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
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
5022
5023
5024
5025
5026
5027
5028
5029
5030
5031
5032
5033
5034
5035
5036
5037
5038
5039
5040
5041
5042
5043
5044
5045
5046
5047
5048
5049
5050
5051
5052
5053
5054
5055
5056
5057
5058
5059
5060
5061
5062
5063
5064
5065
5066
5067
5068
5069
5070
5071
5072
5073
5074
5075
5076
5077
5078
5079
5080
5081
5082
5083
5084
5085
5086
5087
5088
5089
5090
5091
5092
5093
5094
5095
5096
5097
5098
5099
5100
5101
5102
5103
5104
5105
5106
5107
5108
5109
5110
5111
5112
5113
5114
5115
5116
5117
5118
5119
5120
5121
5122
5123
5124
5125
5126
5127
5128
5129
5130
5131
5132
5133
5134
5135
5136
5137
5138
5139
5140
5141
5142
5143
5144
5145
5146
5147
5148
5149
5150
5151
5152
5153
5154
5155
5156
5157
5158
5159
5160
5161
5162
5163
5164
5165
5166
5167
5168
5169
5170
5171
5172
5173
5174
5175
5176
5177
5178
5179
5180
5181
5182
5183
5184
5185
5186
5187
5188
5189
5190
5191
5192
5193
5194
5195
5196
5197
5198
5199
5200
5201
5202
5203
5204
5205
5206
5207
5208
5209
5210
5211
5212
5213
5214
5215
5216
5217
5218
5219
5220
5221
5222
5223
5224
5225
5226
5227
5228
5229
5230
5231
5232
5233
5234
5235
5236
5237
5238
5239
5240
5241
5242
5243
5244
5245
5246
5247
5248
5249
5250
5251
5252
5253
5254
5255
5256
5257
5258
5259
5260
5261
5262
5263
5264
5265
5266
5267
5268
5269
5270
5271
5272
5273
5274
5275
5276
5277
5278
5279
5280
5281
5282
5283
5284
5285
5286
5287
5288
5289
5290
5291
5292
5293
5294
5295
5296
5297
5298
5299
5300
5301
5302
5303
5304
5305
5306
5307
5308
5309
5310
5311
5312
5313
5314
5315
5316
5317
5318
5319
5320
5321
5322
5323
5324
5325
5326
5327
5328
5329
5330
5331
5332
5333
5334
5335
5336
5337
5338
5339
5340
5341
5342
5343
5344
5345
5346
5347
5348
5349
5350
5351
5352
5353
5354
5355
5356
5357
5358
5359
5360
5361
5362
5363
5364
5365
5366
5367
5368
5369
5370
5371
5372
5373
5374
5375
5376
5377
5378
5379
5380
5381
5382
5383
5384
5385
5386
5387
5388
5389
5390
5391
5392
5393
5394
5395
5396
5397
5398
5399
5400
5401
5402
5403
5404
5405
5406
5407
5408
5409
5410
5411
5412
5413
5414
5415
5416
5417
5418
5419
5420
5421
5422
5423
5424
5425
5426
5427
5428
5429
5430
5431
5432
5433
5434
5435
5436
5437
5438
5439
5440
5441
5442
5443
5444
5445
5446
5447
5448
5449
5450
5451
5452
5453
5454
5455
5456
5457
5458
5459
5460
5461
5462
5463
5464
5465
5466
5467
5468
5469
5470
5471
5472
5473
5474
5475
5476
5477
5478
5479
5480
5481
5482
5483
5484
5485
5486
5487
5488
5489
5490
5491
5492
5493
5494
5495
5496
5497
5498
5499
5500
5501
5502
5503
5504
5505
5506
5507
5508
5509
5510
5511
5512
5513
5514
5515
5516
5517
5518
5519
5520
5521
5522
5523
5524
5525
5526
5527
5528
5529
5530
5531
5532
5533
5534
5535
5536
5537
5538
5539
5540
5541
5542
5543
5544
5545
5546
5547
5548
5549
5550
5551
5552
5553
5554
5555
5556
5557
5558
5559
5560
5561
5562
5563
5564
5565
5566
5567
5568
5569
5570
5571
5572
5573
5574
5575
5576
5577
5578
5579
5580
5581
5582
5583
5584
5585
5586
5587
5588
5589
5590
5591
5592
5593
5594
5595
5596
5597
5598
5599
5600
5601
5602
5603
5604
5605
5606
5607
5608
5609
5610
5611
5612
5613
5614
5615
5616
5617
5618
5619
5620
5621
5622
5623
5624
5625
5626
5627
5628
5629
5630
5631
5632
5633
5634
5635
5636
5637
5638
5639
5640
5641
5642
5643
5644
5645
5646
5647
5648
5649
5650
5651
5652
5653
5654
5655
5656
5657
5658
5659
5660
5661
5662
5663
5664
5665
5666
5667
5668
5669
5670
5671
5672
5673
5674
5675
5676
5677
5678
5679
5680
5681
5682
5683
|
/* NSC -- new Scala compiler
* Copyright 2005-2011 LAMP/EPFL
* @author Martin Odersky
*/
package scala.tools.nsc
package symtab
import scala.collection.{ mutable, immutable }
import scala.ref.WeakReference
import scala.collection.mutable.ListBuffer
import ast.TreeGen
import util.{ Position, NoPosition }
import util.Statistics._
import Flags._
import scala.util.control.ControlThrowable
import scala.annotation.tailrec
/* A standard type pattern match:
case ErrorType =>
// internal: error
case WildcardType =>
// internal: unknown
case NoType =>
case NoPrefix =>
case ThisType(sym) =>
// sym.this.type
case SuperType(thistpe, supertpe) =>
// super references
case SingleType(pre, sym) =>
// pre.sym.type
case ConstantType(value) =>
// Int(2)
case TypeRef(pre, sym, args) =>
// pre.sym[targs]
// Outer.this.C would be represented as TypeRef(ThisType(Outer), C, List())
case RefinedType(parents, defs) =>
// parent1 with ... with parentn { defs }
case ExistentialType(tparams, result) =>
// result forSome { tparams }
case AnnotatedType(annots, tp, selfsym) =>
// tp @annots
// the following are non-value types; you cannot write them down in Scala source.
case TypeBounds(lo, hi) =>
// >: lo <: hi
case ClassInfoType(parents, defs, clazz) =>
// same as RefinedType except as body of class
case MethodType(paramtypes, result) =>
// (paramtypes)result
// For instance def m(): T is represented as MethodType(List(), T)
case NullaryMethodType(result) => // eliminated by uncurry
// an eval-by-name type
// For instance def m: T is represented as NullaryMethodType(T)
case PolyType(tparams, result) =>
// [tparams]result where result is a (Nullary)MethodType or ClassInfoType
// The remaining types are not used after phase `typer'.
case OverloadedType(pre, tparams, alts) =>
// all alternatives of an overloaded ident
case AntiPolyType(pre, targs) =>
// rarely used, disappears when combined with a PolyType
case TypeVar(inst, constr) =>
// a type variable
// Replace occurrences of type parameters with type vars, where
// inst is the instantiation and constr is a list of bounds.
case DeBruijnIndex(level, index)
// for dependent method types: a type referring to a method parameter.
// Not presently used, it seems.
*/
trait Types extends reflect.generic.Types { self: SymbolTable =>
import definitions._
//statistics
def uniqueTypeCount = if (uniques == null) 0 else uniques.size
private var explainSwitch = false
private final val emptySymbolSet = immutable.Set.empty[Symbol]
private final val alternativeNarrow = false
private final val LogPendingSubTypesThreshold = 50
private final val LogPendingBaseTypesThreshold = 50
private final val LogVolatileThreshold = 50
/** A don't care value for the depth parameter in lubs/glbs and related operations */
private final val AnyDepth = -3
/** Decrement depth unless it is a don't care */
private final def decr(depth: Int) = if (depth == AnyDepth) AnyDepth else depth - 1
private final val printLubs = false
/** The current skolemization level, needed for the algorithms
* in isSameType, isSubType that do constraint solving under a prefix
*/
var skolemizationLevel = 0
/** A log of type variable with their original constraints. Used in order
* to undo constraints in the case of isSubType/isSameType failure.
*/
object undoLog {
private type UndoLog = List[(TypeVar, TypeConstraint)]
private[nsc] var log: UndoLog = List()
/** Undo all changes to constraints to type variables upto `limit'
*/
private def undoTo(limit: UndoLog) {
while ((log ne limit) && log.nonEmpty) {
val (tv, constr) = log.head
tv.constr = constr
log = log.tail
}
}
private[Types] def record(tv: TypeVar) = {
log ::= (tv, tv.constr.cloneInternal)
}
private[nsc] def clear() {
if (settings.debug.value)
self.log("Clearing " + log.size + " entries from the undoLog.")
log = Nil
}
// `block` should not affect constraints on typevars
def undo[T](block: => T): T = {
val before = log
try block
finally undoTo(before)
}
// if `block` evaluates to false, it should not affect constraints on typevars
def undoUnless(block: => Boolean): Boolean = {
val before = log
var result = false
try result = block
finally if (!result) undoTo(before)
result
}
}
/** A map from lists to compound types that have the given list as parents.
* This is used to avoid duplication in the computation of base type sequences and baseClasses.
* It makes use of the fact that these two operations depend only on the parents,
* not on the refinement.
*/
val intersectionWitness = new mutable.WeakHashMap[List[Type], WeakReference[Type]]
private object gen extends {
val global : Types.this.type = Types.this
} with TreeGen
import gen._
/** A proxy for a type (identified by field `underlying') that forwards most
* operations to it (for exceptions, see WrappingProxy, which forwards even more operations).
* every operation that is overridden for some kind of types should be forwarded.
*/
trait SimpleTypeProxy extends Type {
def underlying: Type
// the following operations + those in RewrappingTypeProxy are all operations
// in class Type that are overridden in some subclass
// Important to keep this up-to-date when new operations are added!
override def isTrivial = underlying.isTrivial
override def isHigherKinded: Boolean = underlying.isHigherKinded
override def typeConstructor: Type = underlying.typeConstructor
override def isNotNull = underlying.isNotNull
override def isError = underlying.isError
override def isErroneous = underlying.isErroneous
override def isStable: Boolean = underlying.isStable
override def isVolatile = underlying.isVolatile
override def finalResultType = underlying.finalResultType
override def paramSectionCount = underlying.paramSectionCount
override def paramss = underlying.paramss
override def params = underlying.params
override def paramTypes = underlying.paramTypes
override def termSymbol = underlying.termSymbol
override def termSymbolDirect = underlying.termSymbolDirect
override def typeParams = underlying.typeParams
override def boundSyms = underlying.boundSyms
override def typeSymbol = underlying.typeSymbol
override def typeSymbolDirect = underlying.typeSymbolDirect
override def widen = underlying.widen
override def typeOfThis = underlying.typeOfThis
override def bounds = underlying.bounds
override def parents = underlying.parents
override def prefix = underlying.prefix
override def decls = underlying.decls
override def baseType(clazz: Symbol) = underlying.baseType(clazz)
override def baseTypeSeq = underlying.baseTypeSeq
override def baseTypeSeqDepth = underlying.baseTypeSeqDepth
override def baseClasses = underlying.baseClasses
}
/** A proxy for a type (identified by field `underlying') that forwards most
* operations to it. Every operation that is overridden for some kind of types is
* forwarded here. Some operations are rewrapped again.
*/
trait RewrappingTypeProxy extends SimpleTypeProxy {
protected def maybeRewrap(newtp: Type) = if (newtp eq underlying) this else rewrap(newtp)
protected def rewrap(newtp: Type): Type
// the following are all operations in class Type that are overridden in some subclass
// Important to keep this up-to-date when new operations are added!
override def widen = maybeRewrap(underlying.widen)
override def narrow = underlying.narrow
override def deconst = maybeRewrap(underlying.deconst)
override def resultType = maybeRewrap(underlying.resultType)
override def resultType(actuals: List[Type]) = maybeRewrap(underlying.resultType(actuals))
override def finalResultType = maybeRewrap(underlying.finalResultType)
override def paramSectionCount = 0
override def paramss: List[List[Symbol]] = List()
override def params: List[Symbol] = List()
override def paramTypes: List[Type] = List()
override def typeArgs = underlying.typeArgs
override def notNull = maybeRewrap(underlying.notNull)
override def instantiateTypeParams(formals: List[Symbol], actuals: List[Type]) = underlying.instantiateTypeParams(formals, actuals)
override def skolemizeExistential(owner: Symbol, origin: AnyRef) = underlying.skolemizeExistential(owner, origin)
override def normalize = maybeRewrap(underlying.normalize)
override def dealias = maybeRewrap(underlying.dealias)
override def cloneInfo(owner: Symbol) = maybeRewrap(underlying.cloneInfo(owner))
override def atOwner(owner: Symbol) = maybeRewrap(underlying.atOwner(owner))
override def prefixString = underlying.prefixString
override def isComplete = underlying.isComplete
override def complete(sym: Symbol) = underlying.complete(sym)
override def load(sym: Symbol) { underlying.load(sym) }
override def withAnnotations(annots: List[AnnotationInfo]) = maybeRewrap(underlying.withAnnotations(annots))
override def withoutAnnotations = maybeRewrap(underlying.withoutAnnotations)
}
/** The base class for all types */
abstract class Type extends AbsType {
/** Types for which asSeenFrom always is the identity, no matter what
* prefix or owner.
*/
def isTrivial: Boolean = false
/** Is this type higher-kinded, i.e., is it a type constructor @M */
def isHigherKinded: Boolean = false
/** Does this type denote a stable reference (i.e. singleton type)? */
def isStable: Boolean = false
/** Is this type dangerous (i.e. it might contain conflicting
* type information when empty, so that it can be constructed
* so that type unsoundness results.) A dangerous type has an underlying
* type of the form T_1 with T_n { decls }, where one of the
* T_i (i > 1) is an abstract type.
*/
def isVolatile: Boolean = false
/** Is this type guaranteed not to have `null' as a value? */
def isNotNull: Boolean = false
/** Is this type a structural refinement type (it 'refines' members that have not been inherited) */
def isStructuralRefinement: Boolean = false
/** Does this type depend immediately on an enclosing method parameter?
* i.e., is it a singleton type whose termSymbol refers to an argument of the symbol's owner (which is a method)
*/
def isImmediatelyDependent: Boolean = false
/** Does this depend on an enclosing method parameter? */
def isDependent: Boolean = IsDependentCollector.collect(this)
/** True for WildcardType or BoundedWildcardType */
def isWildcard = false
/** The term symbol associated with the type
* Note that the symbol of the normalized type is returned (@see normalize)
*/
def termSymbol: Symbol = NoSymbol
/** The type symbol associated with the type
* Note that the symbol of the normalized type is returned (@see normalize)
*/
def typeSymbol: Symbol = NoSymbol
/** The term symbol *directly* associated with the type
*/
def termSymbolDirect: Symbol = termSymbol
/** The type symbol *directly* associated with the type
*/
def typeSymbolDirect: Symbol = typeSymbol
/** The base type underlying a type proxy,
* identity on all other types */
def underlying: Type = this
/** Widen from singleton type to its underlying non-singleton
* base type by applying one or more `underlying' dereferences,
* identity for all other types.
*
* class Outer { class C ; val x: C }
* val o: Outer
* <o.x.type>.widen = o.C
*/
def widen: Type = this
/** Map a constant type or not-null-type to its underlying base type,
* identity for all other types.
*/
def deconst: Type = this
/** The type of `this' of a class type or reference type
*/
def typeOfThis: Type = typeSymbol.typeOfThis
/** Map to a singleton type which is a subtype of this type.
* The fallback implemented here gives
* T.narrow = (T {}).this.type
* Overridden where we know more about where types come from.
*
* todo: change to singleton type of an existentially defined variable
* of the right type instead of making this a `this` of a refined type.
*/
def narrow: Type =
if (phase.erasedTypes) this
else if (alternativeNarrow) { // investigate why this does not work!
val tparam = commonOwner(this) freshExistential ".type" setInfo singletonBounds(this)
tparam.tpe
} else {
val cowner = commonOwner(this)
refinedType(List(this), cowner, EmptyScope, cowner.pos).narrow
}
/** For a TypeBounds type, itself;
* for a reference denoting an abstract type, its bounds,
* for all other types, a TypeBounds type all of whose bounds are this type.
*/
def bounds: TypeBounds = TypeBounds(this, this)
/** For a class or intersection type, its parents.
* For a TypeBounds type, the parents of its hi bound.
* inherited by typerefs, singleton types, and refinement types,
* The empty list for all other types */
def parents: List[Type] = List()
/** For a typeref or single-type, the prefix of the normalized type (@see normalize).
* NoType for all other types. */
def prefix: Type = NoType
/** A chain of all typeref or singletype prefixes of this type, longest first.
* (Only used from safeToString.)
*/
def prefixChain: List[Type] = this match {
case TypeRef(pre, _, _) => pre :: pre.prefixChain
case SingleType(pre, _) => pre :: pre.prefixChain
case _ => List()
}
/** This type, without its type arguments @M */
def typeConstructor: Type = this
/** For a typeref, its arguments. The empty list for all other types */
def typeArgs: List[Type] = List()
/** For a (nullary) method or poly type, its direct result type,
* the type itself for all other types. */
def resultType: Type = this
def resultType(actuals: List[Type]) = this
/** Only used for dependent method types. */
def resultApprox: Type = if(settings.YdepMethTpes.value) ApproximateDependentMap(resultType) else resultType
/** If this is a TypeRef `clazz`[`T`], return the argument `T`
* otherwise return this type
*/
def remove(clazz: Symbol): Type = this
/** For a curried/nullary method or poly type its non-method result type,
* the type itself for all other types */
def finalResultType: Type = this
/** For a method type, the number of its value parameter sections,
* 0 for all other types */
def paramSectionCount: Int = 0
/** For a method or poly type, a list of its value parameter sections,
* the empty list for all other types */
def paramss: List[List[Symbol]] = List()
/** For a method or poly type, its first value parameter section,
* the empty list for all other types */
def params: List[Symbol] = List()
/** For a method or poly type, the types of its first value parameter section,
* the empty list for all other types */
def paramTypes: List[Type] = List()
/** For a (potentially wrapped) poly type, its type parameters,
* the empty list for all other types */
def typeParams: List[Symbol] = List()
/** For a (potentially wrapped) poly or existential type, its bound symbols,
* the empty list for all other types */
def boundSyms: immutable.Set[Symbol] = emptySymbolSet
/** Mixin a NotNull trait unless type already has one
* ...if the option is given, since it is causing typing bugs.
*/
def notNull: Type =
if (!settings.Ynotnull.value || isNotNull || phase.erasedTypes) this
else NotNullType(this)
/** Replace formal type parameter symbols with actual type arguments.
*
* Amounts to substitution except for higher-kinded types. (See overridden method in TypeRef) -- @M
*/
def instantiateTypeParams(formals: List[Symbol], actuals: List[Type]): Type =
if (sameLength(formals, actuals)) this.subst(formals, actuals) else ErrorType
/** If this type is an existential, turn all existentially bound variables to type skolems.
* @param owner The owner of the created type skolems
* @param origin The tree whose type was an existential for which the skolem was created.
*/
def skolemizeExistential(owner: Symbol, origin: AnyRef): Type = this
/** A simple version of skolemizeExistential for situations where
* owner or unpack location do not matter (typically used in subtype tests)
*/
def skolemizeExistential: Type = skolemizeExistential(NoSymbol, null)
/** Reduce to beta eta-long normal form.
* Expands type aliases and converts higher-kinded TypeRefs to PolyTypes.
* Functions on types are also implemented as PolyTypes.
*
* Example: (in the below, <List> is the type constructor of List)
* TypeRef(pre, <List>, List()) is replaced by
* PolyType(X, TypeRef(pre, <List>, List(X)))
*/
def normalize = this // @MAT
/** Expands type aliases. */
def dealias = this
/** Is this type produced as a repair for an error? */
def isError: Boolean = typeSymbol.isError || termSymbol.isError
/** Is this type produced as a repair for an error? */
def isErroneous: Boolean = ErroneousCollector.collect(this)
/** Does this type denote a reference type which can be null? */
// def isNullable: Boolean = false
/** For a classtype or refined type, its defined or declared members;
* inherited by subtypes and typerefs.
* The empty scope for all other types.
*/
def decls: Scope = EmptyScope
/** The defined or declared members with name `name' in this type;
* an OverloadedSymbol if several exist, NoSymbol if none exist.
* Alternatives of overloaded symbol appear in the order they are declared.
*/
def decl(name: Name): Symbol = findDecl(name, 0)
/** The non-private defined or declared members with name `name' in this type;
* an OverloadedSymbol if several exist, NoSymbol if none exist.
* Alternatives of overloaded symbol appear in the order they are declared.
*/
def nonPrivateDecl(name: Name): Symbol = findDecl(name, PRIVATE)
/** A list of all members of this type (defined or inherited)
* Members appear in linearization order of their owners.
* Members with the same owner appear in reverse order of their declarations.
*/
def members: List[Symbol] = findMember(nme.ANYNAME, 0, 0, false).alternatives
/** A list of all non-private members of this type (defined or inherited) */
def nonPrivateMembers: List[Symbol] =
findMember(nme.ANYNAME, PRIVATE | BRIDGES, 0, false).alternatives
/** A list of all non-private members of this type (defined or inherited),
* admitting members with given flags `admit`
*/
def nonPrivateMembersAdmitting(admit: Long): List[Symbol] =
findMember(nme.ANYNAME, (PRIVATE | BRIDGES) & ~admit, 0, false).alternatives
/** A list of all implicit symbols of this type (defined or inherited) */
def implicitMembers: List[Symbol] =
findMember(nme.ANYNAME, BRIDGES, IMPLICIT, false).alternatives
/** A list of all deferred symbols of this type (defined or inherited) */
def deferredMembers: List[Symbol] =
findMember(nme.ANYNAME, BRIDGES, DEFERRED, false).alternatives
/** The member with given name,
* an OverloadedSymbol if several exist, NoSymbol if none exist */
def member(name: Name): Symbol = findMember(name, BRIDGES, 0, false)
/** The non-private member with given name,
* an OverloadedSymbol if several exist, NoSymbol if none exist.
* Bridges are excluded from the result
*/
def nonPrivateMember(name: Name): Symbol =
findMember(name, PRIVATE | BRIDGES, 0, false)
/** The non-private member with given name, admitting members with given flags `admit`
* an OverloadedSymbol if several exist, NoSymbol if none exist
*/
def nonPrivateMemberAdmitting(name: Name, admit: Long): Symbol =
findMember(name, (PRIVATE | BRIDGES) & ~admit, 0, false)
/** The non-local member with given name,
* an OverloadedSymbol if several exist, NoSymbol if none exist */
def nonLocalMember(name: Name): Symbol =
findMember(name, LOCAL | BRIDGES, 0, false)
/** The least type instance of given class which is a supertype
* of this type. Example:
* class D[T]
* class C extends p.D[Int]
* ThisType(C).baseType(D) = p.D[Int]
*/
def baseType(clazz: Symbol): Type = NoType
/** This type as seen from prefix `pre' and class `clazz'. This means:
* Replace all thistypes of `clazz' or one of its subclasses
* by `pre' and instantiate all parameters by arguments of `pre'.
* Proceed analogously for thistypes referring to outer classes.
*
* Example:
* class D[T] { def m: T }
* class C extends p.D[Int]
* T.asSeenFrom(ThisType(C), D) (where D is owner of m)
* = Int
*/
def asSeenFrom(pre: Type, clazz: Symbol): Type =
if (!isTrivial && (!phase.erasedTypes || pre.typeSymbol == ArrayClass)) {
incCounter(asSeenFromCount)
val start = startTimer(asSeenFromNanos)
val m = new AsSeenFromMap(pre.normalize, clazz)
val tp = m apply this
val result = existentialAbstraction(m.capturedParams, tp)
stopTimer(asSeenFromNanos, start)
result
} else this
/** The info of `sym', seen as a member of this type.
*
* Example:
* class D[T] { def m: T }
* class C extends p.D[Int]
* ThisType(C).memberType(m) = Int
*/
def memberInfo(sym: Symbol): Type = {
sym.info.asSeenFrom(this, sym.owner)
}
/** The type of `sym', seen as a member of this type. */
def memberType(sym: Symbol): Type = sym match {
case meth: MethodSymbol =>
meth.typeAsMemberOf(this)
case _ =>
computeMemberType(sym)
}
def computeMemberType(sym: Symbol): Type = sym.tpeHK match { //@M don't prematurely instantiate higher-kinded types, they will be instantiated by transform, typedTypeApply, etc. when really necessary
case OverloadedType(_, alts) =>
OverloadedType(this, alts)
case tp =>
tp.asSeenFrom(this, sym.owner)
}
/** Substitute types `to' for occurrences of references to
* symbols `from' in this type.
*/
def subst(from: List[Symbol], to: List[Type]): Type =
new SubstTypeMap(from, to) apply this
/** Substitute symbols `to' for occurrences of symbols
* `from' in this type.
* !!! NOTE !!!: If you need to do a substThis and a substSym, the substThis has to come
* first, as otherwise symbols will immediately get rebound in typeRef to the old
* symbol.
*/
def substSym(from: List[Symbol], to: List[Symbol]): Type =
if (from eq to) this
else new SubstSymMap(from, to) apply this
/** Substitute all occurrences of `ThisType(from)' in this type
* by `to'.
* !!! NOTE !!!: If you need to do a substThis and a substSym, the substThis has to come
* first, as otherwise symbols will immediately get rebound in typeRef to the old
* symbol.
*/
def substThis(from: Symbol, to: Type): Type =
new SubstThisMap(from, to) apply this
def substSuper(from: Type, to: Type): Type =
new SubstSuperMap(from, to) apply this
/** Returns all parts of this type which satisfy predicate `p' */
def filter(p: Type => Boolean): List[Type] = new FilterTypeCollector(p).collect(this).toList
/** Returns optionally first type (in a preorder traversal) which satisfies predicate `p',
* or None if none exists.
*/
def find(p: Type => Boolean): Option[Type] = new FindTypeCollector(p).collect(this)
/** Apply `f' to each part of this type */
def foreach(f: Type => Unit) { new ForEachTypeTraverser(f).traverse(this) }
/** Apply `f' to each part of this type; children get mapped before their parents */
def map(f: Type => Type): Type = new TypeMap {
def apply(x: Type) = f(mapOver(x))
} apply this
/** Is there part of this type which satisfies predicate `p'? */
def exists(p: Type => Boolean): Boolean = !find(p).isEmpty
/** Does this type contain a reference to this symbol? */
def contains(sym: Symbol): Boolean = new ContainsCollector(sym).collect(this)
/** Does this type contain a reference to this type */
def containsTp(tp: Type): Boolean = new ContainsTypeCollector(tp).collect(this)
/** Is this type a subtype of that type? */
def <:<(that: Type): Boolean = {
if (util.Statistics.enabled) stat_<:<(that)
else {
(this eq that) ||
(if (explainSwitch) explain("<:", isSubType, this, that)
else isSubType(this, that, AnyDepth))
}
}
/** Can this type only be subtyped by bottom types?
* This is assessed to be the case if the class is final,
* and all type parameters (if any) are invariant.
*/
def isFinalType = (
typeSymbol.isFinal &&
(typeSymbol.typeParams forall (_.variance == 0))
)
/** Is this type a subtype of that type in a pattern context?
* Any type arguments on the right hand side are replaced with
* fresh existentials, except for Arrays.
*
* See bug1434.scala for an example of code which would fail
* if only a <:< test were applied.
