summaryrefslogtreecommitdiffstats
path: root/runtime/doc/eval.txt
blob: d52f7fe169ee72ca6641e413c950c846cb649e93 (plain)
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
*eval.txt*	For Vim version 9.1.  Last change: 2023 Dec 09


		  VIM REFERENCE MANUAL	  by Bram Moolenaar


Expression evaluation			*expression* *expr* *E15* *eval*
							*E1002*
Using expressions is introduced in chapter 41 of the user manual |usr_41.txt|.

Note: Expression evaluation can be disabled at compile time.  If this has been
done, the features in this document are not available.  See |+eval| and
|no-eval-feature|.

This file is mainly about the backwards compatible (legacy) Vim script.  For
specifics of Vim9 script, which can execute much faster, supports type
checking and much more, see |vim9.txt|.  Where the syntax or semantics differ
a remark is given.

1.  Variables			|variables|
    1.1 Variable types
    1.2 Function references		|Funcref|
    1.3 Lists				|Lists|
    1.4 Dictionaries			|Dictionaries|
    1.5 Blobs				|Blobs|
    1.6 More about variables		|more-variables|
2.  Expression syntax		|expression-syntax|
3.  Internal variable		|internal-variables|
4.  Builtin Functions		|functions|
5.  Defining functions		|user-functions|
6.  Curly braces names		|curly-braces-names|
7.  Commands			|expression-commands|
8.  Exception handling		|exception-handling|
9.  Examples			|eval-examples|
10. Vim script version		|vimscript-version|
11. No +eval feature		|no-eval-feature|
12. The sandbox			|eval-sandbox|
13. Textlock			|textlock|
14. Vim script library		|vim-script-library|

Testing support is documented in |testing.txt|.
Profiling is documented at |profiling|.

==============================================================================
1. Variables						*variables*

1.1 Variable types ~
					*E712* *E896* *E897* *E899* *E1098*
					*E1107* *E1135* *E1138*
There are ten types of variables:

							*Number* *Integer*
Number		A 32 or 64 bit signed number.  |expr-number|
		The number of bits is available in |v:numbersize|.
		Examples:  -123  0x10  0177  0o177 0b1011

Float		A floating point number. |floating-point-format| *Float*
		Examples: 123.456  1.15e-6  -1.1e3

String		A NUL terminated string of 8-bit unsigned characters (bytes).
		|expr-string| Examples: "ab\txx\"--"  'x-z''a,c'

List		An ordered sequence of items, see |List| for details.
		Example: [1, 2, ['a', 'b']]

Dictionary	An associative, unordered array: Each entry has a key and a
		value. |Dictionary|
		Examples:
			{'blue': "#0000ff", 'red': "#ff0000"}
			#{blue: "#0000ff", red: "#ff0000"}

Funcref		A reference to a function |Funcref|.
		Example: function("strlen")
		It can be bound to a dictionary and arguments, it then works
		like a Partial.
		Example: function("Callback", [arg], myDict)

Special		|v:false|, |v:true|, |v:none| and |v:null|.  *Special*

Job		Used for a job, see |job_start()|. *Job* *Jobs*

Channel		Used for a channel, see |ch_open()|. *Channel* *Channels*

Blob		Binary Large Object. Stores any sequence of bytes.  See |Blob|
		for details
		Example: 0zFF00ED015DAF
		0z is an empty Blob.

The Number and String types are converted automatically, depending on how they
are used.

Conversion from a Number to a String is by making the ASCII representation of
the Number.  Examples:
	Number 123	-->	String "123" ~
	Number 0	-->	String "0" ~
	Number -1	-->	String "-1" ~
							*octal*
Conversion from a String to a Number only happens in legacy Vim script, not in
Vim9 script.  It is done by converting the first digits to a number.
Hexadecimal "0xf9", Octal "017" or "0o17", and Binary "0b10"
numbers are recognized
NOTE: when using |Vim9| script or |scriptversion-4| octal with a leading "0"
is not recognized.  The 0o notation requires patch 8.2.0886.
If the String doesn't start with digits, the result is zero.
Examples:
	String "456"	-->	Number 456 ~
	String "6bar"	-->	Number 6 ~
	String "foo"	-->	Number 0 ~
	String "0xf1"	-->	Number 241 ~
	String "0100"	-->	Number 64 ~
	String "0o100"	-->	Number 64 ~
	String "0b101"	-->	Number 5 ~
	String "-8"	-->	Number -8 ~
	String "+8"	-->	Number 0 ~

To force conversion from String to Number, add zero to it: >
	:echo "0100" + 0
<	64 ~

To avoid a leading zero to cause octal conversion, or for using a different
base, use |str2nr()|.

						*TRUE* *FALSE* *Boolean*
For boolean operators Numbers are used.  Zero is FALSE, non-zero is TRUE.
You can also use |v:false| and |v:true|, in Vim9 script |false| and |true|.
When TRUE is returned from a function it is the Number one, FALSE is the
number zero.

Note that in the command: >
	:if "foo"
	:" NOT executed
"foo" is converted to 0, which means FALSE.  If the string starts with a
non-zero number it means TRUE: >
	:if "8foo"
	:" executed
To test for a non-empty string, use empty(): >
	:if !empty("foo")

<						*falsy* *truthy*
An expression can be used as a condition, ignoring the type and only using
whether the value is "sort of true" or "sort of false".  Falsy is:
	the number zero
	empty string, blob, list or dictionary
Other values are truthy.  Examples:
	0	falsy
	1	truthy
	-1	truthy
	0.0	falsy
	0.1	truthy
	''	falsy
	'x'	truthy
	[]	falsy
	[0]	truthy
	{}	falsy
	#{x: 1} truthy
	0z	falsy
	0z00	truthy

							*non-zero-arg*
Function arguments often behave slightly different from |TRUE|: If the
argument is present and it evaluates to a non-zero Number, |v:true| or a
non-empty String, then the value is considered to be TRUE.
Note that " " and "0" are also non-empty strings, thus considered to be TRUE.
A List, Dictionary or Float is not a Number or String, thus evaluate to FALSE.

		*E611* *E745* *E728* *E703* *E729* *E730* *E731* *E908* *E910*
		*E913* *E974* *E975* *E976* *E1319* *E1320* *E1321* *E1322*
		*E1323* *E1324*
|List|, |Dictionary|, |Funcref|, |Job|, |Channel|, |Blob|, |Class| and
|object| types are not automatically converted.

							*E805* *E806* *E808*
When mixing Number and Float the Number is converted to Float.  Otherwise
there is no automatic conversion of Float.  You can use str2float() for String
to Float, printf() for Float to String and float2nr() for Float to Number.

			*E362* *E891* *E892* *E893* *E894* *E907* *E911* *E914*
When expecting a Float a Number can also be used, but nothing else.

						*no-type-checking*
You will not get an error if you try to change the type of a variable.


1.2 Function references ~
					*Funcref* *E695* *E718* *E1192*
A Funcref variable is obtained with the |function()| function, the |funcref()|
function, (in |Vim9| script) the name of a function, or created with the
lambda expression |expr-lambda|.  It can be used in an expression in the place
of a function name, before the parenthesis around the arguments, to invoke the
function it refers to.  Example in |Vim9| script: >

	:var Fn = MyFunc
	:echo Fn()

Legacy script: >
	:let Fn = function("MyFunc")
	:echo Fn()
<							*E704* *E705* *E707*
A Funcref variable must start with a capital, "s:", "w:", "t:" or "b:".  You
can use "g:" but the following name must still start with a capital.  You
cannot have both a Funcref variable and a function with the same name.

A special case is defining a function and directly assigning its Funcref to a
Dictionary entry.  Example: >
	:function dict.init() dict
	:   let self.val = 0
	:endfunction

The key of the Dictionary can start with a lower case letter.  The actual
function name is not used here.  Also see |numbered-function|.

A Funcref can also be used with the |:call| command: >
	:call Fn()
	:call dict.init()

The name of the referenced function can be obtained with |string()|. >
	:let func = string(Fn)

You can use |call()| to invoke a Funcref and use a list variable for the
arguments: >
	:let r = call(Fn, mylist)
<
								*Partial*
A Funcref optionally binds a Dictionary and/or arguments.  This is also called
a Partial.  This is created by passing the Dictionary and/or arguments to
function() or funcref().  When calling the function the Dictionary and/or
arguments will be passed to the function.  Example: >

	let Cb = function('Callback', ['foo'], myDict)
	call Cb('bar')

This will invoke the function as if using: >
	call myDict.Callback('foo', 'bar')

This is very useful when passing a function around, e.g. in the arguments of
|ch_open()|.

Note that binding a function to a Dictionary also happens when the function is
a member of the Dictionary: >

	let myDict.myFunction = MyFunction
	call myDict.myFunction()

Here MyFunction() will get myDict passed as "self".  This happens when the
"myFunction" member is accessed.  When making assigning "myFunction" to
otherDict and calling it, it will be bound to otherDict: >

	let otherDict.myFunction = myDict.myFunction
	call otherDict.myFunction()

Now "self" will be "otherDict".  But when the dictionary was bound explicitly
this won't happen: >

	let myDict.myFunction = function(MyFunction, myDict)
	let otherDict.myFunction = myDict.myFunction
	call otherDict.myFunction()

Here "self" will be "myDict", because it was bound explicitly.


1.3 Lists ~
						*list* *List* *Lists* *E686*
A List is an ordered sequence of items.  An item can be of any type.  Items
can be accessed by their index number.  Items can be added and removed at any
position in the sequence.


List creation ~
							*E696* *E697*
A List is created with a comma-separated list of items in square brackets.
Examples: >
	:let mylist = [1, two, 3, "four"]
	:let emptylist = []

An item can be any expression.  Using a List for an item creates a
List of Lists: >
	:let nestlist = [[11, 12], [21, 22], [31, 32]]

An extra comma after the last item is ignored.


List index ~
							*list-index* *E684*
An item in the List can be accessed by putting the index in square brackets
after the List.  Indexes are zero-based, thus the first item has index zero. >
	:let item = mylist[0]		" get the first item: 1
	:let item = mylist[2]		" get the third item: 3

When the resulting item is a list this can be repeated: >
	:let item = nestlist[0][1]	" get the first list, second item: 12
<
A negative index is counted from the end.  Index -1 refers to the last item in
the List, -2 to the last but one item, etc. >
	:let last = mylist[-1]		" get the last item: "four"

To avoid an error for an invalid index use the |get()| function.  When an item
is not available it returns zero or the default value you specify: >
	:echo get(mylist, idx)
	:echo get(mylist, idx, "NONE")


List concatenation ~
							*list-concatenation*
Two lists can be concatenated with the "+" operator: >
	:let longlist = mylist + [5, 6]
	:let mylist += [7, 8]

To prepend or append an item, turn the item into a list by putting [] around
it.  To change a list in-place, refer to |list-modification| below.


Sublist ~
							*sublist*
A part of the List can be obtained by specifying the first and last index,
separated by a colon in square brackets: >
	:let shortlist = mylist[2:-1]	" get List [3, "four"]

Omitting the first index is similar to zero.  Omitting the last index is
similar to -1. >
	:let endlist = mylist[2:]	" from item 2 to the end: [3, "four"]
	:let shortlist = mylist[2:2]	" List with one item: [3]
	:let otherlist = mylist[:]	" make a copy of the List

Notice that the last index is inclusive.  If you prefer using an exclusive
index use the |slice()| method.

If the first index is beyond the last item of the List or the second item is
before the first item, the result is an empty list.  There is no error
message.

If the second index is equal to or greater than the length of the list the
length minus one is used: >
	:let mylist = [0, 1, 2, 3]
	:echo mylist[2:8]		" result: [2, 3]

NOTE: mylist[s:e] means using the variable "s:e" as index.  Watch out for
using a single letter variable before the ":".  Insert a space when needed:
mylist[s : e].


List identity ~
							*list-identity*
When variable "aa" is a list and you assign it to another variable "bb", both
variables refer to the same list.  Thus changing the list "aa" will also
change "bb": >
	:let aa = [1, 2, 3]
	:let bb = aa
	:call add(aa, 4)
	:echo bb
<	[1, 2, 3, 4]

Making a copy of a list is done with the |copy()| function.  Using [:] also
works, as explained above.  This creates a shallow copy of the list: Changing
a list item in the list will also change the item in the copied list: >
	:let aa = [[1, 'a'], 2, 3]
	:let bb = copy(aa)
	:call add(aa, 4)
	:let aa[0][1] = 'aaa'
	:echo aa
<	[[1, aaa], 2, 3, 4] >
	:echo bb
<	[[1, aaa], 2, 3]

To make a completely independent list use |deepcopy()|.  This also makes a
copy of the values in the list, recursively.  Up to a hundred levels deep.

The operator "is" can be used to check if two variables refer to the same
List.  "isnot" does the opposite.  In contrast "==" compares if two lists have
the same value. >
	:let alist = [1, 2, 3]
	:let blist = [1, 2, 3]
	:echo alist is blist
<	0 >
	:echo alist == blist
<	1

Note about comparing lists: Two lists are considered equal if they have the
same length and all items compare equal, as with using "==".  There is one
exception: When comparing a number with a string they are considered
different.  There is no automatic type conversion, as with using "==" on
variables.  Example: >
	echo 4 == "4"
<	1 >
	echo [4] == ["4"]
<	0

Thus comparing Lists is more strict than comparing numbers and strings.  You
can compare simple values this way too by putting them in a list: >

	:let a = 5
	:let b = "5"
	:echo a == b
<	1 >
	:echo [a] == [b]
<	0


List unpack ~

To unpack the items in a list to individual variables, put the variables in
square brackets, like list items: >
	:let [var1, var2] = mylist

When the number of variables does not match the number of items in the list
this produces an error.  To handle any extra items from the list append ";"
and a variable name: >
	:let [var1, var2; rest] = mylist

This works like: >
	:let var1 = mylist[0]
	:let var2 = mylist[1]
	:let rest = mylist[2:]

Except that there is no error if there are only two items.  "rest" will be an
empty list then.


List modification ~
							*list-modification*
To change a specific item of a list use |:let| this way: >
	:let list[4] = "four"
	:let listlist[0][3] = item

To change part of a list you can specify the first and last item to be
modified.  The value must at least have the number of items in the range: >
	:let list[3:5] = [3, 4, 5]

Adding and removing items from a list is done with functions.  Here are a few
examples: >
	:call insert(list, 'a')		" prepend item 'a'
	:call insert(list, 'a', 3)	" insert item 'a' before list[3]
	:call add(list, "new")		" append String item
	:call add(list, [1, 2])		" append a List as one new item
	:call extend(list, [1, 2])	" extend the list with two more items
	:let i = remove(list, 3)	" remove item 3
	:unlet list[3]			" idem
	:let l = remove(list, 3, -1)	" remove items 3 to last item
	:unlet list[3 : ]		" idem
	:call filter(list, 'v:val !~ "x"')  " remove items with an 'x'

Changing the order of items in a list: >
	:call sort(list)		" sort a list alphabetically
	:call reverse(list)		" reverse the order of items
	:call uniq(sort(list))		" sort and remove duplicates


For loop ~

The |:for| loop executes commands for each item in a List, String or Blob.
A variable is set to each item in sequence.  Example with a List: >
	:for item in mylist
	:   call Doit(item)
	:endfor

This works like: >
	:let index = 0
	:while index < len(mylist)
	:   let item = mylist[index]
	:   :call Doit(item)
	:   let index = index + 1
	:endwhile

If all you want to do is modify each item in the list then the |map()|
function will be a simpler method than a for loop.

Just like the |:let| command, |:for| also accepts a list of variables.  This
requires the argument to be a List of Lists. >
	:for [lnum, col] in [[1, 3], [2, 8], [3, 0]]
	:   call Doit(lnum, col)
	:endfor

This works like a |:let| command is done for each list item.  Again, the types
must remain the same to avoid an error.

It is also possible to put remaining items in a List variable: >
	:for [i, j; rest] in listlist
	:   call Doit(i, j)
	:   if !empty(rest)
	:      echo "remainder: " .. string(rest)
	:   endif
	:endfor

For a Blob one byte at a time is used.

For a String one character, including any composing characters, is used as a
String.  Example: >
	for c in text
	  echo 'This character is ' .. c
	endfor


List functions ~
						*E714*
Functions that are useful with a List: >
	:let r = call(funcname, list)	" call a function with an argument list
	:if empty(list)			" check if list is empty
	:let l = len(list)		" number of items in list
	:let big = max(list)		" maximum value in list
	:let small = min(list)		" minimum value in list
	:let xs = count(list, 'x')	" count nr of times 'x' appears in list
	:let i = index(list, 'x')	" index of first 'x' in list
	:let lines = getline(1, 10)	" get ten text lines from buffer
	:call append('$', lines)	" append text lines in buffer
	:let list = split("a b c")	" create list from items in a string
	:let string = join(list, ', ')	" create string from list items
	:let s = string(list)		" String representation of list
	:call map(list, '">> " .. v:val')  " prepend ">> " to each item

Don't forget that a combination of features can make things simple.  For
example, to add up all the numbers in a list: >
	:exe 'let sum = ' .. join(nrlist, '+')


1.4 Dictionaries ~
				*dict* *Dict* *Dictionaries* *Dictionary*
A Dictionary is an associative array: Each entry has a key and a value.  The
entry can be located with the key.  The entries are stored without a specific
ordering.


Dictionary creation ~
						*E720* *E721* *E722* *E723*
A Dictionary is created with a comma-separated list of entries in curly
braces.  Each entry has a key and a value, separated by a colon.  Each key can
only appear once.  Examples: >
	:let mydict = {1: 'one', 2: 'two', 3: 'three'}
	:let emptydict = {}
<							*E713* *E716* *E717*
A key is always a String.  You can use a Number, it will be converted to a
String automatically.  Thus the String '4' and the number 4 will find the same
entry.  Note that the String '04' and the Number 04 are different, since the
Number will be converted to the String '4', leading zeros are dropped.  The
empty string can also be used as a key.

In |Vim9| script a literal key can be used if it consists only of alphanumeric
characters, underscore and dash, see |vim9-literal-dict|.
						*literal-Dict* *#{}*
To avoid having to put quotes around every key the #{} form can be used in
legacy script.  This does require the key to consist only of ASCII letters,
digits, '-' and '_'.  Example: >
	:let mydict = #{zero: 0, one_key: 1, two-key: 2, 333: 3}
Note that 333 here is the string "333".  Empty keys are not possible with #{}.
In |Vim9| script the #{} form cannot be used because it can be confused with
the start of a comment.

A value can be any expression.  Using a Dictionary for a value creates a
nested Dictionary: >
	:let nestdict = {1: {11: 'a', 12: 'b'}, 2: {21: 'c'}}

An extra comma after the last entry is ignored.


Accessing entries ~

The normal way to access an entry is by putting the key in square brackets: >
	:let val = mydict["one"]
	:let mydict["four"] = 4

You can add new entries to an existing Dictionary this way, unlike Lists.

