode enter(Tree pat,
int index,
PatternNode target,
Symbol casted,
CaseEnv env) {
switch (target) {
case ConstrPat(Symbol newCasted):
return enter1(pat, index, target, newCasted, env);
case SequencePat(Symbol newCasted, int len):
return enter1(pat, index, target, newCasted, env);
default:
return enter1(pat, index, target, casted, env);
}
}
public PatternNode enter1(Tree pat,
int index,
PatternNode target,
Symbol casted,
CaseEnv env) {
//System.out.println("enter(" + pat + ", " + index + ", " + target + ", " + casted + ")");
// get pattern arguments
Tree[] patArgs = patternArgs(pat);
// get case fields
//assert patArgs.length == nCaseComponents(pat);
// advance one step in pattern
Header curHeader = (Header)target.and;
// check if we have to add a new header
if (curHeader == null) {
assert index >= 0 : casted;
if (casted.pos == Position.NOPOS) {
Symbol atSym = casted.type().lookup(AT_N);
//System.out.println("casted type = " + typeOf(casted));
Type seqType = casted.type().baseType(defs.SEQ_CLASS).typeArgs()[0];
Tree t = make.Select(
pat.pos,
make.Ident(pat.pos, casted.name)
.setType(typeOf(casted))
.setSymbol(casted),
AT_N);
switch (typeOf(atSym)) {
case OverloadedType(Symbol[] alts, Type[] alttypes):
infer.methodAlternative(t, alts, alttypes,
new Type[]{defs.INT_TYPE}, seqType);
t = make.Apply(pat.pos, t,
new Tree[]{
make.Literal(pat.pos, new Integer(index))
.setType(defs.INT_TYPE)
}).setType(seqType);
break;
default:
t.setSymbol(atSym);
t.setType(typeOf(atSym));
t = make.Apply(pat.pos, t,
new Tree[]{
make.Literal(pat.pos, new Integer(index))
.setType(defs.INT_TYPE)
}).setType(seqType);
}
target.and = curHeader = makeHeader(pat.pos, seqType, t);
} else {
Symbol ts = ((ClassSymbol) casted.type().symbol())
.caseFieldAccessor(index);
// target.and = curHeader = makeHeader(
// pat.pos,
// getHeaderType(typeOf0(ts)),
// make.Select(
// pat.pos,
// make.Ident(pat.pos, casted.name)
// .setType(typeOf(casted))
// .setSymbol(casted),
// ts.name)
// .setType(getHeaderType(typeOf0(ts)))
// .setSymbol(ts));
target.and = curHeader = makeHeader(
pat.pos,
getHeaderType(typeOf0(ts)),
make.Apply(
pat.pos,
make.Select(
pat.pos,
make.Ident(pat.pos, casted.name)
.setType(typeOf(casted))
.setSymbol(casted),
ts.name)
.setType(Type.MethodType(
Symbol.EMPTY_ARRAY,
getHeaderType(typeOf0(ts))))
.setSymbol(ts),
Tree.EMPTY_ARRAY).setType(getHeaderType(typeOf0(ts))));
}
curHeader.or = patternNode(pat, curHeader, env);
return enter(patArgs, curHeader.or, casted, env);
}
// find most recent header
while (curHeader.next != null)
curHeader = curHeader.next;
// create node
PatternNode patNode = patternNode(pat, curHeader, env);
PatternNode next = curHeader;
// enter node
while (true)
if (superPat(next, patNode))
return enter(patArgs, next, casted, env);
else if (isDefaultPat(next) ||
((next.or == null) && isDefaultPat(patNode)))
return enter(
patArgs,
(curHeader = (curHeader.next =
makeHeader(patNode.pos, curHeader.type, curHeader.selector))).or
= patNode,
casted,
env);
else if (next.or == null)
return enter(patArgs, next.or = patNode, casted, env);
else
next = next.or;
}
public PatternNode enter(Tree[] pats, PatternNode target, Symbol casted, CaseEnv env) {
switch (target) {