*/
def matchesPattern(that: Type): Boolean = {
(this <:< that) || ((this, that) match {
case (TypeRef(_, ArrayClass, List(arg1)), TypeRef(_, ArrayClass, List(arg2))) if arg2.typeSymbol.typeParams.nonEmpty =>
arg1 matchesPattern arg2
case (_, TypeRef(_, _, args)) =>
val newtp = existentialAbstraction(args map (_.typeSymbol), that)
!(that =:= newtp) && (this <:< newtp)
case _ =>
false
})
}
def stat_<:<(that: Type): Boolean = {
incCounter(subtypeCount)
val start = startTimer(subtypeNanos)
val result =
(this eq that) ||
(if (explainSwitch) explain("<:", isSubType, this, that)
else isSubType(this, that, AnyDepth))
stopTimer(subtypeNanos, start)
result
}
/** Is this type a weak subtype of that type? True also for numeric types, i.e. Int weak_<:< Long.
*/
def weak_<:<(that: Type): Boolean = {
incCounter(subtypeCount)
val start = startTimer(subtypeNanos)
val result =
((this eq that) ||
(if (explainSwitch) explain("weak_<:", isWeakSubType, this, that)
else isWeakSubType(this, that)))
stopTimer(subtypeNanos, start)
result
}
/** Is this type equivalent to that type? */
def =:=(that: Type): Boolean = (
(this eq that) ||
(if (explainSwitch) explain("=", isSameType, this, that)
else isSameType(this, that))
);
/** Does this type implement symbol `sym' with same or stronger type?
*/
def specializes(sym: Symbol): Boolean =
if (explainSwitch) explain("specializes", specializesSym, this, sym)
else specializesSym(this, sym)
/** Is this type close enough to that type so that members
* with the two type would override each other?
* This means:
* - Either both types are polytypes with the same number of
* type parameters and their result types match after renaming
* corresponding type parameters
* - Or both types are (nullary) method types with equivalent type parameter types
* and matching result types
* - Or both types are equivalent
* - Or phase.erasedTypes is false and both types are neither method nor
* poly types.
*/
def matches(that: Type): Boolean = matchesType(this, that, !phase.erasedTypes)
/** Same as matches, except that non-method types are always assumed to match.
*/
def looselyMatches(that: Type): Boolean = matchesType(this, that, true)
/** The shortest sorted upwards closed array of types that contains
* this type as first element.
*
* A list or array of types ts is upwards closed if
*
* for all t in ts:
* for all typerefs p.s[args] such that t <: p.s[args]
* there exists a typeref p'.s[args'] in ts such that
* t <: p'.s['args] <: p.s[args],
*
* and
*
* for all singleton types p.s such that t <: p.s
* there exists a singleton type p'.s in ts such that
* t <: p'.s <: p.s
*
* Sorting is with respect to Symbol.isLess() on type symbols.
*/
def baseTypeSeq: BaseTypeSeq = baseTypeSingletonSeq(this)
/** The maximum depth (@see maxDepth)
* of each type in the BaseTypeSeq of this type.
*/
def baseTypeSeqDepth: Int = 1
/** The list of all baseclasses of this type (including its own typeSymbol)
* in reverse linearization order, starting with the class itself and ending
* in class Any.
*/
def baseClasses: List[Symbol] = List()
/**
* @param sym the class symbol
* @return the index of given class symbol in the BaseTypeSeq of this type,
* or -1 if no base type with given class symbol exists.
*/
def baseTypeIndex(sym: Symbol): Int = {
val bts = baseTypeSeq
var lo = 0
var hi = bts.length - 1
while (lo <= hi) {
val mid = (lo + hi) / 2
val btssym = bts.typeSymbol(mid)
if (sym == btssym) return mid
else if (sym isLess btssym) hi = mid - 1
else if (btssym isLess sym) lo = mid + 1
else abort()
}
-1
}
/** If this is a poly- or methodtype, a copy with cloned type / value parameters
* owned by `owner'. Identity for all other types.
*/
def cloneInfo(owner: Symbol) = this
/** Make sure this type is correct as the info of given owner; clone it if not.
*/
def atOwner(owner: Symbol) = this
protected def objectPrefix = "object "
protected def packagePrefix = "package "
def trimPrefix(str: String) = str stripPrefix objectPrefix stripPrefix packagePrefix
/** The string representation of this type used as a prefix */
def prefixString = trimPrefix(toString) + "#"
/** The string representation of this type, with singletypes explained */
def toLongString = {
val str = toString
if (str endsWith ".type") str + " (with underlying type " + widen + ")"
else str
}
/** A test whether a type contains any unification type variables */
def isGround: Boolean = this match {
case TypeVar(_, constr) =>
constr.instValid && constr.inst.isGround
case TypeRef(pre, sym, args) =>
sym.isPackageClass || pre.isGround && (args forall (_.isGround))
case SingleType(pre, sym) =>
sym.isPackageClass || pre.isGround
case ThisType(_) | NoPrefix | WildcardType | NoType | ErrorType | ConstantType(_) =>
true
case _ =>
typeVarToOriginMap(this) eq this
}
/** If this is a symbol loader type, load and assign a new type to
* `sym'.
*/
def load(sym: Symbol) {}
private def findDecl(name: Name, excludedFlags: Int): Symbol = {
var alts: List[Symbol] = List()
var sym: Symbol = NoSymbol
var e: ScopeEntry = decls.lookupEntry(name)
while (e ne null) {
if (!e.sym.hasFlag(excludedFlags)) {
if (sym == NoSymbol) sym = e.sym
else {
if (alts.isEmpty) alts = List(sym)
alts = e.sym :: alts
}
}
e = decls.lookupNextEntry(e)
}
if (alts.isEmpty) sym
else (baseClasses.head.newOverloaded(this, alts))
}
/**
* Find member(s) in this type. If several members matching criteria are found, they are
* returned in an OverloadedSymbol
*
* @param name The member's name, where nme.ANYNAME means `unspecified'
* @param excludedFlags Returned members do not have these flags
* @param requiredFlags Returned members do have these flags
* @param stableOnly If set, return only members that are types or stable values
*/
//TODO: use narrow only for modules? (correct? efficiency gain?)
def findMember(name: Name, excludedFlags: Long, requiredFlags: Long, stableOnly: Boolean): Symbol = {
val suspension = TypeVar.Suspension
// if this type contains type variables, put them to sleep for a while -- don't just wipe them out by
// replacing them by the corresponding type parameter, as that messes up (e.g.) type variables in type refinements
// without this, the matchesType call would lead to type variables on both sides
// of a subtyping/equality judgement, which can lead to recursive types being constructed.
// See (t0851) for a situation where this happens.
if (!this.isGround) {
// PP: The foreach below was formerly expressed as:
// for(tv @ TypeVar(_, _) <- this) { suspension suspend tv }
//
// The tree checker failed this saying a TypeVar is required, but a (Type @unchecked) was found.
// This is a consequence of using a pattern match and variable binding + ticket #1503, which
// was addressed by weakening the type of bindings in pattern matches if they occur on the right.
// So I'm not quite sure why this works at all, as the checker is right that it is mistyped.
// For now I modified it as below, which achieves the same without error.
//
// make each type var in this type use its original type for comparisons instead of collecting constraints
this foreach {
case tv: TypeVar => suspension suspend tv
case _ => ()
}
}
incCounter(findMemberCount)
val start = startTimer(findMemberNanos)
//Console.println("find member " + name.decode + " in " + this + ":" + this.baseClasses)//DEBUG
var members: Scope = null
var member: Symbol = NoSymbol
var excluded = excludedFlags | DEFERRED
var continue = true
var self: Type = null
var membertpe: Type = null
while (continue) {
continue = false
val bcs0 = baseClasses
var bcs = bcs0
while (!bcs.isEmpty) {
val decls = bcs.head.info.decls
var entry =
if (name == nme.ANYNAME) decls.elems else decls.lookupEntry(name)
while (entry ne null) {
val sym = entry.sym
if (sym hasAllFlags requiredFlags) {
val excl = sym.getFlag(excluded)
if (excl == 0L &&
(// omit PRIVATE LOCALS unless selector class is contained in class owning the def.
(bcs eq bcs0) ||
!sym.isPrivateLocal ||
(bcs0.head.hasTransOwner(bcs.head)))) {
if (name.isTypeName || stableOnly && sym.isStable) {
stopTimer(findMemberNanos, start)
suspension.resumeAll
return sym
} else if (member == NoSymbol) {
member = sym
} else if (members eq null) {
if (member.name != sym.name ||
!(member == sym ||
member.owner != sym.owner &&
!sym.isPrivate && {
if (self eq null) self = this.narrow
if (membertpe eq null) membertpe = self.memberType(member)
(membertpe matches self.memberType(sym))
})) {
members = new Scope(List(member, sym))
}
} else {
var prevEntry = members.lookupEntry(sym.name)
while ((prevEntry ne null) &&
!(prevEntry.sym == sym ||
prevEntry.sym.owner != sym.owner &&
!sym.hasFlag(PRIVATE) && {
if (self eq null) self = this.narrow
self.memberType(prevEntry.sym) matches self.memberType(sym)
})) {
prevEntry = members lookupNextEntry prevEntry
}
if (prevEntry eq null) {
members enter sym
}
}
} else if (excl == DEFERRED.toLong) {
continue = true
}
}
entry = if (name == nme.ANYNAME) entry.next else decls lookupNextEntry entry
} // while (entry ne null)
// excluded = excluded | LOCAL
bcs = if (name == nme.CONSTRUCTOR) Nil else bcs.tail
} // while (!bcs.isEmpty)
excluded = excludedFlags
} // while (continue)
stopTimer(findMemberNanos, start)
suspension.resumeAll
if (members eq null) {
if (member == NoSymbol) incCounter(noMemberCount)
member
} else {
incCounter(multMemberCount)
baseClasses.head.newOverloaded(this, members.toList)
}
}
/** The existential skolems and existentially quantified variables which are free in this type */
def existentialSkolems: List[Symbol] = {
var boundSyms: List[Symbol] = List()
var skolems: List[Symbol] = List()
for (t <- this) {
t match {
case ExistentialType(quantified, qtpe) =>
boundSyms = boundSyms ::: quantified
case TypeRef(_, sym, _) =>
if ((sym hasFlag EXISTENTIAL) && !(boundSyms contains sym) && !(skolems contains sym))
skolems = sym :: skolems
case _ =>
}
}
skolems
}
/** Return the annotations on this type. */
def annotations: List[AnnotationInfo] = Nil
/** Test for the presence of an annotation */
def hasAnnotation(clazz: Symbol) = annotations exists { _.atp.typeSymbol == clazz }
/** Add an annotation to this type */
def withAnnotation(annot: AnnotationInfo) = withAnnotations(List(annot))
/** Add a number of annotations to this type */
def withAnnotations(annots: List[AnnotationInfo]): Type =
annots match {
case Nil => this
case _ => AnnotatedType(annots, this, NoSymbol)
}
/** Remove any annotations from this type */
def withoutAnnotations = this
/** Remove any annotations from this type and from any
* types embedded in this type. */
def stripAnnotations = StripAnnotationsMap(this)
/** Set the self symbol of an annotated type, or do nothing
* otherwise. */
def withSelfsym(sym: Symbol) = this
/** The selfsym of an annotated type, or NoSymbol of anything else */
def selfsym: Symbol = NoSymbol
/** The kind of this type; used for debugging */
def kind: String = "unknown type of class "+getClass()
}
// Subclasses ------------------------------------------------------------
trait UniqueType {
override lazy val hashCode: Int = super.hashCode()
}
/** A base class for types that defer some operations
* to their immediate supertype.
*/
abstract class SubType extends Type {
def supertype: Type
override def parents: List[Type] = supertype.parents
override def decls: Scope = supertype.decls
override def baseType(clazz: Symbol): Type = supertype.baseType(clazz)
override def baseTypeSeq: BaseTypeSeq = supertype.baseTypeSeq
override def baseTypeSeqDepth: Int = supertype.baseTypeSeqDepth
override def baseClasses: List[Symbol] = supertype.baseClasses
override def isNotNull = supertype.isNotNull
}
case class NotNullType(override val underlying: Type) extends SubType with RewrappingTypeProxy {
def supertype = underlying
protected def rewrap(newtp: Type): Type = NotNullType(newtp)
override def isNotNull: Boolean = true
override def notNull = this
override def deconst: Type = underlying //todo: needed?
override def safeToString: String = underlying.toString + " with NotNull"
override def kind = "NotNullType"
}
/** A base class for types that represent a single value
* (single-types and this-types).
*/
abstract class SingletonType extends SubType with SimpleTypeProxy {
def supertype = underlying
override def isTrivial = false
override def isStable = true
override def isVolatile = underlying.isVolatile
override def widen: Type = underlying.widen
override def baseTypeSeq: BaseTypeSeq = {
incCounter(singletonBaseTypeSeqCount)
underlying.baseTypeSeq prepend this
}
override def isHigherKinded = false // singleton type classifies objects, thus must be kind *
override def safeToString: String = prefixString + "type"
/*
override def typeOfThis: Type = typeSymbol.typeOfThis
override def bounds: TypeBounds = TypeBounds(this, this)
override def prefix: Type = NoType
override def typeArgs: List[Type] = List()
override def typeParams: List[Symbol] = List()
*/
}
/** An object representing an erroneous type */
case object ErrorType extends Type {
// todo see whether we can do without
override def isError: Boolean = true
override def decls: Scope = new ErrorScope(NoSymbol)
override def findMember(name: Name, excludedFlags: Long, requiredFlags: Long, stableOnly: Boolean): Symbol = {
var sym = decls lookup name
if (sym == NoSymbol) {
sym = NoSymbol.newErrorSymbol(name)
decls enter sym
}
sym
}
override def baseType(clazz: Symbol): Type = this
override def safeToString: String = "<error>"
override def narrow: Type = this
// override def isNullable: Boolean = true
override def kind = "ErrorType"
}
/** An object representing an unknown type, used during type inference.
* If you see WildcardType outside of inference it is almost certainly a bug.
*/
case object WildcardType extends Type {
override def isWildcard = true
override def safeToString: String = "?"
// override def isNullable: Boolean = true
override def kind = "WildcardType"
}
case class BoundedWildcardType(override val bounds: TypeBounds) extends Type {
override def isWildcard = true
override def safeToString: String = "?" + bounds
override def kind = "BoundedWildcardType"
}
/** An object representing a non-existing type */
case object NoType extends Type {
override def isTrivial: Boolean = true
override def safeToString: String = "<notype>"
// override def isNullable: Boolean = true
override def kind = "NoType"
}
/** An object representing a non-existing prefix */
case object NoPrefix extends Type {
override def isTrivial: Boolean = true
override def isStable: Boolean = true
override def prefixString = ""
override def safeToString: String = "<noprefix>"
// override def isNullable: Boolean = true
override def kind = "NoPrefixType"
}
/** A class for this-types of the form <sym>.this.type
*/
abstract case class ThisType(sym: Symbol) extends SingletonType {
//assert(sym.isClass && !sym.isModuleClass || sym.isRoot, sym)
override def isTrivial: Boolean = sym.isPackageClass
override def isNotNull = true
override def typeSymbol = sym
override def underlying: Type = sym.typeOfThis
override def isVolatile = false
override def isHigherKinded = sym.isRefinementClass && underlying.isHigherKinded
override def prefixString =
if (settings.debug.value) sym.nameString + ".this."
else if (sym.isAnonOrRefinementClass) "this."
else if (sym.printWithoutPrefix) ""
else if (sym.isModuleClass) sym.fullName + "."
else sym.nameString + ".this."
override def safeToString: String =
if (sym.isRoot) "<root>"
else if (sym.isEmptyPackageClass) "<empty>"
else super.safeToString
override def narrow: Type = this
override def kind = "ThisType"
}
object ThisType extends ThisTypeExtractor {
def apply(sym: Symbol): Type =
if (!phase.erasedTypes) unique(new ThisType(sym) with UniqueType)
else if (sym.isImplClass) sym.typeOfThis
else sym.tpe
}
/** A class for singleton types of the form <prefix>.<sym.name>.type.
* Cannot be created directly; one should always use
* `singleType' for creation.
*/
case class SingleType(pre: Type, sym: Symbol) extends SingletonType {
override val isTrivial: Boolean = pre.isTrivial
// override def isNullable = underlying.isNullable
override def isNotNull = underlying.isNotNull
private var underlyingCache: Type = NoType
private var underlyingPeriod = NoPeriod
override def underlying: Type = {
val period = underlyingPeriod
if (period != currentPeriod) {
underlyingPeriod = currentPeriod
if (!isValid(period)) {
underlyingCache = pre.memberType(sym).resultType;
assert(underlyingCache ne this, this)
}
}
underlyingCache
}
// more precise conceptually, but causes cyclic errors: (paramss exists (_ contains sym))
override def isImmediatelyDependent = (sym ne NoSymbol) && (sym.owner.isMethod && sym.isValueParameter)
override def isVolatile : Boolean = underlying.isVolatile && !sym.isStable
/*
override def narrow: Type = {
if (phase.erasedTypes) this
else {
val thissym = refinedType(List(this), sym.owner, EmptyScope).typeSymbol
if (sym.owner != NoSymbol) {
//Console.println("narrowing module " + sym + thissym.owner);
thissym.typeOfThis = this
}
thissym.thisType
}
}
*/
override def narrow: Type = this
override def termSymbol = sym
override def prefix: Type = pre
override def prefixString: String =
if ((sym.isEmptyPackage || sym.isInterpreterWrapper || sym.isPredefModule || sym.isScalaPackage) && !settings.debug.value) ""
else pre.prefixString + sym.nameString + "."
override def kind = "SingleType"
}
object SingleType extends SingleTypeExtractor
abstract case class SuperType(thistpe: Type, supertpe: Type) extends SingletonType {
override val isTrivial: Boolean = thistpe.isTrivial && supertpe.isTrivial
override def isNotNull = true;
override def typeSymbol = thistpe.typeSymbol
override def underlying = supertpe
override def prefix: Type = supertpe.prefix
override def prefixString = thistpe.prefixString.replaceAll("""this\.$""", "super.")
override def narrow: Type = thistpe.narrow
override def kind = "SuperType"
}
object SuperType extends SuperTypeExtractor {
def apply(thistp: Type, supertp: Type): Type =
if (phase.erasedTypes) supertp
else unique(new SuperType(thistp, supertp) with UniqueType)
}
/** A class for the bounds of abstract types and type parameters
*/
abstract case class TypeBounds(lo: Type, hi: Type) extends SubType {
def supertype = hi
override val isTrivial: Boolean = lo.isTrivial && hi.isTrivial
override def bounds: TypeBounds = this
def containsType(that: Type) = that match {
case TypeBounds(_, _) => that <:< this
case _ => lo <:< that && that <:< hi
}
// override def isNullable: Boolean = NullClass.tpe <:< lo;
override def safeToString = ">: " + lo + " <: " + hi
override def kind = "TypeBoundsType"
}
object TypeBounds extends TypeBoundsExtractor {
def empty: TypeBounds = apply(NothingClass.tpe, AnyClass.tpe)
def upper(hi: Type): TypeBounds = apply(NothingClass.tpe, hi)
def lower(lo: Type): TypeBounds = apply(lo, AnyClass.tpe)
def apply(lo: Type, hi: Type): TypeBounds =
unique(new TypeBounds(lo, hi) with UniqueType)
}
/** A common base class for intersection types and class types
*/
abstract class CompoundType extends Type {
var baseTypeSeqCache: BaseTypeSeq = _
private var baseTypeSeqPeriod = NoPeriod
private var baseClassesCache: List[Symbol] = _
private var baseClassesPeriod = NoPeriod
override def baseTypeSeq: BaseTypeSeq = {
val period = baseTypeSeqPeriod;
if (period != currentPeriod) { // no caching in IDE
baseTypeSeqPeriod = currentPeriod
if (!isValidForBaseClasses(period)) {
if (parents.exists(_.exists(_.isInstanceOf[TypeVar]))) {
// rename type vars to fresh type params, take base type sequence of
// resulting type, and rename back all the entries in that sequence
var tvs = Set[TypeVar]()
for (p <- parents)
for (t <- p) t match {
case tv: TypeVar => tvs += tv
case _ =>
}
val varToParamMap: Map[Type, Symbol] = tvs map (tv => tv -> tv.origin.typeSymbol.cloneSymbol) toMap
val paramToVarMap = varToParamMap map (_.swap)
val varToParam = new TypeMap {
def apply(tp: Type) = varToParamMap get tp match {
case Some(sym) => sym.tpe
case _ => mapOver(tp)
}
}
val paramToVar = new TypeMap {
def apply(tp: Type) = tp match {
case TypeRef(_, tsym, _) if paramToVarMap.isDefinedAt(tsym) => paramToVarMap(tsym)
case _ => mapOver(tp)
}
}
val bts = copyRefinedType(this.asInstanceOf[RefinedType], parents map varToParam, varToParam mapOver decls).baseTypeSeq
baseTypeSeqCache = bts lateMap paramToVar
} else {
incCounter(compoundBaseTypeSeqCount)
baseTypeSeqCache = undetBaseTypeSeq
baseTypeSeqCache = if (typeSymbol.isRefinementClass)
memo(compoundBaseTypeSeq(this))(_.baseTypeSeq updateHead typeSymbol.tpe)
else
compoundBaseTypeSeq(this)
// [Martin] suppressing memo-ization solves the problem with "same type after erasure" errors
// when compiling with
// scalac scala.collection.IterableViewLike.scala scala.collection.IterableLike.scala
// I have not yet figured out precisely why this is the case.
// My current assumption is that taking memos forces baseTypeSeqs to be computed
// at stale types (i.e. the underlying typeSymbol has already another type).
// I do not yet see precisely why this would cause a problem, but it looks
// fishy in any case.
}
}
//Console.println("baseTypeSeq(" + typeSymbol + ") = " + baseTypeSeqCache.toList);//DEBUG
}
if (baseTypeSeqCache eq undetBaseTypeSeq)
throw new TypeError("illegal cyclic inheritance involving " + typeSymbol)
baseTypeSeqCache
}
override def baseTypeSeqDepth: Int = baseTypeSeq.maxDepth
override def baseClasses: List[Symbol] = {
def computeBaseClasses: List[Symbol] =
if (parents.isEmpty) List(typeSymbol)
else {
//Console.println("computing base classes of " + typeSymbol + " at phase " + phase);//DEBUG
// optimized, since this seems to be performance critical
val superclazz = parents.head
var mixins = parents.tail
val sbcs = superclazz.baseClasses
var bcs = sbcs
def isNew(clazz: Symbol): Boolean = (
superclazz.baseTypeIndex(clazz) < 0 &&
{ var p = bcs;
while ((p ne sbcs) && (p.head != clazz)) p = p.tail;
p eq sbcs
}
);
while (!mixins.isEmpty) {
def addMixinBaseClasses(mbcs: List[Symbol]): List[Symbol] =
if (mbcs.isEmpty) bcs
else if (isNew(mbcs.head)) mbcs.head :: addMixinBaseClasses(mbcs.tail)
else addMixinBaseClasses(mbcs.tail);
bcs = addMixinBaseClasses(mixins.head.baseClasses)
mixins = mixins.tail
}
typeSymbol :: bcs
}
val period = baseClassesPeriod
if (period != currentPeriod) {
baseClassesPeriod = currentPeriod
if (!isValidForBaseClasses(period)) {
baseClassesCache = null
baseClassesCache = memo(computeBaseClasses)(typeSymbol :: _.baseClasses.tail)
}
}
if (baseClassesCache eq null)
throw new TypeError("illegal cyclic reference involving " + typeSymbol)
baseClassesCache
}
/** The slightly less idiomatic use of Options is due to
* performance considerations. A version using for comprehensions
* might be too slow (this is deemed a hotspot of the type checker).
*
* See with Martin before changing this method.
*/
def memo[A](op1: => A)(op2: Type => A): A = {
def updateCache(): A = {
intersectionWitness(parents) = new WeakReference(this)
op1
}
intersectionWitness get parents match {
case Some(ref) =>
ref.get match {
case Some(w) => if (w eq this) op1 else op2(w)
case None => updateCache()
}
case None => updateCache()
}
}
override def baseType(sym: Symbol): Type = {
val index = baseTypeIndex(sym)
if (index >= 0) baseTypeSeq(index) else NoType
}
override def narrow: Type = typeSymbol.thisType
override def isNotNull: Boolean = parents exists (_.isNotNull)
override def isStructuralRefinement: Boolean =
typeSymbol.isAnonOrRefinementClass &&
(decls.toList exists { entry => !entry.isConstructor && entry.allOverriddenSymbols.isEmpty })
// override def isNullable: Boolean =
// parents forall (p => p.isNullable && !p.typeSymbol.isAbstractType);
override def safeToString: String =
parents.mkString("", " with ", "") +
(if (settings.debug.value || parents.isEmpty || (decls.elems ne null))
decls.mkString("{", "; ", "}") else "")
}
/** A class representing intersection types with refinements of the form
* `<parents_0> with ... with <parents_n> { decls }'
* Cannot be created directly;
* one should always use `refinedType' for creation.
*/
case class RefinedType(override val parents: List[Type],
override val decls: Scope) extends CompoundType {
override def isHigherKinded = (
parents.nonEmpty &&
(parents forall (_.isHigherKinded)) &&
!phase.erasedTypes // @MO to AM: please check this class!
)
override def typeParams =
if (isHigherKinded) parents.head.typeParams
else super.typeParams
//@M may result in an invalid type (references to higher-order args become dangling )
override def typeConstructor =
copyRefinedType(this, parents map (_.typeConstructor), decls)
private def dummyArgs = typeParams map (_.typeConstructor)
/* MO to AM: This is probably not correct
* If they are several higher-kinded parents with different bounds we need
* to take the intersection of their bounds
*/
override def normalize = {
if (isHigherKinded) {
typeFun(
typeParams,
RefinedType(
parents map {
case TypeRef(pre, sym, List()) => TypeRef(pre, sym, dummyArgs)
case p => p
},
decls,
typeSymbol))
}
else super.normalize
}
/** A refined type P1 with ... with Pn { decls } is volatile if
* one of the parent types Pi is an abstract type, and
* either i > 1, or decls or a following parent Pj, j > 1, contributes
* an abstract member.
* A type contributes an abstract member if it has an abstract member which
* is also a member of the whole refined type. A scope `decls' contributes
* an abstract member if it has an abstract definition which is also
* a member of the whole type.
*/
override def isVolatile = {
def isVisible(m: Symbol) =
this.nonPrivateMember(m.name).alternatives contains m
def contributesAbstractMembers(p: Type) =
p.deferredMembers exists isVisible
((parents exists (_.isVolatile))
||
(parents dropWhile (! _.typeSymbol.isAbstractType) match {
case ps @ (_ :: ps1) =>
(ps ne parents) ||
(ps1 exists contributesAbstractMembers) ||
(decls.iterator exists (m => m.isDeferred && isVisible(m)))
case _ =>
false
}))
}
override def kind = "RefinedType"
}
object RefinedType extends RefinedTypeExtractor {
def apply(parents: List[Type], decls: Scope, clazz: Symbol) =
new RefinedType(parents, decls) { override def typeSymbol = clazz }
}
/** A class representing a class info
*/
case class ClassInfoType(
override val parents: List[Type],
override val decls: Scope,
override val typeSymbol: Symbol) extends CompoundType
{
/** refs indices */
private final val NonExpansive = 0
private final val Expansive = 1
/** initialization states */
private final val UnInitialized = 0
private final val Initializing = 1
private final val Initialized = 2
private type RefMap = Map[Symbol, immutable.Set[Symbol]]
/** All type parameters reachable from given type parameter
* by a path which contains at least one expansive reference.
* @See Kennedy, Pierce: On Decidability of Nominal Subtyping with Variance
*/
def expansiveRefs(tparam: Symbol) = {
if (state == UnInitialized) {
computeRefs()
while (state != Initialized) propagate()
}
getRefs(Expansive, tparam)
}
/* The rest of this class is auxiliary code for `expansiveRefs'
*/
/** The type parameters which are referenced type parameters of this class.