For keys that consist entirely of letters, digits and underscore the following
form can be used |expr-entry|: >
	:let val = mydict.one
	:let mydict.four = 4

Since an entry can be any type, also a List and a Dictionary, the indexing and
key lookup can be repeated: >
	:echo dict.key[idx].key


Dictionary to List conversion ~

You may want to loop over the entries in a dictionary.  For this you need to
turn the Dictionary into a List and pass it to |:for|.

Most often you want to loop over the keys, using the |keys()| function: >
	:for key in keys(mydict)
	:   echo key .. ': ' .. mydict[key]
	:endfor

The List of keys is unsorted.  You may want to sort them first: >
	:for key in sort(keys(mydict))

To loop over the values use the |values()| function:  >
	:for v in values(mydict)
	:   echo "value: " .. v
	:endfor

If you want both the key and the value use the |items()| function.  It returns
a List in which each item is a List with two items, the key and the value: >
	:for [key, value] in items(mydict)
	:   echo key .. ': ' .. value
	:endfor


Dictionary identity ~
							*dict-identity*
Just like Lists you need to use |copy()| and |deepcopy()| to make a copy of a
Dictionary.  Otherwise, assignment results in referring to the same
Dictionary: >
	:let onedict = {'a': 1, 'b': 2}
	:let adict = onedict
	:let adict['a'] = 11
	:echo onedict['a']
	11

Two Dictionaries compare equal if all the key-value pairs compare equal.  For
more info see |list-identity|.


Dictionary modification ~
							*dict-modification*
To change an already existing entry of a Dictionary, or to add a new entry,
use |:let| this way: >
	:let dict[4] = "four"
	:let dict['one'] = item

Removing an entry from a Dictionary is done with |remove()| or |:unlet|.
Three ways to remove the entry with key "aaa" from dict: >
	:let i = remove(dict, 'aaa')
	:unlet dict.aaa
	:unlet dict['aaa']

Merging a Dictionary with another is done with |extend()|: >
	:call extend(adict, bdict)
This extends adict with all entries from bdict.  Duplicate keys cause entries
in adict to be overwritten.  An optional third argument can change this.
Note that the order of entries in a Dictionary is irrelevant, thus don't
expect ":echo adict" to show the items from bdict after the older entries in
adict.

Weeding out entries from a Dictionary can be done with |filter()|: >
	:call filter(dict, 'v:val =~ "x"')
This removes all entries from "dict" with a value not matching 'x'.
This can also be used to remove all entries: >
	call filter(dict, 0)

In some situations it is not allowed to remove or add entries to a Dictionary.
Especially when iterating over all the entries.  You will get *E1313* or
another error in that case.


Dictionary function ~
				*Dictionary-function* *self* *E725* *E862*
When a function is defined with the "dict" attribute it can be used in a
special way with a dictionary.  Example: >
	:function Mylen() dict
	:   return len(self.data)
	:endfunction
	:let mydict = {'data': [0, 1, 2, 3], 'len': function("Mylen")}
	:echo mydict.len()

This is like a method in object oriented programming.  The entry in the
Dictionary is a |Funcref|.  The local variable "self" refers to the dictionary
the function was invoked from.  When using |Vim9| script you can use classes
and objects, see `:class`.

It is also possible to add a function without the "dict" attribute as a
Funcref to a Dictionary, but the "self" variable is not available then.

				*numbered-function* *anonymous-function*
To avoid the extra name for the function it can be defined and directly
assigned to a Dictionary in this way: >
	:let mydict = {'data': [0, 1, 2, 3]}
	:function mydict.len()
	:   return len(self.data)
	:endfunction
	:echo mydict.len()

The function will then get a number and the value of dict.len is a |Funcref|
that references this function.  The function can only be used through a
|Funcref|.  It will automatically be deleted when there is no |Funcref|
remaining that refers to it.

It is not necessary to use the "dict" attribute for a numbered function.

If you get an error for a numbered function, you can find out what it is with
a trick.  Assuming the function is 42, the command is: >
	:function g:42


Functions for Dictionaries ~
							*E715*
Functions that can be used with a Dictionary: >
	:if has_key(dict, 'foo')	" TRUE if dict has entry with key "foo"
	:if empty(dict)			" TRUE if dict is empty
	:let l = len(dict)		" number of items in dict
	:let big = max(dict)		" maximum value in dict
	:let small = min(dict)		" minimum value in dict
	:let xs = count(dict, 'x')	" count nr of times 'x' appears in dict
	:let s = string(dict)		" String representation of dict
	:call map(dict, '">> " .. v:val')  " prepend ">> " to each item


1.5 Blobs ~
						*blob* *Blob* *Blobs* *E978*
A Blob is a binary object.  It can be used to read an image from a file and
send it over a channel, for example.

A Blob mostly behaves like a |List| of numbers, where each number has the
value of an 8-bit byte, from 0 to 255.


Blob creation ~

A Blob can be created with a |blob-literal|: >
	:let b = 0zFF00ED015DAF
Dots can be inserted between bytes (pair of hex characters) for readability,
they don't change the value: >
	:let b = 0zFF00.ED01.5DAF

A blob can be read from a file with |readfile()| passing the {type} argument
set to "B", for example: >
	:let b = readfile('image.png', 'B')

A blob can be read from a channel with the |ch_readblob()| function.


Blob index ~
							*blob-index* *E979*
A byte in the Blob can be accessed by putting the index in square brackets
after the Blob.  Indexes are zero-based, thus the first byte has index zero. >
	:let myblob = 0z00112233
	:let byte = myblob[0]		" get the first byte: 0x00
	:let byte = myblob[2]		" get the third byte: 0x22

A negative index is counted from the end.  Index -1 refers to the last byte in
the Blob, -2 to the last but one byte, etc. >
	:let last = myblob[-1]		" get the last byte: 0x33

To avoid an error for an invalid index use the |get()| function.  When an item
is not available it returns -1 or the default value you specify: >
	:echo get(myblob, idx)
	:echo get(myblob, idx, 999)


Blob iteration ~

The |:for| loop executes commands for each byte of a Blob.  The loop variable is
set to each byte in the Blob.  Example: >
	:for byte in 0z112233
	:   call Doit(byte)
	:endfor
This calls Doit() with 0x11, 0x22 and 0x33.


Blob concatenation ~

Two blobs can be concatenated with the "+" operator: >
	:let longblob = myblob + 0z4455
	:let myblob += 0z6677

To change a blob in-place see |blob-modification| below.


Part of a blob ~

A part of the Blob can be obtained by specifying the first and last index,
separated by a colon in square brackets: >
	:let myblob = 0z00112233
	:let shortblob = myblob[1:2]	" get 0z1122
	:let shortblob = myblob[2:-1]	" get 0z2233

Omitting the first index is similar to zero.  Omitting the last index is
similar to -1. >
	:let endblob = myblob[2:]	" from item 2 to the end: 0z2233
	:let shortblob = myblob[2:2]	" Blob with one byte: 0z22
	:let otherblob = myblob[:]	" make a copy of the Blob

If the first index is beyond the last byte of the Blob or the second index is
before the first index, the result is an empty Blob.  There is no error
message.

If the second index is equal to or greater than the length of the list the
length minus one is used: >
	:echo myblob[2:8]		" result: 0z2233


Blob modification ~
					*blob-modification* *E1182* *E1184*
To change a specific byte of a blob use |:let| this way: >
	:let blob[4] = 0x44

When the index is just one beyond the end of the Blob, it is appended. Any
higher index is an error.

To change a sequence of bytes the [:] notation can be used: >
	let blob[1:3] = 0z445566
The length of the replaced bytes must be exactly the same as the value
provided. *E972*

To change part of a blob you can specify the first and last byte to be
modified.  The value must have the same number of bytes in the range: >
	:let blob[3:5] = 0z334455

You can also use the functions |add()|, |remove()| and |insert()|.


Blob identity ~

Blobs can be compared for equality: >
	if blob == 0z001122
And for equal identity: >
	if blob is otherblob
<							*blob-identity* *E977*
When variable "aa" is a Blob and you assign it to another variable "bb", both
variables refer to the same Blob.  Then the "is" operator returns true.

When making a copy using [:] or |copy()| the values are the same, but the
identity is different: >
	:let blob = 0z112233
	:let blob2 = blob
	:echo blob == blob2
<	1 >
	:echo blob is blob2
<	1 >
	:let blob3 = blob[:]
	:echo blob == blob3
<	1 >
	:echo blob is blob3
<	0

Making a copy of a Blob is done with the |copy()| function.  Using [:] also
works, as explained above.


1.6 More about variables ~
							*more-variables*
If you need to know the type of a variable or expression, use the |type()|
function.

When the '!' flag is included in the 'viminfo' option, global variables that
start with an uppercase letter, and don't contain a lowercase letter, are
stored in the viminfo file |viminfo-file|.

When the 'sessionoptions' option contains "global", global variables that
start with an uppercase letter and contain at least one lowercase letter are
stored in the session file |session-file|.

variable name		can be stored where ~
my_var_6		not
My_Var_6		session file
MY_VAR_6		viminfo file


In legacy script it is possible to form a variable name with curly braces, see
|curly-braces-names|.

==============================================================================
2. Expression syntax					*expression-syntax*
							*E1143*
Expression syntax summary, from least to most significant:

|expr1|	expr2
	expr2 ? expr1 : expr1	if-then-else

|expr2|	expr3
	expr3 || expr3 ...	logical OR

|expr3|	expr4
	expr4 && expr4 ...	logical AND

|expr4|	expr5
	expr5 == expr5		equal
	expr5 != expr5		not equal
	expr5 >	 expr5		greater than
	expr5 >= expr5		greater than or equal
	expr5 <	 expr5		smaller than
	expr5 <= expr5		smaller than or equal
	expr5 =~ expr5		regexp matches
	expr5 !~ expr5		regexp doesn't match

	expr5 ==? expr5		equal, ignoring case
	expr5 ==# expr5		equal, match case
	etc.			As above, append ? for ignoring case, # for
				matching case

	expr5 is expr5		same |List|, |Dictionary| or |Blob| instance
	expr5 isnot expr5	different |List|, |Dictionary| or |Blob|
				instance

|expr5|	expr6
	expr6 << expr6		bitwise left shift
	expr6 >> expr6		bitwise right shift

|expr6|	expr7
	expr7 +	 expr7 ...	number addition, list or blob concatenation
	expr7 -	 expr7 ...	number subtraction
	expr7 .	 expr7 ...	string concatenation
	expr7 .. expr7 ...	string concatenation

|expr7|	expr8
	expr8 *	 expr8 ...	number multiplication
	expr8 /	 expr8 ...	number division
	expr8 %	 expr8 ...	number modulo

|expr8|	expr9
	<type>expr9		type check and conversion (|Vim9| only)

|expr9|	expr10
	! expr9			logical NOT
	- expr9			unary minus
	+ expr9			unary plus

|expr10|  expr11
	expr10[expr1]		byte of a String or item of a |List|
	expr10[expr1 : expr1]	substring of a String or sublist of a |List|
	expr10.name		entry in a |Dictionary|
	expr10(expr1, ...)	function call with |Funcref| variable
	expr10->name(expr1, ...)	|method| call

|expr11|  number		number constant
	"string"		string constant, backslash is special
	'string'		string constant, ' is doubled
	[expr1, ...]		|List|
	{expr1: expr1, ...}	|Dictionary|
	#{key: expr1, ...}	legacy |Dictionary|
	&option			option value
	(expr1)			nested expression
	variable		internal variable
	va{ria}ble		internal variable with curly braces
	$VAR			environment variable
	@r			contents of register 'r'
	function(expr1, ...)	function call
	func{ti}on(expr1, ...)	function call with curly braces
	{args -> expr1}		legacy lambda expression
	(args) => expr1		Vim9 lambda expression


"..." indicates that the operations in this level can be concatenated.
Example: >
	&nu || &list && &shell == "csh"

All expressions within one level are parsed from left to right.

Expression nesting is limited to 1000 levels deep (300 when build with MSVC)
to avoid running out of stack and crashing. *E1169*


expr1				*expr1* *ternary* *falsy-operator* *??* *E109*
-----

The ternary operator: expr2 ? expr1 : expr1
The falsy operator:   expr2 ?? expr1

Ternary operator ~

In legacy script the expression before the '?' is evaluated to a number.  If
it evaluates to |TRUE|, the result is the value of the expression between the
'?' and ':', otherwise the result is the value of the expression after the
':'.

In |Vim9| script the first expression must evaluate to a boolean, see
|vim9-boolean|.

Example: >
	:echo lnum == 1 ? "top" : lnum

Since the first expression is an "expr2", it cannot contain another ?:.  The
other two expressions can, thus allow for recursive use of ?:.
Example: >
	:echo lnum == 1 ? "top" : lnum == 1000 ? "last" : lnum

To keep this readable, using |line-continuation| is suggested: >
	:echo lnum == 1
	:\	? "top"
	:\	: lnum == 1000
	:\		? "last"
	:\		: lnum

You should always put a space before the ':', otherwise it can be mistaken for
use in a variable such as "a:1".

Falsy operator ~

This is also known as the "null coalescing operator", but that's too
complicated, thus we just call it the falsy operator.

The expression before the '??' is evaluated.  If it evaluates to
|truthy|, this is used as the result.  Otherwise the expression after the '??'
is evaluated and used as the result.  This is most useful to have a default
value for an expression that may result in zero or empty: >
	echo theList ?? 'list is empty'
	echo GetName() ?? 'unknown'

These are similar, but not equal: >
	expr2 ?? expr1
	expr2 ? expr2 : expr1
In the second line "expr2" is evaluated twice.  And in |Vim9| script the type
of expr2 before "?" must be a boolean.


expr2 and expr3						*expr2* *expr3*
---------------

expr3 || expr3 ..	logical OR		*expr-barbar*
expr4 && expr4 ..	logical AND		*expr-&&*

The "||" and "&&" operators take one argument on each side.

In legacy script the arguments are (converted to) Numbers.

In |Vim9| script the values must be boolean, see |vim9-boolean|.  Use "!!" to
convert any type to a boolean.

The result is:
    input			 output ~
n1	n2		n1 || n2	n1 && n2 ~
|FALSE|	|FALSE|		|FALSE|		|FALSE|
|FALSE|	|TRUE|		|TRUE|		|FALSE|
|TRUE|	|FALSE|		|TRUE|		|FALSE|
|TRUE|	|TRUE|		|TRUE|		|TRUE|

The operators can be concatenated, for example: >

	&nu || &list && &shell == "csh"

Note that "&&" takes precedence over "||", so this has the meaning of: >

	&nu || (&list && &shell == "csh")

Once the result is known, the expression "short-circuits", that is, further
arguments are not evaluated.  This is like what happens in C.  For example: >

	let a = 1
	echo a || b

This is valid even if there is no variable called "b" because "a" is |TRUE|,
so the result must be |TRUE|.  Similarly below: >

	echo exists("b") && b == "yes"

This is valid whether "b" has been defined or not.  The second clause will
only be evaluated if "b" has been defined.


expr4							*expr4* *E1153*
-----

expr5 {cmp} expr5

Compare two expr5 expressions.  In legacy script the result is a 0 if it
evaluates to false, or 1 if it evaluates to true.  In |Vim9| script the result
is |true| or |false|.

			*expr-==*  *expr-!=*  *expr->*	 *expr->=*
			*expr-<*   *expr-<=*  *expr-=~*  *expr-!~*
			*expr-==#* *expr-!=#* *expr->#*  *expr->=#*
			*expr-<#*  *expr-<=#* *expr-=~#* *expr-!~#*
			*expr-==?* *expr-!=?* *expr->?*  *expr->=?*
			*expr-<?*  *expr-<=?* *expr-=~?* *expr-!~?*
			*expr-is* *expr-isnot* *expr-is#* *expr-isnot#*
			*expr-is?* *expr-isnot?* *E1072*
		use 'ignorecase'    match case	   ignore case ~
equal			==		==#		==?
not equal		!=		!=#		!=?
greater than		>		>#		>?
greater than or equal	>=		>=#		>=?
smaller than		<		<#		<?
smaller than or equal	<=		<=#		<=?
regexp matches		=~		=~#		=~?
regexp doesn't match	!~		!~#		!~?
same instance		is		is#		is?
different instance	isnot		isnot#		isnot?

Examples:
"abc" ==# "Abc"	  evaluates to 0
"abc" ==? "Abc"	  evaluates to 1
"abc" == "Abc"	  evaluates to 1 if 'ignorecase' is set, 0 otherwise
NOTE: In |Vim9| script 'ignorecase' is not used.

							*E691* *E692*
A |List| can only be compared with a |List| and only "equal", "not equal",
"is" and "isnot" can be used.  This compares the values of the list,
recursively.  Ignoring case means case is ignored when comparing item values.

							*E735* *E736*
A |Dictionary| can only be compared with a |Dictionary| and only "equal", "not
equal", "is" and "isnot" can be used.  This compares the key/values of the
|Dictionary| recursively.  Ignoring case means case is ignored when comparing
item values.

							*E694*
A |Funcref| can only be compared with a |Funcref| and only "equal", "not
equal", "is" and "isnot" can be used.  Case is never ignored.  Whether
arguments or a Dictionary are bound (with a partial) matters.  The
Dictionaries must also be equal (or the same, in case of "is") and the
arguments must be equal (or the same).

To compare Funcrefs to see if they refer to the same function, ignoring bound
Dictionary and arguments, use |get()| to get the function name: >
	if get(Part1, 'name') == get(Part2, 'name')
	   " Part1 and Part2 refer to the same function
<							*E1037*
Using "is" or "isnot" with a |List|, |Dictionary| or |Blob| checks whether
the expressions are referring to the same |List|, |Dictionary| or |Blob|
instance.  A copy of a |List| is different from the original |List|.  When
using "is" without a |List|, |Dictionary| or |Blob|, it is equivalent to
using "equal", using "isnot" equivalent to using "not equal".  Except that
a different type means the values are different: >
	echo 4 == '4'
	1
	echo 4 is '4'
	0
	echo 0 is []
	0
"is#"/"isnot#" and "is?"/"isnot?" can be used to match and ignore case.
In |Vim9| script this doesn't work, two strings are never identical.

In legacy script, when comparing a String with a Number, the String is
converted to a Number, and the comparison is done on Numbers.  This means
that: >
	echo 0 == 'x'
	1
because 'x' converted to a Number is zero.  However: >
	echo [0] == ['x']
	0
Inside a List or Dictionary this conversion is not used.

In |Vim9| script the types must match.

When comparing two Strings, this is done with strcmp() or stricmp().  This
results in the mathematical difference (comparing byte values), not
necessarily the alphabetical difference in the local language.

When using the operators with a trailing '#', or the short version and
'ignorecase' is off, the comparing is done with strcmp(): case matters.

When using the operators with a trailing '?', or the short version and
'ignorecase' is set, the comparing is done with stricmp(): case is ignored.

'smartcase' is not used.