case ConstrPat(Symbol newCasted):
casted = newCasted;
break;
case SequencePat(Symbol newCasted, int len):
casted = newCasted;
break;
}
for (int i = 0; i < pats.length; i++)
target = enter1(pats[i], i, target, casted, env);
return target;
}
protected int nCaseComponents(Tree tree) {
switch (tree) {
case Apply(Tree fn, _):
Type tpe = typeOf(tree.type.symbol().constructor());
//System.out.println("~~~ " + tree.type() + ", " + tree.type().symbol().constructor());
switch (tpe) {
// I'm not sure if this is a good idea, but obviously, currently all case classes
// without constructor arguments have type NoType
case NoType:
return 0;
case MethodType(Symbol[] args, _):
return args.length;
case PolyType(Symbol[] tvars, MethodType(Symbol[] args, _)):
return args.length;
case PolyType(Symbol[] tvars, _):
return 0;
default:
throw new ApplicationError("not yet implemented;" +
"pattern matching for " + tree + ": " + tpe);
}
}
return 0;
}
//////////// generator methods
public Tree toTree() {
TreeList ts = new TreeList();
ts.append(
make.ValDef(selector.pos,
0,
root.symbol().name,
gen.mkType(selector.pos, selector.type),
selector).setType(defs.UNIT_TYPE).setSymbol(root.symbol()));
ts.append(
make.ValDef(selector.pos,
Modifiers.MUTABLE,
resultVar.name,
gen.mkType(selector.pos, typeOf(resultVar)),
Tree.Empty).setType(defs.UNIT_TYPE).setSymbol(resultVar));
ts.append(
make.If(
selector.pos,
toTree(root.and),
make.Ident(selector.pos,
resultVar.name).setType(typeOf(resultVar)).setSymbol(resultVar),
mkThrowMatchError(selector.pos, typeOf(resultVar))).setType(typeOf(resultVar)));
return mkBlock(selector.pos, ts.toArray(), typeOf(resultVar));
}
protected Tree toTree(PatternNode node) {
Tree res = gen.mkBooleanLit(node.pos, false);
while (node != null)
switch (node) {
case Header(Tree selector, Header next):
//res = mkAnd(mkNegate(res), toTree(node.or, selector));
//System.out.println("HEADER TYPE = " + selector.type);
res = mkOr(res, toTree(node.or, selector));
node = next;
break;
case Body(ValDef[][] bound, Tree[] guard, Tree[] body):
for (int i = guard.length - 1; i >= 0; i--) {
Tree[] ts = new Tree[bound[i].length + 1];
System.arraycopy(bound[i], 0, ts, 0, bound[i].length);
ts[bound[i].length] = mkBlock(body[i].pos,
new Tree[]{
make.Assign(
body[i].pos,
make.Ident(body[i].pos, resultVar.name)
.setType(typeOf(resultVar)).setSymbol(resultVar),
body[i]).setType(defs.UNIT_TYPE),
gen.mkBooleanLit(body[i].pos, true)
}, defs.BOOLEAN_TYPE);
if (guard[i] != Tree.Empty)
ts[bound[i].length] = mkAnd(guard[i], ts[bound[i].length]);
res = mkOr(mkBlock(body[i].pos, ts, defs.BOOLEAN_TYPE), res);
}
return res;
default:
throw new ApplicationError();
}
return res;
}
protected Tree toTree(PatternNode node, Tree selector) {
if (node == null)
return gen.mkBooleanLit(selector.pos, false);
switch (node) {
case DefaultPat():
return toTree(node.and);
case ConstrPat(Symbol casted):
return make.If(
selector.pos,
mkIs(selector.duplicate(), node.type),
mkBlock(selector.pos,
new Tree[]{
make.ValDef(selector.pos,
0,
casted.name,
gen.mkType(selector.pos, node.type),
mkAs(selector.duplicate(), node.type))
.setType(defs.UNIT_TYPE).setSymbol(casted),
toTree(node.and)}, defs.BOOLEAN_TYPE),
toTree(node.or, selector.duplicate())).setType(defs.BOOLEAN_TYPE);