* Two entries: refs(0): Non-expansive references
* refs(1): Expansive references
*/
private var refs: Array[RefMap] = _
/** The initialization state of the class: UnInialized --> Initializing --> Initialized
*/
private var state = UnInitialized
/** Get references for given type parameter
* @param which in {NonExpansive, Expansive}
* @param from The type parameter from which references originate.
*/
private def getRefs(which: Int, from: Symbol): Set[Symbol] = refs(which) get from match {
case Some(set) => set
case none => Set()
}
/** Augment existing refs map with reference <pre>from -> to</pre>
* @param which <- {NonExpansive, Expansive}
*/
private def addRef(which: Int, from: Symbol, to: Symbol) {
refs(which) = refs(which) + (from -> (getRefs(which, from) + to))
}
/** Augment existing refs map with references <pre>from -> sym</pre>, for
* all elements <pre>sym</pre> of set `to'.
* @param which <- {NonExpansive, Expansive}
*/
private def addRefs(which: Int, from: Symbol, to: Set[Symbol]) {
refs(which) = refs(which) + (from -> (getRefs(which, from) ++ to))
}
/** The ClassInfoType which belongs to the class containing given type parameter
*/
private def classInfo(tparam: Symbol): ClassInfoType =
tparam.owner.info.resultType match {
case ci: ClassInfoType => ci
case _ => classInfo(ObjectClass) // something's wrong; fall back to safe value
// (this can happen only for erroneous programs).
}
/** Compute initial (one-step) references and set state to `Initializing'.
*/
private def computeRefs() {
refs = Array(Map(), Map())
for (tparam <- typeSymbol.typeParams) {
val enterRefs = new TypeMap {
def apply(tp: Type): Type = {
tp match {
case TypeRef(_, sym, args) =>
for ((tparam1, arg) <- sym.info.typeParams zip args)
if (arg contains tparam) {
addRef(NonExpansive, tparam, tparam1)
if (arg.typeSymbol != tparam) addRef(Expansive, tparam, tparam1)
}
case _ =>
}
mapOver(tp)
}
}
for (p <- parents) enterRefs(p)
}
state = Initializing
}
/** Propagate to form transitive closure.
* Set state to Initialized if no change resulted from propagation.
* @return true iff there as a change in last iteration
*/
private def propagate(): Boolean = {
if (state == UnInitialized) computeRefs()
//Console.println("Propagate "+symbol+", initial expansive = "+refs(Expansive)+", nonexpansive = "+refs(NonExpansive))//DEBUG
val lastRefs = Array(refs(0), refs(1))
state = Initialized
var change = false
for ((from, targets) <- refs(NonExpansive).iterator)
for (target <- targets) {
var thatInfo = classInfo(target)
if (thatInfo.state != Initialized)
change = change | thatInfo.propagate()
addRefs(NonExpansive, from, thatInfo.getRefs(NonExpansive, target))
addRefs(Expansive, from, thatInfo.getRefs(Expansive, target))
}
for ((from, targets) <- refs(Expansive).iterator)
for (target <- targets) {
var thatInfo = classInfo(target)
if (thatInfo.state != Initialized)
change = change | thatInfo.propagate()
addRefs(Expansive, from, thatInfo.getRefs(NonExpansive, target))
}
change = change || refs(0) != lastRefs(0) || refs(1) != lastRefs(1)
if (change) state = Initializing
//else Console.println("Propagate "+symbol+", final expansive = "+refs(Expansive)+", nonexpansive = "+refs(NonExpansive))//DEBUG
change
}
// override def isNullable: Boolean =
// symbol == AnyClass ||
// symbol != NothingClass && (symbol isSubClass ObjectClass) && !(symbol isSubClass NonNullClass);
// override def isNonNull: Boolean = symbol == NonNullClass || super.isNonNull;
override def kind = "ClassInfoType"
}
object ClassInfoType extends ClassInfoTypeExtractor
class PackageClassInfoType(decls: Scope, clazz: Symbol)
extends ClassInfoType(List(), decls, clazz)
/** A class representing a constant type.
*
* @param value ...
*/
abstract case class ConstantType(value: Constant) extends SingletonType {
override def underlying: Type = value.tpe
assert(underlying.typeSymbol != UnitClass)
override def isTrivial: Boolean = true
override def isNotNull = value.value != null
override def deconst: Type = underlying
override def safeToString: String =
underlying.toString + "(" + value.escapedStringValue + ")"
// override def isNullable: Boolean = value.value eq null
// override def isNonNull: Boolean = value.value ne null
override def kind = "ConstantType"
}
object ConstantType extends ConstantTypeExtractor {
def apply(value: Constant): ConstantType = {
class UniqueConstantType extends ConstantType(value) with UniqueType {
/** Save the type of 'value'. For Java enums, it depends on finding the linked class,
* which might not be found after 'flatten'. */
private lazy val _tpe: Type = value.tpe
override def underlying: Type = _tpe
}
unique(new UniqueConstantType)
}
}
private var volatileRecursions: Int = 0
private val pendingVolatiles = new mutable.HashSet[Symbol]
/** A class for named types of the form
* `<prefix>.<sym.name>[args]'
* Cannot be created directly; one should always use `typeRef'
* for creation. (@M: Otherwise hashing breaks)
*
* @M: a higher-kinded type is represented as a TypeRef with sym.info.typeParams.nonEmpty, but args.isEmpty
* @param pre ...
* @param sym ...
* @param args ...
*/
abstract case class TypeRef(pre: Type, sym: Symbol, args: List[Type]) extends Type {
// assert(!sym.isAbstractType || pre.isStable || pre.isError)
// assert(!pre.isInstanceOf[ClassInfoType], this)
// assert(!(sym hasFlag (PARAM | EXISTENTIAL)) || pre == NoPrefix, this)
// assert(args.isEmpty || !sym.info.typeParams.isEmpty, this)
// assert(args.isEmpty || ((sym ne AnyClass) && (sym ne NothingClass))
private val parentsCache = new ListOfTypesCache {
@inline final def calculate() = thisInfo.parents map transform
}
private var baseTypeSeqCache: BaseTypeSeq = _
private var baseTypeSeqPeriod = NoPeriod
override def isStable: Boolean = {
sym == NothingClass ||
sym == SingletonClass ||
sym.isAliasType && normalize.isStable ||
sym.isAbstractType && (bounds.hi.typeSymbol isSubClass SingletonClass)
}
override def isVolatile: Boolean = {
sym.isAliasType && normalize.isVolatile ||
sym.isAbstractType && {
// need to be careful not to fall into an infinite recursion here
// because volatile checking is done before all cycles are detected.
// the case to avoid is an abstract type directly or
// indirectly upper-bounded by itself. See #2918
try {
volatileRecursions += 1
if (volatileRecursions < LogVolatileThreshold)
bounds.hi.isVolatile
else if (pendingVolatiles(sym))
true // we can return true here, because a cycle will be detected
// here afterwards and an error will result anyway.
else
try {
pendingVolatiles += sym
bounds.hi.isVolatile
} finally {
pendingVolatiles -= sym
}
} finally {
volatileRecursions -= 1
}
}
}
override lazy val isTrivial: Boolean =
!sym.isTypeParameter && pre.isTrivial && args.forall(_.isTrivial)
override def isNotNull =
sym.isModuleClass || sym == NothingClass || isValueClass(sym) || super.isNotNull
// @M: propagate actual type params (args) to `tp', by replacing formal type parameters with actual ones
// if tp is higher kinded, the "actual" type arguments are types that simply reference the corresponding type parameters (unbound type variables)
def transform(tp: Type): Type = {
val res = tp.asSeenFrom(pre, sym.owner)
if (sym.typeParams.isEmpty || (args exists (_.isError)) || isRaw(sym, args)/*#2266/2305*/) res
else res.instantiateTypeParams(sym.typeParams, typeArgsOrDummies)
}
//@M! use appliedType on the polytype that represents the bounds (or if aliastype, the rhs)
def transformInfo(tp: Type): Type = appliedType(tp.asSeenFrom(pre, sym.owner), typeArgsOrDummies)
def thisInfo =
if (sym.isAliasType) normalize
else if (sym.isNonClassType) transformInfo(sym.info)
else sym.info
def relativeInfo = if (sym.isNonClassType) transformInfo(pre.memberInfo(sym)) else pre.memberInfo(sym)
override def typeSymbol = if (sym.isAliasType) normalize.typeSymbol else sym
override def termSymbol = if (sym.isAliasType) normalize.termSymbol else super.termSymbol
override def typeSymbolDirect = sym
override def termSymbolDirect = super.termSymbol
/* @MAT
whenever you see `tp.typeSymbol.isXXXX' and then act on tp based on that predicate, you're on thin ice,
as `typeSymbol' (and `prefix') automatically normalize, but the other inspectors don't.
In other words, even if `tp.normalize.sym.isXXX' is true, `tp.sym.isXXX' may be false (if sym were a public method to access the non-normalized typeSymbol)...
In retrospect, I think `tp.typeSymbol.isXXX' or (worse) `tp.typeSymbol==XXX' should be replaced by `val tp = tp0.asXXX'.
A type's typeSymbol should never be inspected directly.
*/
override def bounds: TypeBounds =
if (sym.isAbstractType) thisInfo.bounds // transform(thisInfo.bounds).asInstanceOf[TypeBounds] // ??? seems to be doing asSeenFrom twice
else super.bounds
override def parents: List[Type] = parentsCache.get()
override def typeOfThis = transform(sym.typeOfThis)
/*
override def narrow =
if (sym.isModuleClass) transform(sym.thisType)
else if (sym.isAliasType) normalize.narrow
else super.narrow
*/
override def narrow =
if (sym.isModuleClass) singleType(pre, sym.sourceModule)
else if (sym.isAliasType) normalize.narrow
else super.narrow
override def prefix: Type =
if (sym.isAliasType) normalize.prefix
else pre
override def typeArgs: List[Type] = args
private def typeArgsOrDummies = if (!isHigherKinded) args else dummyArgs
// @MAT was typeSymbol.unsafeTypeParams, but typeSymbol normalizes now
private def typeParamsDirect =
if (isDefinitionsInitialized) sym.typeParams
else sym.unsafeTypeParams
// placeholders derived from type params
private def dummyArgs = typeParamsDirect map (_.typeConstructor) //@M must be .typeConstructor
// (!result.isEmpty) IFF isHigherKinded
override def typeParams: List[Symbol] = if (isHigherKinded) typeParamsDirect else List()
override def typeConstructor = TypeRef(pre, sym, Nil)
// note: does not go through typeRef. There's no need to because neither `pre' nor `sym' changes.
// And there's a performance advantage to call TypeRef directly.
// a reference (in a Scala program) to a type that has type parameters, but where the reference does not include type arguments
// note that it doesn't matter whether the symbol refers to a java or scala symbol,
// it does matter whether it occurs in java or scala code
// typerefs w/o type params that occur in java signatures/code are considered raw types, and are represented as existential types
override def isHigherKinded = args.isEmpty && typeParamsDirect.nonEmpty
override def instantiateTypeParams(formals: List[Symbol], actuals: List[Type]): Type =
if (isHigherKinded) {
val substTps = formals.intersect(typeParams)
if (sameLength(substTps, typeParams))
typeRef(pre, sym, actuals)
else if (sameLength(formals, actuals)) // partial application (needed in infer when bunching type arguments from classes and methods together)
typeRef(pre, sym, dummyArgs).subst(formals, actuals)
else ErrorType
}
else
super.instantiateTypeParams(formals, actuals)
private var normalized: Type = null
@inline private def betaReduce: Type = {
assert(sameLength(sym.info.typeParams, typeArgs), this)
// isHKSubType0 introduces synthetic type params so that betaReduce can first apply sym.info to typeArgs before calling asSeenFrom
// asSeenFrom then skips synthetic type params, which are used to reduce HO subtyping to first-order subtyping, but which can't be instantiated from the given prefix and class
// appliedType(sym.info, typeArgs).asSeenFrom(pre, sym.owner) // this crashes pos/depmet_implicit_tpbetareduce.scala
transform(sym.info.resultType)
}
// @M: initialize (by sym.info call) needed (see test/files/pos/ticket0137.scala)
@inline private def etaExpand: Type = {
val tpars = sym.info.typeParams // must go through sym.info for typeParams to initialise symbol
typeFunAnon(tpars, typeRef(pre, sym, tpars map (_.tpeHK))) // todo: also beta-reduce?
}
override def dealias: Type =
if (sym.isAliasType && sameLength(sym.info.typeParams, args)) {
betaReduce.dealias
} else this
def normalize0: Type =
if (pre eq WildcardType) WildcardType // arises when argument-dependent types are approximated (see def depoly in implicits)
else if (isHigherKinded) etaExpand // eta-expand, subtyping relies on eta-expansion of higher-kinded types
else if (sym.isAliasType && sameLength(sym.info.typeParams, args))
betaReduce.normalize // beta-reduce, but don't do partial application -- cycles have been checked in typeRef
else if (sym.isRefinementClass)
sym.info.normalize // I think this is okay, but see #1241 (r12414), #2208, and typedTypeConstructor in Typers
else {
if(sym.isAliasType) ErrorType //println("!!error: "+(pre, sym, sym.info, sym.info.typeParams, args))
else super.normalize
}
// TODO: test case that is compiled in a specific order and in different runs
override def normalize: Type = {
if (phase.erasedTypes) normalize0
else {
if (normalized == null)
normalized = normalize0
normalized
}
}
override def decls: Scope = {
sym.info match {
case TypeRef(_, sym1, _) =>
assert(sym1 != sym, this) // @MAT was != typeSymbol
case _ =>
}
thisInfo.decls
}
override def baseType(clazz: Symbol): Type =
if (sym == clazz) this
else if (sym.isClass) transform(sym.info.baseType(clazz))
else
try {
basetypeRecursions += 1
if (basetypeRecursions < LogPendingBaseTypesThreshold)
relativeInfo.baseType(clazz)
else if (pendingBaseTypes contains this)
if (clazz == AnyClass) clazz.tpe else NoType
else
try {
pendingBaseTypes += this
relativeInfo.baseType(clazz)
} finally {
pendingBaseTypes -= this
}
} finally {
basetypeRecursions -= 1
}
override def baseTypeSeq: BaseTypeSeq = {
val period = baseTypeSeqPeriod
if (period != currentPeriod) {
baseTypeSeqPeriod = currentPeriod
if (!isValidForBaseClasses(period)) {
incCounter(typerefBaseTypeSeqCount)
baseTypeSeqCache = undetBaseTypeSeq
baseTypeSeqCache =
if (sym.isAbstractType) transform(bounds.hi).baseTypeSeq prepend this
else sym.info.baseTypeSeq map transform
}
}
if (baseTypeSeqCache == undetBaseTypeSeq)
throw new TypeError("illegal cyclic inheritance involving " + sym)
baseTypeSeqCache
}
override def baseTypeSeqDepth: Int = baseTypeSeq.maxDepth
override def baseClasses: List[Symbol] = thisInfo.baseClasses
// override def isNullable: Boolean = sym.info.isNullable
override def safeToString: String = {
if (!settings.debug.value) {
this match {
case TypeRef(_, RepeatedParamClass, arg :: _) => return arg + "*"
case TypeRef(_, ByNameParamClass, arg :: _) => return "=> " + arg
case _ =>
if (isFunctionType(this))
return normalize.typeArgs.init.mkString("(", ", ", ")") + " => " + normalize.typeArgs.last
else if (isTupleTypeOrSubtype(this))
return normalize.typeArgs.mkString("(", ", ", if (hasLength(normalize.typeArgs, 1)) ",)" else ")")
else if (sym.isAliasType && prefixChain.exists(_.termSymbol.isSynthetic)) {
val normed = normalize;
if (normed ne this) return normed.toString
}
}
}
val monopart =
if (!settings.debug.value &&
(shorthands contains sym.fullName) &&
(sym.ownerChain forall (_.isClass))) // ensure that symbol is not a local copy with a name coincidence
sym.name.toString
else
pre.prefixString + sym.nameString
var str = monopart + (if (args.isEmpty) "" else args.mkString("[", ",", "]"))
//if (sym.nameString startsWith "moduleType")
// str += ("_in_"+sym.ownerChain)
if (sym.isPackageClass)
packagePrefix + str
else if (sym.isModuleClass)
objectPrefix + str
else if (sym.isAnonymousClass && sym.isInitialized && !settings.debug.value && !phase.erasedTypes)
thisInfo.parents.mkString(" with ") + {
if (sym.isStructuralRefinement)
((decls.toList filter { entry =>
!entry.isConstructor && entry.allOverriddenSymbols.isEmpty && !entry.isPrivate
}) map { entry => entry.defString }).mkString("{", "; ", "}")
else
""
}
else if (sym.isRefinementClass && sym.isInitialized)
thisInfo.toString
else str
}
override def prefixString =
if (settings.debug.value)
super.prefixString
else if (sym.printWithoutPrefix)
""
else if (sym.isPackageClass)
sym.fullName + "."
else if (isStable && (sym.name endsWith ".type"))
sym.name.toString dropRight 4
else
super.prefixString
override def kind = "TypeRef"
}
object TypeRef extends TypeRefExtractor {
def apply(pre: Type, sym: Symbol, args: List[Type]): Type = {
unique(new TypeRef(pre, sym, args) with UniqueType)
}
}
/** A class representing a method type with parameters.
* Note that a parameterless method is represented by a NullaryMethodType:
*
* def m(): Int MethodType(Nil, Int)
* def m: Int NullaryMethodType(Int)
*/
case class MethodType(override val params: List[Symbol],
override val resultType: Type) extends Type {
override def isTrivial: Boolean = isTrivial0
private lazy val isTrivial0 =
resultType.isTrivial && params.forall{p => p.tpe.isTrivial && (
!settings.YdepMethTpes.value || !(params.exists(_.tpe.contains(p)) || resultType.contains(p)))
}
def isImplicit = params.nonEmpty && params.head.isImplicit
def isJava = false // can we do something like for implicits? I.e. do Java methods without parameters need to be recognized?
//assert(paramTypes forall (pt => !pt.typeSymbol.isImplClass))//DEBUG
override def paramSectionCount: Int = resultType.paramSectionCount + 1
override def paramss: List[List[Symbol]] = params :: resultType.paramss
override def paramTypes = params map (_.tpe)
override def boundSyms = immutable.Set[Symbol](params ++ resultType.boundSyms: _*)
// AM to TR: #dropNonContraintAnnotations
// this is needed for plugins to work correctly, only TypeConstraint annotations are supposed to be carried over
// TODO: this should probably be handled in a more structured way in adapt -- remove this map in resultType and watch the continuations tests fail
object dropNonContraintAnnotations extends TypeMap {
override val dropNonConstraintAnnotations = true
def apply(x: Type) = mapOver(x)
}
override def resultType(actuals: List[Type]) =
if (isTrivial) dropNonContraintAnnotations(resultType)
else {
if (sameLength(actuals, params)) {
val idm = new InstantiateDependentMap(params, actuals)
val res = idm(resultType)
// println("resultTypeDep "+(params, actuals, resultType, idm.existentialsNeeded, "\n= "+ res))
existentialAbstraction(idm.existentialsNeeded, res)
} else {
// Thread.dumpStack()
// println("resultType "+(params, actuals, resultType))
if (phase.erasedTypes) resultType
else existentialAbstraction(params, resultType)
}
}
// implicit args can only be depended on in result type: TODO this may be generalised so that the only constraint is dependencies are acyclic
def approximate: MethodType = MethodType(params, resultApprox)
override def finalResultType: Type = resultType.finalResultType
override def safeToString: String =
params.map(_.defString).mkString("(", ",", ")") + resultType
override def cloneInfo(owner: Symbol) = {
val vparams = cloneSymbols(params, owner)
copyMethodType(this, vparams, resultType.substSym(params, vparams).cloneInfo(owner))
}
override def atOwner(owner: Symbol) =
if ((params exists (_.owner != owner)) || (resultType.atOwner(owner) ne resultType))
cloneInfo(owner)
else
this
override def kind = "MethodType"
}
object MethodType extends MethodTypeExtractor
class JavaMethodType(ps: List[Symbol], rt: Type) extends MethodType(ps, rt) {
override def isJava = true
}
case class NullaryMethodType(override val resultType: Type) extends Type {
// AM to TR: #dropNonContraintAnnotations
// change isTrivial to the commented version and watch continuations-run/t3225.scala fail
// isTrivial implies asSeenFrom is bypassed, since it's supposed to be the identity map
// it's not really the identity due to dropNonContraintAnnotations
override def isTrivial: Boolean = false //resultType.isTrivial -- `false` to make continuations plugin work (so that asSeenFromMap drops non-constrain annotations even when type doesn't change otherwise)
override def prefix: Type = resultType.prefix
override def narrow: Type = resultType.narrow
override def finalResultType: Type = resultType.finalResultType
override def termSymbol: Symbol = resultType.termSymbol
override def typeSymbol: Symbol = resultType.typeSymbol
override def parents: List[Type] = resultType.parents
override def decls: Scope = resultType.decls
override def baseTypeSeq: BaseTypeSeq = resultType.baseTypeSeq
override def baseTypeSeqDepth: Int = resultType.baseTypeSeqDepth
override def baseClasses: List[Symbol] = resultType.baseClasses
override def baseType(clazz: Symbol): Type = resultType.baseType(clazz)
override def boundSyms = resultType.boundSyms
override def isVolatile = resultType.isVolatile
override def safeToString: String = "=> "+ resultType
override def kind = "NullaryMethodType"
}
object NullaryMethodType extends NullaryMethodTypeExtractor
/** A type function or the type of a polymorphic value (and thus of kind *).
*
* Before the introduction of NullaryMethodType, a polymorphic nullary method (e.g, def isInstanceOf[T]: Boolean)
* used to be typed as PolyType(tps, restpe), and a monomorphic one as PolyType(Nil, restpe)
* This is now: PolyType(tps, NullaryMethodType(restpe)) and NullaryMethodType(restpe)
* by symmetry to MethodTypes: PolyType(tps, MethodType(params, restpe)) and MethodType(params, restpe)
*
* Thus, a PolyType(tps, TypeRef(...)) unambiguously indicates a type function (which results from eta-expanding a type constructor alias).
* Similarly, PolyType(tps, ClassInfoType(...)) is a type constructor.
*
* A polytype is of kind * iff its resultType is a (nullary) method type.
*/
case class PolyType(override val typeParams: List[Symbol], override val resultType: Type)
extends Type {
//assert(!(typeParams contains NoSymbol), this)
assert(typeParams nonEmpty, this) // used to be a marker for nullary method type, illegal now (see @NullaryMethodType)
override def paramSectionCount: Int = resultType.paramSectionCount
override def paramss: List[List[Symbol]] = resultType.paramss
override def params: List[Symbol] = resultType.params
override def paramTypes: List[Type] = resultType.paramTypes
override def parents: List[Type] = resultType.parents
override def decls: Scope = resultType.decls
override def termSymbol: Symbol = resultType.termSymbol
override def typeSymbol: Symbol = resultType.typeSymbol
override def boundSyms = immutable.Set[Symbol](typeParams ++ resultType.boundSyms: _*)
override def prefix: Type = resultType.prefix
override def baseTypeSeq: BaseTypeSeq = resultType.baseTypeSeq
override def baseTypeSeqDepth: Int = resultType.baseTypeSeqDepth
override def baseClasses: List[Symbol] = resultType.baseClasses
override def baseType(clazz: Symbol): Type = resultType.baseType(clazz)
override def narrow: Type = resultType.narrow
override def isVolatile = resultType.isVolatile
override def finalResultType: Type = resultType.finalResultType
/** @M: typeDefSig wraps a TypeBounds in a PolyType
* to represent a higher-kinded type parameter
* wrap lo&hi in polytypes to bind variables
*/
override def bounds: TypeBounds =
TypeBounds(typeFun(typeParams, resultType.bounds.lo),
typeFun(typeParams, resultType.bounds.hi))
override def isHigherKinded = !typeParams.isEmpty
override def safeToString: String =
(typeParams map (_.defString) mkString ("[", ",", "]"))+ resultType
override def cloneInfo(owner: Symbol) = {
val tparams = cloneSymbols(typeParams, owner)
PolyType(tparams, resultType.substSym(typeParams, tparams).cloneInfo(owner))
}
override def atOwner(owner: Symbol) =
if ((typeParams exists (_.owner != owner)) || (resultType.atOwner(owner) ne resultType))
cloneInfo(owner)
else
this
override def kind = "PolyType"
}
object PolyType extends PolyTypeExtractor
case class ExistentialType(quantified: List[Symbol],
override val underlying: Type) extends RewrappingTypeProxy
{
override protected def rewrap(newtp: Type) = existentialAbstraction(quantified, newtp)
override def isTrivial = false
override def isStable: Boolean = false
override def bounds = TypeBounds(maybeRewrap(underlying.bounds.lo), maybeRewrap(underlying.bounds.hi))
override def parents = underlying.parents map maybeRewrap
override def boundSyms = quantified.toSet
override def prefix = maybeRewrap(underlying.prefix)
override def typeArgs = underlying.typeArgs map maybeRewrap
override def params = underlying.params mapConserve { param =>
val tpe1 = rewrap(param.tpe)
if (tpe1 eq param.tpe) param else param.cloneSymbol.setInfo(tpe1)
}
override def paramTypes = underlying.paramTypes map maybeRewrap
override def instantiateTypeParams(formals: List[Symbol], actuals: List[Type]) = {
// maybeRewrap(underlying.instantiateTypeParams(formals, actuals))
val quantified1 = new SubstTypeMap(formals, actuals) mapOver quantified
val underlying1 = underlying.instantiateTypeParams(formals, actuals)
if ((quantified1 eq quantified) && (underlying1 eq underlying)) this
else existentialAbstraction(quantified1, underlying1.substSym(quantified, quantified1))
}
override def baseType(clazz: Symbol) = maybeRewrap(underlying.baseType(clazz))
override def baseTypeSeq = underlying.baseTypeSeq map maybeRewrap
override def isHigherKinded = false
override def skolemizeExistential(owner: Symbol, origin: AnyRef) = {
def mkSkolem(tparam: Symbol): Symbol = {
val skolem = new TypeSkolem(
if (owner == NoSymbol) tparam.owner else owner,
tparam.pos, tparam.name.toTypeName, origin)
skolem.setInfo(tparam.info.cloneInfo(skolem))
.setFlag(tparam.flags | EXISTENTIAL)
.resetFlag(PARAM)
}
val skolems = quantified map mkSkolem
for (skolem <- skolems)
skolem setInfo skolem.info.substSym(quantified, skolems)
underlying.substSym(quantified, skolems)
}
private def wildcardArgsString(available: Set[Symbol], args: List[Type]): List[String] = args match {
case TypeRef(_, sym, _) :: args1 if (available contains sym) =>
("_"+sym.infoString(sym.info)) :: wildcardArgsString(available - sym, args1)
case arg :: args1 if !(quantified exists (arg contains _)) =>
arg.toString :: wildcardArgsString(available, args1)
case _ =>
List()
}
override def safeToString: String = {
if (!(quantified exists (_.isSingletonExistential)) && !settings.debug.value)
// try to represent with wildcards first
underlying match {
case TypeRef(pre, sym, args) if args.nonEmpty =>
val wargs = wildcardArgsString(quantified.toSet, args)
if (sameLength(wargs, args))
return TypeRef(pre, sym, List()) + wargs.mkString("[", ", ", "]")
case _ =>
}
var ustr = underlying.toString
underlying match {
case MethodType(_, _) | NullaryMethodType(_) | PolyType(_, _) => ustr = "("+ustr+")"
case _ =>
}
val str =
ustr+(quantified map (_.existentialToString) mkString(" forSome { ", "; ", " }"))
if (settings.explaintypes.value) "("+str+")" else str
}
override def cloneInfo(owner: Symbol) = {
val tparams = cloneSymbols(quantified, owner)
ExistentialType(tparams, underlying.substSym(quantified, tparams))
}
override def atOwner(owner: Symbol) =
if (quantified exists (_.owner != owner)) cloneInfo(owner) else this
override def kind = "ExistentialType"
def withTypeVars(op: Type => Boolean): Boolean = withTypeVars(op, AnyDepth)
def withTypeVars(op: Type => Boolean, depth: Int): Boolean = {
val quantifiedFresh = cloneSymbols(quantified)
val tvars = quantifiedFresh map (tparam => TypeVar(tparam))
val underlying1 = underlying.instantiateTypeParams(quantified, tvars) // fuse subst quantified -> quantifiedFresh -> tvars
op(underlying1) && {
solve(tvars, quantifiedFresh, quantifiedFresh map (x => 0), false, depth) &&
isWithinBounds(NoPrefix, NoSymbol, quantifiedFresh, tvars map (_.constr.inst))
}
}
}
object ExistentialType extends ExistentialTypeExtractor
/** A class containing the alternatives and type prefix of an overloaded symbol.