The "=~" and "!~" operators match the lefthand argument with the righthand
argument, which is used as a pattern.  See |pattern| for what a pattern is.
This matching is always done like 'magic' was set and 'cpoptions' is empty, no
matter what the actual value of 'magic' or 'cpoptions' is.  This makes scripts
portable.  To avoid backslashes in the regexp pattern to be doubled, use a
single-quote string, see |literal-string|.
Since a string is considered to be a single line, a multi-line pattern
(containing \n, backslash-n) will not match.  However, a literal NL character
can be matched like an ordinary character.  Examples:
	"foo\nbar" =~ "\n"	evaluates to 1
	"foo\nbar" =~ "\\n"	evaluates to 0


expr5						*expr5* *bitwise-shift*
-----
expr6 << expr6	bitwise left shift				*expr-<<*
expr6 >> expr6	bitwise right shift				*expr->>*
							*E1282* *E1283*
The "<<" and ">>" operators can be used to perform bitwise left or right shift
of the left operand by the number of bits specified by the right operand.  The
operands are used as positive numbers.  When shifting right with ">>" the
topmost bit (sometimes called the sign bit) is cleared.  If the right operand
(shift amount) is more than the maximum number of bits in a number
(|v:numbersize|) the result is zero.


expr6 and expr7				*expr6* *expr7* *E1036* *E1051*
---------------
expr7 + expr7   Number addition, |List| or |Blob| concatenation	*expr-+*
expr7 - expr7   Number subtraction				*expr--*
expr7 . expr7   String concatenation				*expr-.*
expr7 .. expr7  String concatenation				*expr-..*

For |Lists| only "+" is possible and then both expr7 must be a list.  The
result is a new list with the two lists Concatenated.

For String concatenation ".." is preferred, since "." is ambiguous, it is also
used for |Dict| member access and floating point numbers.
In |Vim9| script and when |vimscript-version| is 2 or higher, using "." is not
allowed.

In |Vim9| script the arguments of ".." are converted to String for simple
types: Number, Float, Special and Bool.  For other types |string()| should be
used.

expr8 * expr8  Number multiplication				*expr-star*
expr8 / expr8  Number division					*expr-/*
expr8 % expr8  Number modulo					*expr-%*

In legacy script, for all operators except "." and "..", Strings are converted
to Numbers.

For bitwise operators see |and()|, |or()| and |xor()|.

Note the difference between "+" and ".." in legacy script:
	"123" + "456" = 579
	"123" .. "456" = "123456"

Since '..' has the same precedence as '+' and '-', you need to read: >
	1 .. 90 + 90.0
As: >
	(1 .. 90) + 90.0
That works in legacy script, since the String "190" is automatically converted
to the Number 190, which can be added to the Float 90.0.  However: >
	1 .. 90 * 90.0
Should be read as: >
	1 .. (90 * 90.0)
Since '..' has lower precedence than '*'.  This does NOT work, since this
attempts to concatenate a Float and a String.

When dividing a Number by zero the result depends on the value:
	  0 / 0  = -0x80000000	(like NaN for Float)
	 >0 / 0  =  0x7fffffff	(like positive infinity)
	 <0 / 0  = -0x7fffffff	(like negative infinity)
	(before Vim 7.2 it was always 0x7fffffff)
In |Vim9| script dividing a number by zero is an error.	*E1154*

When 64-bit Number support is enabled:
	  0 / 0  = -0x8000000000000000	(like NaN for Float)
	 >0 / 0  =  0x7fffffffffffffff	(like positive infinity)
	 <0 / 0  = -0x7fffffffffffffff	(like negative infinity)

When the righthand side of '%' is zero, the result is 0.

None of these work for |Funcref|s.

".", ".." and "%" do not work for Float. *E804* *E1035*


expr8							*expr8*
-----
<type>expr9

This is only available in |Vim9| script, see |type-casting|.


expr9							*expr9*
-----
! expr9			logical NOT		*expr-!*
- expr9			unary minus		*expr-unary--*
+ expr9			unary plus		*expr-unary-+*

For '!' |TRUE| becomes |FALSE|, |FALSE| becomes |TRUE| (one).
For '-' the sign of the number is changed.
For '+' the number is unchanged.  Note: "++" has no effect.

In legacy script a String will be converted to a Number first.  Note that if
the string does not start with a digit you likely don't get what you expect.

In |Vim9| script an error is given when "-" or "+" is used and the type is not
a number.

In |Vim9| script "!" can be used for any type and the result is always a
boolean.  Use "!!" to convert any type to a boolean, according to whether the
value is |falsy|.

These three can be repeated and mixed.  Examples:
	!-1	    == 0
	!!8	    == 1
	--9	    == 9


expr10							*expr10*
------
This expression is either |expr11| or a sequence of the alternatives below,
in any order.  E.g., these are all possible:
	expr10[expr1].name
	expr10.name[expr1]
	expr10(expr1, ...)[expr1].name
	expr10->(expr1, ...)[expr1]
Evaluation is always from left to right.

expr10[expr1]		item of String or |List|	*expr-[]* *E111*
						*E909* *subscript* *E1062*
In legacy Vim script:
If expr10 is a Number or String this results in a String that contains the
expr1'th single byte from expr10.  expr10 is used as a String (a number is
automatically converted to a String), expr1 as a Number.  This doesn't
recognize multibyte encodings, see `byteidx()` for an alternative, or use
`split()` to turn the string into a list of characters.  Example, to get the
byte under the cursor: >
	:let c = getline(".")[col(".") - 1]

In |Vim9| script:					*E1147* *E1148*
If expr10 is a String this results in a String that contains the expr1'th
single character (including any composing characters) from expr10.  To use byte
indexes use |strpart()|.

Index zero gives the first byte or character.  Careful: text column numbers
start with one!

If the length of the String is less than the index, the result is an empty
String.  A negative index always results in an empty string (reason: backward
compatibility).  Use [-1:] to get the last byte or character.
In Vim9 script a negative index is used like with a list: count from the end.

If expr10 is a |List| then it results the item at index expr1.  See |list-index|
for possible index values.  If the index is out of range this results in an
error.  Example: >
	:let item = mylist[-1]		" get last item

Generally, if a |List| index is equal to or higher than the length of the
|List|, or more negative than the length of the |List|, this results in an
error.


expr10[expr1a : expr1b]	substring or |sublist|		*expr-[:]* *substring*

If expr10 is a String this results in the substring with the bytes or
characters from expr1a to and including expr1b.  expr10 is used as a String,
expr1a and expr1b are used as a Number.

In legacy Vim script the indexes are byte indexes.  This doesn't recognize
multibyte encodings, see |byteidx()| for computing the indexes.  If expr10 is
a Number it is first converted to a String.

In Vim9 script the indexes are character indexes and include composing
characters.  To use byte indexes use |strpart()|.  To use character indexes
without including composing characters use |strcharpart()|.

The item at index expr1b is included, it is inclusive.  For an exclusive index
use the |slice()| function.

If expr1a is omitted zero is used.  If expr1b is omitted the length of the
string minus one is used.

A negative number can be used to measure from the end of the string.  -1 is
the last character, -2 the last but one, etc.

If an index goes out of range for the string characters are omitted.  If
expr1b is smaller than expr1a the result is an empty string.

Examples: >
	:let c = name[-1:]		" last byte of a string
	:let c = name[0:-1]		" the whole string
	:let c = name[-2:-2]		" last but one byte of a string
	:let s = line(".")[4:]		" from the fifth byte to the end
	:let s = s[:-3]			" remove last two bytes
<
							*slice*
If expr10 is a |List| this results in a new |List| with the items indicated by
the indexes expr1a and expr1b.  This works like with a String, as explained
just above. Also see |sublist| below.  Examples: >
	:let l = mylist[:3]		" first four items
	:let l = mylist[4:4]		" List with one item
	:let l = mylist[:]		" shallow copy of a List

If expr10 is a |Blob| this results in a new |Blob| with the bytes in the
indexes expr1a and expr1b, inclusive.  Examples: >
	:let b = 0zDEADBEEF
	:let bs = b[1:2]		" 0zADBE
	:let bs = b[:]			" copy of 0zDEADBEEF

Using expr10[expr1] or expr10[expr1a : expr1b] on a |Funcref| results in an
error.

Watch out for confusion between a namespace and a variable followed by a colon
for a sublist: >
	mylist[n:]     " uses variable n
	mylist[s:]     " uses namespace s:, error!


expr10.name		entry in a |Dictionary|		*expr-entry*
							*E1203* *E1229*
If expr10 is a |Dictionary| and it is followed by a dot, then the following
name will be used as a key in the |Dictionary|.  This is just like:
expr10[name].

The name must consist of alphanumeric characters, just like a variable name,
but it may start with a number.  Curly braces cannot be used.

There must not be white space before or after the dot.

Examples: >
	:let dict = {"one": 1, 2: "two"}
	:echo dict.one		" shows "1"
	:echo dict.2		" shows "two"
	:echo dict .2		" error because of space before the dot

Note that the dot is also used for String concatenation.  To avoid confusion
always put spaces around the dot for String concatenation.


expr10(expr1, ...)	|Funcref| function call		*E1085*

When expr10 is a |Funcref| type variable, invoke the function it refers to.


expr10->name([args])	method call			*method* *->*
expr10->{lambda}([args])
							*E260* *E276* *E1265*
For methods that are also available as global functions this is the same as: >
	name(expr10 [, args])
There can also be methods specifically for the type of "expr10".

This allows for chaining, passing the value that one method returns to the
next method: >
	mylist->filter(filterexpr)->map(mapexpr)->sort()->join()
<
Example of using a lambda: >
	GetPercentage()->{x -> x * 100}()->printf('%d%%')
<
When using -> the |expr9| operators will be applied first, thus: >
	-1.234->string()
Is equivalent to: >
	(-1.234)->string()
And NOT: >
	-(1.234->string())

What comes after "->" can be a name, a simple expression (not containing any
parenthesis), or any expression in parentheses: >
	base->name(args)
	base->some.name(args)
	base->alist[idx](args)
	base->(getFuncRef())(args)
Note that in the last call the base is passed to the function resulting from
"(getFuncRef())", inserted before "args".  *E1275*

							*E274*
"->name(" must not contain white space.  There can be white space before the
"->" and after the "(", thus you can split the lines like this: >
	mylist
	\ ->filter(filterexpr)
	\ ->map(mapexpr)
	\ ->sort()
	\ ->join()

When using the lambda form there must be no white space between the } and the
(.


							*expr11*
number
------
number			number constant			*expr-number*

			*0x* *hex-number* *0o* *octal-number* *binary-number*
Decimal, Hexadecimal (starting with 0x or 0X), Binary (starting with 0b or 0B)
and Octal (starting with 0, 0o or 0O).

Assuming 64 bit numbers are used (see |v:numbersize|) an unsigned number is
truncated to 0x7fffffffffffffff or 9223372036854775807.  You can use -1 to get
0xffffffffffffffff.

						*floating-point-format*
Floating point numbers can be written in two forms:

	[-+]{N}.{M}
	[-+]{N}.{M}[eE][-+]{exp}

{N} and {M} are numbers.  Both {N} and {M} must be present and can only
contain digits, except that in |Vim9| script in {N} single quotes between
digits are ignored.
[-+] means there is an optional plus or minus sign.
{exp} is the exponent, power of 10.
Only a decimal point is accepted, not a comma.  No matter what the current
locale is.

Examples:
	123.456
	+0.0001
	55.0
	-0.123
	1.234e03
	1.0E-6
	-3.1416e+88

These are INVALID:
	3.		empty {M}
	1e40		missing .{M}

Rationale:
Before floating point was introduced, the text "123.456" was interpreted as
the two numbers "123" and "456", both converted to a string and concatenated,
resulting in the string "123456".  Since this was considered pointless, and we
could not find it intentionally being used in Vim scripts, this backwards
incompatibility was accepted in favor of being able to use the normal notation
for floating point numbers.

							*float-pi* *float-e*
A few useful values to copy&paste: >
	:let pi = 3.14159265359
	:let e  = 2.71828182846
Or, if you don't want to write them in as floating-point literals, you can
also use functions, like the following: >
	:let pi = acos(-1.0)
	:let e  = exp(1.0)
<
						*floating-point-precision*
The precision and range of floating points numbers depends on what "double"
means in the library Vim was compiled with.  There is no way to change this at
runtime.

The default for displaying a |Float| is to use 6 decimal places, like using
printf("%g", f).  You can select something else when using the |printf()|
function.  Example: >
	:echo printf('%.15e', atan(1))
<	7.853981633974483e-01



string					*string* *String* *expr-string* *E114*
------
"string"		string constant		*expr-quote*

Note that double quotes are used.

A string constant accepts these special characters:
\...	three-digit octal number (e.g., "\316")
\..	two-digit octal number (must be followed by non-digit)
\.	one-digit octal number (must be followed by non-digit)
\x..	byte specified with two hex numbers (e.g., "\x1f")
\x.	byte specified with one hex number (must be followed by non-hex char)
\X..	same as \x..
\X.	same as \x.
\u....	character specified with up to 4 hex numbers, stored according to the
	current value of 'encoding' (e.g., "\u02a4")
\U....	same as \u but allows up to 8 hex numbers.
\b	backspace <BS>
\e	escape <Esc>
\f	formfeed 0x0C
\n	newline <NL>
\r	return <CR>
\t	tab <Tab>
\\	backslash
\"	double quote
\<xxx>	Special key named "xxx".  e.g. "\<C-W>" for CTRL-W.  This is for use
	in mappings, the 0x80 byte is escaped.
	To use the double quote character it must be escaped: "<M-\">".
	Don't use <Char-xxxx> to get a UTF-8 character, use \uxxxx as
	mentioned above.
\<*xxx>	Like \<xxx> but prepends a modifier instead of including it in the
	character.  E.g. "\<C-w>" is one character 0x17 while "\<*C-w>" is four
	bytes: 3 for the CTRL modifier and then character "W".

Note that "\xff" is stored as the byte 255, which may be invalid in some
encodings.  Use "\u00ff" to store character 255 according to the current value
of 'encoding'.

Note that "\000" and "\x00" force the end of the string.


blob-literal				*blob-literal* *E973*
------------

Hexadecimal starting with 0z or 0Z, with an arbitrary number of bytes.
The sequence must be an even number of hex characters.  Example: >
	:let b = 0zFF00ED015DAF


literal-string						*literal-string* *E115*
---------------
'string'		string constant			*expr-'*

Note that single quotes are used.

This string is taken as it is.  No backslashes are removed or have a special
meaning.  The only exception is that two quotes stand for one quote.

Single quoted strings are useful for patterns, so that backslashes do not need
to be doubled.  These two commands are equivalent: >
	if a =~ "\\s*"
	if a =~ '\s*'


interpolated-string				*$quote* *interpolated-string*
--------------------
$"string"		interpolated string constant		*expr-$quote*
$'string'		interpolated literal string constant	*expr-$'*

Interpolated strings are an extension of the |string| and |literal-string|,
allowing the inclusion of Vim script expressions (see |expr1|).  Any
expression returning a value can be enclosed between curly braces.  The value
is converted to a string.  All the text and results of the expressions
are concatenated to make a new string.
							*E1278* *E1279*
To include an opening brace '{' or closing brace '}' in the string content
double it.  For double quoted strings using a backslash also works.  A single
closing brace '}' will result in an error.

Examples: >
	let your_name = input("What's your name? ")
<	What's your name?  Peter ~
>
	echo
	echo $"Hello, {your_name}!"
<	Hello, Peter! ~
>
	echo $"The square root of {{9}} is {sqrt(9)}"
<	The square root of {9} is 3.0 ~

						*string-offset-encoding*
A string consists of multiple characters.  How the characters are stored
depends on 'encoding'.  Most common is UTF-8, which uses one byte for ASCII
characters, two bytes for other latin characters and more bytes for other
characters.

A string offset can count characters or bytes.  Other programs may use
UTF-16 encoding (16-bit words) and an offset of UTF-16 words.  Some functions
use byte offsets, usually for UTF-8 encoding.  Other functions use character
offsets, in which case the encoding doesn't matter.

The different offsets for the string "a©😊" are below:

  UTF-8 offsets:
      [0]: 61, [1]: C2, [2]: A9, [3]: F0, [4]: 9F, [5]: 98, [6]: 8A
  UTF-16 offsets:
      [0]: 0061, [1]: 00A9, [2]: D83D, [3]: DE0A
  UTF-32 (character) offsets:
      [0]: 00000061, [1]: 000000A9, [2]: 0001F60A

You can use the "g8" and "ga" commands on a character to see the
decimal/hex/octal values.

The functions |byteidx()|, |utf16idx()| and |charidx()| can be used to convert
between these indices.  The functions |strlen()|, |strutf16len()| and
|strcharlen()| return the number of bytes, UTF-16 code units and characters in
a string respectively.

option						*expr-option* *E112* *E113*
------
&option			option value, local value if possible
&g:option		global option value
&l:option		local option value

Examples: >
	echo "tabstop is " .. &tabstop
	if &insertmode

Any option name can be used here.  See |options|.  When using the local value
and there is no buffer-local or window-local value, the global value is used
anyway.


register						*expr-register* *@r*
--------
@r			contents of register 'r'

The result is the contents of the named register, as a single string.
Newlines are inserted where required.  To get the contents of the unnamed
register use @" or @@.  See |registers| for an explanation of the available
registers.

When using the '=' register you get the expression itself, not what it
evaluates to.  Use |eval()| to evaluate it.


nesting						*expr-nesting* *E110*
-------
(expr1)			nested expression


environment variable					*expr-env*
--------------------
$VAR			environment variable

The String value of any environment variable.  When it is not defined, the
result is an empty string.

The functions `getenv()` and `setenv()` can also be used and work for
environment variables with non-alphanumeric names.
The function `environ()` can be used to get a Dict with all environment
variables.


						*expr-env-expand*
Note that there is a difference between using $VAR directly and using
expand("$VAR").  Using it directly will only expand environment variables that
are known inside the current Vim session.  Using expand() will first try using
the environment variables known inside the current Vim session.  If that
fails, a shell will be used to expand the variable.  This can be slow, but it
does expand all variables that the shell knows about.  Example: >
	:echo $shell
	:echo expand("$shell")
The first one probably doesn't echo anything, the second echoes the $shell
variable (if your shell supports it).


internal variable			*expr-variable* *E1015* *E1089*
-----------------
variable		internal variable
See below |internal-variables|.


function call		*expr-function* *E116* *E118* *E119* *E120*
-------------
function(expr1, ...)	function call
See below |functions|.


lambda expression				*expr-lambda* *lambda*
-----------------
{args -> expr1}		legacy lambda expression		*E451*
(args) => expr1		|Vim9| lambda expression

A lambda expression creates a new unnamed function which returns the result of
evaluating |expr1|.  Lambda expressions differ from |user-functions| in
the following ways:

1. The body of the lambda expression is an |expr1| and not a sequence of |Ex|
   commands.
2. The prefix "a:" should not be used for arguments.  E.g.: >
	:let F = {arg1, arg2 -> arg1 - arg2}
	:echo F(5, 2)
<	3

The arguments are optional.  Example: >
	:let F = {-> 'error function'}
	:echo F('ignored')
<	error function

The |Vim9| lambda does not only use a different syntax, it also adds type
checking and can be split over multiple lines, see |vim9-lambda|.