case SequencePat(Symbol casted, int len):
Symbol lenSym = casted.type().lookup(LENGTH_N);
Tree t = make.Select(selector.pos, mkAs(selector.duplicate(), node.type), LENGTH_N);
switch (typeOf(lenSym)) {
case OverloadedType(Symbol[] alts, Type[] alttypes):
infer.methodAlternative(t, alts, alttypes, new Type[0], defs.INT_TYPE);
break;
default:
t.setSymbol(lenSym);
t.setType(typeOf(lenSym));
}
return make.If(
selector.pos,
mkAnd(
mkIs(selector.duplicate(), node.type),
mkEquals(
make.Apply(
selector.pos, t,
Tree.EMPTY_ARRAY).setType(defs.INT_TYPE),
make.Literal(selector.pos, new Integer(len))
.setType(defs.INT_TYPE))),
mkBlock(selector.pos,
new Tree[]{
make.ValDef(selector.pos,
0,
casted.name,
gen.mkType(selector.pos, node.type),
mkAs(selector.duplicate(), node.type))
.setType(defs.UNIT_TYPE).setSymbol(casted),
toTree(node.and)}, defs.BOOLEAN_TYPE),
toTree(node.or, selector.duplicate()))
.setType(defs.BOOLEAN_TYPE);
case ConstantPat(Object value):
return make.If(
selector.pos,
mkEquals(selector.duplicate(),
make.Literal(selector.pos, value)
.setType(node.type)),
toTree(node.and),
toTree(node.or, selector.duplicate())).setType(defs.BOOLEAN_TYPE);
case VariablePat(Tree tree):
return make.If(
selector.pos,
mkEquals(selector.duplicate(), tree),
toTree(node.and),
toTree(node.or, selector.duplicate())).setType(defs.BOOLEAN_TYPE);
default:
throw new ApplicationError();
}
}
protected Tree mkBlock(int pos, Tree[] ts, Type tpe) {
if (ts.length == 1)
return ts[0];
else if (ts.length > 1)
switch (ts[ts.length - 1]) {
case Block(Tree[] ts0):
Tree[] ts1 = new Tree[ts0.length + ts.length - 1];
System.arraycopy(ts, 0, ts1, 0, ts.length - 1);
System.arraycopy(ts0, 0, ts1, ts.length - 1, ts0.length);
return mkBlock(pos, ts1, tpe);
}
return make.Block(pos, ts).setType(tpe);
}
protected Tree mkNegate(Tree tree) {
switch (tree) {
case Literal(Object value):
return gen.mkBooleanLit(tree.pos, !((Boolean)value).booleanValue());
}
return make.Apply(
tree.pos,
gen.Select(tree, NOT_N),
Tree.EMPTY_ARRAY).setType(defs.BOOLEAN_TYPE);
}
protected Tree mkAnd(Tree left, Tree right) {
switch (left) {
case Literal(Object value):
return ((Boolean)value).booleanValue() ? right : left;
}
switch (right) {
case Literal(Object value):
if (((Boolean)value).booleanValue()) return left;
}
Symbol fun = left.type.lookup(AND_N);
return make.Apply(
left.pos,
make.Select(
left.pos,
left,
AND_N).setType(typeOf(fun)).setSymbol(fun),
new Tree[]{right}).setType(defs.BOOLEAN_TYPE);
}
protected Tree mkOr(Tree left, Tree right) {
switch (left) {
case Literal(Object value):
return ((Boolean)value).booleanValue() ? left : right;
}
switch (right) {
case Literal(Object value):
if (!((Boolean)value).booleanValue()) return left;
}
Symbol fun = left.type.lookup(OR_N);
return make.Apply(
left.pos,
make.Select(
left.pos,
left,
OR_N).setType(typeOf(fun)).setSymbol(fun),
new Tree[]{right}).setType(defs.BOOLEAN_TYPE);
}
protected Tree mkIs(Tree tree, Type type) {
return
make.Apply(
tree.pos,
make.TypeApply(
tree.pos,
make.Select(
tree.pos,
tree,
defs.IS.name).setType(typeOf(defs.IS)).setSymbol(defs.IS),
new Tree[]{gen.mkType(tree.pos, type)})
.setType(Type.MethodType(Symbol.EMPTY_ARRAY, defs.BOOLEAN_TYPE)),