* Not used after phase `typer'.
*/
case class OverloadedType(pre: Type, alternatives: List[Symbol]) extends Type {
override def prefix: Type = pre
override def safeToString =
(alternatives map pre.memberType).mkString("", " <and> ", "")
override def kind = "OverloadedType"
}
/** A class remembering a type instantiation for some a set of overloaded
* polymorphic symbols.
* Not used after phase `typer'.
*/
case class AntiPolyType(pre: Type, targs: List[Type]) extends Type {
override def safeToString =
pre.toString + targs.mkString("(with type arguments ", ",", ")");
override def memberType(sym: Symbol) = appliedType(pre.memberType(sym), targs)
// override def memberType(sym: Symbol) = pre.memberType(sym) match {
// case PolyType(tparams, restp) =>
// restp.subst(tparams, targs)
// /* I don't think this is needed, as existential types close only over value types
// case ExistentialType(tparams, qtpe) =>
// existentialAbstraction(tparams, qtpe.memberType(sym))
// */
// case ErrorType =>
// ErrorType
// }
override def kind = "AntiPolyType"
}
//private var tidCount = 0 //DEBUG
//@M
// a TypeVar used to be a case class with only an origin and a constr
// then, constr became mutable (to support UndoLog, I guess), but pattern-matching returned the original constr0 (a bug)
// now, pattern-matching returns the most recent constr
object TypeVar {
// encapsulate suspension so we can automatically link the suspension of cloned typevars to their original if this turns out to be necessary
def Suspension = new Suspension
class Suspension {
private val suspended = mutable.HashSet[TypeVar]()
def suspend(tv: TypeVar): Unit = {
tv.suspended = true
suspended += tv
}
def resumeAll: Unit = {
for(tv <- suspended) {
tv.suspended = false
}
suspended.clear
}
}
def unapply(tv: TypeVar): Some[(Type, TypeConstraint)] = Some((tv.origin, tv.constr))
def apply(origin: Type, constr: TypeConstraint) = new TypeVar(origin, constr, List(), List())
def apply(tparam: Symbol) = new TypeVar(tparam.tpeHK, new TypeConstraint, List(), tparam.typeParams) // TODO why not initialise TypeConstraint with bounds of tparam?
def apply(origin: Type, constr: TypeConstraint, args: List[Type], params: List[Symbol]) = new TypeVar(origin, constr, args, params)
}
/** A class representing a type variable
* Not used after phase `typer'.
* A higher-kinded type variable has type arguments (a list of Type's) and type parameters (list of Symbols)
* A TypeVar whose list of args is non-empty can only be instantiated by a higher-kinded type that can be applied to these args
* a typevar is much like a typeref, except it has special logic for type equality/subtyping
*/
class TypeVar(val origin: Type, val constr0: TypeConstraint, override val typeArgs: List[Type], override val params: List[Symbol]) extends Type {
// params are needed to keep track of variance (see mapOverArgs in SubstMap)
assert(typeArgs.isEmpty || sameLength(typeArgs, params))
// var tid = { tidCount += 1; tidCount } //DEBUG
/** The constraint associated with the variable */
var constr = constr0
def instValid = constr.instValid
/** The variable's skolemization level */
val level = skolemizationLevel
/**
* two occurrences of a higher-kinded typevar, e.g. ?CC[Int] and ?CC[String], correspond to
* *two instances* of TypeVar that share the *same* TypeConstraint
* constr for ?CC only tracks type constructors anyway, so when ?CC[Int] <:< List[Int] and ?CC[String] <:< Iterable[String]
* ?CC's hibounds contains List and Iterable
*/
def applyArgs(newArgs: List[Type]): TypeVar =
if (newArgs.isEmpty) this // SubstMap relies on this (though this check is redundant when called from appliedType...)
else TypeVar(origin, constr, newArgs, params) // @M TODO: interaction with undoLog??
// newArgs.length may differ from args.length (could've been empty before)
// example: when making new typevars, you start out with C[A], then you replace C by ?C, which should yield ?C[A], then A by ?A, ?C[?A]
// we need to track a TypeVar's arguments, and map over them (see TypeMap::mapOver)
// TypeVars get applied to different arguments over time (in asSeenFrom)
// -- see pos/tcpoly_infer_implicit_tuplewrapper.scala
// thus: make new TypeVar's for every application of a TV to args,
// inference may generate several TypeVar's for a single type parameter that must be inferred,
// only one of them is in the set of tvars that need to be solved, but
// they share the same TypeConstraint instance
// <region name="constraint mutators + undoLog">
// invariant: before mutating constr, save old state in undoLog (undoLog is used to reset constraints to avoid piling up unrelated ones)
def setInst(tp: Type) {
// assert(!(tp containsTp this), this)
undoLog record this
constr.inst = tp
}
def addLoBound(tp: Type, isNumericBound: Boolean = false) {
assert(tp != this) // implies there is a cycle somewhere (?)
//println("addLoBound: "+(safeToString, debugString(tp))) //DEBUG
undoLog record this
constr.addLoBound(tp, isNumericBound)
}
def addHiBound(tp: Type, isNumericBound: Boolean = false) {
// assert(tp != this)
//println("addHiBound: "+(safeToString, debugString(tp))) //DEBUG
undoLog record this
constr.addHiBound(tp, isNumericBound)
}
// </region>
// ignore subtyping&equality checks while true -- see findMember
private[TypeVar] var suspended = false
/** Called when a TypeVar is involved in a subtyping check. Result is whether
* this TypeVar could plausibly be a [super/sub]type of argument `tp` and if so,
* tracks tp as a [lower/upper] bound of this TypeVar.
*
* if (isLowerBound) this typevar could be a subtype, track tp as a lower bound
* if (!isLowerBound) this typevar could be a supertype, track tp as an upper bound
*
* If isNumericBound is true, the subtype check is performed with weak_<:< instead of <:<.
*/
def registerBound(tp: Type, isLowerBound: Boolean, isNumericBound: Boolean = false): Boolean = {
// println("regBound: "+(safeToString, debugString(tp), isLowerBound)) //@MDEBUG
if (isLowerBound) assert(tp != this)
def checkSubtypeLower(tp1: Type, tp2: Type) =
if (isNumericBound) tp1 weak_<:< tp2
else tp1 <:< tp2
// swaps the arguments if it's an upper bound
def checkSubtype(tp1: Type, tp2: Type) =
if (isLowerBound) checkSubtypeLower(tp1, tp2)
else checkSubtypeLower(tp2, tp1)
def addBound(tp: Type) = {
if (isLowerBound) addLoBound(tp, isNumericBound)
else addHiBound(tp, isNumericBound)
// println("addedBound: "+(this, tp)) // @MDEBUG
true
}
/** Simple case: type arguments can be ignored, because either this typevar has
* no type parameters, or we are comparing to Any/Nothing.
*
* The latter condition is needed because HK unification is limited to constraints of the shape
* TC1[T1,..., TN] <: TC2[T'1,...,T'N]
* which would preclude the following important constraints:
* Nothing <: ?TC[?T]
* ?TC[?T] <: Any
*/
def unifySimple = (params.isEmpty || tp.typeSymbol == NothingClass || tp.typeSymbol == AnyClass) &&
addBound(tp)
/** Full case: involving a check of the form
* TC1[T1,..., TN] <: TC2[T'1,...,T'N]
* Checks subtyping of higher-order type vars, and uses variances as defined in the
* type parameter we're trying to infer (the result will be sanity-checked later)
*/
def unifyFull(tp: Type) = sameLength(typeArgs, tp.typeArgs) && { // this is a higher-kinded type var with same arity as tp
// side effect: adds the type constructor itself as a bound
addBound(tp.typeConstructor)
if (isLowerBound) isSubArgs(tp.typeArgs, typeArgs, params)
else isSubArgs(typeArgs, tp.typeArgs, params)
}
/** TODO: need positive/negative test cases demonstrating this is correct.
*/
def unifyParents =
if (isLowerBound) tp.parents exists unifyFull
else tp.parents forall unifyFull
// TODO: fancier unification, maybe rewrite constraint as follows?
// val sym = constr.hiBounds map {_.typeSymbol} find { _.typeParams.length == typeArgs.length}
// this <: tp.baseType(sym)
if (suspended) checkSubtype(tp, origin)
else if (constr.instValid) checkSubtype(tp, constr.inst) // type var is already set
else isRelatable(tp) && {
unifySimple || unifyFull(tp) || unifyFull(tp.dealias) || unifyFull(tp.widen) || unifyParents
}
}
def registerTypeEquality(tp: Type, typeVarLHS: Boolean): Boolean = { //println("regTypeEq: "+(safeToString, debugString(tp), typeVarLHS)) //@MDEBUG
def checkIsSameType(tp: Type) =
if(typeVarLHS) constr.inst =:= tp
else tp =:= constr.inst
if (suspended) tp =:= origin
else if (constr.instValid) checkIsSameType(tp)
else isRelatable(tp) && {
val newInst = wildcardToTypeVarMap(tp)
if (constr.isWithinBounds(newInst)) {
setInst(tp)
true
} else false
}
}
/**
* ?A.T =:= tp is rewritten as the constraint ?A <: {type T = tp}
*
* TODO: make these constraints count (incorporate them into implicit search in applyImplicitArgs)
* (T corresponds to @param sym)
*/
def registerTypeSelection(sym: Symbol, tp: Type): Boolean = {
val bound = refinedType(List(WildcardType), NoSymbol)
val bsym = bound.typeSymbol.newAliasType(NoPosition, sym.name.toTypeName)
bsym setInfo tp
bound.decls enter bsym
registerBound(bound, false)
}
/** Can this variable be related in a constraint to type `tp'?
* This is not the case if `tp' contains type skolems whose
* skolemization level is higher than the level of this variable.
*/
def isRelatable(tp: Type): Boolean =
!tp.exists { t =>
t.typeSymbol match {
case ts: TypeSkolem => ts.level > level
case _ => false
}
}
override val isHigherKinded = typeArgs.isEmpty && !params.isEmpty
override def normalize: Type =
if (constr.instValid) constr.inst
else if (isHigherKinded) { // get here when checking higher-order subtyping of the typevar by itself (TODO: check whether this ever happens?)
typeFun(params, applyArgs(params map (_.typeConstructor)))
} else {
super.normalize
}
override def typeSymbol = origin.typeSymbol
override def safeToString: String = {
def varString = "?"+(if (settings.explaintypes.value) level else "")+
origin+
(if(typeArgs.isEmpty) "" else (typeArgs map (_.safeToString)).mkString("[ ", ", ", " ]")) // +"#"+tid //DEBUG
if (constr.inst eq null) "<null " + origin + ">"
// else if (settings.debug.value) varString+"(@"+constr.## +")"+constr.toString
else if (constr.inst eq NoType) varString
else constr.inst.toString
}
override def isStable = origin.isStable
override def isVolatile = origin.isVolatile
override def kind = "TypeVar"
def cloneInternal = {
assert(!suspended) // cloning a suspended type variable when it's suspended will cause the clone to never be resumed with the current implementation
TypeVar(origin, constr cloneInternal, typeArgs, params) // @M TODO: clone args/params?
}
}
/** A type carrying some annotations. Created by the typechecker
* when eliminating ``Annotated'' trees (see typedAnnotated).
*
* @param annotations the list of annotations on the type
* @param underlying the type without the annotation
* @param selfsym a "self" symbol with type <code>underlying</code>;
* only available if -Yself-in-annots is turned on. Can be NoSymbol
* if it is not used.
*/
case class AnnotatedType(override val annotations: List[AnnotationInfo],
override val underlying: Type,
override val selfsym: Symbol)
extends RewrappingTypeProxy {
assert(!annotations.isEmpty)
override protected def rewrap(tp: Type) = AnnotatedType(annotations, tp, selfsym)
override def isTrivial: Boolean = isTrivial0
private lazy val isTrivial0 = underlying.isTrivial && (annotations forall (_.isTrivial))
override def safeToString: String = {
val attString =
if (annotations.isEmpty)
""
else
annotations.mkString(" @", " @", "")
underlying + attString
}
/** Add a number of annotations to this type */
override def withAnnotations(annots: List[AnnotationInfo]): Type =
copy(annots:::this.annotations)
/** Remove any annotations from this type */
override def withoutAnnotations = underlying.withoutAnnotations
/** Set the self symbol */
override def withSelfsym(sym: Symbol) =
AnnotatedType(annotations, underlying, sym)
/** Drop the annotations on the bounds, unless but the low and high bounds are
* exactly tp. */
override def bounds: TypeBounds = {
val oftp = underlying.bounds
oftp match {
case TypeBounds(lo, hi) if ((lo eq this) && (hi eq this)) => TypeBounds(this,this)
case _ => oftp
}
}
// ** Replace formal type parameter symbols with actual type arguments. * /
override def instantiateTypeParams(formals: List[Symbol], actuals: List[Type]) = {
val annotations1 = annotations.map(info => AnnotationInfo(info.atp.instantiateTypeParams(
formals, actuals), info.args, info.assocs).setPos(info.pos))
val underlying1 = underlying.instantiateTypeParams(formals, actuals)
if ((annotations1 eq annotations) && (underlying1 eq underlying)) this
else AnnotatedType(annotations1, underlying1, selfsym)
}
/** Return the base type sequence of tp, dropping the annotations, unless the base type sequence of tp
* is precisely tp itself. */
override def baseTypeSeq: BaseTypeSeq = {
val oftp = underlying.baseTypeSeq
if ((oftp.length == 1) && (oftp(0) eq underlying))
baseTypeSingletonSeq(this)
else
oftp
}
override def kind = "AnnotatedType"
}
object AnnotatedType extends AnnotatedTypeExtractor
/** A class representing types with a name. When an application uses
* named arguments, the named argument types for calling isApplicable
* are represented as NamedType.
*/
case class NamedType(name: Name, tp: Type) extends Type {
override def safeToString: String = name.toString +": "+ tp
}
/** A class representing an as-yet unevaluated type.
*/
abstract class LazyType extends Type with AbsLazyType {
override def kind = "LazyType"
}
// Creators ---------------------------------------------------------------
/** Rebind symbol `sym' to an overriding member in type
* `pre'.
*/
private def rebind(pre: Type, sym: Symbol): Symbol = {
val owner = sym.owner
if (owner.isClass && owner != pre.typeSymbol && !sym.isEffectivelyFinal && !sym.isClass) {
//Console.println("rebind "+pre+" "+sym)//DEBUG
val rebind = pre.nonPrivateMember(sym.name).suchThat(sym => sym.isType || sym.isStable)
if (rebind == NoSymbol) sym
else {
// Console.println("rebound "+pre+" "+sym+" to "+rebind)//DEBUG
rebind
}
} else sym
}
/** Convert a `super' prefix to a this-type if `sym'
* is abstract or final.
*/
private def removeSuper(tp: Type, sym: Symbol): Type = tp match {
case SuperType(thistp, _) =>
if (sym.isEffectivelyFinal || sym.isDeferred) thistp
else tp
case _ =>
tp
}
/** The canonical creator for single-types */
def singleType(pre: Type, sym: Symbol): Type = {
if (phase.erasedTypes)
sym.tpe.resultType
else if (sym.isRootPackage)
ThisType(RootClass)
else {
var sym1 = rebind(pre, sym)
val pre1 = removeSuper(pre, sym1)
if (pre1 ne pre) sym1 = rebind(pre1, sym1)
// why not do the hash-consing in the SingleType.apply()
// factory, like the other UniqueTypes?
unique(new SingleType(pre1, sym1) with UniqueType)
}
}
/** the canonical creator for a refined type with a given scope */
def refinedType(parents: List[Type], owner: Symbol, decls: Scope, pos : Position): Type = {
if (phase.erasedTypes)
if (parents.isEmpty) ObjectClass.tpe else parents.head
else {
val clazz = owner.newRefinementClass(NoPosition)
val result = RefinedType(parents, decls, clazz)
clazz.setInfo(result)
result
}
}
/** The canonical creator for a refined type with an initially empty scope.
*
* @param parents ...
* @param owner ...
* @return ...
*/
def refinedType(parents: List[Type], owner: Symbol): Type =
refinedType(parents, owner, new Scope, owner.pos)
def copyRefinedType(original: RefinedType, parents: List[Type], decls: Scope) =
if ((parents eq original.parents) && (decls eq original.decls)) original
else {
val owner = if (original.typeSymbol == NoSymbol) NoSymbol else original.typeSymbol.owner
val result = refinedType(parents, owner)
val syms1 = decls.toList
for (sym <- syms1)
result.decls.enter(sym.cloneSymbol(result.typeSymbol))
val syms2 = result.decls.toList
val resultThis = result.typeSymbol.thisType
for (sym <- syms2)
sym.setInfo(sym.info.substThis(original.typeSymbol, resultThis).substSym(syms1, syms2))
result
}
/** The canonical creator for typerefs
* todo: see how we can clean this up a bit
*/
def typeRef(pre: Type, sym: Symbol, args: List[Type]): Type = {
// type alias selections are rebound in TypeMap ("coevolved", actually -- see #3731)
// e.g., when type parameters that are referenced by the alias are instantiated in
// the prefix. See pos/depmet_rebind_typealias.
def rebindTR(pre: Type, sym: Symbol) =
if (sym.isAbstractType) rebind(pre, sym) else sym
val sym1 = rebindTR(pre, sym)
// we require that object is initialized, thus info.typeParams instead of typeParams.
if (sym1.isAliasType && sameLength(sym1.info.typeParams, args)) {
if (sym1.lockOK) TypeRef(pre, sym1, args) // don't expand type alias (cycles checked by lockOK)
else throw new TypeError("illegal cyclic reference involving " + sym1)
}
else {
val pre1 = removeSuper(pre, sym1)
if (pre1 ne pre)
typeRef(pre1, rebindTR(pre1, sym1), args)
else pre match {
case _: CompoundType if sym1.isClass =>
// sharpen prefix so that it is maximal and still contains the class.
pre.parents.reverse dropWhile (_.member(sym1.name) != sym1) match {
case Nil => TypeRef(pre, sym1, args)
case parent :: _ => typeRef(parent, sym1, args)
}
case _ =>
TypeRef(pre, sym1, args)
}
}
}
/** The canonical creator for implicit method types */
def JavaMethodType(params: List[Symbol], resultType: Type): JavaMethodType =
new JavaMethodType(params, resultType) // don't unique this!
/** Create a new MethodType of the same class as tp, i.e. keep JavaMethodType */
def copyMethodType(tp: Type, params: List[Symbol], restpe: Type): Type = tp match {
case _: JavaMethodType => JavaMethodType(params, restpe)
case _ => MethodType(params, restpe)
}
/** A creator for intersection type where intersections of a single type are
* replaced by the type itself, and repeated parent classes are merged.
*/
def intersectionType(tps: List[Type], owner: Symbol): Type = tps match {
case List(tp) =>
tp
case _ =>
refinedType(tps, owner)
/*
def merge(tps: List[Type]): List[Type] = tps match {
case tp :: tps1 =>
val tps1a = tps1 filter (_.typeSymbol.==(tp.typeSymbol))
val tps1b = tps1 filter (_.typeSymbol.!=(tp.typeSymbol))
mergePrefixAndArgs(tps1a, -1) match {
case Some(tp1) => tp1 :: merge(tps1b)
case None => throw new MalformedType(
"malformed type: "+refinedType(tps, owner)+" has repeated parent class "+
tp.typeSymbol+" with incompatible prefixes or type arguments")
}
case _ => tps
}
refinedType(merge(tps), owner)
*/
}
/** A creator for intersection type where intersections of a single type are
* replaced by the type itself. */
def intersectionType(tps: List[Type]): Type = tps match {
case List(tp) => tp
case _ => refinedType(tps, commonOwner(tps))
}
/** A creator for type applications */
def appliedType(tycon: Type, args: List[Type]): Type =
if (args.isEmpty) tycon //@M! `if (args.isEmpty) tycon' is crucial (otherwise we create new types in phases after typer and then they don't get adapted (??))
else tycon match {
case TypeRef(pre, sym @ (NothingClass|AnyClass), _) => typeRef(pre, sym, Nil) //@M drop type args to Any/Nothing
case TypeRef(pre, sym, _) => typeRef(pre, sym, args)
case PolyType(tparams, restpe) => restpe.instantiateTypeParams(tparams, args)
case ExistentialType(tparams, restpe) => ExistentialType(tparams, appliedType(restpe, args))
case st: SingletonType => appliedType(st.widen, args) // @M TODO: what to do? see bug1
case RefinedType(parents, decls) => RefinedType(parents map (appliedType(_, args)), decls) // MO to AM: please check
case TypeBounds(lo, hi) => TypeBounds(appliedType(lo, args), appliedType(hi, args))
case tv@TypeVar(_, _) => tv.applyArgs(args)
case AnnotatedType(annots, underlying, self) => AnnotatedType(annots, appliedType(underlying, args), self)
case ErrorType => tycon
case WildcardType => tycon // needed for neg/t0226
case _ => abort(debugString(tycon))
}
/** A creator for type parameterizations that strips empty type parameter lists.
* Use this factory method to indicate the type has kind * (it's a polymorphic value)
* until we start tracking explicit kinds equivalent to typeFun (except that the latter requires tparams nonEmpty)
*/
def polyType(tparams: List[Symbol], tpe: Type): Type =
if (tparams nonEmpty) typeFun(tparams, tpe)
else tpe // it's okay to be forgiving here
/** A creator for anonymous type functions, where the symbol for the type function still needs to be created
*
* TODO:
* type params of anonymous type functions, which currently can only arise from normalising type aliases, are owned by the type alias of which they are the eta-expansion
* higher-order subtyping expects eta-expansion of type constructors that arise from a class; here, the type params are owned by that class, but is that the right thing to do?
*/
def typeFunAnon(tps: List[Symbol], body: Type): Type = typeFun(tps, body)
/** A creator for a type functions, assuming the type parameters tps already have the right owner
*/
def typeFun(tps: List[Symbol], body: Type): Type = PolyType(tps, body)
/** A creator for existential types. This generates:
*
* tpe1 where { tparams }
*
* where `tpe1' is the result of extrapolating `tpe' wrt to `tparams'. Extrapolating means
* that type variables in `tparams' occurring in covariant positions are replaced by upper bounds,
* (minus any SingletonClass markers),
* type variables in `tparams' occurring in contravariant positions are replaced by upper bounds,
* provided the resulting type is legal wrt to stability, and does not contain any
* type variable in `tparams'.
* The abstraction drops all type parameters that are not directly or indirectly
* referenced by type `tpe1'.
* If there are no remaining type parameters, simply returns result type `tpe'.
*/
def existentialAbstraction(tparams: List[Symbol], tpe0: Type): Type =
if (tparams.isEmpty) tpe0
else {
var occurCount = emptySymCount ++ (tparams map (_ -> 0))
val tpe = deAlias(tpe0)
def countOccs(tp: Type) =
for (t <- tp) {
t match {
case TypeRef(_, sym, _) =>
occurCount get sym match {
case Some(count) => occurCount += (sym -> (count + 1))
case none =>
}
case _ =>
}
}
countOccs(tpe)
for (tparam <- tparams) countOccs(tparam.info)
val extrapolate = new TypeMap {
variance = 1
def apply(tp: Type): Type = {
val tp1 = mapOver(tp)
tp1 match {
case TypeRef(pre, sym, args) if (variance != 0) && (occurCount isDefinedAt sym) =>
val repl = if (variance == 1) dropSingletonType(tp1.bounds.hi) else tp1.bounds.lo
//println("eliminate "+sym+"/"+repl+"/"+occurCount(sym)+"/"+(tparams exists (repl.contains)))//DEBUG
if (repl.typeSymbol != NothingClass && repl.typeSymbol != NullClass &&
occurCount(sym) == 1 && !(tparams exists (repl.contains)))
repl
else tp1
case _ =>
tp1
}
}
override def mapOver(tp: Type): Type = tp match {
case SingleType(pre, sym) =>
if (sym.isPackageClass) tp // short path
else {
val pre1 = this(pre)
if ((pre1 eq pre) || !pre1.isStable) tp
else singleType(pre1, sym)
}
case _ => super.mapOver(tp)
}
override def mapOver(tree: Tree) =
tree match {
case tree:Ident if tree.tpe.isStable =>
// Do not discard the types of existential ident's.
// The symbol of the Ident itself cannot be listed
// in the existential's parameters, so the
// resulting existential type would be ill-formed.
Some(tree)
case _ =>
super.mapOver(tree)
}
}
val tpe1 = extrapolate(tpe)
var tparams0 = tparams
var tparams1 = tparams0 filter tpe1.contains
while (tparams1 != tparams0) {
tparams0 = tparams1
tparams1 = tparams filter { p =>
tparams1 exists { p1 => p1 == p || (p1.info contains p) }
}
}
if (tparams1.isEmpty) tpe1
else tpe1 match {
case ExistentialType(tparams2, tpe2) => ExistentialType(tparams1 ::: tparams2, tpe2)
case _ => ExistentialType(tparams1, tpe1)
}
}
/** Remove any occurrences of type aliases from this type */
object deAlias extends TypeMap {
def apply(tp: Type): Type = mapOver {
tp match {
case TypeRef(pre, sym, args) if sym.isAliasType => tp.normalize
case _ => tp
}
}
}
/** Remove any occurrence of type <singleton> from this type and its parents */
object dropSingletonType extends TypeMap {
def apply(tp: Type): Type = {
tp match {
case TypeRef(_, SingletonClass, _) =>
AnyClass.tpe
case tp1 @ RefinedType(parents, decls) =>
var parents1 = parents filter (_.typeSymbol != SingletonClass)
if (parents1.isEmpty) parents1 = List(AnyClass.tpe)
if (parents1.tail.isEmpty && decls.isEmpty) mapOver(parents1.head)
else mapOver(copyRefinedType(tp1, parents1, decls))
case tp1 =>
mapOver(tp1)
}
}
}
// Hash consing --------------------------------------------------------------
private val initialUniquesCapacity = 4096
private var uniques: util.HashSet[Type] = _
private var uniqueRunId = NoRunId
private def unique[T <: Type](tp: T): T = {
incCounter(rawTypeCount)
if (uniqueRunId != currentRunId) {
uniques = util.HashSet[Type]("uniques", initialUniquesCapacity)
uniqueRunId = currentRunId
}
(uniques findEntryOrUpdate tp).asInstanceOf[T]
}
// Helper Classes ---------------------------------------------------------
/** @PP: Unable to see why these apparently constant types should need vals
* in every TypeConstraint, I lifted them out.
*/
private lazy val numericLoBound = IntClass.tpe
private lazy val numericHiBound = intersectionType(List(ByteClass.tpe, CharClass.tpe), ScalaPackageClass)
/** A class expressing upper and lower bounds constraints of type variables,
* as well as their instantiations.