							*closure*
Lambda expressions can access outer scope variables and arguments.  This is
often called a closure.  Example where "i" and "a:arg" are used in a lambda
while they already exist in the function scope.  They remain valid even after
the function returns: >
	:function Foo(arg)
	:  let i = 3
	:  return {x -> x + i - a:arg}
	:endfunction
	:let Bar = Foo(4)
	:echo Bar(6)
<	5

Note that the variables must exist in the outer scope before the lambda is
defined for this to work.  See also |:func-closure|.

Lambda and closure support can be checked with: >
	if has('lambda')

Examples for using a lambda expression with |sort()|, |map()| and |filter()|: >
	:echo map([1, 2, 3], {idx, val -> val + 1})
<	[2, 3, 4] >
	:echo sort([3,7,2,1,4], {a, b -> a - b})
<	[1, 2, 3, 4, 7]

The lambda expression is also useful for Channel, Job and timer: >
	:let timer = timer_start(500,
			\ {-> execute("echo 'Handler called'", "")},
			\ {'repeat': 3})
<	Handler called
	Handler called
	Handler called

Note that it is possible to cause memory to be used and not freed if the
closure is referenced by the context it depends on: >
	function Function()
	   let x = 0
	   let F = {-> x}
	 endfunction
The closure uses "x" from the function scope, and "F" in that same scope
refers to the closure.  This cycle results in the memory not being freed.
Recommendation: don't do this.

Notice how execute() is used to execute an Ex command.  That's ugly though.
In Vim9 script you can use a command block, see |inline-function|.

Although you can use the loop variable of a `for` command, it must still exist
when the closure is called, otherwise you get an error.  *E1302*

Lambda expressions have internal names like '<lambda>42'.  If you get an error
for a lambda expression, you can find what it is with the following command: >
	:function <lambda>42
See also: |numbered-function|

==============================================================================
3. Internal variable			*internal-variables* *E461* *E1001*

An internal variable name can be made up of letters, digits and '_'.  But it
cannot start with a digit.  In legacy script it is also possible to use curly
braces, see |curly-braces-names|.

In legacy script an internal variable is created with the ":let" command
|:let|.  An internal variable is explicitly destroyed with the ":unlet"
command |:unlet|.
Using a name that is not an internal variable or refers to a variable that has
been destroyed results in an error.

In |Vim9| script `:let` is not used and variables work differently, see |:var|.

						*variable-scope*
There are several name spaces for variables.  Which one is to be used is
specified by what is prepended:

		(nothing) In a function: local to the function;
			  in a legacy script: global;
			  in a |Vim9|  script: local to the script
|buffer-variable|    b:	  Local to the current buffer.
|window-variable|    w:	  Local to the current window.
|tabpage-variable|   t:	  Local to the current tab page.
|global-variable|    g:	  Global.
|local-variable|     l:	  Local to a function (only in a legacy function)
|script-variable|    s:	  Local to a |:source|'ed Vim script.
|function-argument|  a:	  Function argument (only in a legacy function).
|vim-variable|       v:	  Global, predefined by Vim.

The scope name by itself can be used as a |Dictionary|.  For example, to
delete all script-local variables: >
	:for k in keys(s:)
	:    unlet s:[k]
	:endfor

Note: in Vim9 script variables can also be local to a block of commands, see
|vim9-scopes|.
						*buffer-variable* *b:var* *b:*
A variable name that is preceded with "b:" is local to the current buffer.
Thus you can have several "b:foo" variables, one for each buffer.
This kind of variable is deleted when the buffer is wiped out or deleted with
|:bdelete|.

One local buffer variable is predefined:
					*b:changedtick* *changetick*
b:changedtick	The total number of changes to the current buffer.  It is
		incremented for each change.  An undo command is also a change
		in this case.  Resetting 'modified' when writing the buffer is
		also counted.
		This can be used to perform an action only when the buffer has
		changed.  Example: >
		    :if my_changedtick != b:changedtick
		    :	let my_changedtick = b:changedtick
		    :	call My_Update()
		    :endif
<		You cannot change or delete the b:changedtick variable.
		If you need more information about the change see
		|listener_add()|.

						*window-variable* *w:var* *w:*
A variable name that is preceded with "w:" is local to the current window.  It
is deleted when the window is closed.

						*tabpage-variable* *t:var* *t:*
A variable name that is preceded with "t:" is local to the current tab page,
It is deleted when the tab page is closed. {not available when compiled
without the |+windows| feature}

						*global-variable* *g:var* *g:*
Inside functions and in |Vim9| script global variables are accessed with "g:".
Omitting this will access a variable local to a function or script.  "g:"
can also be used in any other place if you like.

						*local-variable* *l:var* *l:*
Inside functions local variables are accessed without prepending anything.
But you can also prepend "l:" if you like.  However, without prepending "l:"
you may run into reserved variable names.  For example "count".  By itself it
refers to "v:count".  Using "l:count" you can have a local variable with the
same name.

						*script-variable* *s:var*
In a legacy Vim script variables starting with "s:" can be used.  They cannot
be accessed from outside of the scripts, thus are local to the script.
In |Vim9| script the "s:" prefix can be omitted, variables are script-local by
default.

They can be used in:
- commands executed while the script is sourced
- functions defined in the script
- autocommands defined in the script
- functions and autocommands defined in functions and autocommands which were
  defined in the script (recursively)
- user defined commands defined in the script
Thus not in:
- other scripts sourced from this one
- mappings
- menus
- etc.

Script variables can be used to avoid conflicts with global variable names.
Take this example: >

	let s:counter = 0
	function MyCounter()
	  let s:counter = s:counter + 1
	  echo s:counter
	endfunction
	command Tick call MyCounter()

You can now invoke "Tick" from any script, and the "s:counter" variable in
that script will not be changed, only the "s:counter" in the script where
"Tick" was defined is used.

Another example that does the same: >

	let s:counter = 0
	command Tick let s:counter = s:counter + 1 | echo s:counter

When calling a function and invoking a user-defined command, the context for
script variables is set to the script where the function or command was
defined.

The script variables are also available when a function is defined inside a
function that is defined in a script.  Example: >

	let s:counter = 0
	function StartCounting(incr)
	  if a:incr
	    function MyCounter()
	      let s:counter = s:counter + 1
	    endfunction
	  else
	    function MyCounter()
	      let s:counter = s:counter - 1
	    endfunction
	  endif
	endfunction

This defines the MyCounter() function either for counting up or counting down
when calling StartCounting().  It doesn't matter from where StartCounting() is
called, the s:counter variable will be accessible in MyCounter().

When the same script is sourced again it will use the same script variables.
They will remain valid as long as Vim is running.  This can be used to
maintain a counter: >

	if !exists("s:counter")
	  let s:counter = 1
	  echo "script executed for the first time"
	else
	  let s:counter = s:counter + 1
	  echo "script executed " .. s:counter .. " times now"
	endif

Note that this means that filetype plugins don't get a different set of script
variables for each buffer.  Use local buffer variables instead |b:var|.


PREDEFINED VIM VARIABLES			*vim-variable* *v:var* *v:*
							*E963* *E1063*
Some variables can be set by the user, but the type cannot be changed.

					*v:argv* *argv-variable*
v:argv		The command line arguments Vim was invoked with.  This is a
		list of strings.  The first item is the Vim command.
		See |v:progpath| for the command with full path.

					*v:beval_col* *beval_col-variable*
v:beval_col	The number of the column, over which the mouse pointer is.
		This is the byte index in the |v:beval_lnum| line.
		Only valid while evaluating the 'balloonexpr' option.

					*v:beval_bufnr* *beval_bufnr-variable*
v:beval_bufnr	The number of the buffer, over which the mouse pointer is. Only
		valid while evaluating the 'balloonexpr' option.

					*v:beval_lnum* *beval_lnum-variable*
v:beval_lnum	The number of the line, over which the mouse pointer is. Only
		valid while evaluating the 'balloonexpr' option.

					*v:beval_text* *beval_text-variable*
v:beval_text	The text under or after the mouse pointer.  Usually a word as
		it is useful for debugging a C program.  'iskeyword' applies,
		but a dot and "->" before the position is included.  When on a
		']' the text before it is used, including the matching '[' and
		word before it.  When on a Visual area within one line the
		highlighted text is used.  Also see |<cexpr>|.
		Only valid while evaluating the 'balloonexpr' option.

					*v:beval_winnr* *beval_winnr-variable*
v:beval_winnr	The number of the window, over which the mouse pointer is. Only
		valid while evaluating the 'balloonexpr' option.  The first
		window has number zero (unlike most other places where a
		window gets a number).

					*v:beval_winid* *beval_winid-variable*
v:beval_winid	The |window-ID| of the window, over which the mouse pointer
		is.  Otherwise like v:beval_winnr.

					*v:char* *char-variable*
v:char		Argument for evaluating 'formatexpr' and used for the typed
		character when using <expr> in an abbreviation |:map-<expr>|.
		It is also used by the |InsertCharPre| and |InsertEnter| events.

			*v:charconvert_from* *charconvert_from-variable*
v:charconvert_from
		The name of the character encoding of a file to be converted.
		Only valid while evaluating the 'charconvert' option.

			*v:charconvert_to* *charconvert_to-variable*
v:charconvert_to
		The name of the character encoding of a file after conversion.
		Only valid while evaluating the 'charconvert' option.

					*v:cmdarg* *cmdarg-variable*
v:cmdarg	This variable is used for two purposes:
		1. The extra arguments given to a file read/write command.
		   Currently these are "++enc=" and "++ff=".  This variable is
		   set before an autocommand event for a file read/write
		   command is triggered.  There is a leading space to make it
		   possible to append this variable directly after the
		   read/write command.  Note: The "+cmd" argument isn't
		   included here, because it will be executed anyway.
		2. When printing a PostScript file with ":hardcopy" this is
		   the argument for the ":hardcopy" command.  This can be used
		   in 'printexpr'.

					*v:cmdbang* *cmdbang-variable*
v:cmdbang	Set like v:cmdarg for a file read/write command.  When a "!"
		was used the value is 1, otherwise it is 0.  Note that this
		can only be used in autocommands.  For user commands |<bang>|
		can be used.
						*v:collate* *collate-variable*
v:collate	The current locale setting for collation order of the runtime
		environment.  This allows Vim scripts to be aware of the
		current locale encoding.  Technical: it's the value of
		LC_COLLATE.  When not using a locale the value is "C".
		This variable can not be set directly, use the |:language|
		command.
		See |multi-lang|.

								*v:colornames*
v:colornames    A dictionary that maps color names to hex color strings. These
		color names can be used with the |highlight-guifg|,
		|highlight-guibg|, and |highlight-guisp| parameters. Updating
		an entry in v:colornames has no immediate effect on the syntax
		highlighting. The highlight commands (probably in a
		colorscheme script) need to be re-evaluated in order to use
		the updated color values. For example: >

		    :let v:colornames['fuscia'] = '#cf3ab4'
		    :let v:colornames['mauve'] = '#915f6d'
		    :highlight Normal guifg=fuscia guibg=mauve
<
		This cannot be used to override the |cterm-colors| but it can
		be used to override other colors. For example, the X11 colors
		defined in the `colors/lists/default.vim` (previously defined
		in |rgb.txt|). When defining new color names in a plugin, the
		recommended practice is to set a color entry only when it does
		not already exist. For example: >

		    :call extend(v:colornames, {
			\ 'fuscia': '#cf3ab4',
			\ 'mauve': '#915f6d,
			\ }, 'keep')
<
		Using |extend()| with the 'keep' option updates each color only
		if it did not exist in |v:colornames|. Doing so allows the
		user to choose the precise color value for a common name
		by setting it in their |.vimrc|.

		It is possible to remove entries from this dictionary but
		doing so is NOT recommended, because it is disruptive to
		other scripts. It is also unlikely to achieve the desired
		result because the |:colorscheme| and |:highlight| commands will
		both automatically load all `colors/lists/default.vim` color
		scripts.

				*v:completed_item* *completed_item-variable*
v:completed_item
		|Dictionary| containing the |complete-items| for the most
		recently completed word after |CompleteDone|.  The
		|Dictionary| is empty if the completion failed.
		Note: Plugins can modify the value to emulate the builtin
		|CompleteDone| event behavior.

					*v:count* *count-variable*
v:count		The count given for the last Normal mode command.  Can be used
		to get the count before a mapping.  Read-only.  Example: >
	:map _x :<C-U>echo "the count is " .. v:count<CR>
<		Note: The <C-U> is required to remove the line range that you
		get when typing ':' after a count.
		When there are two counts, as in "3d2w", they are multiplied,
		just like what happens in the command, "d6w" for the example.
		Also used for evaluating the 'formatexpr' option.
		"count" also works, for backwards compatibility, unless
		|scriptversion| is 3 or higher.

					*v:count1* *count1-variable*
v:count1	Just like "v:count", but defaults to one when no count is
		used.

						*v:ctype* *ctype-variable*
v:ctype		The current locale setting for characters of the runtime
		environment.  This allows Vim scripts to be aware of the
		current locale encoding.  Technical: it's the value of
		LC_CTYPE.  When not using a locale the value is "C".
		This variable can not be set directly, use the |:language|
		command.
		See |multi-lang|.

					*v:dying* *dying-variable*
v:dying		Normally zero.  When a deadly signal is caught it's set to
		one.  When multiple signals are caught the number increases.
		Can be used in an autocommand to check if Vim didn't
		terminate normally. {only works on Unix}
		Example: >
	:au VimLeave * if v:dying | echo "\nAAAAaaaarrrggghhhh!!!\n" | endif
<		Note: if another deadly signal is caught when v:dying is one,
		VimLeave autocommands will not be executed.

					*v:exiting* *exiting-variable*
v:exiting	Vim exit code.  Normally zero, non-zero when something went
		wrong.  The value is v:null before invoking the |VimLeavePre|
		and |VimLeave| autocmds.  See |:q|, |:x| and |:cquit|.
		Example: >
			:au VimLeave * echo "Exit value is " .. v:exiting
<
					*v:echospace* *echospace-variable*
v:echospace	Number of screen cells that can be used for an `:echo` message
		in the last screen line before causing the |hit-enter-prompt|.
		Depends on 'showcmd', 'ruler' and 'columns'.  You need to
		check 'cmdheight' for whether there are full-width lines
		available above the last line.

					*v:errmsg* *errmsg-variable*
v:errmsg	Last given error message.  It's allowed to set this variable.
		Example: >
	:let v:errmsg = ""
	:silent! next
	:if v:errmsg != ""
	:  ... handle error
<		"errmsg" also works, for backwards compatibility, unless
		|scriptversion| is 3 or higher.

				*v:errors* *errors-variable* *assert-return*
v:errors	Errors found by assert functions, such as |assert_true()|.
		This is a list of strings.
		The assert functions append an item when an assert fails.
		The return value indicates this: a one is returned if an item
		was added to v:errors, otherwise zero is returned.
		To remove old results make it empty: >
	:let v:errors = []
<		If v:errors is set to anything but a list it is made an empty
		list by the assert function.

					*v:event* *event-variable*
v:event		Dictionary containing information about the current
		|autocommand|.  See the specific event for what it puts in
		this dictionary.
		The dictionary is emptied when the |autocommand| finishes,
		please refer to |dict-identity| for how to get an independent
		copy of it.  Use |deepcopy()| if you want to keep the
		information after the event triggers.  Example: >
			au TextYankPost * let g:foo = deepcopy(v:event)
<
					*v:exception* *exception-variable*
v:exception	The value of the exception most recently caught and not
		finished.  See also |v:throwpoint| and |throw-variables|.
		Example: >
	:try
	:  throw "oops"
	:catch /.*/
	:  echo "caught " .. v:exception
	:endtry
<		Output: "caught oops".

					*v:false* *false-variable*
v:false		A Number with value zero. Used to put "false" in JSON.  See
		|json_encode()|.
		When used as a string this evaluates to "v:false". >
			echo v:false
<			v:false ~
		That is so that eval() can parse the string back to the same
		value.  Read-only.
		In |Vim9| script "false" can be used which has a boolean type.

					*v:fcs_reason* *fcs_reason-variable*
v:fcs_reason	The reason why the |FileChangedShell| event was triggered.
		Can be used in an autocommand to decide what to do and/or what
		to set v:fcs_choice to.  Possible values:
			deleted		file no longer exists
			conflict	file contents, mode or timestamp was
					changed and buffer is modified
			changed		file contents has changed
			mode		mode of file changed
			time		only file timestamp changed

					*v:fcs_choice* *fcs_choice-variable*
v:fcs_choice	What should happen after a |FileChangedShell| event was
		triggered.  Can be used in an autocommand to tell Vim what to
		do with the affected buffer:
			reload		Reload the buffer (does not work if
					the file was deleted).
			edit		Reload the buffer and detect the
					values for options such as
					'fileformat', 'fileencoding', 'binary'
					(does not work if the file was
					deleted).
			ask		Ask the user what to do, as if there
					was no autocommand.  Except that when
					only the timestamp changed nothing
					will happen.
			<empty>		Nothing, the autocommand should do
					everything that needs to be done.
		The default is empty.  If another (invalid) value is used then
		Vim behaves like it is empty, there is no warning message.

					*v:fname* *fname-variable*
v:fname		When evaluating 'includeexpr': the file name that was
		detected.  Empty otherwise.

					*v:fname_in* *fname_in-variable*
v:fname_in	The name of the input file.  Valid while evaluating:
			option		used for ~
			'charconvert'	file to be converted
			'diffexpr'	original file
			'patchexpr'	original file
			'printexpr'	file to be printed
		And set to the swap file name for |SwapExists|.

					*v:fname_out* *fname_out-variable*
v:fname_out	The name of the output file.  Only valid while
		evaluating:
			option		used for ~
			'charconvert'	resulting converted file (*)
			'diffexpr'	output of diff
			'patchexpr'	resulting patched file
		(*) When doing conversion for a write command (e.g., ":w
		file") it will be equal to v:fname_in.  When doing conversion
		for a read command (e.g., ":e file") it will be a temporary
		file and different from v:fname_in.

					*v:fname_new* *fname_new-variable*
v:fname_new	The name of the new version of the file.  Only valid while
		evaluating 'diffexpr'.

					*v:fname_diff* *fname_diff-variable*
v:fname_diff	The name of the diff (patch) file.  Only valid while
		evaluating 'patchexpr'.