Tree.EMPTY_ARRAY).setType(defs.BOOLEAN_TYPE);
}
protected Tree mkAs(Tree tree, Type type) {
return
make.Apply(
tree.pos,
make.TypeApply(
tree.pos,
make.Select(
tree.pos,
tree,
defs.AS.name).setType(typeOf(defs.AS)).setSymbol(defs.AS),
new Tree[]{gen.mkType(tree.pos, type)})
.setType(Type.MethodType(Symbol.EMPTY_ARRAY, type)),
Tree.EMPTY_ARRAY).setType(type);
}
protected Tree mkEquals(Tree left, Tree right) {
Symbol fun = left.type.lookup(EQUALS_N);
switch (typeOf(fun)) {
case OverloadedType(Symbol[] alts, Type[] alttypes):
//System.out.println("**** " + left.type);
Tree t = make.Select(left.pos, left, EQUALS_N);
//for (int i = 0; i < alttypes.length; i++)
// System.out.println(alts[i] + ": " + alttypes[i]);
infer.methodAlternative(t, alts, alttypes,
new Type[]{right.type}, defs.BOOLEAN_TYPE);
return make.Apply(left.pos, t, new Tree[]{right}).setType(defs.BOOLEAN_TYPE);
default:
//System.out.println("#### " + left.type + ": " + fun);
return make.Apply(
left.pos,
make.Select(
left.pos,
left,
EQUALS_N).setType(typeOf(fun)).setSymbol(fun),
new Tree[]{right}).setType(defs.BOOLEAN_TYPE);
}
}
protected Tree mkThrowMatchError(int pos, Type type) {
Symbol matchErrorModule = defs.SCALA.members().lookup(MATCHERROR_N);
outer: switch (typeOf(matchErrorModule)) {
case OverloadedType(Symbol[] alts, Type[] alttypes):
for (int i = 0; i < alts.length; i++)
switch (alttypes[i]) {
case TypeRef(_, _, _):
matchErrorModule = alts[i];
break outer;
}
}
Symbol failMethod = typeOf(matchErrorModule).lookup(FAIL_N);
return
make.Apply(
pos,
make.TypeApply(
pos,
make.Select(
pos,
make.Select(
pos,
make.Ident(pos, Names.scala).setType(typeOf(defs.SCALA)).setSymbol(defs.SCALA),
MATCHERROR_N)
.setSymbol(matchErrorModule)
.setType(typeOf(matchErrorModule)),
FAIL_N).setType(typeOf(failMethod)).setSymbol(failMethod),
new Tree[]{gen.mkType(pos, type)})
.setType(((Type.PolyType) typeOf(failMethod)).result.subst(
typeOf(failMethod).typeParams(),
new Type[]{type})),
new Tree[]{
make.Literal(pos, unit.toString()).setType(defs.STRING_TYPE),
make.Literal(pos, new Integer(Position.line(pos))).setType(defs.INT_TYPE)
}).setType(type);
}
class CaseEnv {
protected ValDef[] boundVars = new ValDef[4];
protected int numVars = 0;
public void newBoundVar(int pos, Symbol sym, Type type, Tree init) {
sym.setOwner(PatternMatcher.this.owner); // FIXME should be corrected earlier
if (numVars == boundVars.length) {
ValDef[] newVars = new ValDef[numVars * 2];
System.arraycopy(boundVars, 0, newVars, 0, numVars);
boundVars = newVars;
}
sym.setType(type);
boundVars[numVars++] = (ValDef)make.ValDef(
pos,
0,
sym.name,
gen.mkType(pos, type),
init.duplicate()).setType(defs.UNIT_TYPE).setSymbol(sym);
}
public ValDef[] boundVars() {
ValDef[] newVars = new ValDef[numVars];
System.arraycopy(boundVars, 0, newVars, 0, numVars);
return newVars;
}
public boolean equals(Object obj) {
if (!(obj instanceof CaseEnv))
return false;
CaseEnv env = (CaseEnv)obj;
if (env.numVars != numVars)
return false;
for (int i = 0; i < numVars; i++)
if ((boundVars[i].name != env.boundVars[i].name) ||
!boundVars[i].tpe.type.isSameAs(env.boundVars[i].tpe.type) ||
(boundVars[i].rhs != env.boundVars[i].rhs))
return false;
return true;
}
}
}
|