*/
class TypeConstraint(lo0: List[Type], hi0: List[Type], numlo0: Type, numhi0: Type) {
def this(lo0: List[Type], hi0: List[Type]) = this(lo0, hi0, NoType, NoType)
def this() = this(List(), List())
private var lobounds = lo0
private var hibounds = hi0
private var numlo = numlo0
private var numhi = numhi0
def loBounds: List[Type] = if (numlo == NoType) lobounds else numlo :: lobounds
def hiBounds: List[Type] = if (numhi == NoType) hibounds else numhi :: hibounds
def addLoBound(tp: Type, isNumericBound: Boolean = false) {
if (isNumericBound && isNumericValueType(tp)) {
if (numlo == NoType || isNumericSubType(numlo, tp))
numlo = tp
else if (!isNumericSubType(tp, numlo))
numlo = numericLoBound
}
else lobounds ::= tp
}
def addHiBound(tp: Type, isNumericBound: Boolean = false) {
if (isNumericBound && isNumericValueType(tp)) {
if (numhi == NoType || isNumericSubType(tp, numhi))
numhi = tp
else if (!isNumericSubType(numhi, tp))
numhi = numericHiBound
}
else hibounds ::= tp
}
def isWithinBounds(tp: Type): Boolean =
lobounds.forall(_ <:< tp) &&
hibounds.forall(tp <:< _) &&
(numlo == NoType || (numlo weak_<:< tp)) &&
(numhi == NoType || (tp weak_<:< numhi))
var inst: Type = NoType // @M reduce visibility?
def instValid = (inst ne null) && (inst ne NoType)
def cloneInternal = {
val tc = new TypeConstraint(lobounds, hibounds, numlo, numhi)
tc.inst = inst
tc
}
override def toString =
(loBounds map (_.safeToString)).mkString("[ _>:(", ",", ") ") +
(hiBounds map (_.safeToString)).mkString("| _<:(", ",", ") ] _= ") +
inst.safeToString
}
/** A prototype for mapping a function over all possible types
*/
abstract class TypeMap extends Function1[Type, Type] {
// deferred inherited: def apply(tp: Type): Type
/** The variance relative to start. If you want variances to be significant, set
* variance = 1
* at the top of the typemap.
*/
var variance = 0
/** Should this map drop annotations that are not
* type-constraint annotations?
*/
val dropNonConstraintAnnotations = false
/** Check whether two lists have elements that are eq-equal */
def allEq[T <: AnyRef](l1: List[T], l2: List[T]) =
(l1 corresponds l2)(_ eq _)
// #3731: return sym1 for which holds: pre bound sym.name to sym and pre1 now binds sym.name to sym1, conceptually exactly the same symbol as sym
// the selection of sym on pre must be updated to the selection of sym1 on pre1,
// since sym's info was probably updated by the TypeMap to yield a new symbol sym1 with transformed info
// @returns sym1
protected def coevolveSym(pre: Type, pre1: Type, sym: Symbol): Symbol =
if((pre ne pre1) && sym.isAliasType) // only need to rebind type aliases here, as typeRef already handles abstract types (they are allowed to be rebound more liberally)
(pre, pre1) match {
case (RefinedType(_, decls), RefinedType(_, decls1)) => // don't look at parents -- it would be an error to override alias types anyway
//val sym1 =
decls1.lookup(sym.name)
// assert(decls.lookupAll(sym.name).toList.length == 1)
// assert(decls1.lookupAll(sym.name).toList.length == 1)
// assert(sym1.isAliasType)
// println("coevolved "+ sym +" : "+ sym.info +" to "+ sym1 +" : "+ sym1.info +" with "+ pre +" -> "+ pre1)
// sym1
case _ => // TODO: is there another way a typeref's symbol can refer to a symbol defined in its pre?
// val sym1 = pre1.nonPrivateMember(sym.name).suchThat(sym => sym.isAliasType)
// println("??coevolve "+ sym +" : "+ sym.info +" to "+ sym1 +" : "+ sym1.info +" with "+ pre +" -> "+ pre1)
sym
}
else sym
/** Map this function over given type */
def mapOver(tp: Type): Type = tp match {
case TypeRef(pre, sym, args) =>
val pre1 = this(pre)
//val args1 = args mapConserve this(_)
val args1 = if (args.isEmpty) args
else {
val tparams = sym.typeParams
if (tparams.isEmpty) args
else mapOverArgs(args, tparams)
}
if ((pre1 eq pre) && (args1 eq args)) tp
else typeRef(pre1, coevolveSym(pre, pre1, sym), args1)
case ThisType(_) => tp
case SingleType(pre, sym) =>
if (sym.isPackageClass) tp // short path
else {
val pre1 = this(pre)
if (pre1 eq pre) tp
else singleType(pre1, sym)
}
case MethodType(params, result) =>
variance = -variance
val params1 = mapOver(params)
variance = -variance
val result1 = this(result)
if ((params1 eq params) && (result1 eq result)) tp
// for new dependent types: result1.substSym(params, params1)?
else copyMethodType(tp, params1, result1.substSym(params, params1))
case PolyType(tparams, result) =>
variance = -variance
val tparams1 = mapOver(tparams)
variance = -variance
var result1 = this(result)
if ((tparams1 eq tparams) && (result1 eq result)) tp
else PolyType(tparams1, result1.substSym(tparams, tparams1))
case NullaryMethodType(result) =>
val result1 = this(result)
if (result1 eq result) tp
else NullaryMethodType(result1)
case ConstantType(_) => tp
case SuperType(thistp, supertp) =>
val thistp1 = this(thistp)
val supertp1 = this(supertp)
if ((thistp1 eq thistp) && (supertp1 eq supertp)) tp
else SuperType(thistp1, supertp1)
case TypeBounds(lo, hi) =>
variance = -variance
val lo1 = this(lo)
variance = -variance
val hi1 = this(hi)
if ((lo1 eq lo) && (hi1 eq hi)) tp
else TypeBounds(lo1, hi1)
case BoundedWildcardType(bounds) =>
val bounds1 = this(bounds)
if (bounds1 eq bounds) tp
else BoundedWildcardType(bounds1.asInstanceOf[TypeBounds])
case rtp @ RefinedType(parents, decls) =>
val parents1 = parents mapConserve (this)
val decls1 = mapOver(decls)
//if ((parents1 eq parents) && (decls1 eq decls)) tp
//else refinementOfClass(tp.typeSymbol, parents1, decls1)
copyRefinedType(rtp, parents1, decls1)
case ExistentialType(tparams, result) =>
val tparams1 = mapOver(tparams)
var result1 = this(result)
if ((tparams1 eq tparams) && (result1 eq result)) tp
else ExistentialType(tparams1, result1.substSym(tparams, tparams1))
case OverloadedType(pre, alts) =>
val pre1 = if (pre.isInstanceOf[ClassInfoType]) pre else this(pre)
if (pre1 eq pre) tp
else OverloadedType(pre1, alts)
case AntiPolyType(pre, args) =>
val pre1 = this(pre)
val args1 = args mapConserve (this)
if ((pre1 eq pre) && (args1 eq args)) tp
else AntiPolyType(pre1, args1)
case tv@TypeVar(_, constr) =>
if (constr.instValid) this(constr.inst)
else tv.applyArgs(mapOverArgs(tv.typeArgs, tv.params)) //@M !args.isEmpty implies !typeParams.isEmpty
case NotNullType(tp) =>
val tp1 = this(tp)
if (tp1 eq tp) tp
else NotNullType(tp1)
case AnnotatedType(annots, atp, selfsym) =>
val annots1 = mapOverAnnotations(annots)
val atp1 = this(atp)
if ((annots1 eq annots) && (atp1 eq atp)) tp
else if (annots1.isEmpty) atp1
else AnnotatedType(annots1, atp1, selfsym)
/*
case ErrorType => tp
case WildcardType => tp
case NoType => tp
case NoPrefix => tp
*/
case _ =>
tp
// throw new Error("mapOver inapplicable for " + tp);
}
def mapOverArgs(args: List[Type], tparams: List[Symbol]): List[Type] =
map2Conserve(args, tparams) { (arg, tparam) =>
val v = variance
if (tparam.isContravariant) variance = -variance
else if (!tparam.isCovariant) variance = 0
val arg1 = this(arg)
variance = v
arg1
}
/** Map this function over given scope */
def mapOver(scope: Scope): Scope = {
val elems = scope.toList
val elems1 = mapOver(elems)
if (elems1 eq elems) scope
else new Scope(elems1)
}
/** Map this function over given list of symbols */
def mapOver(origSyms: List[Symbol]): List[Symbol] = {
val change = origSyms exists { sym =>
val v = variance
if (sym.isAliasType) variance = 0
val result = this(sym.info)
variance = v
result ne sym.info
}
if (!change) origSyms // fast path in case nothing changes due to map
else { // map is not the identity --> do cloning properly
val clonedSyms = origSyms map (_.cloneSymbol)
val clonedInfos = clonedSyms map (_.info.substSym(origSyms, clonedSyms))
val transformedInfos = clonedInfos mapConserve (this)
(clonedSyms, transformedInfos).zipped map (_ setInfo _)
clonedSyms
}
}
def mapOverAnnotations(annots: List[AnnotationInfo])
: List[AnnotationInfo] = {
val newAnnots = annots.flatMap(mapOver(_))
if (allEq(newAnnots, annots))
annots
else
newAnnots
}
def mapOver(annot: AnnotationInfo): Option[AnnotationInfo] = {
val AnnotationInfo(atp, args, assocs) = annot
if (dropNonConstraintAnnotations &&
!(atp.typeSymbol isNonBottomSubClass TypeConstraintClass))
return None
val atp1 = mapOver(atp)
val args1 = mapOverAnnotArgs(args)
// there is no need to rewrite assocs, as they are constants
if ((args eq args1) && (atp eq atp1))
Some(annot)
else if (sameLength(args1, args))
Some(AnnotationInfo(atp1, args1, assocs).setPos(annot.pos))
else
None
}
/** Map over a set of annotation arguments. If any
* of the arguments cannot be mapped, then return Nil. */
def mapOverAnnotArgs(args: List[Tree]): List[Tree] = {
val args1 = args flatMap (x => mapOver(x))
if (!sameLength(args1, args))
Nil
else if (allEq(args, args1))
args
else
args1
}
def mapOver(tree: Tree): Option[Tree] =
Some(mapOver(tree, ()=>return None))
/** Map a tree that is part of an annotation argument.
* If the tree cannot be mapped, then invoke giveup().
* The default is to transform the tree with
* TypeMapTransformer.
*/
def mapOver(tree: Tree, giveup: ()=>Nothing): Tree =
(new TypeMapTransformer).transform(tree)
/** This transformer leaves the tree alone except to remap
* its types. */
class TypeMapTransformer extends Transformer {
override def transform(tree: Tree) = {
val tree1 = super.transform(tree)
val tpe1 = TypeMap.this(tree1.tpe)
if ((tree eq tree1) && (tree.tpe eq tpe1))
tree
else
tree1.shallowDuplicate.setType(tpe1)
}
}
}
/** A type map that always returns the input type unchanged */
object IdentityTypeMap extends TypeMap {
def apply(tp: Type) = tp
}
abstract class TypeTraverser extends TypeMap {
def traverse(tp: Type): Unit
def apply(tp: Type): Type = { traverse(tp); tp }
}
abstract class TypeCollector[T](initial: T) extends TypeTraverser {
var result: T = _
def collect(tp: Type) = {
result = initial
traverse(tp)
result
}
}
private val emptySymMap = immutable.Map[Symbol, Symbol]()
private val emptySymCount = immutable.Map[Symbol, Int]()
def typeParamsToExistentials(clazz: Symbol, tparams: List[Symbol]): List[Symbol] = {
val eparams = for ((tparam, i) <- tparams.zipWithIndex) yield {
clazz.newExistential(clazz.pos, newTypeName("?"+i)).setInfo(tparam.info.bounds)
}
for (tparam <- eparams) tparam setInfo tparam.info.substSym(tparams, eparams)
eparams
}
// note: it's important to write the two tests in this order,
// as only typeParams forces the classfile to be read. See #400
private def isRawIfWithoutArgs(sym: Symbol) =
sym.isClass && sym.typeParams.nonEmpty && sym.isJavaDefined
def isRaw(sym: Symbol, args: List[Type]) =
!phase.erasedTypes && isRawIfWithoutArgs(sym) && args.isEmpty
/** Is type tp a ``raw type''? */
def isRawType(tp: Type) = tp match {
case TypeRef(_, sym, args) => isRaw(sym, args)
case _ => false
}
/** The raw to existential map converts a ``raw type'' to an existential type.
* It is necessary because we might have read a raw type of a
* parameterized Java class from a class file. At the time we read the type
* the corresponding class file might still not be read, so we do not
* know what the type parameters of the type are. Therefore
* the conversion of raw types to existential types might not have taken place
* in ClassFileparser.sigToType (where it is usually done)
*/
object rawToExistential extends TypeMap {
def apply(tp: Type): Type = tp match {
case TypeRef(pre, sym, List()) if isRawIfWithoutArgs(sym) =>
val eparams = typeParamsToExistentials(sym, sym.typeParams)
existentialAbstraction(eparams, typeRef(pre, sym, eparams map (_.tpe)))
case _ =>
mapOver(tp)
}
}
def singletonBounds(hi: Type) = {
TypeBounds.upper(intersectionType(List(hi, SingletonClass.tpe)))
}
/** A map to compute the asSeenFrom method */
class AsSeenFromMap(pre: Type, clazz: Symbol) extends TypeMap {
override val dropNonConstraintAnnotations = true
var capturedParams: List[Symbol] = List()
override def mapOver(tree: Tree, giveup: ()=>Nothing): Tree = {
object annotationArgRewriter extends TypeMapTransformer {
/** Rewrite `This` trees in annotation argument trees */
def rewriteThis(tree: Tree): Tree =
tree match {
case This(_)
if (tree.symbol isNonBottomSubClass clazz) &&
(pre.widen.typeSymbol isNonBottomSubClass tree.symbol) =>
if (pre.isStable) { // XXX why is this in this method? pull it out and guard the call `annotationArgRewriter.transform(tree)`?
val termSym =
pre.typeSymbol.owner.newValue(
pre.typeSymbol.pos,
pre.typeSymbol.name.toTermName).setInfo(pre) // what symbol should really be used?
mkAttributedQualifier(pre, termSym)
} else
giveup()
case tree => tree
}
override def transform(tree: Tree): Tree = {
val tree1 = rewriteThis(super.transform(tree))
tree1
}
}
annotationArgRewriter.transform(tree)
}
var capturedPre = emptySymMap
def stabilize(pre: Type, clazz: Symbol): Type =
capturedPre.getOrElse(clazz, {
val qvar = clazz freshExistential ".type" setInfo singletonBounds(pre)
capturedPre += (clazz -> qvar)
capturedParams = qvar :: capturedParams
qvar
}).tpe
/** Return pre.baseType(clazz), or if that's NoType and clazz is a refinement, pre itself.
* See bug397.scala for an example where the second alternative is needed.
* The problem is that when forming the base type sequence of an abstract type,
* any refinements in the base type list might be regenerated, and thus acquire
* new class symbols. However, since refinements always have non-interesting prefixes
* it looks OK to me to just take the prefix directly. */
def base(pre: Type, clazz: Symbol) = {
val b = pre.baseType(clazz)
if (b == NoType && clazz.isRefinementClass) pre
else b
}
def apply(tp: Type): Type =
if ((pre eq NoType) || (pre eq NoPrefix) || !clazz.isClass) tp
else tp match {
case ThisType(sym) =>
def toPrefix(pre: Type, clazz: Symbol): Type =
if ((pre eq NoType) || (pre eq NoPrefix) || !clazz.isClass) tp
else if ((sym isNonBottomSubClass clazz) &&
(pre.widen.typeSymbol isNonBottomSubClass sym)) {
val pre1 = pre match {
case SuperType(thistp, _) => thistp
case _ => pre
}
if (!(pre1.isStable ||
pre1.typeSymbol.isPackageClass ||
pre1.typeSymbol.isModuleClass && pre1.typeSymbol.isStatic)) {
stabilize(pre1, sym)
} else {
pre1
}
} else {
toPrefix(base(pre, clazz).prefix, clazz.owner);
}
toPrefix(pre, clazz)
case SingleType(pre, sym) =>
if (sym.isPackageClass) tp // short path
else {
val pre1 = this(pre)
if (pre1 eq pre) tp
else if (pre1.isStable) singleType(pre1, sym)
else pre1.memberType(sym).resultType //todo: this should be rolled into existential abstraction
}
// AM: Martin, is this description accurate?
// walk the owner chain of `clazz` (the original argument to asSeenFrom) until we find the type param's owner (while rewriting pre as we crawl up the owner chain)
// once we're at the owner, extract the information that pre encodes about the type param,
// by minimally subsuming pre to the type instance of the class that owns the type param,
// the type we're looking for is the type instance's type argument at the position corresponding to the type parameter
// optimisation: skip this type parameter if it's not owned by a class, as those params are not influenced by the prefix through which they are seen
// (concretely: type params of anonymous type functions, which currently can only arise from normalising type aliases, are owned by the type alias of which they are the eta-expansion)
// (skolems also aren't affected: they are ruled out by the isTypeParameter check)
case TypeRef(prefix, sym, args) if (sym.isTypeParameter && sym.owner.isClass) =>
def toInstance(pre: Type, clazz: Symbol): Type =
if ((pre eq NoType) || (pre eq NoPrefix) || !clazz.isClass) mapOver(tp)
//@M! see test pos/tcpoly_return_overriding.scala why mapOver is necessary
else {
def throwError = abort("" + tp + sym.locationString + " cannot be instantiated from " + pre.widen)
def instParam(ps: List[Symbol], as: List[Type]): Type =
if (ps.isEmpty) throwError
else if (sym eq ps.head)
// @M! don't just replace the whole thing, might be followed by type application
appliedType(as.head, args mapConserve (this)) // @M: was as.head
else instParam(ps.tail, as.tail);
val symclazz = sym.owner
if (symclazz == clazz && !pre.isInstanceOf[TypeVar] && (pre.widen.typeSymbol isNonBottomSubClass symclazz)) {
pre.baseType(symclazz) match {
case TypeRef(_, basesym, baseargs) =>
//Console.println("instantiating " + sym + " from " + basesym + " with " + basesym.typeParams + " and " + baseargs+", pre = "+pre+", symclazz = "+symclazz);//DEBUG
if (sameLength(basesym.typeParams, baseargs)) {
instParam(basesym.typeParams, baseargs)
} else {
throw new TypeError(
"something is wrong (wrong class file?): "+basesym+
" with type parameters "+
basesym.typeParams.map(_.name).mkString("[",",","]")+
" gets applied to arguments "+baseargs.mkString("[",",","]")+", phase = "+phase)
}
case ExistentialType(tparams, qtpe) =>
capturedParams = capturedParams union tparams
toInstance(qtpe, clazz)
case _ =>
throwError
}
} else toInstance(base(pre, clazz).prefix, clazz.owner)
}
toInstance(pre, clazz)
case _ =>
mapOver(tp)
}
}
/** A base class to compute all substitutions */
abstract class SubstMap[T](from: List[Symbol], to: List[T]) extends TypeMap {
val fromContains = from.toSet // avoiding repeatedly traversing from
assert(sameLength(from, to), "Unsound substitution from "+ from +" to "+ to)
/** Are `sym' and `sym1' the same.
* Can be tuned by subclasses.
*/
protected def matches(sym: Symbol, sym1: Symbol): Boolean = sym eq sym1
/** Map target to type, can be tuned by subclasses */
protected def toType(fromtp: Type, tp: T): Type
def subst(tp: Type, sym: Symbol, from: List[Symbol], to: List[T]): Type =
if (from.isEmpty) tp
// else if (to.isEmpty) error("Unexpected substitution on '%s': from = %s but to == Nil".format(tp, from))
else if (matches(from.head, sym)) toType(tp, to.head)
else subst(tp, sym, from.tail, to.tail)
protected def renameBoundSyms(tp: Type): Type = tp match {
case MethodType(ps, restp) =>
val ps1 = cloneSymbols(ps)
copyMethodType(tp, ps1, renameBoundSyms(restp.substSym(ps, ps1)))
case PolyType(bs, restp) =>
val bs1 = cloneSymbols(bs)
PolyType(bs1, renameBoundSyms(restp.substSym(bs, bs1)))
case ExistentialType(bs, restp) =>
val bs1 = cloneSymbols(bs)
ExistentialType(bs1, restp.substSym(bs, bs1))
case _ =>
tp
}
def apply(tp0: Type): Type = if (from.isEmpty) tp0 else {
val boundSyms = tp0.boundSyms
val tp1 = if (boundSyms exists fromContains) renameBoundSyms(tp0) else tp0
val tp = mapOver(tp1)
tp match {
// @M
// 1) arguments must also be substituted (even when the "head" of the
// applied type has already been substituted)
// example: (subst RBound[RT] from [type RT,type RBound] to
// [type RT&,type RBound&]) = RBound&[RT&]
// 2) avoid loops (which occur because alpha-conversion is
// not performed properly imo)
// e.g. if in class Iterable[a] there is a new Iterable[(a,b)],
// we must replace the a in Iterable[a] by (a,b)
// (must not recurse --> loops)
// 3) replacing m by List in m[Int] should yield List[Int], not just List
case TypeRef(NoPrefix, sym, args) =>
appliedType(subst(tp, sym, from, to), args) // if args.isEmpty, appliedType is the identity
case SingleType(NoPrefix, sym) =>
subst(tp, sym, from, to)
case _ =>
tp
}
}
}
/** A map to implement the `substSym' method. */
class SubstSymMap(from: List[Symbol], to: List[Symbol]) extends SubstMap(from, to) {
protected def toType(fromtp: Type, sym: Symbol) = fromtp match {
case TypeRef(pre, _, args) => typeRef(pre, sym, args)
case SingleType(pre, _) => singleType(pre, sym)
}
override def apply(tp: Type): Type = if (from.isEmpty) tp else {
def subst(sym: Symbol, from: List[Symbol], to: List[Symbol]): Symbol =
if (from.isEmpty) sym
// else if (to.isEmpty) error("Unexpected substitution on '%s': from = %s but to == Nil".format(sym, from))
else if (matches(from.head, sym)) to.head
else subst(sym, from.tail, to.tail)
tp match {
case TypeRef(pre, sym, args) if pre ne NoPrefix =>
val newSym = subst(sym, from, to)
// assert(newSym.typeParams.length == sym.typeParams.length, "typars mismatch in SubstSymMap: "+(sym, sym.typeParams, newSym, newSym.typeParams))
mapOver(typeRef(pre, newSym, args)) // mapOver takes care of subst'ing in args
case SingleType(pre, sym) if pre ne NoPrefix =>
mapOver(singleType(pre, subst(sym, from, to)))
case _ =>
super.apply(tp)
}
}
override def mapOver(tree: Tree, giveup: ()=>Nothing): Tree = {
object trans extends TypeMapTransformer {
def termMapsTo(sym: Symbol) =
if (fromContains(sym))
Some(to(from.indexOf(sym)))
else
None
override def transform(tree: Tree) =
tree match {
case tree@Ident(_) =>
termMapsTo(tree.symbol) match {
case Some(tosym) =>
if (tosym.info.bounds.hi.typeSymbol isSubClass SingletonClass) {
Ident(tosym.existentialToString)
.setSymbol(tosym)
.setPos(tosym.pos)
.setType(dropSingletonType(tosym.info.bounds.hi))
} else {
giveup()
}
case none => super.transform(tree)
}
case tree => super.transform(tree)
}
}
trans.transform(tree)
}
}
/** A map to implement the `subst' method. */
class SubstTypeMap(from: List[Symbol], to: List[Type])
extends SubstMap(from, to) {
protected def toType(fromtp: Type, tp: Type) = tp
override def mapOver(tree: Tree, giveup: ()=>Nothing): Tree = {
object trans extends TypeMapTransformer {
override def transform(tree: Tree) =
tree match {
case Ident(name) if fromContains(tree.symbol) =>
val totpe = to(from.indexOf(tree.symbol))
if (!totpe.isStable) giveup()
else Ident(name).setPos(tree.pos).setSymbol(tree.symbol).setType(totpe)
case _ => super.transform(tree)
}
}
trans.transform(tree)
}
}
/** A map to implement the `substThis' method. */
class SubstThisMap(from: Symbol, to: Type) extends TypeMap {
def apply(tp: Type): Type = tp match {
case ThisType(sym) if (sym == from) => to
case _ => mapOver(tp)
}
}
class SubstSuperMap(from: Type, to: Type) extends TypeMap {
def apply(tp: Type): Type = if (tp eq from) to else mapOver(tp)
}
class SubstWildcardMap(from: List[Symbol]) extends TypeMap {
def apply(tp: Type): Type = try {
tp match {
case TypeRef(_, sym, _) if from contains sym =>
BoundedWildcardType(sym.info.bounds)
case _ =>
mapOver(tp)
}
} catch {
case ex: MalformedType =>
WildcardType
}
}
// dependent method types
object IsDependentCollector extends TypeCollector(false) {
def traverse(tp: Type) {
if(tp isImmediatelyDependent) result = true
else if (!result) mapOver(tp)
}
}
object ApproximateDependentMap extends TypeMap {
def apply(tp: Type): Type =
if(tp isImmediatelyDependent) WildcardType
else mapOver(tp)
}
class InstantiateDependentMap(params: List[Symbol], actuals: List[Type]) extends TypeMap {
private val actualsIndexed = actuals.toIndexedSeq
override val dropNonConstraintAnnotations = true
object ParamWithActual {
def unapply(sym: Symbol): Option[Type] = {
val pid = params indexOf sym
if(pid != -1) Some(actualsIndexed(pid)) else None
}
}
def apply(tp: Type): Type =
mapOver(tp) match {
case SingleType(NoPrefix, ParamWithActual(arg)) if arg.isStable => arg // unsound to replace args by unstable actual #3873
// (soundly) expand type alias selections on implicit arguments, see depmet_implicit_oopsla* test cases -- typically, `param.isImplicit`
case tp1@TypeRef(SingleType(NoPrefix, ParamWithActual(arg)), sym, targs) =>
val res = typeRef(arg, sym, targs)
if(res.typeSymbolDirect isAliasType) res.dealias
else tp1
case tp1 => tp1 // don't return the original `tp`, which may be different from `tp1`, due to `dropNonConstraintAnnotations`
}
def existentialsNeeded: List[Symbol] = existSyms.filter(_ ne null).toList
private val existSyms: Array[Symbol] = new Array(actualsIndexed.size)
private def haveExistential(i: Int) = {assert((i >= 0) && (i <= actualsIndexed.size)); existSyms(i) ne null}
/* Return the type symbol for referencing a parameter inside the existential quantifier.
* (Only needed if the actual is unstable.)