					*v:folddashes* *folddashes-variable*
v:folddashes	Used for 'foldtext': dashes representing foldlevel of a closed
		fold.
		Read-only in the |sandbox|. |fold-foldtext|

					*v:foldlevel* *foldlevel-variable*
v:foldlevel	Used for 'foldtext': foldlevel of closed fold.
		Read-only in the |sandbox|. |fold-foldtext|

					*v:foldend* *foldend-variable*
v:foldend	Used for 'foldtext': last line of closed fold.
		Read-only in the |sandbox|. |fold-foldtext|

					*v:foldstart* *foldstart-variable*
v:foldstart	Used for 'foldtext': first line of closed fold.
		Read-only in the |sandbox|. |fold-foldtext|

					*v:hlsearch* *hlsearch-variable*
v:hlsearch	Variable that indicates whether search highlighting is on.
		Setting it makes sense only if 'hlsearch' is enabled which
		requires |+extra_search|. Setting this variable to zero acts
		like the |:nohlsearch| command, setting it to one acts like >
			let &hlsearch = &hlsearch
<		Note that the value is restored when returning from a
		function. |function-search-undo|.

					*v:insertmode* *insertmode-variable*
v:insertmode	Used for the |InsertEnter| and |InsertChange| autocommand
		events.  Values:
			i	Insert mode
			r	Replace mode
			v	Virtual Replace mode

						*v:key* *key-variable*
v:key		Key of the current item of a |Dictionary|.  Only valid while
		evaluating the expression used with |map()| and |filter()|.
		Read-only.

						*v:lang* *lang-variable*
v:lang		The current locale setting for messages of the runtime
		environment.  This allows Vim scripts to be aware of the
		current language.  Technical: it's the value of LC_MESSAGES.
		The value is system dependent.
		This variable can not be set directly, use the |:language|
		command.
		It can be different from |v:ctype| when messages are desired
		in a different language than what is used for character
		encoding.  See |multi-lang|.

						*v:lc_time* *lc_time-variable*
v:lc_time	The current locale setting for time messages of the runtime
		environment.  This allows Vim scripts to be aware of the
		current language.  Technical: it's the value of LC_TIME.
		This variable can not be set directly, use the |:language|
		command.  See |multi-lang|.

						*v:lnum* *lnum-variable*
v:lnum		Line number for the 'foldexpr' |fold-expr|, 'formatexpr' and
		'indentexpr' expressions, tab page number for 'guitablabel'
		and 'guitabtooltip'.  Only valid while one of these
		expressions is being evaluated.  Read-only when in the
		|sandbox|.

						*v:maxcol* *maxcol-variable*
v:maxcol	Maximum line length.  Depending on where it is used it can be
		screen columns, characters or bytes.  The value currently is
		2147483647 on all systems.

					*v:mouse_win* *mouse_win-variable*
v:mouse_win	Window number for a mouse click obtained with |getchar()|.
		First window has number 1, like with |winnr()|.  The value is
		zero when there was no mouse button click.

					*v:mouse_winid* *mouse_winid-variable*
v:mouse_winid	Window ID for a mouse click obtained with |getchar()|.
		The value is zero when there was no mouse button click.

					*v:mouse_lnum* *mouse_lnum-variable*
v:mouse_lnum	Line number for a mouse click obtained with |getchar()|.
		This is the text line number, not the screen line number.  The
		value is zero when there was no mouse button click.

					*v:mouse_col* *mouse_col-variable*
v:mouse_col	Column number for a mouse click obtained with |getchar()|.
		This is the screen column number, like with |virtcol()|.  The
		value is zero when there was no mouse button click.

					*v:none* *none-variable* *None*
v:none		An empty String. Used to put an empty item in JSON.  See
		|json_encode()|.
		This can also be used as a function argument to use the
		default value, see |none-function_argument|.
		When used as a number this evaluates to zero.
		When used as a string this evaluates to "v:none". >
			echo v:none
<			v:none ~
		That is so that eval() can parse the string back to the same
		value.  Read-only.
		Note that using `== v:none` and `!= v:none`  will often give
		an error.  Instead, use `is v:none` and `isnot v:none` .

					*v:null* *null-variable*
v:null		An empty String. Used to put "null" in JSON.  See
		|json_encode()|.
		When used as a number this evaluates to zero.
		When used as a string this evaluates to "v:null". >
			echo v:null
<			v:null ~
		That is so that eval() can parse the string back to the same
		value.  Read-only.
		In |Vim9| script `null` can be used without "v:".
		In some places `v:null` and `null` can be used for a List,
		Dict, Job, etc. that is not set.  That is slightly different
		than an empty List, Dict, etc.

					*v:numbermax* *numbermax-variable*
v:numbermax	Maximum value of a number.

					*v:numbermin* *numbermin-variable*
v:numbermin	Minimum value of a number (negative).

					*v:numbersize* *numbersize-variable*
v:numbersize	Number of bits in a Number.  This is normally 64, but on some
		systems it may be 32.

					*v:oldfiles* *oldfiles-variable*
v:oldfiles	List of file names that is loaded from the |viminfo| file on
		startup.  These are the files that Vim remembers marks for.
		The length of the List is limited by the ' argument of the
		'viminfo' option (default is 100).
		When the |viminfo| file is not used the List is empty.
		Also see |:oldfiles| and |c_#<|.
		The List can be modified, but this has no effect on what is
		stored in the |viminfo| file later.  If you use values other
		than String this will cause trouble.
		{only when compiled with the |+viminfo| feature}

						    *v:option_new*
v:option_new    New value of the option. Valid while executing an |OptionSet|
		autocommand.
						    *v:option_old*
v:option_old    Old value of the option. Valid while executing an |OptionSet|
		autocommand. Depending on the command used for setting and the
		kind of option this is either the local old value or the
		global old value.
						    *v:option_oldlocal*
v:option_oldlocal
		Old local value of the option. Valid while executing an
		|OptionSet| autocommand.
						    *v:option_oldglobal*
v:option_oldglobal
		Old global value of the option. Valid while executing an
		|OptionSet| autocommand.
						    *v:option_type*
v:option_type   Scope of the set command. Valid while executing an
		|OptionSet| autocommand. Can be either "global" or "local"
						    *v:option_command*
v:option_command
		Command used to set the option. Valid while executing an
		|OptionSet| autocommand.
			value		option was set via   ~
			"setlocal"	|:setlocal| or ":let l:xxx"
			"setglobal"	|:setglobal| or ":let g:xxx"
			"set"		|:set| or |:let|
			"modeline"	|modeline|
					*v:operator* *operator-variable*
v:operator	The last operator given in Normal mode.  This is a single
		character except for commands starting with <g> or <z>,
		in which case it is two characters.  Best used alongside
		|v:prevcount| and |v:register|.  Useful if you want to cancel
		Operator-pending mode and then use the operator, e.g.: >
			:omap O <Esc>:call MyMotion(v:operator)<CR>
<		The value remains set until another operator is entered, thus
		don't expect it to be empty.
		v:operator is not set for |:delete|, |:yank| or other Ex
		commands.
		Read-only.

					*v:prevcount* *prevcount-variable*
v:prevcount	The count given for the last but one Normal mode command.
		This is the v:count value of the previous command.  Useful if
		you want to cancel Visual or Operator-pending mode and then
		use the count, e.g.: >
			:vmap % <Esc>:call MyFilter(v:prevcount)<CR>
<		Read-only.

					*v:profiling* *profiling-variable*
v:profiling	Normally zero.  Set to one after using ":profile start".
		See |profiling|.

					*v:progname* *progname-variable*
v:progname	Contains the name (with path removed) with which Vim was
		invoked.  Allows you to do special initialisations for |view|,
		|evim| etc., or any other name you might symlink to Vim.
		Read-only.

					*v:progpath* *progpath-variable*
v:progpath	Contains the command with which Vim was invoked, in a form
		that when passed to the shell will run the same Vim executable
		as the current one (if $PATH remains unchanged).
		Useful if you want to message a Vim server using a
		|--remote-expr|.
		To get the full path use: >
			echo exepath(v:progpath)
<		If the command has a relative path it will be expanded to the
		full path, so that it still works after `:cd`. Thus starting
		"./vim" results in "/home/user/path/to/vim/src/vim".
		On Linux and other systems it will always be the full path.
		On Mac it may just be "vim" and using exepath() as mentioned
		above should be used to get the full path.
		On MS-Windows the executable may be called "vim.exe", but the
		".exe" is not added to v:progpath.
		Read-only.

				*v:python3_version* *python3-version-variable*
v:python3_version
		Version of Python 3 that Vim was built against.  When
		Python is loaded dynamically (|python-dynamic|), this version
		should exactly match the Python library up to the minor
		version (e.g.  3.10.2 and 3.10.3 are compatible as the minor
		version is "10", whereas 3.9.4 and 3.10.3 are not compatible).
		When |python-stable-abi| is used, this will be the minimum Python
		version that you can use instead. (e.g. if v:python3_version
		indicates 3.9, you can use 3.9, 3.10, or anything above).

		This number is encoded as a hex number following Python ABI
		versioning conventions.  Do the following to have a
		human-readable full version in hex: >
			echo printf("%08X", v:python3_version)
<		You can obtain only the minor version by doing: >
			echo and(v:python3_version>>16,0xff)
<		Read-only.

					*v:register* *register-variable*
v:register	The name of the register in effect for the current normal mode
		command (regardless of whether that command actually used a
		register).  Or for the currently executing normal mode mapping
		(use this in custom commands that take a register).
		If none is supplied it is the default register '"', unless
		'clipboard' contains "unnamed" or "unnamedplus", then it is
		'*' or '+'.
		Also see |getreg()| and |setreg()|

					*v:scrollstart* *scrollstart-variable*
v:scrollstart	String describing the script or function that caused the
		screen to scroll up.  It's only set when it is empty, thus the
		first reason is remembered.  It is set to "Unknown" for a
		typed command.
		This can be used to find out why your script causes the
		hit-enter prompt.

					*v:servername* *servername-variable*
v:servername	The resulting registered |client-server-name| if any.
		Read-only.


v:searchforward			*v:searchforward* *searchforward-variable*
		Search direction:  1 after a forward search, 0 after a
		backward search.  It is reset to forward when directly setting
		the last search pattern, see |quote/|.
		Note that the value is restored when returning from a
		function. |function-search-undo|.
		Read-write.

					*v:shell_error* *shell_error-variable*
v:shell_error	Result of the last shell command.  When non-zero, the last
		shell command had an error.  When zero, there was no problem.
		This only works when the shell returns the error code to Vim.
		The value -1 is often used when the command could not be
		executed.  Read-only.
		Example: >
	:!mv foo bar
	:if v:shell_error
	:  echo 'could not rename "foo" to "bar"!'
	:endif
<		"shell_error" also works, for backwards compatibility, unless
		|scriptversion| is 3 or higher.

					*v:sizeofint* *sizeofint-variable*
v:sizeofint	Number of bytes in an int.  Depends on how Vim was compiled.
		This is only useful for deciding whether a test will give the
		expected result.

					*v:sizeoflong* *sizeoflong-variable*
v:sizeoflong	Number of bytes in a long.  Depends on how Vim was compiled.
		This is only useful for deciding whether a test will give the
		expected result.

				*v:sizeofpointer* *sizeofpointer-variable*
v:sizeofpointer	Number of bytes in a pointer.  Depends on how Vim was compiled.
		This is only useful for deciding whether a test will give the
		expected result.

					*v:statusmsg* *statusmsg-variable*
v:statusmsg	Last given status message.  It's allowed to set this variable.

					*v:swapname* *swapname-variable*
v:swapname	Only valid when executing |SwapExists| autocommands: Name of
		the swap file found.  Read-only.

					*v:swapchoice* *swapchoice-variable*
v:swapchoice	|SwapExists| autocommands can set this to the selected choice
		for handling an existing swap file:
			'o'	Open read-only
			'e'	Edit anyway
			'r'	Recover
			'd'	Delete swapfile
			'q'	Quit
			'a'	Abort
		The value should be a single-character string.  An empty value
		results in the user being asked, as would happen when there is
		no SwapExists autocommand.  The default is empty.

					*v:swapcommand* *swapcommand-variable*
v:swapcommand	Normal mode command to be executed after a file has been
		opened.  Can be used for a |SwapExists| autocommand to have
		another Vim open the file and jump to the right place.  For
		example, when jumping to a tag the value is ":tag tagname\r".
		For ":edit +cmd file" the value is ":cmd\r".

				*v:t_TYPE* *v:t_bool* *t_bool-variable*
v:t_bool	Value of |Boolean| type.  Read-only.  See: |type()|
					*v:t_channel* *t_channel-variable*
v:t_channel	Value of |Channel| type.  Read-only.  See: |type()|
					*v:t_dict* *t_dict-variable*
v:t_dict	Value of |Dictionary| type.  Read-only.  See: |type()|
					*v:t_float* *t_float-variable*
v:t_float	Value of |Float| type.  Read-only.  See: |type()|
					*v:t_func* *t_func-variable*
v:t_func	Value of |Funcref| type.  Read-only.  See: |type()|
					*v:t_job* *t_job-variable*
v:t_job		Value of |Job| type.  Read-only.  See: |type()|
					*v:t_list* *t_list-variable*
v:t_list	Value of |List| type.  Read-only.  See: |type()|
					*v:t_none* *t_none-variable*
v:t_none	Value of |None| type.  Read-only.  See: |type()|
					*v:t_number* *t_number-variable*
v:t_number	Value of |Number| type.  Read-only.  See: |type()|
					*v:t_string* *t_string-variable*
v:t_string	Value of |String| type.  Read-only.  See: |type()|
					*v:t_blob* *t_blob-variable*
v:t_blob	Value of |Blob| type.  Read-only.  See: |type()|
					*v:t_class* *t_class-variable*
v:t_class	Value of |class| type.  Read-only.  See: |type()|
					*v:t_object* *t_object-variable*
v:t_object	Value of |object| type.  Read-only.  See: |type()|
					*v:t_typealias* *t_typealias-variable*
v:t_typealias	Value of |typealias| type.  Read-only.  See: |type()|

				*v:termresponse* *termresponse-variable*
v:termresponse	The escape sequence returned by the terminal for the |t_RV|
		termcap entry.  It is set when Vim receives an escape sequence
		that starts with ESC [ or CSI, then '>' or '?' and ends in a
		'c', with only digits and ';' in between.
		When this option is set, the TermResponse autocommand event is
		fired, so that you can react to the response from the
		terminal.  You can use |terminalprops()| to see what Vim
		figured out about the terminal.
		The response from a new xterm is: "<Esc>[> Pp ; Pv ; Pc c".  Pp
		is the terminal type: 0 for vt100 and 1 for vt220.  Pv is the
		patch level (since this was introduced in patch 95, it's
		always 95 or higher).  Pc is always zero.
		If Pv is 141 or higher then Vim will try to request terminal
		codes.  This only works with xterm |xterm-codes|.
		{only when compiled with |+termresponse| feature}

						*v:termblinkresp*
v:termblinkresp	The escape sequence returned by the terminal for the |t_RC|
		termcap entry.  This is used to find out whether the terminal
		cursor is blinking. This is used by |term_getcursor()|.

						*v:termstyleresp*
v:termstyleresp	The escape sequence returned by the terminal for the |t_RS|
		termcap entry.  This is used to find out what the shape of the
		cursor is.  This is used by |term_getcursor()|.

						*v:termrbgresp*
v:termrbgresp	The escape sequence returned by the terminal for the |t_RB|
		termcap entry.  This is used to find out what the terminal
		background color is, see 'background'.

						*v:termrfgresp*
v:termrfgresp	The escape sequence returned by the terminal for the |t_RF|
		termcap entry.  This is used to find out what the terminal
		foreground color is.

						*v:termu7resp*
v:termu7resp	The escape sequence returned by the terminal for the |t_u7|
		termcap entry.  This is used to find out what the terminal
		does with ambiguous width characters, see 'ambiwidth'.

					*v:testing* *testing-variable*
v:testing	Must be set before using `test_garbagecollect_now()`.
		Also, when set certain error messages won't be shown for 2
		seconds. (e.g. "'dictionary' option is empty")

				*v:this_session* *this_session-variable*
v:this_session	Full filename of the last loaded or saved session file.  See
		|:mksession|.  It is allowed to set this variable.  When no
		session file has been saved, this variable is empty.
		"this_session" also works, for backwards compatibility, unless
		|scriptversion| is 3 or higher

					*v:throwpoint* *throwpoint-variable*
v:throwpoint	The point where the exception most recently caught and not
		finished was thrown.  Not set when commands are typed.  See
		also |v:exception| and |throw-variables|.
		Example: >
	:try
	:  throw "oops"
	:catch /.*/
	:  echo "Exception from" v:throwpoint
	:endtry
<		Output: "Exception from test.vim, line 2"

						*v:true* *true-variable*
v:true		A Number with value one. Used to put "true" in JSON.  See
		|json_encode()|.
		When used as a string this evaluates to "v:true". >
			echo v:true
<			v:true ~
		That is so that eval() can parse the string back to the same
		value.  Read-only.
		In |Vim9| script "true" can be used which has a boolean type.
						*v:val* *val-variable*
v:val		Value of the current item of a |List| or |Dictionary|.  Only
		valid while evaluating the expression used with |map()| and
		|filter()|.  Read-only.

					*v:version* *version-variable*
v:version	Version number of Vim: Major version number times 100 plus
		minor version number.  Version 5.0 is 500.  Version 5.1
		is 501.  Read-only.  "version" also works, for backwards
		compatibility, unless |scriptversion| is 3 or higher.
		Use |has()| to check if a certain patch was included, e.g.: >
			if has("patch-7.4.123")
<		Note that patch numbers are specific to the version, thus both
		version 5.0 and 5.1 may have a patch 123, but these are
		completely different.

					*v:versionlong* *versionlong-variable*
v:versionlong	Like v:version, but also including the patchlevel in the last
		four digits.  Version 8.1 with patch 123 has value 8010123.
		This can be used like this: >
			if v:versionlong >= 8010123
<		However, if there are gaps in the list of patches included
		this will not work well.  This can happen if a recent patch
		was included into an older version, e.g. for a security fix.
		Use the has() function to make sure the patch is actually
		included.

				*v:vim_did_enter* *vim_did_enter-variable*
v:vim_did_enter	Zero until most of startup is done.  It is set to one just
		before |VimEnter| autocommands are triggered.

					*v:warningmsg* *warningmsg-variable*
v:warningmsg	Last given warning message.  It's allowed to set this variable.

					*v:windowid* *windowid-variable*
v:windowid	When any X11 based GUI is running or when running in a
		terminal and Vim connects to the X server (|-X|) this will be
		set to the window ID.
		When an MS-Windows GUI is running this will be set to the
		window handle.
		Otherwise the value is zero.
		Note: for windows inside Vim use |winnr()| or |win_getid()|,
		see |window-ID|.

==============================================================================
4. Builtin Functions					*functions*

See |function-list| for a list grouped by what the function is used for.

The alphabetic list of all builtin functions and details are in a separate
help file: |builtin-functions|.