*/
def existSymFor(actualIdx: Int) =
if (haveExistential(actualIdx)) existSyms(actualIdx)
else {
val oldSym = params(actualIdx)
val symowner = oldSym.owner
val bound = singletonBounds(actualsIndexed(actualIdx))
val sym = symowner.newExistential(oldSym.pos, newTypeName(oldSym.name + ".type"))
sym.setInfo(bound)
sym.setFlag(oldSym.flags)
existSyms(actualIdx) = sym
sym
}
//AM propagate more info to annotations -- this seems a bit ad-hoc... (based on code by spoon)
override def mapOver(arg: Tree, giveup: ()=>Nothing): Tree = {
object treeTrans extends Transformer {
override def transform(tree: Tree): Tree = {
tree match {
case RefParamAt(pid) =>
// TODO: this should be simplified; in the stable case, one can probably
// just use an Ident to the tree.symbol. Why an existential in the non-stable case?
val actual = actualsIndexed(pid)
if (actual.isStable && actual.typeSymbol != NothingClass) {
mkAttributedQualifier(actualsIndexed(pid), tree.symbol)
} else {
val sym = existSymFor(pid)
(Ident(sym.name)
copyAttrs tree
setType typeRef(NoPrefix, sym, Nil))
}
case _ => super.transform(tree)
}
}
object RefParamAt {
def unapply(tree: Tree): Option[Int] = tree match {
case Ident(_) => Some(params indexOf tree.symbol) filterNot (_ == -1)
case _ => None
}
}
}
treeTrans.transform(arg)
}
}
object StripAnnotationsMap extends TypeMap {
def apply(tp: Type): Type = tp match {
case AnnotatedType(_, atp, _) =>
mapOver(atp)
case tp =>
mapOver(tp)
}
}
/** A map to convert every occurrence of a wildcard type to a fresh
* type variable */
object wildcardToTypeVarMap extends TypeMap {
def apply(tp: Type): Type = tp match {
case WildcardType =>
TypeVar(tp, new TypeConstraint)
case BoundedWildcardType(bounds) =>
TypeVar(tp, new TypeConstraint(List(bounds.lo), List(bounds.hi)))
case _ =>
mapOver(tp)
}
}
/** A map to convert every occurrence of a type variable to a
wildcard type */
object typeVarToOriginMap extends TypeMap {
def apply(tp: Type): Type = tp match {
case TypeVar(origin, _) => origin
case _ => mapOver(tp)
}
}
/** A map to implement the `contains' method */
class ContainsCollector(sym: Symbol) extends TypeCollector(false) {
def traverse(tp: Type) {
if (!result) {
tp.normalize match {
case TypeRef(_, sym1, _) if (sym == sym1) => result = true
case SingleType(_, sym1) if (sym == sym1) => result = true
case _ => mapOver(tp)
}
}
}
override def mapOver(arg: Tree) = {
for (t <- arg) {
traverse(t.tpe)
if (t.symbol == sym)
result = true
}
Some(arg)
}
}
/** A map to implement the `contains' method */
class ContainsTypeCollector(t: Type) extends TypeCollector(false) {
def traverse(tp: Type) {
if (!result) {
if (tp eq t) result = true
else mapOver(tp)
}
}
override def mapOver(arg: Tree) = {
for (t <- arg) {
traverse(t.tpe)
}
Some(arg)
}
}
/** A map to implement the `filter' method */
class FilterTypeCollector(p: Type => Boolean) extends TypeCollector(new ListBuffer[Type]) {
def traverse(tp: Type) {
if (p(tp)) result += tp
mapOver(tp)
}
}
class ForEachTypeTraverser(f: Type => Unit) extends TypeTraverser {
def traverse(tp: Type) {
f(tp)
mapOver(tp)
}
}
/** A map to implement the `filter' method */
class FindTypeCollector(p: Type => Boolean) extends TypeCollector[Option[Type]](None) {
def traverse(tp: Type) {
if (result.isEmpty) {
if (p(tp)) result = Some(tp)
mapOver(tp)
}
}
}
/** A map to implement the `contains' method */
object ErroneousCollector extends TypeCollector(false) {
def traverse(tp: Type) {
if (!result) {
result = tp.isError
mapOver(tp)
}
}
}
/** A map to compute the most deeply nested owner that contains all the symbols
* of thistype or prefixless typerefs/singletype occurrences in given type.
*/
object commonOwnerMap extends TypeMap {
var result: Symbol = _
def init = { result = NoSymbol }
def apply(tp: Type): Type = {
assert(tp ne null)
tp.normalize match {
case ThisType(sym) =>
register(sym)
case TypeRef(NoPrefix, sym, args) =>
register(sym.owner); args foreach apply
case SingleType(NoPrefix, sym) =>
register(sym.owner)
case _ =>
mapOver(tp)
}
tp
}
private def register(sym: Symbol) {
while (result != NoSymbol && sym != result && !(sym isNestedIn result))
result = result.owner;
}
}
class MissingAliasControl extends ControlThrowable
val missingAliasException = new MissingAliasControl
class MissingTypeControl extends ControlThrowable
object adaptToNewRunMap extends TypeMap {
private def adaptToNewRun(pre: Type, sym: Symbol): Symbol = {
if (phase.flatClasses) {
sym
} else if (sym.isModuleClass) {
val adaptedSym = adaptToNewRun(pre, sym.sourceModule)
// Handle nested objects properly
if (adaptedSym.isLazy) adaptedSym.lazyAccessor else adaptedSym.moduleClass
} else if ((pre eq NoPrefix) || (pre eq NoType) || sym.isPackageClass) {
sym
} else {
var rebind0 = pre.findMember(sym.name, BRIDGE, 0, true)
if (rebind0 == NoSymbol) {
if (sym.isAliasType) throw missingAliasException
if (settings.debug.value) println(pre+"."+sym+" does no longer exist, phase = "+phase)
throw new MissingTypeControl // For build manager and presentation compiler purposes
//assert(false, pre+"."+sym+" does no longer exist, phase = "+phase)
}
/** The two symbols have the same fully qualified name */
def corresponds(sym1: Symbol, sym2: Symbol): Boolean =
sym1.name == sym2.name && (sym1.isPackageClass || corresponds(sym1.owner, sym2.owner))
if (!corresponds(sym.owner, rebind0.owner)) {
if (settings.debug.value)
log("ADAPT1 pre = "+pre+", sym = "+sym+sym.locationString+", rebind = "+rebind0+rebind0.locationString)
val bcs = pre.baseClasses.dropWhile(bc => !corresponds(bc, sym.owner));
if (bcs.isEmpty)
assert(pre.typeSymbol.isRefinementClass, pre) // if pre is a refinementclass it might be a structural type => OK to leave it in.
else
rebind0 = pre.baseType(bcs.head).member(sym.name)
if (settings.debug.value) log(
"ADAPT2 pre = " + pre +
", bcs.head = " + bcs.head +
", sym = " + sym+sym.locationString +
", rebind = " + rebind0 + (
if (rebind0 == NoSymbol) ""
else rebind0.locationString
)
)
}
val rebind = rebind0.suchThat(sym => sym.isType || sym.isStable)
if (rebind == NoSymbol) {
if (settings.debug.value) log("" + phase + " " +phase.flatClasses+sym.owner+sym.name+" "+sym.isType)
throw new MalformedType(pre, sym.nameString)
}
rebind
}
}
def apply(tp: Type): Type = tp match {
case ThisType(sym) =>
try {
val sym1 = adaptToNewRun(sym.owner.thisType, sym)
if (sym1 == sym) tp else ThisType(sym1)
} catch {
case ex: MissingTypeControl =>
tp
}
case SingleType(pre, sym) =>
if (sym.isPackage) tp
else {
val pre1 = this(pre)
val sym1 = adaptToNewRun(pre1, sym)
if ((pre1 eq pre) && (sym1 eq sym)) tp
else singleType(pre1, sym1)
}
case TypeRef(pre, sym, args) =>
if (sym.isPackageClass) tp
else {
val pre1 = this(pre)
val args1 = args mapConserve (this)
try {
val sym1 = adaptToNewRun(pre1, sym)
if ((pre1 eq pre) && (sym1 eq sym) && (args1 eq args)/* && sym.isExternal*/) tp
else typeRef(pre1, sym1, args1)
} catch {
case ex: MissingAliasControl =>
apply(tp.dealias)
case _: MissingTypeControl =>
tp
}
}
case MethodType(params, restp) =>
val restp1 = this(restp)
if (restp1 eq restp) tp
else copyMethodType(tp, params, restp1)
case NullaryMethodType(restp) =>
val restp1 = this(restp)
if (restp1 eq restp) tp
else NullaryMethodType(restp1)
case PolyType(tparams, restp) =>
val restp1 = this(restp)
if (restp1 eq restp) tp
else PolyType(tparams, restp1)
// Lukas: we need to check (together) whether we should also include parameter types
// of PolyType and MethodType in adaptToNewRun
case ClassInfoType(parents, decls, clazz) =>
if (clazz.isPackageClass) tp
else {
val parents1 = parents mapConserve (this)
if (parents1 eq parents) tp
else ClassInfoType(parents1, decls, clazz)
}
case RefinedType(parents, decls) =>
val parents1 = parents mapConserve (this)
if (parents1 eq parents) tp
else refinedType(parents1, tp.typeSymbol.owner, decls, tp.typeSymbol.owner.pos)
case SuperType(_, _) => mapOver(tp)
case TypeBounds(_, _) => mapOver(tp)
case TypeVar(_, _) => mapOver(tp)
case AnnotatedType(_,_,_) => mapOver(tp)
case NotNullType(_) => mapOver(tp)
case ExistentialType(_, _) => mapOver(tp)
case _ => tp
}
}
class SubTypePair(val tp1: Type, val tp2: Type) {
override def hashCode = tp1.hashCode * 41 + tp2.hashCode
override def equals(other: Any) = other match {
case stp: SubTypePair =>
(tp1 =:= stp.tp1) && (tp2 =:= stp.tp2)
case _ =>
false
}
override def toString = tp1+" <:<? "+tp2
}
// Helper Methods -------------------------------------------------------------
final val LubGlbMargin = 0
/** The maximum allowable depth of lubs or glbs over types `ts'
* This is the maximum depth of all types in the base type sequences
* of each of the types `ts', plus LubGlbMargin
*/
def lubDepth(ts: List[Type]) = {
var d = 0
for (tp <- ts) d = math.max(d, tp.baseTypeSeqDepth)
d + LubGlbMargin
}
/** Is intersection of given types populated? That is,
* for all types tp1, tp2 in intersection
* for all common base classes bc of tp1 and tp2
* let bt1, bt2 be the base types of tp1, tp2 relative to class bc
* Then:
* bt1 and bt2 have the same prefix, and
* any corresponding non-variant type arguments of bt1 and bt2 are the same
*/
def isPopulated(tp1: Type, tp2: Type): Boolean = {
def isConsistent(tp1: Type, tp2: Type): Boolean = (tp1, tp2) match {
case (TypeRef(pre1, sym1, args1), TypeRef(pre2, sym2, args2)) =>
assert(sym1 == sym2)
pre1 =:= pre2 &&
((args1, args2, sym1.typeParams).zipped forall {
(arg1, arg2, tparam) =>
//if (tparam.variance == 0 && !(arg1 =:= arg2)) Console.println("inconsistent: "+arg1+"!="+arg2)//DEBUG
if (tparam.variance == 0) arg1 =:= arg2
else if (arg1.isInstanceOf[TypeVar])
// if left-hand argument is a typevar, make it compatible with variance
// this is for more precise pattern matching
// todo: work this in the spec of this method
// also: think what happens if there are embedded typevars?
if (tparam.variance < 0) arg1 <:< arg2 else arg2 <:< arg1
else true
})
case (et: ExistentialType, _) =>
et.withTypeVars(isConsistent(_, tp2))
case (_, et: ExistentialType) =>
et.withTypeVars(isConsistent(tp1, _))
}
def check(tp1: Type, tp2: Type) =
if (tp1.typeSymbol.isClass && tp1.typeSymbol.hasFlag(FINAL))
tp1 <:< tp2 || isNumericValueClass(tp1.typeSymbol) && isNumericValueClass(tp2.typeSymbol)
else tp1.baseClasses forall (bc =>
tp2.baseTypeIndex(bc) < 0 || isConsistent(tp1.baseType(bc), tp2.baseType(bc)))
check(tp1, tp2)/* && check(tp2, tp1)*/ // need to investgate why this can't be made symmetric -- neg/gadts1 fails, and run/existials also.
}
/** Does a pattern of type `patType' need an outer test when executed against
* selector type `selType' in context defined by `currentOwner'?
*/
def needsOuterTest(patType: Type, selType: Type, currentOwner: Symbol) = {
def createDummyClone(pre: Type): Type = {
val dummy = currentOwner.enclClass.newValue(NoPosition, nme.ANYNAME).setInfo(pre.widen)
singleType(ThisType(currentOwner.enclClass), dummy)
}
def maybeCreateDummyClone(pre: Type, sym: Symbol): Type = pre match {
case SingleType(pre1, sym1) =>
if (sym1.isModule && sym1.isStatic) {
NoType
} else if (sym1.isModule && sym.owner == sym1.moduleClass) {
val pre2 = maybeCreateDummyClone(pre1, sym1)
if (pre2 eq NoType) pre2
else singleType(pre2, sym1)
} else {
createDummyClone(pre)
}
case ThisType(clazz) =>
if (clazz.isModuleClass)
maybeCreateDummyClone(clazz.typeOfThis, sym)
else if (sym.owner == clazz && (sym.hasFlag(PRIVATE) || sym.privateWithin == clazz))
NoType
else
createDummyClone(pre)
case _ =>
NoType
}
patType match {
case TypeRef(pre, sym, args) =>
val pre1 = maybeCreateDummyClone(pre, sym)
(pre1 ne NoType) && isPopulated(typeRef(pre1, sym, args), selType)
case _ =>
false
}
}
private var subsametypeRecursions: Int = 0
private def isUnifiable(pre1: Type, pre2: Type) =
(beginsWithTypeVarOrIsRefined(pre1) || beginsWithTypeVarOrIsRefined(pre2)) && (pre1 =:= pre2)
/** Returns true iff we are past phase specialize,
* sym1 and sym2 are two existential skolems with equal names and bounds,
* and pre1 and pre2 are equal prefixes
*/
private def isSameSpecializedSkolem(sym1: Symbol, sym2: Symbol, pre1: Type, pre2: Type) = {
sym1.isExistentialSkolem && sym2.isExistentialSkolem &&
sym1.name == sym2.name &&
phase.specialized &&
sym1.info =:= sym2.info &&
pre1 =:= pre2
}
private def equalSymsAndPrefixes(sym1: Symbol, pre1: Type, sym2: Symbol, pre2: Type): Boolean =
if (sym1 == sym2) sym1.hasPackageFlag || phase.erasedTypes || pre1 =:= pre2
else (sym1.name == sym2.name) && isUnifiable(pre1, pre2)
/** Do `tp1' and `tp2' denote equivalent types?
*/
def isSameType(tp1: Type, tp2: Type): Boolean = try {
incCounter(sametypeCount)
subsametypeRecursions += 1
undoLog undoUnless {
isSameType1(tp1, tp2)
}
} finally {
subsametypeRecursions -= 1
// XXX AM TODO: figure out when it is safe and needed to clear the log -- the commented approach below is too eager (it breaks #3281, #3866)
// it doesn't help to keep separate recursion counts for the three methods that now share it
// if (subsametypeRecursions == 0) undoLog.clear()
}
def isDifferentType(tp1: Type, tp2: Type): Boolean = try {
subsametypeRecursions += 1
undoLog undo { // undo type constraints that arise from operations in this block
!isSameType1(tp1, tp2)
}
} finally {
subsametypeRecursions -= 1
// XXX AM TODO: figure out when it is safe and needed to clear the log -- the commented approach below is too eager (it breaks #3281, #3866)
// it doesn't help to keep separate recursion counts for the three methods that now share it
// if (subsametypeRecursions == 0) undoLog.clear()
}
def isDifferentTypeConstructor(tp1: Type, tp2: Type): Boolean = tp1 match {
case TypeRef(pre1, sym1, _) =>
tp2 match {
case TypeRef(pre2, sym2, _) => sym1 != sym2 || isDifferentType(pre1, pre2)
case _ => true
}
case _ => true
}
def normalizePlus(tp: Type) =
if (isRawType(tp)) rawToExistential(tp)
else tp.normalize
/*
todo: change to:
def normalizePlus(tp: Type) = tp match {
case TypeRef(pre, sym, List()) =>
if (!sym.isInitialized) sym.rawInfo.load(sym)
if (sym.isJavaDefined && !sym.typeParams.isEmpty) rawToExistential(tp)
else tp.normalize
case _ => tp.normalize
}
*/
/*
private def isSameType0(tp1: Type, tp2: Type): Boolean = {
if (tp1 eq tp2) return true
((tp1, tp2) match {
case (ErrorType, _) => true
case (WildcardType, _) => true
case (_, ErrorType) => true
case (_, WildcardType) => true
case (NoType, _) => false
case (NoPrefix, _) => tp2.typeSymbol.isPackageClass
case (_, NoType) => false
case (_, NoPrefix) => tp1.typeSymbol.isPackageClass
case (ThisType(sym1), ThisType(sym2))
if (sym1 == sym2) =>
true
case (SingleType(pre1, sym1), SingleType(pre2, sym2))
if (equalSymsAndPrefixes(sym1, pre1, sym2, pre2)) =>
true
/*
case (SingleType(pre1, sym1), ThisType(sym2))
if (sym1.isModule &&
sym1.moduleClass == sym2 &&
pre1 =:= sym2.owner.thisType) =>
true
case (ThisType(sym1), SingleType(pre2, sym2))
if (sym2.isModule &&
sym2.moduleClass == sym1 &&
pre2 =:= sym1.owner.thisType) =>
true
*/
case (ConstantType(value1), ConstantType(value2)) =>
value1 == value2
case (TypeRef(pre1, sym1, args1), TypeRef(pre2, sym2, args2)) =>
equalSymsAndPrefixes(sym1, pre1, sym2, pre2) &&
((tp1.isHigherKinded && tp2.isHigherKinded && tp1.normalize =:= tp2.normalize) ||
isSameTypes(args1, args2))
// @M! normalize reduces higher-kinded case to PolyType's
case (RefinedType(parents1, ref1), RefinedType(parents2, ref2)) =>
def isSubScope(s1: Scope, s2: Scope): Boolean = s2.toList.forall {
sym2 =>
var e1 = s1.lookupEntry(sym2.name)
(e1 ne null) && {
val substSym = sym2.info.substThis(sym2.owner, e1.sym.owner.thisType)
var isEqual = false
while (!isEqual && (e1 ne null)) {
isEqual = e1.sym.info =:= substSym
e1 = s1.lookupNextEntry(e1)
}
isEqual
}
}
//Console.println("is same? " + tp1 + " " + tp2 + " " + tp1.typeSymbol.owner + " " + tp2.typeSymbol.owner)//DEBUG
isSameTypes(parents1, parents2) && isSubScope(ref1, ref2) && isSubScope(ref2, ref1)
case (MethodType(params1, res1), MethodType(params2, res2)) =>
// new dependent types: probably fix this, use substSym as done for PolyType
(isSameTypes(tp1.paramTypes, tp2.paramTypes) &&
res1 =:= res2 &&
tp1.isImplicit == tp2.isImplicit)
case (PolyType(tparams1, res1), PolyType(tparams2, res2)) =>
// assert((tparams1 map (_.typeParams.length)) == (tparams2 map (_.typeParams.length)))
(tparams1.length == tparams2.length) && (tparams1 corresponds tparams2)(_.info =:= _.info.substSym(tparams2, tparams1)) && // @M looks like it might suffer from same problem as #2210
res1 =:= res2.substSym(tparams2, tparams1)
case (ExistentialType(tparams1, res1), ExistentialType(tparams2, res2)) =>
(tparams1.length == tparams2.length) && (tparams1 corresponds tparams2)(_.info =:= _.info.substSym(tparams2, tparams1)) && // @M looks like it might suffer from same problem as #2210
res1 =:= res2.substSym(tparams2, tparams1)
case (TypeBounds(lo1, hi1), TypeBounds(lo2, hi2)) =>
lo1 =:= lo2 && hi1 =:= hi2
case (BoundedWildcardType(bounds), _) =>
bounds containsType tp2
case (_, BoundedWildcardType(bounds)) =>
bounds containsType tp1
case (tv @ TypeVar(_,_), tp) =>
tv.registerTypeEquality(tp, true)
case (tp, tv @ TypeVar(_,_)) =>
tv.registerTypeEquality(tp, false)
case (AnnotatedType(_,_,_), _) =>
annotationsConform(tp1, tp2) && annotationsConform(tp2, tp1) && tp1.withoutAnnotations =:= tp2.withoutAnnotations
case (_, AnnotatedType(_,_,_)) =>
annotationsConform(tp1, tp2) && annotationsConform(tp2, tp1) && tp1.withoutAnnotations =:= tp2.withoutAnnotations
case (_: SingletonType, _: SingletonType) =>
var origin1 = tp1
while (origin1.underlying.isInstanceOf[SingletonType]) {
assert(origin1 ne origin1.underlying, origin1)
origin1 = origin1.underlying
}
var origin2 = tp2
while (origin2.underlying.isInstanceOf[SingletonType]) {
assert(origin2 ne origin2.underlying, origin2)
origin2 = origin2.underlying
}
((origin1 ne tp1) || (origin2 ne tp2)) && (origin1 =:= origin2)
case _ =>
false
}) || {
val tp1n = normalizePlus(tp1)
val tp2n = normalizePlus(tp2)
((tp1n ne tp1) || (tp2n ne tp2)) && isSameType(tp1n, tp2n)
}
}
*/
private def isSameType1(tp1: Type, tp2: Type): Boolean = {
if ((tp1 eq tp2) ||
(tp1 eq ErrorType) || (tp1 eq WildcardType) ||
(tp2 eq ErrorType) || (tp2 eq WildcardType))
true
else if ((tp1 eq NoType) || (tp2 eq NoType))
false
else if (tp1 eq NoPrefix)
tp2.typeSymbol.isPackageClass
else if (tp2 eq NoPrefix)
tp1.typeSymbol.isPackageClass
else {
isSameType2(tp1, tp2) || {
val tp1n = normalizePlus(tp1)
val tp2n = normalizePlus(tp2)
((tp1n ne tp1) || (tp2n ne tp2)) && isSameType(tp1n, tp2n)
}
}
}
def isSameType2(tp1: Type, tp2: Type): Boolean = {
tp1 match {
case tr1: TypeRef =>
tp2 match {
case tr2: TypeRef =>
return (equalSymsAndPrefixes(tr1.sym, tr1.pre, tr2.sym, tr2.pre) &&
((tp1.isHigherKinded && tp2.isHigherKinded && tp1.normalize =:= tp2.normalize) ||
isSameTypes(tr1.args, tr2.args))) ||
((tr1.pre, tr2.pre) match {
case (tv @ TypeVar(_,_), _) => tv.registerTypeSelection(tr1.sym, tr2)
case (_, tv @ TypeVar(_,_)) => tv.registerTypeSelection(tr2.sym, tr1)
case _ => false
})
case _ =>
}
case tt1: ThisType =>
tp2 match {
case tt2: ThisType =>
if (tt1.sym == tt2.sym) return true
case _ =>
}
case st1: SingleType =>
tp2 match {
case st2: SingleType =>
if (equalSymsAndPrefixes(st1.sym, st1.pre, st2.sym, st2.pre)) return true
case _ =>
}
case ct1: ConstantType =>
tp2 match {
case ct2: ConstantType =>
return (ct1.value == ct2.value)
case _ =>
}
case rt1: RefinedType =>
tp2 match {
case rt2: RefinedType => //
def isSubScope(s1: Scope, s2: Scope): Boolean = s2.toList.forall {
sym2 =>
var e1 = s1.lookupEntry(sym2.name)
(e1 ne null) && {
val substSym = sym2.info.substThis(sym2.owner, e1.sym.owner.thisType)
var isEqual = false
while (!isEqual && (e1 ne null)) {
isEqual = e1.sym.info =:= substSym
e1 = s1.lookupNextEntry(e1)
}
isEqual
}
}
//Console.println("is same? " + tp1 + " " + tp2 + " " + tp1.typeSymbol.owner + " " + tp2.typeSymbol.owner)//DEBUG
return isSameTypes(rt1.parents, rt2.parents) && {
val decls1 = rt1.decls
val decls2 = rt2.decls
isSubScope(decls1, decls2) && isSubScope(decls2, decls1)
}
case _ =>
}
case mt1: MethodType =>
tp2 match {
case mt2: MethodType =>
// DEPMETTODO new dependent types: probably fix this, use substSym as done for PolyType
return isSameTypes(mt1.paramTypes, mt2.paramTypes) &&
mt1.resultType =:= mt2.resultType &&
mt1.isImplicit == mt2.isImplicit
// note: no case NullaryMethodType(restpe) => return mt1.params.isEmpty && mt1.resultType =:= restpe
case _ =>
}
case NullaryMethodType(restpe1) =>
tp2 match {
// note: no case mt2: MethodType => return mt2.params.isEmpty && restpe =:= mt2.resultType
case NullaryMethodType(restpe2) =>
return restpe1 =:= restpe2
case _ =>
}
case PolyType(tparams1, res1) =>
tp2 match {
case PolyType(tparams2, res2) =>
// assert((tparams1 map (_.typeParams.length)) == (tparams2 map (_.typeParams.length)))
// @M looks like it might suffer from same problem as #2210
return (
(sameLength(tparams1, tparams2)) && // corresponds does not check length of two sequences before checking the predicate
(tparams1 corresponds tparams2)(_.info =:= _.info.substSym(tparams2, tparams1)) &&
res1 =:= res2.substSym(tparams2, tparams1)
)
case _ =>
}
case ExistentialType(tparams1, res1) =>
tp2 match {
case ExistentialType(tparams2, res2) =>
// @M looks like it might suffer from same problem as #2210
return (
// corresponds does not check length of two sequences before checking the predicate -- faster & needed to avoid crasher in #2956
sameLength(tparams1, tparams2) &&
(tparams1 corresponds tparams2)(_.info =:= _.info.substSym(tparams2, tparams1)) &&
res1 =:= res2.substSym(tparams2, tparams1)
)
case _ =>
}
case TypeBounds(lo1, hi1) =>
tp2 match {
case TypeBounds(lo2, hi2) =>
return lo1 =:= lo2 && hi1 =:= hi2
case _ =>
}
case BoundedWildcardType(bounds) =>
return bounds containsType tp2
case _ =>
}
tp2 match {
case BoundedWildcardType(bounds) =>
return bounds containsType tp1
case _ =>
}
tp1 match {
case tv @ TypeVar(_,_) =>
return tv.registerTypeEquality(tp2, true)
case _ =>
}
tp2 match {
case tv @ TypeVar(_,_) =>
return tv.registerTypeEquality(tp1, false)
case _ =>
}
tp1 match {
case _: AnnotatedType =>
return annotationsConform(tp1, tp2) && annotationsConform(tp2, tp1) && tp1.withoutAnnotations =:= tp2.withoutAnnotations
case _ =>
}
tp2 match {
case _: AnnotatedType =>
return annotationsConform(tp1, tp2) && annotationsConform(tp2, tp1) && tp1.withoutAnnotations =:= tp2.withoutAnnotations
case _ =>
}
tp1 match {
case _: SingletonType =>
tp2 match {
case _: SingletonType =>
@inline def chaseDealiasedUnderlying(tp: Type): Type = {
var origin = tp
var next = origin.underlying.dealias
while (next.isInstanceOf[SingletonType]) {
assert(origin ne next, origin)
origin = next
next = origin.underlying.dealias
}
origin
}
val origin1 = chaseDealiasedUnderlying(tp1)
val origin2 = chaseDealiasedUnderlying(tp2)
((origin1 ne tp1) || (origin2 ne tp2)) && (origin1 =:= origin2)
case _ =>
false
}
case _ =>
false
}
}
/** Are `tps1' and `tps2' lists of pairwise equivalent
* types?
*/
def isSameTypes(tps1: List[Type], tps2: List[Type]): Boolean = (tps1 corresponds tps2)(_ =:= _)
/** True if two lists have the same length. Since calling length on linear sequences
* is O(n), it is an inadvisable way to test length equality.
*/
final def sameLength(xs1: List[_], xs2: List[_]) = compareLengths(xs1, xs2) == 0
@tailrec final def compareLengths(xs1: List[_], xs2: List[_]): Int =
if (xs1.isEmpty) { if (xs2.isEmpty) 0 else -1 }
else if (xs2.isEmpty) 1
else compareLengths(xs1.tail, xs2.tail)
/** Again avoiding calling length, but the lengthCompare interface is clunky.
*/
final def hasLength(xs: List[_], len: Int) = xs.lengthCompare(len) == 0
private val pendingSubTypes = new mutable.HashSet[SubTypePair]
private var basetypeRecursions: Int = 0
private val pendingBaseTypes = new mutable.HashSet[Type]
def isSubType(tp1: Type, tp2: Type): Boolean = isSubType(tp1, tp2, AnyDepth)
def isSubType(tp1: Type, tp2: Type, depth: Int): Boolean = try {
subsametypeRecursions += 1
undoLog undoUnless { // if subtype test fails, it should not affect constraints on typevars
if (subsametypeRecursions >= LogPendingSubTypesThreshold) {
val p = new SubTypePair(tp1, tp2)
if (pendingSubTypes(p))
false
else
try {
pendingSubTypes += p
isSubType2(tp1, tp2, depth)
} finally {
pendingSubTypes -= p
}
} else {
isSubType2(tp1, tp2, depth)
}
}
} finally {
subsametypeRecursions -= 1
// XXX AM TODO: figure out when it is safe and needed to clear the log -- the commented approach below is too eager (it breaks #3281, #3866)
// it doesn't help to keep separate recursion counts for the three methods that now share it
// if (subsametypeRecursions == 0) undoLog.clear()
}
/** Does this type have a prefix that begins with a type variable,
* or is it a refinement type? For type prefixes that fulfil this condition,
* type selections with the same name of equal (wrt) =:= prefixes are
* considered equal wrt =:=
*/
def beginsWithTypeVarOrIsRefined(tp: Type): Boolean = tp match {
case SingleType(pre, sym) =>
!(sym hasFlag PACKAGE) && beginsWithTypeVarOrIsRefined(pre)
case tv@TypeVar(_, constr) =>
!tv.instValid || beginsWithTypeVarOrIsRefined(constr.inst)
case RefinedType(_, _) =>
true
case _ =>
false
}
def instTypeVar(tp: Type): Type = tp match {
case TypeRef(pre, sym, args) =>
typeRef(instTypeVar(pre), sym, args)
case SingleType(pre, sym) =>
singleType(instTypeVar(pre), sym)
case TypeVar(_, constr) =>
instTypeVar(constr.inst)
case _ =>
tp
}
def isErrorOrWildcard(tp: Type) = (tp eq ErrorType) || (tp eq WildcardType)
def isSingleType(tp: Type) = tp match {
case ThisType(_) | SuperType(_, _) | SingleType(_, _) => true
case _ => false
}
def isConstantType(tp: Type) = tp match {
case ConstantType(_) => true
case _ => false
}
// @assume tp1.isHigherKinded || tp2.isHigherKinded
def isHKSubType0(tp1: Type, tp2: Type, depth: Int): Boolean = (
tp1.typeSymbol == NothingClass
||
tp2.typeSymbol == AnyClass // @M Any and Nothing are super-type resp. subtype of every well-kinded type
|| // @M! normalize reduces higher-kinded case to PolyType's
((tp1.normalize.withoutAnnotations , tp2.normalize.withoutAnnotations) match {
case (PolyType(tparams1, res1), PolyType(tparams2, res2)) => // @assume tp1.isHigherKinded && tp2.isHigherKinded (as they were both normalized to PolyType)
sameLength(tparams1, tparams2) && {
if (tparams1.head.owner.isMethod) { // fast-path: polymorphic method type -- type params cannot be captured
(tparams1 corresponds tparams2)((p1, p2) => p2.info.substSym(tparams2, tparams1) <:< p1.info) &&
res1 <:< res2.substSym(tparams2, tparams1)
} else { // normalized higher-kinded type
//@M for an example of why we need to generate fresh symbols, see neg/tcpoly_ticket2101.scala
val tpsFresh = cloneSymbols(tparams1)
(tparams1 corresponds tparams2)((p1, p2) =>
p2.info.substSym(tparams2, tpsFresh) <:< p1.info.substSym(tparams1, tpsFresh)) &&
res1.substSym(tparams1, tpsFresh) <:< res2.substSym(tparams2, tpsFresh)
//@M the forall in the previous test could be optimised to the following,
// but not worth the extra complexity since it only shaves 1s from quick.comp
// (List.forall2(tpsFresh/*optimisation*/, tparams2)((p1, p2) =>
// p2.info.substSym(tparams2, tpsFresh) <:< p1.info /*optimisation, == (p1 from tparams1).info.substSym(tparams1, tpsFresh)*/) &&
// this optimisation holds because inlining cloneSymbols in `val tpsFresh = cloneSymbols(tparams1)` gives:
// val tpsFresh = tparams1 map (_.cloneSymbol)
// for (tpFresh <- tpsFresh) tpFresh.setInfo(tpFresh.info.substSym(tparams1, tpsFresh))
}
} && annotationsConform(tp1.normalize, tp2.normalize)
case (_, _) => false // @assume !tp1.isHigherKinded || !tp2.isHigherKinded
// --> thus, cannot be subtypes (Any/Nothing has already been checked)
}))
/** True if all three arguments have the same number of elements and
* the function is true for all the triples.
*/
@tailrec final def corresponds3[A, B, C](xs1: List[A], xs2: List[B], xs3: List[C], f: (A, B, C) => Boolean): Boolean = {
if (xs1.isEmpty) xs2.isEmpty && xs3.isEmpty
else !xs2.isEmpty && !xs3.isEmpty && f(xs1.head, xs2.head, xs3.head) && corresponds3(xs1.tail, xs2.tail, xs3.tail, f)
}
def isSubArg(t1: Type, t2: Type, variance: Int) =
(variance > 0 || t2 <:< t1) && (variance < 0 || t1 <:< t2)
def isSubArgs(tps1: List[Type], tps2: List[Type], tparams: List[Symbol]): Boolean =
corresponds3(tps1, tps2, tparams map (_.variance), isSubArg)
def differentOrNone(tp1: Type, tp2: Type) = if (tp1 eq tp2) NoType else tp1
/** Does type `tp1' conform to `tp2'?
*/
private def isSubType2(tp1: Type, tp2: Type, depth: Int): Boolean = {
if ((tp1 eq tp2) || isErrorOrWildcard(tp1) || isErrorOrWildcard(tp2)) return true
if ((tp1 eq NoType) || (tp2 eq NoType)) return false
if (tp1 eq NoPrefix) return (tp2 eq NoPrefix) || tp2.typeSymbol.isPackageClass
if (tp2 eq NoPrefix) return tp1.typeSymbol.isPackageClass
if (isSingleType(tp1) && isSingleType(tp2) || isConstantType(tp1) && isConstantType(tp2)) return tp1 =:= tp2
if (tp1.isHigherKinded || tp2.isHigherKinded) return isHKSubType0(tp1, tp2, depth)
/** First try, on the right:
* - unwrap Annotated types, BoundedWildcardTypes,
* - bind TypeVars on the right, if lhs is not Annotated nor BoundedWildcard
* - handle common cases for first-kind TypeRefs on both sides as a fast path.
*/
def firstTry = { incCounter(ctr1); tp2 match {
// fast path: two typerefs, none of them HK
case tr2: TypeRef =>
tp1 match {
case tr1: TypeRef =>
val sym1 = tr1.sym
val sym2 = tr2.sym
val pre1 = tr1.pre
val pre2 = tr2.pre
(((if (sym1 == sym2) phase.erasedTypes || pre1 <:< pre2
else (sym1.name == sym2.name &&
(isUnifiable(pre1, pre2) || isSameSpecializedSkolem(sym1, sym2, pre1, pre2)))) &&
isSubArgs(tr1.args, tr2.args, sym1.typeParams))
||
sym2.isClass && {
val base = tr1 baseType sym2
(base ne tr1) && base <:< tr2
}
||
thirdTryRef(tr1, tr2))
case _ =>
secondTry
}
case AnnotatedType(_, _, _) =>
tp1.withoutAnnotations <:< tp2.withoutAnnotations && annotationsConform(tp1, tp2)
case BoundedWildcardType(bounds) =>
tp1 <:< bounds.hi
case tv2 @ TypeVar(_, constr2) =>
tp1 match {
case AnnotatedType(_, _, _) | BoundedWildcardType(_) =>
secondTry
case _ =>
tv2.registerBound(tp1, true)
}
case _ =>
secondTry
}}
/** Second try, on the left:
* - unwrap AnnotatedTypes, BoundedWildcardTypes,
* - bind typevars,
* - handle existential types by skolemization.
*/
def secondTry = { incCounter(ctr2); tp1 match {
case AnnotatedType(_, _, _) =>
tp1.withoutAnnotations <:< tp2.withoutAnnotations && annotationsConform(tp1, tp2)
case BoundedWildcardType(bounds) =>
tp1.bounds.lo <:< tp2
case tv @ TypeVar(_,_) =>
tv.registerBound(tp2, false)
case ExistentialType(_, _) =>
try {
skolemizationLevel += 1
tp1.skolemizeExistential <:< tp2
} finally {
skolemizationLevel -= 1
}
case _ =>
thirdTry
}}
def thirdTryRef(tp1: Type, tp2: TypeRef): Boolean = {
incCounter(ctr3);
val sym2 = tp2.sym
sym2 match {
case NotNullClass => tp1.isNotNull
case SingletonClass => tp1.isStable || fourthTry
case _: ClassSymbol =>
if (isRaw(sym2, tp2.args))
isSubType(tp1, rawToExistential(tp2), depth)
else if (sym2.name == tpnme.REFINE_CLASS_NAME)
isSubType(tp1, sym2.info, depth)
else
fourthTry
case _: TypeSymbol =>
if (sym2 hasFlag DEFERRED) {
val tp2a = tp2.bounds.lo
isDifferentTypeConstructor(tp2, tp2a) && tp1 <:< tp2a || fourthTry
} else {
isSubType(tp1.normalize, tp2.normalize, depth)
}
case _ =>
fourthTry
}
}
/** Third try, on the right:
* - decompose refined types.
* - handle typerefs, existentials, and notnull types.
* - handle left+right method types, polytypes, typebounds
*/
def thirdTry = { incCounter(ctr3); tp2 match {
case tr2: TypeRef =>
thirdTryRef(tp1, tr2)
case rt2: RefinedType =>
(rt2.parents forall (tp1 <:< _)) &&
(rt2.decls.toList forall tp1.specializes)
case et2: ExistentialType =>
et2.withTypeVars(tp1 <:< _, depth) || fourthTry
case nn2: NotNullType =>
tp1.isNotNull && tp1 <:< nn2.underlying
case mt2: MethodType =>
tp1 match {
case mt1 @ MethodType(params1, res1) =>
val params2 = mt2.params
val res2 = mt2.resultType
(sameLength(params1, params2) &&
matchingParams(params1, params2, mt1.isJava, mt2.isJava) &&
(res1 <:< res2) &&
mt1.isImplicit == mt2.isImplicit)
// TODO: if mt1.params.isEmpty, consider NullaryMethodType?
case _ =>
false
}
case pt2 @ NullaryMethodType(_) =>
tp1 match {
// TODO: consider MethodType mt for which mt.params.isEmpty??
case pt1 @ NullaryMethodType(_) =>
pt1.resultType <:< pt2.resultType
case _ =>
false
}
case TypeBounds(lo2, hi2) =>
tp1 match {
case TypeBounds(lo1, hi1) =>
lo2 <:< lo1 && hi1 <:< hi2
case _ =>
false
}
case _ =>
fourthTry
}}
/** Fourth try, on the left:
* - handle typerefs, refined types, notnull and singleton types.
*/
def fourthTry = { incCounter(ctr4); tp1 match {
case tr1 @ TypeRef(_, sym1, _) =>
sym1 match {
case NothingClass => true
case NullClass =>
tp2 match {
case TypeRef(_, sym2, _) =>
sym2.isClass && (sym2 isNonBottomSubClass ObjectClass) &&
!(tp2.normalize.typeSymbol isNonBottomSubClass NotNullClass)
case _ =>
isSingleType(tp2) && tp1 <:< tp2.widen
}
case _: ClassSymbol =>
if (isRaw(sym1, tr1.args))
isSubType(rawToExistential(tp1), tp2, depth)
else
sym1.name == tpnme.REFINE_CLASS_NAME &&
isSubType(sym1.info, tp2, depth)
case _: TypeSymbol =>
if (sym1 hasFlag DEFERRED) {
val tp1a = tp1.bounds.hi
isDifferentTypeConstructor(tp1, tp1a) && tp1a <:< tp2
} else {
isSubType(tp1.normalize, tp2.normalize, depth)
}
case _ =>
false
}
case RefinedType(parents1, _) =>
parents1 exists (_ <:< tp2)
case _: SingletonType | _: NotNullType =>
tp1.underlying <:< tp2
case _ =>
false
}}
firstTry
}
/** Are `tps1' and `tps2' lists of equal length such
* that all elements of `tps1' conform to corresponding elements
* of `tps2'?
*/
def isSubTypes(tps1: List[Type], tps2: List[Type]): Boolean = (tps1 corresponds tps2)(_ <:< _)
/** Does type `tp' implement symbol `sym' with same or
* stronger type? Exact only if `sym' is a member of some
* refinement type, otherwise we might return false negatives.
*/
def specializesSym(tp: Type, sym: Symbol): Boolean =
tp.typeSymbol == NothingClass ||
tp.typeSymbol == NullClass && (sym.owner isSubClass ObjectClass) ||
(tp.member(sym.name).alternatives exists
(alt => sym == alt || specializesSym(tp.narrow, alt, sym.owner.thisType, sym)))
/** Does member `sym1' of `tp1' have a stronger type
* than member `sym2' of `tp2'?
*/
private def specializesSym(tp1: Type, sym1: Symbol, tp2: Type, sym2: Symbol): Boolean = {
val info1 = tp1.memberInfo(sym1)
val info2 = tp2.memberInfo(sym2).substThis(tp2.typeSymbol, tp1)
//System.out.println("specializes "+tp1+"."+sym1+":"+info1+sym1.locationString+" AND "+tp2+"."+sym2+":"+info2)//DEBUG
sym2.isTerm && (info1 <:< info2) /*&& (!sym2.isStable || sym1.isStable) */ ||
sym2.isAbstractType && {
val memberTp1 = tp1.memberType(sym1)
// println("kinds conform? "+(memberTp1, tp1, sym2, kindsConform(List(sym2), List(memberTp1), tp2, sym2.owner)))
info2.bounds.containsType(memberTp1) &&
kindsConform(List(sym2), List(memberTp1), tp1, sym1.owner)
} ||
sym2.isAliasType && tp2.memberType(sym2).substThis(tp2.typeSymbol, tp1) =:= tp1.memberType(sym1) //@MAT ok
}
/** A function implementing `tp1' matches `tp2' */
final def matchesType(tp1: Type, tp2: Type, alwaysMatchSimple: Boolean): Boolean = {
def matchesQuantified(tparams1: List[Symbol], tparams2: List[Symbol], res1: Type, res2: Type): Boolean = (
sameLength(tparams1, tparams2) &&
matchesType(res1, res2.substSym(tparams2, tparams1), alwaysMatchSimple)
)
def lastTry =
tp2 match {
case ExistentialType(_, res2) if alwaysMatchSimple =>
matchesType(tp1, res2, true)
case MethodType(_, _) =>
false
case PolyType(tparams2, res2) =>
tparams2.isEmpty && matchesType(tp1, res2, alwaysMatchSimple)
case _ =>
alwaysMatchSimple || tp1 =:= tp2
}
tp1 match {
case mt1 @ MethodType(params1, res1) =>
tp2 match {
case mt2 @ MethodType(params2, res2) =>
sameLength(params1, params2) && // useful pre-screening optimization
matchingParams(params1, params2, mt1.isJava, mt2.isJava) &&
matchesType(res1, res2, alwaysMatchSimple) &&
mt1.isImplicit == mt2.isImplicit
case NullaryMethodType(res2) =>
if (params1.isEmpty) matchesType(res1, res2, alwaysMatchSimple)
else matchesType(tp1, res2, alwaysMatchSimple)
case ExistentialType(_, res2) =>
alwaysMatchSimple && matchesType(tp1, res2, true)
case _ =>
false
}
case mt1 @ NullaryMethodType(res1) =>
tp2 match {
case mt2 @ MethodType(Nil, res2) => // could never match if params nonEmpty, and !mt2.isImplicit is implied by empty param list
matchesType(res1, res2, alwaysMatchSimple)
case NullaryMethodType(res2) =>
matchesType(res1, res2, alwaysMatchSimple)
case ExistentialType(_, res2) =>
alwaysMatchSimple && matchesType(tp1, res2, true)
case _ =>
matchesType(res1, tp2, alwaysMatchSimple)
}
case PolyType(tparams1, res1) =>
tp2 match {
case PolyType(tparams2, res2) =>
matchesQuantified(tparams1, tparams2, res1, res2)
case ExistentialType(_, res2) =>
alwaysMatchSimple && matchesType(tp1, res2, true)
case _ =>
false // remember that tparams1.nonEmpty is now an invariant of PolyType
}
case ExistentialType(tparams1, res1) =>
tp2 match {
case ExistentialType(tparams2, res2) =>
matchesQuantified(tparams1, tparams2, res1, res2)
case _ =>
if (alwaysMatchSimple) matchesType(res1, tp2, true)
else lastTry
}
case _ =>
lastTry
}
}
/** matchesType above is an optimized version of the following implementation:
def matchesType2(tp1: Type, tp2: Type, alwaysMatchSimple: Boolean): Boolean = {
def matchesQuantified(tparams1: List[Symbol], tparams2: List[Symbol], res1: Type, res2: Type): Boolean =
tparams1.length == tparams2.length &&
matchesType(res1, res2.substSym(tparams2, tparams1), alwaysMatchSimple)
(tp1, tp2) match {
case (MethodType(params1, res1), MethodType(params2, res2)) =>
params1.length == params2.length && // useful pre-secreening optimization
matchingParams(params1, params2, tp1.isInstanceOf[JavaMethodType], tp2.isInstanceOf[JavaMethodType]) &&
matchesType(res1, res2, alwaysMatchSimple) &&
tp1.isImplicit == tp2.isImplicit
case (PolyType(tparams1, res1), PolyType(tparams2, res2)) =>
matchesQuantified(tparams1, tparams2, res1, res2)
case (NullaryMethodType(rtp1), MethodType(List(), rtp2)) =>
matchesType(rtp1, rtp2, alwaysMatchSimple)
case (MethodType(List(), rtp1), NullaryMethodType(rtp2)) =>
matchesType(rtp1, rtp2, alwaysMatchSimple)
case (ExistentialType(tparams1, res1), ExistentialType(tparams2, res2)) =>
matchesQuantified(tparams1, tparams2, res1, res2)
case (ExistentialType(_, res1), _) if alwaysMatchSimple =>
matchesType(res1, tp2, alwaysMatchSimple)
case (_, ExistentialType(_, res2)) if alwaysMatchSimple =>
matchesType(tp1, res2, alwaysMatchSimple)
case (NullaryMethodType(rtp1), _) =>
matchesType(rtp1, tp2, alwaysMatchSimple)
case (_, NullaryMethodType(rtp2)) =>
matchesType(tp1, rtp2, alwaysMatchSimple)
case (MethodType(_, _), _) => false
case (PolyType(_, _), _) => false
case (_, MethodType(_, _)) => false
case (_, PolyType(_, _)) => false
case _ =>
alwaysMatchSimple || tp1 =:= tp2
}
}
*/
/** Are `syms1' and `syms2' parameter lists with pairwise equivalent types? */
private def matchingParams(syms1: List[Symbol], syms2: List[Symbol], syms1isJava: Boolean, syms2isJava: Boolean): Boolean = syms1 match {
case Nil =>
syms2.isEmpty
case sym1 :: rest1 =>
syms2 match {
case Nil =>
false
case sym2 :: rest2 =>
val tp1 = sym1.tpe
val tp2 = sym2.tpe
(tp1 =:= tp2 ||
syms1isJava && tp2.typeSymbol == ObjectClass && tp1.typeSymbol == AnyClass ||
syms2isJava && tp1.typeSymbol == ObjectClass && tp2.typeSymbol == AnyClass) &&
matchingParams(rest1, rest2, syms1isJava, syms2isJava)
}
}
/** like map2, but returns list `xs' itself - instead of a copy - if function
* `f' maps all elements to themselves.
*/
def map2Conserve[A <: AnyRef, B](xs: List[A], ys: List[B])(f: (A, B) => A): List[A] =
if (xs.isEmpty) xs
else {
val x1 = f(xs.head, ys.head)
val xs1 = map2Conserve(xs.tail, ys.tail)(f)
if ((x1 eq xs.head) && (xs1 eq xs.tail)) xs
else x1 :: xs1
}
/** Solve constraint collected in types `tvars'.
*
* @param tvars All type variables to be instantiated.
* @param tparams The type parameters corresponding to `tvars'
* @param variances The variances of type parameters; need to reverse
* solution direction for all contravariant variables.
* @param upper When `true' search for max solution else min.
*/
def solve(tvars: List[TypeVar], tparams: List[Symbol],
variances: List[Int], upper: Boolean): Boolean =
solve(tvars, tparams, variances, upper, AnyDepth)
def solve(tvars: List[TypeVar], tparams: List[Symbol],
variances: List[Int], upper: Boolean, depth: Int): Boolean = {
val config = tvars zip (tparams zip variances)
def solveOne(tvar: TypeVar, tparam: Symbol, variance: Int) {
if (tvar.constr.inst == NoType) {
val up = if (variance != CONTRAVARIANT) upper else !upper
tvar.constr.inst = null
val bound: Type = if (up) tparam.info.bounds.hi else tparam.info.bounds.lo
//Console.println("solveOne0(tv, tp, v, b)="+(tvar, tparam, variance, bound))
var cyclic = bound contains tparam
for ((tvar2, (tparam2, variance2)) <- config) {
if (tparam2 != tparam &&
((bound contains tparam2) ||
up && (tparam2.info.bounds.lo =:= tparam.tpe) ||
!up && (tparam2.info.bounds.hi =:= tparam.tpe))) {
if (tvar2.constr.inst eq null) cyclic = true
solveOne(tvar2, tparam2, variance2)
}
}
if (!cyclic) {
if (up) {
if (bound.typeSymbol != AnyClass)
tvar addHiBound bound.instantiateTypeParams(tparams, tvars)
for (tparam2 <- tparams)
tparam2.info.bounds.lo.dealias match {
case TypeRef(_, `tparam`, _) =>
tvar addHiBound tparam2.tpe.instantiateTypeParams(tparams, tvars)
case _ =>
}
} else {
if (bound.typeSymbol != NothingClass && bound.typeSymbol != tparam) {
tvar addLoBound bound.instantiateTypeParams(tparams, tvars)
}
for (tparam2 <- tparams)
tparam2.info.bounds.hi.dealias match {
case TypeRef(_, `tparam`, _) =>
tvar addLoBound tparam2.tpe.instantiateTypeParams(tparams, tvars)
case _ =>
}
}
}
tvar.constr.inst = NoType // necessary because hibounds/lobounds may contain tvar
//println("solving "+tvar+" "+up+" "+(if (up) (tvar.constr.hiBounds) else tvar.constr.loBounds)+((if (up) (tvar.constr.hiBounds) else tvar.constr.loBounds) map (_.widen)))
tvar setInst (
if (up) {
if (depth != AnyDepth) glb(tvar.constr.hiBounds, depth) else glb(tvar.constr.hiBounds)
} else {
if (depth != AnyDepth) lub(tvar.constr.loBounds, depth) else lub(tvar.constr.loBounds)
})
//Console.println("solving "+tvar+" "+up+" "+(if (up) (tvar.constr.hiBounds) else tvar.constr.loBounds)+((if (up) (tvar.constr.hiBounds) else tvar.constr.loBounds) map (_.widen))+" = "+tvar.constr.inst)//@MDEBUG
}
}
// println("solving "+tvars+"/"+tparams+"/"+(tparams map (_.info)))
for ((tvar, (tparam, variance)) <- config)
solveOne(tvar, tparam, variance)
tvars forall (tvar => tvar.constr.isWithinBounds(tvar.constr.inst))
}
/** Do type arguments `targs' conform to formal parameters
* `tparams'?
*
* @param tparams ...
* @param targs ...
* @return ...
*/
def isWithinBounds(pre: Type, owner: Symbol, tparams: List[Symbol], targs: List[Type]): Boolean = {
var bounds = instantiatedBounds(pre, owner, tparams, targs)
if (targs.exists(_.annotations.nonEmpty))
bounds = adaptBoundsToAnnotations(bounds, tparams, targs)
(bounds corresponds targs)(_ containsType _)
}
def instantiatedBounds(pre: Type, owner: Symbol, tparams: List[Symbol], targs: List[Type]): List[TypeBounds] =
tparams map (_.info.asSeenFrom(pre, owner).instantiateTypeParams(tparams, targs).bounds)
// Lubs and Glbs ---------------------------------------------------------
/** The least sorted upwards closed upper bound of a non-empty list
* of lists of types relative to the following ordering <= between lists of types:
*
* xs <= ys iff forall y in ys exists x in xs such that x <: y
*
* @See baseTypeSeq for a definition of sorted and upwards closed.