==============================================================================
5. Defining functions					*user-functions*

New functions can be defined.  These can be called just like builtin
functions.  The function takes arguments, executes a sequence of Ex commands
and can return a value.

You can find most information about defining functions in |userfunc.txt|.
For Vim9 functions, which execute much faster, support type checking and more,
see |vim9.txt|.

==============================================================================
6. Curly braces names					*curly-braces-names*

In most places where you can use a variable, you can use a "curly braces name"
variable.  This is a regular variable name with one or more expressions
wrapped in braces {} like this: >
	my_{adjective}_variable

This only works in legacy Vim script, not in |Vim9| script.

When Vim encounters this, it evaluates the expression inside the braces, puts
that in place of the expression, and re-interprets the whole as a variable
name.  So in the above example, if the variable "adjective" was set to
"noisy", then the reference would be to "my_noisy_variable", whereas if
"adjective" was set to "quiet", then it would be to "my_quiet_variable".

One application for this is to create a set of variables governed by an option
value.  For example, the statement >
	echo my_{&background}_message

would output the contents of "my_dark_message" or "my_light_message" depending
on the current value of 'background'.

You can use multiple brace pairs: >
	echo my_{adverb}_{adjective}_message
..or even nest them: >
	echo my_{ad{end_of_word}}_message
where "end_of_word" is either "verb" or "jective".

However, the expression inside the braces must evaluate to a valid single
variable name, e.g. this is invalid: >
	:let foo='a + b'
	:echo c{foo}d
.. since the result of expansion is "ca + bd", which is not a variable name.

						*curly-braces-function-names*
You can call and define functions by an evaluated name in a similar way.
Example: >
	:let func_end='whizz'
	:call my_func_{func_end}(parameter)

This would call the function "my_func_whizz(parameter)".

This does NOT work: >
  :let i = 3
  :let @{i} = ''  " error
  :echo @{i}      " error

==============================================================================
7. Commands						*expression-commands*

Note: in |Vim9| script `:let` is not used.  `:var` is used for variable
declarations and assignments do not use a command.  |vim9-declaration|

:let {var-name} = {expr1}				*:let* *E18*
			Set internal variable {var-name} to the result of the
			expression {expr1}.  The variable will get the type
			from the {expr}.  If {var-name} didn't exist yet, it
			is created.

:let {var-name}[{idx}] = {expr1}			*E689* *E1141*
			Set a list item to the result of the expression
			{expr1}.  {var-name} must refer to a list and {idx}
			must be a valid index in that list.  For nested list
			the index can be repeated.
			This cannot be used to add an item to a |List|.
			This cannot be used to set a byte in a String.  You
			can do that like this: >
				:let var = var[0:2] .. 'X' .. var[4:]
<			When {var-name} is a |Blob| then {idx} can be the
			length of the blob, in which case one byte is
			appended.

					*E711* *E719* *E1165* *E1166* *E1183*
:let {var-name}[{idx1}:{idx2}] = {expr1}		*E708* *E709* *E710*
			Set a sequence of items in a |List| to the result of
			the expression {expr1}, which must be a list with the
			correct number of items.
			{idx1} can be omitted, zero is used instead.
			{idx2} can be omitted, meaning the end of the list.
			When the selected range of items is partly past the
			end of the list, items will be added.

			*:let+=* *:let-=* *:letstar=* *:let/=*  *:let%=*
			*:let.=* *:let..=* *E734* *E985* *E1019*
:let {var} += {expr1}	Like ":let {var} = {var} + {expr1}".
:let {var} -= {expr1}	Like ":let {var} = {var} - {expr1}".
:let {var} *= {expr1}	Like ":let {var} = {var} * {expr1}".
:let {var} /= {expr1}	Like ":let {var} = {var} / {expr1}".
:let {var} %= {expr1}	Like ":let {var} = {var} % {expr1}".
:let {var} .= {expr1}	Like ":let {var} = {var} . {expr1}".
:let {var} ..= {expr1}	Like ":let {var} = {var} .. {expr1}".
			These fail if {var} was not set yet and when the type
			of {var} and {expr1} don't fit the operator.
			`.=` is not supported with Vim script version 2 and
			later, see |vimscript-version|.


:let ${env-name} = {expr1}			*:let-environment* *:let-$*
			Set environment variable {env-name} to the result of
			the expression {expr1}.  The type is always String.

			On some systems making an environment variable empty
			causes it to be deleted.  Many systems do not make a
			difference between an environment variable that is not
			set and an environment variable that is empty.

:let ${env-name} .= {expr1}
			Append {expr1} to the environment variable {env-name}.
			If the environment variable didn't exist yet this
			works like "=".

:let @{reg-name} = {expr1}			*:let-register* *:let-@*
			Write the result of the expression {expr1} in register
			{reg-name}.  {reg-name} must be a single letter, and
			must be the name of a writable register (see
			|registers|).  "@@" can be used for the unnamed
			register, "@/" for the search pattern.
			If the result of {expr1} ends in a <CR> or <NL>, the
			register will be linewise, otherwise it will be set to
			characterwise.
			This can be used to clear the last search pattern: >
				:let @/ = ""
<			This is different from searching for an empty string,
			that would match everywhere.

:let @{reg-name} .= {expr1}
			Append {expr1} to register {reg-name}.  If the
			register was empty it's like setting it to {expr1}.

:let &{option-name} = {expr1}			*:let-option* *:let-&*
			Set option {option-name} to the result of the
			expression {expr1}.  A String or Number value is
			always converted to the type of the option.
			For an option local to a window or buffer the effect
			is just like using the |:set| command: both the local
			value and the global value are changed.
			Example: >
				:let &path = &path .. ',/usr/local/include'
<			This also works for terminal codes in the form t_xx.
			But only for alphanumerical names.  Example: >
				:let &t_k1 = "\<Esc>[234;"
<			When the code does not exist yet it will be created as
			a terminal key code, there is no error.

:let &{option-name} .= {expr1}
			For a string option: Append {expr1} to the value.
			Does not insert a comma like |:set+=|.

:let &{option-name} += {expr1}
:let &{option-name} -= {expr1}
			For a number or boolean option: Add or subtract
			{expr1}.

:let &l:{option-name} = {expr1}
:let &l:{option-name} .= {expr1}
:let &l:{option-name} += {expr1}
:let &l:{option-name} -= {expr1}
			Like above, but only set the local value of an option
			(if there is one).  Works like |:setlocal|.

:let &g:{option-name} = {expr1}
:let &g:{option-name} .= {expr1}
:let &g:{option-name} += {expr1}
:let &g:{option-name} -= {expr1}
			Like above, but only set the global value of an option
			(if there is one).  Works like |:setglobal|.
								*E1093*
:let [{name1}, {name2}, ...] = {expr1}		*:let-unpack* *E687* *E688*
			{expr1} must evaluate to a |List|.  The first item in
			the list is assigned to {name1}, the second item to
			{name2}, etc.
			The number of names must match the number of items in
			the |List|.
			Each name can be one of the items of the ":let"
			command as mentioned above.
			Example: >
				:let [s, item] = GetItem(s)
<			Detail: {expr1} is evaluated first, then the
			assignments are done in sequence.  This matters if
			{name2} depends on {name1}.  Example: >
				:let x = [0, 1]
				:let i = 0
				:let [i, x[i]] = [1, 2]
				:echo x
<			The result is [0, 2].

:let [{name1}, {name2}, ...] .= {expr1}
:let [{name1}, {name2}, ...] += {expr1}
:let [{name1}, {name2}, ...] -= {expr1}
			Like above, but append/add/subtract the value for each
			|List| item.

:let [{name}, ..., ; {lastname}] = {expr1}				*E452*
			Like |:let-unpack| above, but the |List| may have more
			items than there are names.  A list of the remaining
			items is assigned to {lastname}.  If there are no
			remaining items {lastname} is set to an empty list.
			Example: >
				:let [a, b; rest] = ["aval", "bval", 3, 4]
<
:let [{name}, ..., ; {lastname}] .= {expr1}
:let [{name}, ..., ; {lastname}] += {expr1}
:let [{name}, ..., ; {lastname}] -= {expr1}
			Like above, but append/add/subtract the value for each
			|List| item.

						*:let=<<* *:let-heredoc*
					*E990* *E991* *E172* *E221* *E1145*
:let {var-name} =<< [trim] [eval] {endmarker}
text...
text...
{endmarker}
			Set internal variable {var-name} to a |List|
			containing the lines of text bounded by the string
			{endmarker}.

			If "eval" is not specified, then each line of text is
			used as a |literal-string|, except that single quotes
			does not need to be doubled.
			If "eval" is specified, then any Vim expression in the
			form {expr} is evaluated and the result replaces the
			expression, like with |interpolated-string|.
			Example where $HOME is expanded: >
				let lines =<< trim eval END
				  some text
				  See the file {$HOME}/.vimrc
				  more text
				END
<			There can be multiple Vim expressions in a single line
			but an expression cannot span multiple lines.  If any
			expression evaluation fails, then the assignment fails.

			{endmarker} must not contain white space.
			{endmarker} cannot start with a lower case character.
			The last line should end only with the {endmarker}
			string without any other character.  Watch out for
			white space after {endmarker}!

			Without "trim" any white space characters in the lines
			of text are preserved.  If "trim" is specified before
			{endmarker}, then indentation is stripped so you can
			do: >
				let text =<< trim END
				   if ok
				     echo 'done'
				   endif
				END
<			Results in: ["if ok", "  echo 'done'", "endif"]
			The marker must line up with "let" and the indentation
			of the first line is removed from all the text lines.
			Specifically: all the leading indentation exactly
			matching the leading indentation of the first
			non-empty text line is stripped from the input lines.
			All leading indentation exactly matching the leading
			indentation before `let` is stripped from the line
			containing {endmarker}.  Note that the difference
			between space and tab matters here.

			If {var-name} didn't exist yet, it is created.
			Cannot be followed by another command, but can be
			followed by a comment.

			To avoid line continuation to be applied, consider
			adding 'C' to 'cpoptions': >
				set cpo+=C
				let var =<< END
				   \ leading backslash
				END
				set cpo-=C
<
			Examples: >
				let var1 =<< END
				Sample text 1
				    Sample text 2
				Sample text 3
				END

				let data =<< trim DATA
					1 2 3 4
					5 6 7 8
				DATA

				let code =<< trim eval CODE
				   let v = {10 + 20}
				   let h = "{$HOME}"
				   let s = "{Str1()} abc {Str2()}"
				   let n = {MyFunc(3, 4)}
				CODE
<
								*E121*
:let {var-name}	..	List the value of variable {var-name}.  Multiple
			variable names may be given.  Special names recognized
			here:				*E738*
			  g:	global variables
			  b:	local buffer variables
			  w:	local window variables
			  t:	local tab page variables
			  s:	script-local variables
			  l:	local function variables
			  v:	Vim variables.
			This does not work in Vim9 script. |vim9-declaration|

:let			List the values of all variables.  The type of the
			variable is indicated before the value:
			    <nothing>	String
				#	Number
				*	Funcref
			This does not work in Vim9 script. |vim9-declaration|

:unl[et][!] {name} ...			*:unlet* *:unl* *E108* *E795* *E1081*
			Remove the internal variable {name}.  Several variable
			names can be given, they are all removed.  The name
			may also be a |List| or |Dictionary| item.
			With [!] no error message is given for non-existing
			variables.
			One or more items from a |List| can be removed: >
				:unlet list[3]	  " remove fourth item
				:unlet list[3:]   " remove fourth item to last
<			One item from a |Dictionary| can be removed at a time: >
				:unlet dict['two']
				:unlet dict.two
<			This is especially useful to clean up used global
			variables and script-local variables (these are not
			deleted when the script ends).  Function-local
			variables are automatically deleted when the function
			ends.
			In |Vim9| script variables declared in a function or
			script cannot be removed.

:unl[et] ${env-name} ...			*:unlet-environment* *:unlet-$*
			Remove environment variable {env-name}.
			Can mix {name} and ${env-name} in one :unlet command.
			No error message is given for a non-existing
			variable, also without !.
			If the system does not support deleting an environment
			variable, it is made empty.

						*:cons* *:const* *E1018*
:cons[t] {var-name} = {expr1}
:cons[t] [{name1}, {name2}, ...] = {expr1}
:cons[t] [{name}, ..., ; {lastname}] = {expr1}
:cons[t] {var-name} =<< [trim] {marker}
text...
text...
{marker}
			Similar to |:let|, but additionally lock the variable
			after setting the value.  This is the same as locking
			the variable with |:lockvar| just after |:let|, thus: >
				:const x = 1
<			is equivalent to: >
				:let x = 1
				:lockvar! x
<			NOTE: in Vim9 script `:const` works differently, see
			|vim9-const|
			This is useful if you want to make sure the variable
			is not modified.  If the value is a List or Dictionary
			literal then the items also cannot be changed: >
				const ll = [1, 2, 3]
				let ll[1] = 5  " Error!
<			Nested references are not locked: >
				let lvar = ['a']
				const lconst = [0, lvar]
				let lconst[0] = 2  " Error!
				let lconst[1][0] = 'b'  " OK
<							*E995*
			|:const| does not allow to for changing a variable: >
				:let x = 1
				:const x = 2  " Error!
<							*E996*
			Note that environment variables, option values and
			register values cannot be used here, since they cannot
			be locked.

:cons[t]
:cons[t] {var-name}
			If no argument is given or only {var-name} is given,
			the behavior is the same as |:let|.

:lockv[ar][!] [depth] {name} ...			*:lockvar* *:lockv*
			Lock the internal variable {name}.  Locking means that
			it can no longer be changed (until it is unlocked).
			A locked variable can be deleted: >
				:lockvar v
				:let v = 'asdf'	  " fails!
				:unlet v	  " works
<			*E741* *E940* *E1118* *E1119* *E1120* *E1121* *E1122*
			If you try to change a locked variable you get an
			error message: "E741: Value is locked: {name}".
			If you try to lock or unlock a built-in variable you
			get an error message: "E940: Cannot lock or unlock
			variable {name}".

			[depth] is relevant when locking a |List| or
			|Dictionary|.  It specifies how deep the locking goes:
				0	Lock the variable {name} but not its
					value.
				1	Lock the |List| or |Dictionary| itself,
					cannot add or remove items, but can
					still change their values.
				2	Also lock the values, cannot change
					the items.  If an item is a |List| or
					|Dictionary|, cannot add or remove
					items, but can still change the
					values.
				3	Like 2 but for the |List| /
					|Dictionary| in the |List| /
					|Dictionary|, one level deeper.
			The default [depth] is 2, thus when {name} is a |List|
			or |Dictionary| the values cannot be changed.

			Example with [depth] 0: >
				let mylist = [1, 2, 3]
				lockvar 0 mylist
				let mylist[0] = 77	" OK
				call add(mylist, 4)	" OK
				let mylist = [7, 8, 9]  " Error!
<								*E743*
			For unlimited depth use [!] and omit [depth].
			However, there is a maximum depth of 100 to catch
			loops.

			Note that when two variables refer to the same |List|
			and you lock one of them, the |List| will also be
			locked when used through the other variable.
			Example: >
				:let l = [0, 1, 2, 3]
				:let cl = l
				:lockvar l
				:let cl[1] = 99		" won't work!
<			You may want to make a copy of a list to avoid this.
			See |deepcopy()|.

							*E1391* *E1392*
			Locking and unlocking object and class variables is
			currently NOT supported.


:unlo[ckvar][!] [depth] {name} ...		*:unlockvar* *:unlo* *E1246*
			Unlock the internal variable {name}.  Does the
			opposite of |:lockvar|.

			If {name} does not exist:
			- In |Vim9| script an error is given.
			- In legacy script this is silently ignored.

:if {expr1}			*:if* *:end* *:endif* *:en* *E171* *E579* *E580*
:en[dif]		Execute the commands until the next matching `:else`
			or `:endif` if {expr1} evaluates to non-zero.
			Although the short forms work, it is recommended to
			always use `:endif` to avoid confusion and to make
			auto-indenting work properly.

			From Vim version 4.5 until 5.0, every Ex command in
			between the `:if` and `:endif` is ignored.  These two
			commands were just to allow for future expansions in a
			backward compatible way.  Nesting was allowed.  Note
			that any `:else` or `:elseif` was ignored, the `else`
			part was not executed either.

			You can use this to remain compatible with older
			versions: >
				:if version >= 500
				:  version-5-specific-commands
				:endif
<			The commands still need to be parsed to find the
			`endif`.  Sometimes an older Vim has a problem with a
			new command.  For example, `:silent` is recognized as
			a `:substitute` command.  In that case `:execute` can
			avoid problems: >
				:if version >= 600
				:  execute "silent 1,$delete"
				:endif
<
			In |Vim9| script `:endif` cannot be shortened, to
			improve script readability.
			NOTE: The `:append` and `:insert` commands don't work
			properly in between `:if` and `:endif`.

						*:else* *:el* *E581* *E583*
:el[se]			Execute the commands until the next matching `:else`
			or `:endif` if they previously were not being
			executed.
			In |Vim9| script `:else` cannot be shortened, to
			improve script readability.

					*:elseif* *:elsei* *E582* *E584*
:elsei[f] {expr1}	Short for `:else` `:if`, with the addition that there
			is no extra `:endif`.
			In |Vim9| script `:elseif` cannot be shortened, to
			improve script readability.

:wh[ile] {expr1}			*:while* *:endwhile* *:wh* *:endw*
						*E170* *E585* *E588* *E733*
:endw[hile]		Repeat the commands between `:while` and `:endwhile`,
			as long as {expr1} evaluates to non-zero.
			When an error is detected from a command inside the
			loop, execution continues after the `endwhile`.
			Example: >
				:let lnum = 1
				:while lnum <= line("$")
				   :call FixLine(lnum)
				   :let lnum = lnum + 1
				:endwhile
<
			In |Vim9| script `:while`  and `:endwhile` cannot be
			shortened, to improve script readability.
			NOTE: The `:append` and `:insert` commands don't work
			properly inside a `:while` and `:for` loop.

:for {var} in {object}					*:for* *E690* *E732*
:endfo[r]						*:endfo* *:endfor*
			Repeat the commands between `:for` and `:endfor` for
			each item in {object}.  {object} can be a |List|,
			a |Blob| or a |String|. *E1177*

			Variable {var} is set to the value of each item.
			In |Vim9| script the loop variable must not have been
			declared yet, unless when it is a
			global/window/tab/buffer variable.

			When an error is detected for a command inside the
			loop, execution continues after the `endfor`.
			Changing {object} inside the loop affects what items
			are used.  Make a copy if this is unwanted: >
				:for item in copy(mylist)
<
			When {object} is a |List| and not making a copy, in
			legacy script Vim stores a reference to the next item
			in the |List| before executing the commands with the
			current item.  Thus the current item can be removed
			without effect.  Removing any later item means it will
			not be found.  Thus the following example works (an
			inefficient way to make a |List| empty): >
				for item in mylist
				   call remove(mylist, 0)
				endfor
<			Note that reordering the |List| (e.g., with sort() or
			reverse()) may have unexpected effects.
			In |Vim9| script the index is used.  If an item before
			the current one is deleted the next item will be
			skipped.

			When {object} is a |Blob|, Vim always makes a copy to
			iterate over.  Unlike with |List|, modifying the
			|Blob| does not affect the iteration.

			When {object} is a |String| each item is a string with
			one character, plus any combining characters.

			In |Vim9| script `:endfor` cannot be shortened, to
			improve script readability.

:for [{var1}, {var2}, ...] in {listlist}
:endfo[r]							*E1140*
			Like `:for` above, but each item in {listlist} must be
			a list, of which each item is assigned to {var1},
			{var2}, etc.  Example: >
				:for [lnum, col] in [[1, 3], [2, 5], [3, 8]]
				   :echo getline(lnum)[col]
				:endfor
<
						*:continue* *:con* *E586*
:con[tinue]		When used inside a `:while` or `:for` loop, jumps back
			to the start of the loop.
			If it is used after a `:try` inside the loop but
			before the matching `:finally` (if present), the
			commands following the `:finally` up to the matching
			`:endtry` are executed first.  This process applies to
			all nested `:try`s inside the loop.  The outermost
			`:endtry` then jumps back to the start of the loop.

			In |Vim9| script `:cont` is the shortest form, to
			improve script readability.
						*:break* *:brea* *E587*
:brea[k]		When used inside a `:while` or `:for` loop, skips to
			the command after the matching `:endwhile` or
			`:endfor`.
			If it is used after a `:try` inside the loop but
			before the matching `:finally` (if present), the
			commands following the `:finally` up to the matching
			`:endtry` are executed first.  This process applies to
			all nested `:try`s inside the loop.  The outermost
			`:endtry` then jumps to the command after the loop.

			In |Vim9| script `:break` cannot be shortened, to
			improve script readability.

:try						*:try* *:endt* *:endtry*
						*E600* *E601* *E602* *E1032*
:endt[ry]		Change the error handling for the commands between
			`:try` and `:endtry` including everything being
			executed across `:source` commands, function calls,
			or autocommand invocations.

			When an error or interrupt is detected and there is
			a `:finally` command following, execution continues
			after the `:finally`.  Otherwise, or when the
			`:endtry` is reached thereafter, the next
			(dynamically) surrounding `:try` is checked for
			a corresponding `:finally` etc.  Then the script
			processing is terminated.  Whether a function
			definition has an "abort" argument does not matter.
			Example: >
		try | call Unknown() | finally | echomsg "cleanup" | endtry
		echomsg "not reached"
<
			Moreover, an error or interrupt (dynamically) inside
			`:try` and `:endtry` is converted to an exception.  It
			can be caught as if it were thrown by a `:throw`
			command (see `:catch`).  In this case, the script
			processing is not terminated.

			The value "Vim:Interrupt" is used for an interrupt
			exception.  An error in a Vim command is converted
			to a value of the form "Vim({command}):{errmsg}",
			other errors are converted to a value of the form
			"Vim:{errmsg}".  {command} is the full command name,
			and {errmsg} is the message that is displayed if the
			error exception is not caught, always beginning with
			the error number.
			Examples: >
		try | sleep 100 | catch /^Vim:Interrupt$/ | endtry
		try | edit | catch /^Vim(edit):E\d\+/ | echo "error" | endtry
<
			In |Vim9| script `:endtry` cannot be shortened, to
			improve script readability.

					*:cat* *:catch*
					*E603* *E604* *E605* *E654* *E1033*
:cat[ch] /{pattern}/	The following commands until the next `:catch`,
			`:finally`, or `:endtry` that belongs to the same
			`:try` as the `:catch` are executed when an exception
			matching {pattern} is being thrown and has not yet
			been caught by a previous `:catch`.  Otherwise, these
			commands are skipped.
			When {pattern} is omitted all errors are caught.
			Examples: >
		:catch /^Vim:Interrupt$/	 " catch interrupts (CTRL-C)
		:catch /^Vim\%((\a\+)\)\=:E/	 " catch all Vim errors
		:catch /^Vim\%((\a\+)\)\=:/	 " catch errors and interrupts
		:catch /^Vim(write):/		 " catch all errors in :write
		:catch /^Vim\%((\a\+)\)\=:E123:/ " catch error E123
		:catch /my-exception/		 " catch user exception
		:catch /.*/			 " catch everything
		:catch				 " same as /.*/
<
			Another character can be used instead of / around the
			{pattern}, so long as it does not have a special
			meaning (e.g., '|' or '"') and doesn't occur inside
			{pattern}. *E1067*
			Information about the exception is available in
			|v:exception|.  Also see |throw-variables|.
			NOTE: It is not reliable to ":catch" the TEXT of
			an error message because it may vary in different
			locales.
			In |Vim9| script `:catch` cannot be shortened, to
			improve script readability.

					*:fina* *:finally* *E606* *E607*
:fina[lly]		The following commands until the matching `:endtry`
			are executed whenever the part between the matching
			`:try` and the `:finally` is left:  either by falling
			through to the `:finally` or by a `:continue`,
			`:break`, `:finish`, or `:return`, or by an error or
			interrupt or exception (see `:throw`).

			In |Vim9| script `:finally` cannot be shortened, to
			improve script readability and avoid confusion with
			`:final`.

						*:th* *:throw* *E608* *E1129*
:th[row] {expr1}	The {expr1} is evaluated and thrown as an exception.
			If the ":throw" is used after a `:try` but before the
			first corresponding `:catch`, commands are skipped
			until the first `:catch` matching {expr1} is reached.
			If there is no such `:catch` or if the ":throw" is
			used after a `:catch` but before the `:finally`, the
			commands following the `:finally` (if present) up to
			the matching `:endtry` are executed.  If the `:throw`
			is after the `:finally`, commands up to the `:endtry`
			are skipped.  At the ":endtry", this process applies
			again for the next dynamically surrounding `:try`
			(which may be found in a calling function or sourcing
			script), until a matching `:catch` has been found.
			If the exception is not caught, the command processing
			is terminated.
			Example: >
		:try | throw "oops" | catch /^oo/ | echo "caught" | endtry
<			Note that "catch" may need to be on a separate line
			for when an error causes the parsing to skip the whole
			line and not see the "|" that separates the commands.

			In |Vim9| script `:throw` cannot be shortened, to
			improve script readability.

							*:ec* *:echo*
:ec[ho] {expr1} ..	Echoes each {expr1}, with a space in between.  The
			first {expr1} starts on a new line.
			Also see |:comment|.
			Use "\n" to start a new line.  Use "\r" to move the
			cursor to the first column.
			Uses the highlighting set by the `:echohl` command.
			Cannot be followed by a comment.
			Example: >
		:echo "the value of 'shell' is" &shell
<							*:echo-redraw*
			A later redraw may make the message disappear again.
			And since Vim mostly postpones redrawing until it's
			finished with a sequence of commands this happens
			quite often.  To avoid that a command from before the
			`:echo` causes a redraw afterwards (redraws are often
			postponed until you type something), force a redraw
			with the `:redraw` command.  Example: >
		:new | redraw | echo "there is a new window"
<
							*:echon*
:echon {expr1} ..	Echoes each {expr1}, without anything added.  Also see
			|:comment|.
			Uses the highlighting set by the `:echohl` command.
			Cannot be followed by a comment.
			Example: >
				:echon "the value of 'shell' is " &shell
<
			Note the difference between using `:echo`, which is a
			Vim command, and `:!echo`, which is an external shell
			command: >
		:!echo %		--> filename
<			The arguments of ":!" are expanded, see |:_%|. >
		:!echo "%"		--> filename or "filename"
<			Like the previous example.  Whether you see the double
			quotes or not depends on your 'shell'. >
		:echo %			--> nothing
<			The '%' is an illegal character in an expression. >
		:echo "%"		--> %
<			This just echoes the '%' character. >
		:echo expand("%")	--> filename
<			This calls the expand() function to expand the '%'.

							*:echoh* *:echohl*
:echoh[l] {name}	Use the highlight group {name} for the following
			`:echo`, `:echon` and `:echomsg` commands.  Also used
			for the `input()` prompt.  Example: >
		:echohl WarningMsg | echo "Don't panic!" | echohl None
<			Don't forget to set the group back to "None",
			otherwise all following echo's will be highlighted.

							*:echom* *:echomsg*
:echom[sg] {expr1} ..	Echo the expression(s) as a true message, saving the
			message in the |message-history|.
			Spaces are placed between the arguments as with the
			`:echo` command.  But unprintable characters are
			displayed, not interpreted.
			The parsing works slightly different from `:echo`,
			more like `:execute`.  All the expressions are first
			evaluated and concatenated before echoing anything.
			If expressions does not evaluate to a Number or
			String, string() is used to turn it into a string.
			Uses the highlighting set by the `:echohl` command.
			Example: >
		:echomsg "It's a Zizzer Zazzer Zuzz, as you can plainly see."
<			See |:echo-redraw| to avoid the message disappearing
			when the screen is redrawn.

					*:echow* *:echowin* *:echowindow*
:[N]echow[indow] {expr1} ..
			Like |:echomsg| but when the messages popup window is
			available the message is displayed there.  This means
			it will show for three seconds and avoid a
			|hit-enter| prompt.  If you want to hide it before
			that, press Esc in Normal mode (when it would
			otherwise beep).  If it disappears too soon you can
			use `:messages` to see the text.
			When [N] is given then the window will show up for
			this number of seconds.  The last `:echowindow` with a
			count matters, it is used once only.
			The message window is available when Vim was compiled
			with the +timer and the +popupwin features.

							*:echoe* *:echoerr*
:echoe[rr] {expr1} ..	Echo the expression(s) as an error message, saving the
			message in the |message-history|.  When used in a
			script or function the line number will be added.
			Spaces are placed between the arguments as with the
			`:echomsg` command.  When used inside a try conditional,
			the message is raised as an error exception instead
			(see |try-echoerr|).
			Example: >
		:echoerr "This script just failed!"
<			If you just want a highlighted message use `:echohl`.
			And to get a beep: >
		:exe "normal \<Esc>"

:echoc[onsole] {expr1} ..				*:echoc* *:echoconsole*
			Intended for testing: works like `:echomsg` but when
			running in the GUI and started from a terminal write
			the text to stdout.

							*:eval*
:eval {expr}		Evaluate {expr} and discard the result.  Example: >
				:eval Getlist()->Filter()->append('$')

<			The expression is supposed to have a side effect,
			since the resulting value is not used.  In the example
			the `append()` call appends the List with text to the
			buffer.  This is similar to `:call` but works with any
			expression.
			In |Vim9| script an expression without an effect will
			result in error *E1207* .  This should help noticing
			mistakes.

			The command can be shortened to `:ev` or `:eva`, but
			these are hard to recognize and therefore not to be
			used.

			The command cannot be followed by "|" and another
			command, since "|" is seen as part of the expression.


							*:exe* *:execute*
:exe[cute] {expr1} ..	Executes the string that results from the evaluation
			of {expr1} as an Ex command.
			Multiple arguments are concatenated, with a space in
			between.  To avoid the extra space use the ".."
			operator to concatenate strings into one argument.
			{expr1} is used as the processed command, command line
			editing keys are not recognized.
			Cannot be followed by a comment.
			Examples: >
		:execute "buffer" nextbuf
		:execute "normal" count .. "w"
<
			":execute" can be used to append a command to commands
			that don't accept a '|'.  Example: >
		:execute '!ls' | echo "theend"

<			":execute" is also a nice way to avoid having to type
			control characters in a Vim script for a ":normal"
			command: >
		:execute "normal ixxx\<Esc>"
<			This has an <Esc> character, see |expr-string|.

			Be careful to correctly escape special characters in
			file names.  The |fnameescape()| function can be used
			for Vim commands, |shellescape()| for |:!| commands.
			Examples: >
		:execute "e " .. fnameescape(filename)
		:execute "!ls " .. shellescape(filename, 1)
<
			Note: The executed string may be any command-line, but
			starting or ending "if", "while" and "for" does not
			always work, because when commands are skipped the
			":execute" is not evaluated and Vim loses track of
			where blocks start and end.  Also "break" and
			"continue" should not be inside ":execute".
			This example does not work, because the ":execute" is
			not evaluated and Vim does not see the "while", and
			gives an error for finding an ":endwhile": >
		:if 0
		: execute 'while i > 5'
		:  echo "test"
		: endwhile
		:endif
<
			It is allowed to have a "while" or "if" command
			completely in the executed string: >
		:execute 'while i < 5 | echo i | let i = i + 1 | endwhile'
<

							*:exe-comment*
			":execute", ":echo" and ":echon" cannot be followed by
			a comment directly, because they see the '"' as the
			start of a string.  But, you can use '|' followed by a
			comment.  Example: >
		:echo "foo" | "this is a comment

==============================================================================
8. Exception handling					*exception-handling*

The Vim script language comprises an exception handling feature.  This section
explains how it can be used in a Vim script.

Exceptions may be raised by Vim on an error or on interrupt, see
|catch-errors| and |catch-interrupt|.  You can also explicitly throw an
exception by using the ":throw" command, see |throw-catch|.


TRY CONDITIONALS					*try-conditionals*

Exceptions can be caught or can cause cleanup code to be executed.  You can
use a try conditional to specify catch clauses (that catch exceptions) and/or
a finally clause (to be executed for cleanup).
   A try conditional begins with a |:try| command and ends at the matching
|:endtry| command.  In between, you can use a |:catch| command to start
a catch clause, or a |:finally| command to start a finally clause.  There may
be none or multiple catch clauses, but there is at most one finally clause,
which must not be followed by any catch clauses.  The lines before the catch
clauses and the finally clause is called a try block. >

     :try
     :	...
     :	...				TRY BLOCK
     :	...
     :catch /{pattern}/
     :	...
     :	...				CATCH CLAUSE
     :	...
     :catch /{pattern}/
     :	...
     :	...				CATCH CLAUSE
     :	...
     :finally
     :	...
     :	...				FINALLY CLAUSE
     :	...
     :endtry

The try conditional allows to watch code for exceptions and to take the
appropriate actions.  Exceptions from the try block may be caught.  Exceptions
from the try block and also the catch clauses may cause cleanup actions.
   When no exception is thrown during execution of the try block, the control
is transferred to the finally clause, if present.  After its execution, the
script continues with the line following the ":endtry".
   When an exception occurs during execution of the try block, the remaining
lines in the try block are skipped.  The exception is matched against the
patterns specified as arguments to the ":catch" commands.  The catch clause
after the first matching ":catch" is taken, other catch clauses are not
executed.  The catch clause ends when the next ":catch", ":finally", or
":endtry" command is reached - whatever is first.  Then, the finally clause
(if present) is executed.  When the ":endtry" is reached, the script execution
continues in the following line as usual.
   When an exception that does not match any of the patterns specified by the
":catch" commands is thrown in the try block, the exception is not caught by
that try conditional and none of the catch clauses is executed.  Only the
finally clause, if present, is taken.  The exception pends during execution of
the finally clause.  It is resumed at the ":endtry", so that commands after
the ":endtry" are not executed and the exception might be caught elsewhere,
see |try-nesting|.
   When during execution of a catch clause another exception is thrown, the
remaining lines in that catch clause are not executed.  The new exception is
not matched against the patterns in any of the ":catch" commands of the same
try conditional and none of its catch clauses is taken.  If there is, however,
a finally clause, it is executed, and the exception pends during its
execution.  The commands following the ":endtry" are not executed.  The new
exception might, however, be caught elsewhere, see |try-nesting|.
   When during execution of the finally clause (if present) an exception is
thrown, the remaining lines in the finally clause are skipped.  If the finally
clause has been taken because of an exception from the try block or one of the
catch clauses, the original (pending) exception is discarded.  The commands
following the ":endtry" are not executed, and the exception from the finally
clause is propagated and can be caught elsewhere, see |try-nesting|.

The finally clause is also executed, when a ":break" or ":continue" for
a ":while" loop enclosing the complete try conditional is executed from the
try block or a catch clause.  Or when a ":return" or ":finish" is executed
from the try block or a catch clause of a try conditional in a function or
sourced script, respectively.  The ":break", ":continue", ":return", or
":finish" pends during execution of the finally clause and is resumed when the
":endtry" is reached.  It is, however, discarded when an exception is thrown
from the finally clause.
   When a ":break" or ":continue" for a ":while" loop enclosing the complete
try conditional or when a ":return" or ":finish" is encountered in the finally
clause, the rest of the finally clause is skipped, and the ":break",
":continue", ":return" or ":finish" is executed as usual.  If the finally
clause has been taken because of an exception or an earlier ":break",
":continue", ":return", or ":finish" from the try block or a catch clause,
this pending exception or command is discarded.

For examples see |throw-catch| and |try-finally|.


NESTING OF TRY CONDITIONALS				*try-nesting*

Try conditionals can be nested arbitrarily.  That is, a complete try
conditional can be put into the try block, a catch clause, or the finally
clause of another try conditional.  If the inner try conditional does not
catch an exception thrown in its try block or throws a new exception from one
of its catch clauses or its finally clause, the outer try conditional is
checked according to the rules above.  If the inner try conditional is in the
try block of the outer try conditional, its catch clauses are checked, but
otherwise only the finally clause is executed.  It does not matter for
nesting, whether the inner try conditional is directly contained in the outer
one, or whether the outer one sources a script or calls a function containing
the inner try conditional.

When none of the active try conditionals catches an exception, just their
finally clauses are executed.  Thereafter, the script processing terminates.
An error message is displayed in case of an uncaught exception explicitly
thrown by a ":throw" command.  For uncaught error and interrupt exceptions
implicitly raised by Vim, the error message(s) or interrupt message are shown
as usual.

For examples see |throw-catch|.


EXAMINING EXCEPTION HANDLING CODE			*except-examine*

Exception handling code can get tricky.  If you are in doubt what happens, set
'verbose' to 13 or use the ":13verbose" command modifier when sourcing your
script file.  Then you see when an exception is thrown, discarded, caught, or
finished.  When using a verbosity level of at least 14, things pending in
a finally clause are also shown.  This information is also given in debug mode
(see |debug-scripts|).


THROWING AND CATCHING EXCEPTIONS			*throw-catch*

You can throw any number or string as an exception.  Use the |:throw| command
and pass the value to be thrown as argument: >
	:throw 4711
	:throw "string"
<							*throw-expression*
You can also specify an expression argument.  The expression is then evaluated
first, and the result is thrown: >
	:throw 4705 + strlen("string")
	:throw strpart("strings", 0, 6)

An exception might be thrown during evaluation of the argument of the ":throw"
command.  Unless it is caught there, the expression evaluation is abandoned.
The ":throw" command then does not throw a new exception.
   Example: >

	:function! Foo(arg)
	:  try
	:    throw a:arg
	:  catch /foo/
	:  endtry
	:  return 1
	:endfunction
	:
	:function! Bar()
	:  echo "in Bar"
	:  return 4710
	:endfunction
	:
	:throw Foo("arrgh") + Bar()

This throws "arrgh", and "in Bar" is not displayed since Bar() is not
executed. >
	:throw Foo("foo") + Bar()
however displays "in Bar" and throws 4711.