*/
private def lubList(tss: List[List[Type]], depth: Int): List[Type] =
if (tss.tail.isEmpty) tss.head
else if (tss exists (_.isEmpty)) List()
else {
val ts0 = tss map (_.head)
val sym = minSym(ts0)
if (ts0 forall (_.typeSymbol == sym))
mergePrefixAndArgs(elimSub(ts0, depth), 1, depth).toList ::: lubList(tss map (_.tail), depth)
else
lubList(tss map (ts => if (ts.head.typeSymbol == sym) ts.tail else ts), depth)
}
private def lubBaseTypeSeq(tss: List[BaseTypeSeq], depth: Int): List[Type] =
lubList(tss map (_.toList), depth)
/** The minimal symbol (wrt Symbol.isLess) of a list of types */
private def minSym(tps: List[Type]): Symbol =
(tps.head.typeSymbol /: tps.tail) {
(sym1, tp2) => if (tp2.typeSymbol isLess sym1) tp2.typeSymbol else sym1
}
/** A minimal type list which has a given list of types as its base type sequence */
def spanningTypes(ts: List[Type]): List[Type] = ts match {
case List() => List()
case first :: rest =>
first :: spanningTypes(
rest filter (t => !first.typeSymbol.isSubClass(t.typeSymbol)))
}
/** Eliminate from list of types all elements which are a supertype
* of some other element of the list. */
private def elimSuper(ts: List[Type]): List[Type] = ts match {
case List() => List()
case t :: ts1 =>
val rest = elimSuper(ts1 filter (t1 => !(t <:< t1)))
if (rest exists (t1 => t1 <:< t)) rest else t :: rest
}
/** A collector that tests for existential types appearing at given variance in a type */
class ContainsVariantExistentialCollector(v: Int) extends TypeCollector(false) {
def traverse(tp: Type) = tp match {
case ExistentialType(_, _) if (variance == v) => result = true
case _ => mapOver(tp)
}
def init() = {
variance = 1
this
}
}
val containsCovariantExistentialCollector = new ContainsVariantExistentialCollector(1)
val containsContravariantExistentialCollector = new ContainsVariantExistentialCollector(-1)
/** Eliminate from list of types all elements which are a subtype
* of some other element of the list. */
private def elimSub(ts: List[Type], depth: Int): List[Type] = {
def elimAnonymousClass(t: Type) = t match {
case TypeRef(pre, clazz, List()) if clazz.isAnonymousClass =>
clazz.classBound.asSeenFrom(pre, clazz.owner)
case _ =>
t
}
def elimSub0(ts: List[Type]): List[Type] = ts match {
case List() => List()
case t :: ts1 =>
val rest = elimSub0(ts1 filter (t1 => !isSubType(t1, t, decr(depth))))
if (rest exists (t1 => isSubType(t, t1, decr(depth)))) rest else t :: rest
}
val ts0 = elimSub0(ts)
if (ts0.isEmpty || ts0.tail.isEmpty) ts0
else {
val ts1 = ts0 mapConserve (t => elimAnonymousClass(t.underlying))
if (ts1 eq ts0) ts0
else elimSub(ts1, depth)
}
}
private def stripExistentialsAndTypeVars(ts: List[Type]): (List[Type], List[Symbol]) = {
val quantified = ts flatMap {
case ExistentialType(qs, _) => qs
case t => List()
}
def stripType(tp: Type) = tp match {
case ExistentialType(_, res) =>
res
case TypeVar(_, constr) =>
if (constr.instValid) constr.inst
else abort("trying to do lub/glb of typevar "+tp)
case t => t
}
val strippedTypes = ts mapConserve stripType
(strippedTypes, quantified)
}
def weakLub(ts: List[Type]) =
if (ts.nonEmpty && (ts forall isNumericValueType)) (numericLub(ts), true)
else if (ts.nonEmpty && (ts exists (_.annotations.nonEmpty)))
(annotationsLub(lub(ts map (_.withoutAnnotations)), ts), true)
else (lub(ts), false)
def weakGlb(ts: List[Type]) = {
if (ts.nonEmpty && (ts forall isNumericValueType)) {
val nglb = numericGlb(ts)
if (nglb != NoType) (nglb, true)
else (glb(ts), false)
} else if (ts.nonEmpty && (ts exists (_.annotations.nonEmpty))) {
(annotationsGlb(glb(ts map (_.withoutAnnotations)), ts), true)
} else (glb(ts), false)
}
def numericLub(ts: List[Type]) =
ts reduceLeft ((t1, t2) =>
if (isNumericSubType(t1, t2)) t2
else if (isNumericSubType(t2, t1)) t1
else IntClass.tpe)
def numericGlb(ts: List[Type]) =
ts reduceLeft ((t1, t2) =>
if (isNumericSubType(t1, t2)) t1
else if (isNumericSubType(t2, t1)) t2
else NoType)
def isWeakSubType(tp1: Type, tp2: Type) =
tp1.deconst.normalize match {
case TypeRef(_, sym1, _) if isNumericValueClass(sym1) =>
tp2.deconst.normalize match {
case TypeRef(_, sym2, _) if isNumericValueClass(sym2) =>
isNumericSubClass(sym1, sym2)
case tv2 @ TypeVar(_, _) =>
tv2.registerBound(tp1, isLowerBound = true, isNumericBound = true)
case _ =>
isSubType(tp1, tp2)
}
case tv1 @ TypeVar(_, _) =>
tp2.deconst.normalize match {
case TypeRef(_, sym2, _) if isNumericValueClass(sym2) =>
tv1.registerBound(tp2, isLowerBound = false, isNumericBound = true)
case _ =>
isSubType(tp1, tp2)
}
case _ =>
isSubType(tp1, tp2)
}
def isNumericSubType(tp1: Type, tp2: Type) =
isNumericValueType(tp1) && isNumericValueType(tp2) &&
isNumericSubClass(tp1.typeSymbol, tp2.typeSymbol)
private val lubResults = new mutable.HashMap[(Int, List[Type]), Type]
private val glbResults = new mutable.HashMap[(Int, List[Type]), Type]
def lub(ts: List[Type]): Type = try {
lub(ts, lubDepth(ts))
} finally {
lubResults.clear()
glbResults.clear()
}
/** The least upper bound wrt <:< of a list of types */
def lub(ts: List[Type], depth: Int): Type = {
def lub0(ts0: List[Type]): Type = elimSub(ts0, depth) match {
case List() => NothingClass.tpe
case List(t) => t
case ts @ PolyType(tparams, _) :: _ =>
val tparams1 = (tparams, matchingBounds(ts, tparams).transpose).zipped map
((tparam, bounds) => tparam.cloneSymbol.setInfo(glb(bounds, depth)))
PolyType(tparams1, lub0(matchingInstTypes(ts, tparams1)))
case ts @ MethodType(params, _) :: rest =>
MethodType(params, lub0(matchingRestypes(ts, params map (_.tpe))))
case ts @ NullaryMethodType(_) :: rest =>
NullaryMethodType(lub0(matchingRestypes(ts, Nil)))
case ts @ TypeBounds(_, _) :: rest =>
TypeBounds(glb(ts map (_.bounds.lo), depth), lub(ts map (_.bounds.hi), depth))
case ts =>
lubResults get (depth, ts) match {
case Some(lubType) =>
lubType
case None =>
lubResults((depth, ts)) = AnyClass.tpe
val res = if (depth < 0) AnyClass.tpe else lub1(ts)
lubResults((depth, ts)) = res
res
}
}
def lub1(ts0: List[Type]): Type = {
val (ts, tparams) = stripExistentialsAndTypeVars(ts0)
val bts: List[BaseTypeSeq] = ts map (_.baseTypeSeq)
val lubBaseTypes: List[Type] = lubBaseTypeSeq(bts, depth)
val lubParents = spanningTypes(lubBaseTypes)
val lubOwner = commonOwner(ts)
val lubBase = intersectionType(lubParents, lubOwner)
val lubType =
if (phase.erasedTypes || depth == 0) lubBase
else {
val lubRefined = refinedType(lubParents, lubOwner)
val lubThisType = lubRefined.typeSymbol.thisType
val narrowts = ts map (_.narrow)
def lubsym(proto: Symbol): Symbol = {
val prototp = lubThisType.memberInfo(proto)
val syms = narrowts map (t =>
t.nonPrivateMember(proto.name).suchThat(sym =>
sym.tpe matches prototp.substThis(lubThisType.typeSymbol, t)))
if (syms contains NoSymbol) NoSymbol
else {
val symtypes =
(narrowts, syms).zipped map ((t, sym) => t.memberInfo(sym).substThis(t.typeSymbol, lubThisType))
if (proto.isTerm) // possible problem: owner of info is still the old one, instead of new refinement class
proto.cloneSymbol(lubRefined.typeSymbol).setInfoOwnerAdjusted(lub(symtypes, decr(depth)))
else if (symtypes.tail forall (symtypes.head =:=))
proto.cloneSymbol(lubRefined.typeSymbol).setInfoOwnerAdjusted(symtypes.head)
else {
def lubBounds(bnds: List[TypeBounds]): TypeBounds =
TypeBounds(glb(bnds map (_.lo), decr(depth)), lub(bnds map (_.hi), decr(depth)))
lubRefined.typeSymbol.newAbstractType(proto.pos, proto.name.toTypeName)
.setInfoOwnerAdjusted(lubBounds(symtypes map (_.bounds)))
}
}
}
def refines(tp: Type, sym: Symbol): Boolean = {
val syms = tp.nonPrivateMember(sym.name).alternatives;
!syms.isEmpty && (syms forall (alt =>
// todo alt != sym is strictly speaking not correct, but without it we lose
// efficiency.
alt != sym && !specializesSym(lubThisType, sym, tp, alt)))
}
for (sym <- lubBase.nonPrivateMembers) {
// add a refinement symbol for all non-class members of lubBase
// which are refined by every type in ts.
if (!sym.isClass && !sym.isConstructor && (narrowts forall (t => refines(t, sym))))
try {
val lsym = lubsym(sym)
if (lsym != NoSymbol) addMember(lubThisType, lubRefined, lubsym(sym))
} catch {
case ex: NoCommonType =>
}
}
if (lubRefined.decls.isEmpty) lubBase
else {
// println("refined lub of "+ts+"/"+narrowts+" is "+lubRefined+", baseclasses = "+(ts map (_.baseTypeSeq) map (_.toList)))
lubRefined
}
}
existentialAbstraction(tparams, lubType)
}
if (printLubs) {
println(indent + "lub of " + ts + " at depth "+depth)//debug
indent = indent + " "
assert(indent.length <= 100)
}
val res = lub0(ts)
if (printLubs) {
indent = indent dropRight 2
println(indent + "lub of " + ts + " is " + res)//debug
}
if (ts forall (_.isNotNull)) res.notNull else res
}
val GlbFailure = new Throwable
/** A global counter for glb calls in the `specializes' query connected to the `addMembers'
* call in `glb'. There's a possible infinite recursion when `specializes' calls
* memberType, which calls baseTypeSeq, which calls mergePrefixAndArgs, which calls glb.
* The counter breaks this recursion after two calls.
* If the recursion is broken, no member is added to the glb.
*/
private var globalGlbDepth = 0
private final val globalGlbLimit = 2
def glb(ts: List[Type]): Type = try {
glb(ts, lubDepth(ts))
} finally {
lubResults.clear()
glbResults.clear()
}
/** The greatest lower bound wrt <:< of a list of types */
private def glb(ts: List[Type], depth: Int): Type = {
def glb0(ts0: List[Type]): Type = elimSuper(ts0) match {
case List() => AnyClass.tpe
case List(t) => t
case ts @ PolyType(tparams, _) :: _ =>
val tparams1 = (tparams, matchingBounds(ts, tparams).transpose).zipped map
((tparam, bounds) => tparam.cloneSymbol.setInfo(lub(bounds, depth)))
PolyType(tparams1, glb0(matchingInstTypes(ts, tparams1)))
case ts @ MethodType(params, _) :: rest =>
MethodType(params, glb0(matchingRestypes(ts, params map (_.tpe))))
case ts @ NullaryMethodType(_) :: rest =>
NullaryMethodType(glb0(matchingRestypes(ts, Nil)))
case ts @ TypeBounds(_, _) :: rest =>
TypeBounds(lub(ts map (_.bounds.lo), depth), glb(ts map (_.bounds.hi), depth))
case ts =>
glbResults get (depth, ts) match {
case Some(glbType) =>
glbType
case _ =>
glbResults((depth, ts)) = NothingClass.tpe
val res = if (depth < 0) NothingClass.tpe else glb1(ts)
glbResults((depth, ts)) = res
res
}
}
def glb1(ts0: List[Type]): Type = {
try {
val (ts, tparams) = stripExistentialsAndTypeVars(ts0)
val glbOwner = commonOwner(ts)
def refinedToParents(t: Type): List[Type] = t match {
case RefinedType(ps, _) => ps flatMap refinedToParents
case _ => List(t)
}
def refinedToDecls(t: Type): List[Scope] = t match {
case RefinedType(ps, decls) =>
val dss = ps flatMap refinedToDecls
if (decls.isEmpty) dss else decls :: dss
case _ => List()
}
val ts1 = ts flatMap refinedToParents
val glbBase = intersectionType(ts1, glbOwner)
val glbType =
if (phase.erasedTypes || depth == 0) glbBase
else {
val glbRefined = refinedType(ts1, glbOwner)
val glbThisType = glbRefined.typeSymbol.thisType
def glbsym(proto: Symbol): Symbol = {
val prototp = glbThisType.memberInfo(proto)
val syms = for (t <- ts;
alt <- (t.nonPrivateMember(proto.name).alternatives);
if glbThisType.memberInfo(alt) matches prototp
) yield alt
val symtypes = syms map glbThisType.memberInfo
assert(!symtypes.isEmpty)
proto.cloneSymbol(glbRefined.typeSymbol).setInfoOwnerAdjusted(
if (proto.isTerm) glb(symtypes, decr(depth))
else {
def isTypeBound(tp: Type) = tp match {
case TypeBounds(_, _) => true
case _ => false
}
def glbBounds(bnds: List[Type]): TypeBounds = {
val lo = lub(bnds map (_.bounds.lo), decr(depth))
val hi = glb(bnds map (_.bounds.hi), decr(depth))
if (lo <:< hi) TypeBounds(lo, hi)
else throw GlbFailure
}
val symbounds = symtypes filter isTypeBound
var result: Type =
if (symbounds.isEmpty)
TypeBounds.empty
else glbBounds(symbounds)
for (t <- symtypes if !isTypeBound(t))
if (result.bounds containsType t) result = t
else throw GlbFailure
result
})
}
if (globalGlbDepth < globalGlbLimit)
try {
globalGlbDepth += 1
val dss = ts flatMap refinedToDecls
for (ds <- dss; val sym <- ds.iterator)
if (globalGlbDepth < globalGlbLimit && !(glbThisType specializes sym))
try {
addMember(glbThisType, glbRefined, glbsym(sym))
} catch {
case ex: NoCommonType =>
}
} finally {
globalGlbDepth -= 1
}
if (glbRefined.decls.isEmpty) glbBase else glbRefined
}
existentialAbstraction(tparams, glbType)
} catch {
case GlbFailure =>
if (ts forall (t => NullClass.tpe <:< t)) NullClass.tpe
else NothingClass.tpe
}
}
// if (settings.debug.value) { println(indent + "glb of " + ts + " at depth "+depth); indent = indent + " " } //DEBUG
val res = glb0(ts)
// if (settings.debug.value) { indent = indent.substring(0, indent.length() - 2); log(indent + "glb of " + ts + " is " + res) }//DEBUG
if (ts exists (_.isNotNull)) res.notNull else res
}
/** The most deeply nested owner that contains all the symbols
* of thistype or prefixless typerefs/singletype occurrences in given type.
*/
private def commonOwner(t: Type): Symbol = {
commonOwnerMap.init
commonOwnerMap.apply(t)
commonOwnerMap.result
}
/** The most deeply nested owner that contains all the symbols
* of thistype or prefixless typerefs/singletype occurrences in given list
* of types.
*/
private def commonOwner(tps: List[Type]): Symbol = {
// if (settings.debug.value) log("computing common owner of types " + tps)//DEBUG
commonOwnerMap.init
tps foreach { tp => commonOwnerMap.apply(tp); () }
commonOwnerMap.result
}
/** Compute lub (if variance == 1) or glb (if variance == -1) of given list
* of types `tps'. All types in `tps' are typerefs or singletypes
* with the same symbol.
* Return `Some(x)' if the computation succeeds with result `x'.
* Return `None' if the computation fails.
*/
def mergePrefixAndArgs(tps: List[Type], variance: Int, depth: Int): Option[Type] = tps match {
case List(tp) =>
Some(tp)
case TypeRef(_, sym, _) :: rest =>
val pres = tps map (_.prefix) // prefix normalizes automatically
val pre = if (variance == 1) lub(pres, depth) else glb(pres, depth)
val argss = tps map (_.normalize.typeArgs) // symbol equality (of the tp in tps) was checked using typeSymbol, which normalizes, so should normalize before retrieving arguments
val capturedParams = new ListBuffer[Symbol]
try {
if (sym == ArrayClass && phase.erasedTypes) {
// special treatment for lubs of array types after erasure:
// if argss contain one value type and some other type, the lub is Object
// if argss contain several reference types, the lub is an array over lub of argtypes
if (argss exists (_.isEmpty)) {
None // something is wrong: an array without a type arg.
} else {
val args = argss map (_.head)
if (args.tail forall (_ =:= args.head)) Some(typeRef(pre, sym, List(args.head)))
else if (args exists (arg => isValueClass(arg.typeSymbol))) Some(ObjectClass.tpe)
else Some(typeRef(pre, sym, List(lub(args))))
}
} else {
val args = (sym.typeParams, argss.transpose).zipped map {
(tparam, as) =>
if (depth == 0)
if (tparam.variance == variance) AnyClass.tpe
else if (tparam.variance == -variance) NothingClass.tpe
else NoType
else
if (tparam.variance == variance) lub(as, decr(depth))
else if (tparam.variance == -variance) glb(as, decr(depth))
else {
val l = lub(as, decr(depth))
val g = glb(as, decr(depth))
if (l <:< g) l
else { // Martin: I removed this, because incomplete. Not sure there is a good way to fix it. For the moment we
// just err on the conservative side, i.e. with a bound that is too high.
// if(!(tparam.info.bounds contains tparam)){ //@M can't deal with f-bounds, see #2251
val qvar = commonOwner(as) freshExistential "" setInfo TypeBounds(g, l)
capturedParams += qvar
qvar.tpe
}
}
}
if (args contains NoType) None
else Some(existentialAbstraction(capturedParams.toList, typeRef(pre, sym, args)))
}
} catch {
case ex: MalformedType => None
case ex: IndexOutOfBoundsException => // transpose freaked out because of irregular argss
// catching just in case (shouldn't happen, but also doesn't cost us)
if (settings.debug.value) log("transposed irregular matrix!?"+ (tps, argss))
None
}
case SingleType(_, sym) :: rest =>
val pres = tps map (_.prefix)
val pre = if (variance == 1) lub(pres, depth) else glb(pres, depth)
try {
Some(singleType(pre, sym))
} catch {
case ex: MalformedType => None
}
case ExistentialType(tparams, quantified) :: rest =>
mergePrefixAndArgs(quantified :: rest, variance, depth) map (existentialAbstraction(tparams, _))
case _ =>
assert(false, tps); None
}
/** Make symbol `sym' a member of scope `tp.decls'
* where `thistp' is the narrowed owner type of the scope.
*/
def addMember(thistp: Type, tp: Type, sym: Symbol) {
assert(sym != NoSymbol)
// if (settings.debug.value) log("add member " + sym+":"+sym.info+" to "+thistp) //DEBUG
if (!(thistp specializes sym)) {
if (sym.isTerm)
for (alt <- tp.nonPrivateDecl(sym.name).alternatives)
if (specializesSym(thistp, sym, thistp, alt))
tp.decls unlink alt;
tp.decls enter sym
}
}
/** All types in list must be polytypes with type parameter lists of
* same length as tparams.
* Returns list of list of bounds infos, where corresponding type
* parameters are renamed to tparams.
*/
private def matchingBounds(tps: List[Type], tparams: List[Symbol]): List[List[Type]] =
tps map {
case PolyType(tparams1, _) if sameLength(tparams1, tparams) =>
tparams1 map (tparam => tparam.info.substSym(tparams1, tparams))
case _ =>
throw new NoCommonType(tps)
}
/** All types in list must be polytypes with type parameter lists of
* same length as tparams.
* Returns list of instance types, where corresponding type
* parameters are renamed to tparams.
*/
private def matchingInstTypes(tps: List[Type], tparams: List[Symbol]): List[Type] =
tps map {
case PolyType(tparams1, restpe) if sameLength(tparams1, tparams) =>
restpe.substSym(tparams1, tparams)
case _ =>
throw new NoCommonType(tps)
}
/** All types in list must be method types with equal parameter types.
* Returns list of their result types.
*/
private def matchingRestypes(tps: List[Type], pts: List[Type]): List[Type] =
tps map {
case MethodType(params1, res) if (isSameTypes(params1 map (_.tpe), pts)) =>
res
case NullaryMethodType(res) if pts isEmpty =>
res
case _ =>
throw new NoCommonType(tps)
}
// TODO: this desperately needs to be cleaned up
// plan: split into kind inference and subkinding
// every Type has a (cached) Kind
def kindsConform(tparams: List[Symbol], targs: List[Type], pre: Type, owner: Symbol): Boolean = checkKindBounds0(tparams, targs, pre, owner, false).isEmpty
/** Check well-kindedness of type application (assumes arities are already checked) -- @M
*
* This check is also performed when abstract type members become concrete (aka a "type alias") -- then tparams.length==1
* (checked one type member at a time -- in that case, prefix is the name of the type alias)
*
* Type application is just like value application: it's "contravariant" in the sense that
* the type parameters of the supplied type arguments must conform to the type parameters of
* the required type parameters:
* - their bounds must be less strict
* - variances must match (here, variances are absolute, the variance of a type parameter does not influence the variance of its higher-order parameters)
* - @M TODO: are these conditions correct,sufficient&necessary?
*
* e.g. class Iterable[t, m[+x <: t]] --> the application Iterable[Int, List] is okay, since
* List's type parameter is also covariant and its bounds are weaker than <: Int
*/
def checkKindBounds0(tparams: List[Symbol], targs: List[Type], pre: Type, owner: Symbol, explainErrors: Boolean): List[(Type, Symbol, List[(Symbol, Symbol)], List[(Symbol, Symbol)], List[(Symbol, Symbol)])] = {
var error = false
def transform(tp: Type, clazz: Symbol): Type = tp.asSeenFrom(pre, clazz) // instantiate type params that come from outside the abstract type we're currently checking
def transformedBounds(p: Symbol, o: Symbol) = transform(p.info.instantiateTypeParams(tparams, targs).bounds, o)
/** Check whether <arg>sym1</arg>'s variance conforms to <arg>sym2</arg>'s variance
*
* If <arg>sym2</arg> is invariant, <arg>sym1</arg>'s variance is irrelevant. Otherwise they must be equal.
*/
def variancesMatch(sym1: Symbol, sym2: Symbol): Boolean = (sym2.variance==0 || sym1.variance==sym2.variance)
// check that the type parameters <arg>hkargs</arg> to a higher-kinded type conform to the expected params <arg>hkparams</arg>
def checkKindBoundsHK(hkargs: List[Symbol], arg: Symbol, param: Symbol, paramowner: Symbol, underHKParams: List[Symbol], withHKArgs: List[Symbol]): (List[(Symbol, Symbol)], List[(Symbol, Symbol)], List[(Symbol, Symbol)]) = {
def bindHKParams(tp: Type) = tp.substSym(underHKParams, withHKArgs)
// @M sometimes hkargs != arg.typeParams, the symbol and the type may have very different type parameters
val hkparams = param.typeParams
if (settings.debug.value) {
log("checkKindBoundsHK expected: "+ param +" with params "+ hkparams +" by definition in "+ paramowner)
log("checkKindBoundsHK supplied: "+ arg +" with params "+ hkargs +" from "+ owner)
log("checkKindBoundsHK under params: "+ underHKParams +" with args "+ withHKArgs)
}
if (!sameLength(hkargs, hkparams)) {
if(arg == AnyClass || arg == NothingClass) (Nil, Nil, Nil) // Any and Nothing are kind-overloaded
else {error = true; (List((arg, param)), Nil, Nil)} // shortcut: always set error, whether explainTypesOrNot
} else {
val _arityMismatches = if(explainErrors) new ListBuffer[(Symbol, Symbol)] else null
val _varianceMismatches = if(explainErrors) new ListBuffer[(Symbol, Symbol)] else null
val _stricterBounds = if(explainErrors)new ListBuffer[(Symbol, Symbol)] else null
def varianceMismatch(a: Symbol, p: Symbol) { if(explainErrors) _varianceMismatches += ((a, p)) else error = true}
def stricterBound(a: Symbol, p: Symbol) { if(explainErrors) _stricterBounds += ((a, p)) else error = true }
def arityMismatches(as: Iterable[(Symbol, Symbol)]) { if(explainErrors) _arityMismatches ++= as }
def varianceMismatches(as: Iterable[(Symbol, Symbol)]) { if(explainErrors) _varianceMismatches ++= as }
def stricterBounds(as: Iterable[(Symbol, Symbol)]) { if(explainErrors) _stricterBounds ++= as }
for ((hkarg, hkparam) <- hkargs zip hkparams) {
if (hkparam.typeParams.isEmpty && hkarg.typeParams.isEmpty) { // base-case: kind *
if (!variancesMatch(hkarg, hkparam))
varianceMismatch(hkarg, hkparam)
// instantiateTypeParams(tparams, targs) --> higher-order bounds may contain references to type arguments
// substSym(hkparams, hkargs) --> these types are going to be compared as types of kind *
// --> their arguments use different symbols, but are conceptually the same
// (could also replace the types by polytypes, but can't just strip the symbols, as ordering is lost then)
if (!(bindHKParams(transformedBounds(hkparam, paramowner)) <:< transform(hkarg.info.bounds, owner)))
stricterBound(hkarg, hkparam)
if (settings.debug.value) {
log("checkKindBoundsHK base case: "+ hkparam +" declared bounds: "+ transformedBounds(hkparam, paramowner) +" after instantiating earlier hkparams: "+ bindHKParams(transformedBounds(hkparam, paramowner)))
log("checkKindBoundsHK base case: "+ hkarg +" has bounds: "+ transform(hkarg.info.bounds, owner))
}
} else {
if(settings.debug.value) log("checkKindBoundsHK recursing to compare params of "+ hkparam +" with "+ hkarg)
val (am, vm, sb) = checkKindBoundsHK(hkarg.typeParams, hkarg, hkparam, paramowner, underHKParams ++ hkparam.typeParams, withHKArgs ++ hkarg.typeParams)
arityMismatches(am)
varianceMismatches(vm)
stricterBounds(sb)
}
if(!explainErrors && error) return (Nil, Nil, Nil) // stop as soon as we encountered an error
}
if(!explainErrors) (Nil, Nil, Nil)
else (_arityMismatches.toList, _varianceMismatches.toList, _stricterBounds.toList)
}
}
val errors = new ListBuffer[(Type, Symbol, List[(Symbol, Symbol)], List[(Symbol, Symbol)], List[(Symbol, Symbol)])]
(tparams zip targs).foreach{ case (tparam, targ) if (targ.isHigherKinded || !tparam.typeParams.isEmpty) =>
// @M must use the typeParams of the type targ, not the typeParams of the symbol of targ!!
val tparamsHO = targ.typeParams
val (arityMismatches, varianceMismatches, stricterBounds) =
checkKindBoundsHK(tparamsHO, targ.typeSymbolDirect, tparam, tparam.owner, tparam.typeParams, tparamsHO) // NOTE: *not* targ.typeSymbol, which normalizes
if(!explainErrors) {if(error) return List((NoType, NoSymbol, Nil, Nil, Nil))}
else if (arityMismatches.nonEmpty || varianceMismatches.nonEmpty || stricterBounds.nonEmpty) {
errors += ((targ, tparam, arityMismatches, varianceMismatches, stricterBounds))
}
// case (tparam, targ) => println("no check: "+(tparam, targ, tparam.typeParams.isEmpty))
case _ =>
}
errors.toList
}
// Errors and Diagnostics -----------------------------------------------------
/** A throwable signalling a type error */
class TypeError(var pos: Position, val msg: String) extends Throwable(msg) {
def this(msg: String) = this(NoPosition, msg)
}
class NoCommonType(tps: List[Type]) extends Throwable(
"lub/glb of incompatible types: " + tps.mkString("", " and ", "")) with ControlThrowable
/** A throwable signalling a malformed type */
class MalformedType(msg: String) extends TypeError(msg) {
def this(pre: Type, tp: String) = this("malformed type: " + pre + "#" + tp)
}
/** An exception signalling a variance annotation/usage conflict */
class VarianceError(msg: String) extends TypeError(msg)
/** The current indentation string for traces */
private var indent: String = ""
/** Perform operation `p' on arguments `tp1',
* `arg2' and print trace of computation.
*/
private def explain[T](op: String, p: (Type, T) => Boolean, tp1: Type, arg2: T): Boolean = {
Console.println(indent + tp1 + " " + op + " " + arg2 + "?" /* + "("+tp1.getClass+","+arg2.asInstanceOf[AnyRef].getClass+")"*/)
indent = indent + " "
val result = p(tp1, arg2)
indent = indent dropRight 2
Console.println(indent + result)
result
}
/** If option `explaintypes' is set, print a subtype trace for
* `found <:< required'.
*/
def explainTypes(found: Type, required: Type) {
if (settings.explaintypes.value) withTypesExplained(found <:< required)
}
/** If option `explaintypes' is set, print a subtype trace for
* `op(found, required)'.
*/
def explainTypes(op: (Type, Type) => Any, found: Type, required: Type) {
if (settings.explaintypes.value) withTypesExplained(op(found, required))
}
/** Execute `op' while printing a trace of the operations on types executed.
*/
def withTypesExplained[A](op: => A): A = {
val s = explainSwitch
try { explainSwitch = true; op } finally { explainSwitch = s }
}
def objToAny(tp: Type): Type =
if (!phase.erasedTypes && tp.typeSymbol == ObjectClass) AnyClass.tpe
else tp
val shorthands = Set(
"scala.collection.immutable.List",
"scala.collection.immutable.Nil",
"scala.collection.Seq",
"scala.collection.Traversable",
"scala.collection.Iterable",
"scala.collection.mutable.StringBuilder",
"scala.collection.IndexedSeq",
"scala.collection.Iterator")
}
|