Any other command that takes an expression as argument might also be
abandoned by an (uncaught) exception during the expression evaluation.  The
exception is then propagated to the caller of the command.
   Example: >

	:if Foo("arrgh")
	:  echo "then"
	:else
	:  echo "else"
	:endif

Here neither of "then" or "else" is displayed.

							*catch-order*
Exceptions can be caught by a try conditional with one or more |:catch|
commands, see |try-conditionals|.   The values to be caught by each ":catch"
command can be specified as a pattern argument.  The subsequent catch clause
gets executed when a matching exception is caught.
   Example: >

	:function! Foo(value)
	:  try
	:    throw a:value
	:  catch /^\d\+$/
	:    echo "Number thrown"
	:  catch /.*/
	:    echo "String thrown"
	:  endtry
	:endfunction
	:
	:call Foo(0x1267)
	:call Foo('string')

The first call to Foo() displays "Number thrown", the second "String thrown".
An exception is matched against the ":catch" commands in the order they are
specified.  Only the first match counts.  So you should place the more
specific ":catch" first.  The following order does not make sense: >

	:  catch /.*/
	:    echo "String thrown"
	:  catch /^\d\+$/
	:    echo "Number thrown"

The first ":catch" here matches always, so that the second catch clause is
never taken.

							*throw-variables*
If you catch an exception by a general pattern, you may access the exact value
in the variable |v:exception|: >

	:  catch /^\d\+$/
	:    echo "Number thrown.  Value is" v:exception

You may also be interested where an exception was thrown.  This is stored in
|v:throwpoint|.  Note that "v:exception" and "v:throwpoint" are valid for the
exception most recently caught as long it is not finished.
   Example: >

	:function! Caught()
	:  if v:exception != ""
	:    echo 'Caught "' . v:exception .. '" in ' .. v:throwpoint
	:  else
	:    echo 'Nothing caught'
	:  endif
	:endfunction
	:
	:function! Foo()
	:  try
	:    try
	:      try
	:	 throw 4711
	:      finally
	:	 call Caught()
	:      endtry
	:    catch /.*/
	:      call Caught()
	:      throw "oops"
	:    endtry
	:  catch /.*/
	:    call Caught()
	:  finally
	:    call Caught()
	:  endtry
	:endfunction
	:
	:call Foo()

This displays >

	Nothing caught
	Caught "4711" in function Foo, line 4
	Caught "oops" in function Foo, line 10
	Nothing caught

A practical example:  The following command ":LineNumber" displays the line
number in the script or function where it has been used: >

	:function! LineNumber()
	:    return substitute(v:throwpoint, '.*\D\(\d\+\).*', '\1', "")
	:endfunction
	:command! LineNumber try | throw "" | catch | echo LineNumber() | endtry
<
							*try-nested*
An exception that is not caught by a try conditional can be caught by
a surrounding try conditional: >

	:try
	:  try
	:    throw "foo"
	:  catch /foobar/
	:    echo "foobar"
	:  finally
	:    echo "inner finally"
	:  endtry
	:catch /foo/
	:  echo "foo"
	:endtry

The inner try conditional does not catch the exception, just its finally
clause is executed.  The exception is then caught by the outer try
conditional.  The example displays "inner finally" and then "foo".

							*throw-from-catch*
You can catch an exception and throw a new one to be caught elsewhere from the
catch clause: >

	:function! Foo()
	:  throw "foo"
	:endfunction
	:
	:function! Bar()
	:  try
	:    call Foo()
	:  catch /foo/
	:    echo "Caught foo, throw bar"
	:    throw "bar"
	:  endtry
	:endfunction
	:
	:try
	:  call Bar()
	:catch /.*/
	:  echo "Caught" v:exception
	:endtry

This displays "Caught foo, throw bar" and then "Caught bar".

							*rethrow*
There is no real rethrow in the Vim script language, but you may throw
"v:exception" instead: >

	:function! Bar()
	:  try
	:    call Foo()
	:  catch /.*/
	:    echo "Rethrow" v:exception
	:    throw v:exception
	:  endtry
	:endfunction
<							*try-echoerr*
Note that this method cannot be used to "rethrow" Vim error or interrupt
exceptions, because it is not possible to fake Vim internal exceptions.
Trying so causes an error exception.  You should throw your own exception
denoting the situation.  If you want to cause a Vim error exception containing
the original error exception value, you can use the |:echoerr| command: >

	:try
	:  try
	:    asdf
	:  catch /.*/
	:    echoerr v:exception
	:  endtry
	:catch /.*/
	:  echo v:exception
	:endtry

This code displays

	Vim(echoerr):Vim:E492: Not an editor command:	asdf ~


CLEANUP CODE						*try-finally*

Scripts often change global settings and restore them at their end.  If the
user however interrupts the script by pressing CTRL-C, the settings remain in
an inconsistent state.  The same may happen to you in the development phase of
a script when an error occurs or you explicitly throw an exception without
catching it.  You can solve these problems by using a try conditional with
a finally clause for restoring the settings.  Its execution is guaranteed on
normal control flow, on error, on an explicit ":throw", and on interrupt.
(Note that errors and interrupts from inside the try conditional are converted
to exceptions.  When not caught, they terminate the script after the finally
clause has been executed.)
Example: >

	:try
	:  let s:saved_ts = &ts
	:  set ts=17
	:
	:  " Do the hard work here.
	:
	:finally
	:  let &ts = s:saved_ts
	:  unlet s:saved_ts
	:endtry

This method should be used locally whenever a function or part of a script
changes global settings which need to be restored on failure or normal exit of
that function or script part.

							*break-finally*
Cleanup code works also when the try block or a catch clause is left by
a ":continue", ":break", ":return", or ":finish".
   Example: >

	:let first = 1
	:while 1
	:  try
	:    if first
	:      echo "first"
	:      let first = 0
	:      continue
	:    else
	:      throw "second"
	:    endif
	:  catch /.*/
	:    echo v:exception
	:    break
	:  finally
	:    echo "cleanup"
	:  endtry
	:  echo "still in while"
	:endwhile
	:echo "end"

This displays "first", "cleanup", "second", "cleanup", and "end". >

	:function! Foo()
	:  try
	:    return 4711
	:  finally
	:    echo "cleanup\n"
	:  endtry
	:  echo "Foo still active"
	:endfunction
	:
	:echo Foo() "returned by Foo"

This displays "cleanup" and "4711 returned by Foo".  You don't need to add an
extra ":return" in the finally clause.  (Above all, this would override the
return value.)

							*except-from-finally*
Using either of ":continue", ":break", ":return", ":finish", or ":throw" in
a finally clause is possible, but not recommended since it abandons the
cleanup actions for the try conditional.  But, of course, interrupt and error
exceptions might get raised from a finally clause.
   Example where an error in the finally clause stops an interrupt from
working correctly: >

	:try
	:  try
	:    echo "Press CTRL-C for interrupt"
	:    while 1
	:    endwhile
	:  finally
	:    unlet novar
	:  endtry
	:catch /novar/
	:endtry
	:echo "Script still running"
	:sleep 1

If you need to put commands that could fail into a finally clause, you should
think about catching or ignoring the errors in these commands, see
|catch-errors| and |ignore-errors|.


CATCHING ERRORS						*catch-errors*

If you want to catch specific errors, you just have to put the code to be
watched in a try block and add a catch clause for the error message.  The
presence of the try conditional causes all errors to be converted to an
exception.  No message is displayed and |v:errmsg| is not set then.  To find
the right pattern for the ":catch" command, you have to know how the format of
the error exception is.
   Error exceptions have the following format: >

	Vim({cmdname}):{errmsg}
or >
	Vim:{errmsg}

{cmdname} is the name of the command that failed; the second form is used when
the command name is not known.  {errmsg} is the error message usually produced
when the error occurs outside try conditionals.  It always begins with
a capital "E", followed by a two or three-digit error number, a colon, and
a space.

Examples:

The command >
	:unlet novar
normally produces the error message >
	E108: No such variable: "novar"
which is converted inside try conditionals to an exception >
	Vim(unlet):E108: No such variable: "novar"

The command >
	:dwim
normally produces the error message >
	E492: Not an editor command: dwim
which is converted inside try conditionals to an exception >
	Vim:E492: Not an editor command: dwim

You can catch all ":unlet" errors by a >
	:catch /^Vim(unlet):/
or all errors for misspelled command names by a >
	:catch /^Vim:E492:/

Some error messages may be produced by different commands: >
	:function nofunc
and >
	:delfunction nofunc
both produce the error message >
	E128: Function name must start with a capital: nofunc
which is converted inside try conditionals to an exception >
	Vim(function):E128: Function name must start with a capital: nofunc
or >
	Vim(delfunction):E128: Function name must start with a capital: nofunc
respectively.  You can catch the error by its number independently on the
command that caused it if you use the following pattern: >
	:catch /^Vim(\a\+):E128:/

Some commands like >
	:let x = novar
produce multiple error messages, here: >
	E121: Undefined variable: novar
	E15: Invalid expression:  novar
Only the first is used for the exception value, since it is the most specific
one (see |except-several-errors|).  So you can catch it by >
	:catch /^Vim(\a\+):E121:/

You can catch all errors related to the name "nofunc" by >
	:catch /\<nofunc\>/

You can catch all Vim errors in the ":write" and ":read" commands by >
	:catch /^Vim(\(write\|read\)):E\d\+:/

You can catch all Vim errors by the pattern >
	:catch /^Vim\((\a\+)\)\=:E\d\+:/
<
							*catch-text*
NOTE: You should never catch the error message text itself: >
	:catch /No such variable/
only works in the English locale, but not when the user has selected
a different language by the |:language| command.  It is however helpful to
cite the message text in a comment: >
	:catch /^Vim(\a\+):E108:/   " No such variable


IGNORING ERRORS						*ignore-errors*

You can ignore errors in a specific Vim command by catching them locally: >

	:try
	:  write
	:catch
	:endtry

But you are strongly recommended NOT to use this simple form, since it could
catch more than you want.  With the ":write" command, some autocommands could
be executed and cause errors not related to writing, for instance: >

	:au BufWritePre * unlet novar

There could even be such errors you are not responsible for as a script
writer: a user of your script might have defined such autocommands.  You would
then hide the error from the user.
   It is much better to use >

	:try
	:  write
	:catch /^Vim(write):/
	:endtry

which only catches real write errors.  So catch only what you'd like to ignore
intentionally.

For a single command that does not cause execution of autocommands, you could
even suppress the conversion of errors to exceptions by the ":silent!"
command: >
	:silent! nunmap k
This works also when a try conditional is active.


CATCHING INTERRUPTS					*catch-interrupt*

When there are active try conditionals, an interrupt (CTRL-C) is converted to
the exception "Vim:Interrupt".  You can catch it like every exception.  The
script is not terminated, then.
   Example: >

	:function! TASK1()
	:  sleep 10
	:endfunction

	:function! TASK2()
	:  sleep 20
	:endfunction

	:while 1
	:  let command = input("Type a command: ")
	:  try
	:    if command == ""
	:      continue
	:    elseif command == "END"
	:      break
	:    elseif command == "TASK1"
	:      call TASK1()
	:    elseif command == "TASK2"
	:      call TASK2()
	:    else
	:      echo "\nIllegal command:" command
	:      continue
	:    endif
	:  catch /^Vim:Interrupt$/
	:    echo "\nCommand interrupted"
	:    " Caught the interrupt.  Continue with next prompt.
	:  endtry
	:endwhile

You can interrupt a task here by pressing CTRL-C; the script then asks for
a new command.  If you press CTRL-C at the prompt, the script is terminated.

For testing what happens when CTRL-C would be pressed on a specific line in
your script, use the debug mode and execute the |>quit| or |>interrupt|
command on that line.  See |debug-scripts|.


CATCHING ALL						*catch-all*

The commands >

	:catch /.*/
	:catch //
	:catch

catch everything, error exceptions, interrupt exceptions and exceptions
explicitly thrown by the |:throw| command.  This is useful at the top level of
a script in order to catch unexpected things.
   Example: >

	:try
	:
	:  " do the hard work here
	:
	:catch /MyException/
	:
	:  " handle known problem
	:
	:catch /^Vim:Interrupt$/
	:    echo "Script interrupted"
	:catch /.*/
	:  echo "Internal error (" .. v:exception .. ")"
	:  echo " - occurred at " .. v:throwpoint
	:endtry
	:" end of script

Note: Catching all might catch more things than you want.  Thus, you are
strongly encouraged to catch only for problems that you can really handle by
specifying a pattern argument to the ":catch".
   Example: Catching all could make it nearly impossible to interrupt a script
by pressing CTRL-C: >

	:while 1
	:  try
	:    sleep 1
	:  catch
	:  endtry
	:endwhile


EXCEPTIONS AND AUTOCOMMANDS				*except-autocmd*

Exceptions may be used during execution of autocommands.  Example: >

	:autocmd User x try
	:autocmd User x   throw "Oops!"
	:autocmd User x catch
	:autocmd User x   echo v:exception
	:autocmd User x endtry
	:autocmd User x throw "Arrgh!"
	:autocmd User x echo "Should not be displayed"
	:
	:try
	:  doautocmd User x
	:catch
	:  echo v:exception
	:endtry

This displays "Oops!" and "Arrgh!".

							*except-autocmd-Pre*
For some commands, autocommands get executed before the main action of the
command takes place.  If an exception is thrown and not caught in the sequence
of autocommands, the sequence and the command that caused its execution are
abandoned and the exception is propagated to the caller of the command.
   Example: >

	:autocmd BufWritePre * throw "FAIL"
	:autocmd BufWritePre * echo "Should not be displayed"
	:
	:try
	:  write
	:catch
	:  echo "Caught:" v:exception "from" v:throwpoint
	:endtry

Here, the ":write" command does not write the file currently being edited (as
you can see by checking 'modified'), since the exception from the BufWritePre
autocommand abandons the ":write".  The exception is then caught and the
script displays: >

	Caught: FAIL from BufWrite Auto commands for "*"
<
							*except-autocmd-Post*
For some commands, autocommands get executed after the main action of the
command has taken place.  If this main action fails and the command is inside
an active try conditional, the autocommands are skipped and an error exception
is thrown that can be caught by the caller of the command.
   Example: >

	:autocmd BufWritePost * echo "File successfully written!"
	:
	:try
	:  write /i/m/p/o/s/s/i/b/l/e
	:catch
	:  echo v:exception
	:endtry

This just displays: >

	Vim(write):E212: Can't open file for writing (/i/m/p/o/s/s/i/b/l/e)

If you really need to execute the autocommands even when the main action
fails, trigger the event from the catch clause.
   Example: >

	:autocmd BufWritePre  * set noreadonly
	:autocmd BufWritePost * set readonly
	:
	:try
	:  write /i/m/p/o/s/s/i/b/l/e
	:catch
	:  doautocmd BufWritePost /i/m/p/o/s/s/i/b/l/e
	:endtry
<
You can also use ":silent!": >

	:let x = "ok"
	:let v:errmsg = ""
	:autocmd BufWritePost * if v:errmsg != ""
	:autocmd BufWritePost *   let x = "after fail"
	:autocmd BufWritePost * endif
	:try
	:  silent! write /i/m/p/o/s/s/i/b/l/e
	:catch
	:endtry
	:echo x

This displays "after fail".

If the main action of the command does not fail, exceptions from the
autocommands will be catchable by the caller of the command:  >

	:autocmd BufWritePost * throw ":-("
	:autocmd BufWritePost * echo "Should not be displayed"
	:
	:try
	:  write
	:catch
	:  echo v:exception
	:endtry
<
							*except-autocmd-Cmd*
For some commands, the normal action can be replaced by a sequence of
autocommands.  Exceptions from that sequence will be catchable by the caller
of the command.
   Example:  For the ":write" command, the caller cannot know whether the file
had actually been written when the exception occurred.  You need to tell it in
some way. >

	:if !exists("cnt")
	:  let cnt = 0
	:
	:  autocmd BufWriteCmd * if &modified
	:  autocmd BufWriteCmd *   let cnt = cnt + 1
	:  autocmd BufWriteCmd *   if cnt % 3 == 2
	:  autocmd BufWriteCmd *     throw "BufWriteCmdError"
	:  autocmd BufWriteCmd *   endif
	:  autocmd BufWriteCmd *   write | set nomodified
	:  autocmd BufWriteCmd *   if cnt % 3 == 0
	:  autocmd BufWriteCmd *     throw "BufWriteCmdError"
	:  autocmd BufWriteCmd *   endif
	:  autocmd BufWriteCmd *   echo "File successfully written!"
	:  autocmd BufWriteCmd * endif
	:endif
	:
	:try
	:	write
	:catch /^BufWriteCmdError$/
	:  if &modified
	:    echo "Error on writing (file contents not changed)"
	:  else
	:    echo "Error after writing"
	:  endif
	:catch /^Vim(write):/
	:    echo "Error on writing"
	:endtry

When this script is sourced several times after making changes, it displays
first >
	File successfully written!
then >
	Error on writing (file contents not changed)
then >
	Error after writing
etc.

							*except-autocmd-ill*
You cannot spread a try conditional over autocommands for different events.
The following code is ill-formed: >

	:autocmd BufWritePre  * try
	:
	:autocmd BufWritePost * catch
	:autocmd BufWritePost *   echo v:exception
	:autocmd BufWritePost * endtry
	:
	:write


EXCEPTION HIERARCHIES AND PARAMETERIZED EXCEPTIONS	*except-hier-param*

Some programming languages allow to use hierarchies of exception classes or to
pass additional information with the object of an exception class.  You can do
similar things in Vim.
   In order to throw an exception from a hierarchy, just throw the complete
class name with the components separated by a colon, for instance throw the
string "EXCEPT:MATHERR:OVERFLOW" for an overflow in a mathematical library.
   When you want to pass additional information with your exception class, add
it in parentheses, for instance throw the string "EXCEPT:IO:WRITEERR(myfile)"
for an error when writing "myfile".
   With the appropriate patterns in the ":catch" command, you can catch for
base classes or derived classes of your hierarchy.  Additional information in
parentheses can be cut out from |v:exception| with the ":substitute" command.
   Example: >

	:function! CheckRange(a, func)
	:  if a:a < 0
	:    throw "EXCEPT:MATHERR:RANGE(" .. a:func .. ")"
	:  endif
	:endfunction
	:
	:function! Add(a, b)
	:  call CheckRange(a:a, "Add")
	:  call CheckRange(a:b, "Add")
	:  let c = a:a + a:b
	:  if c < 0
	:    throw "EXCEPT:MATHERR:OVERFLOW"
	:  endif
	:  return c
	:endfunction
	:
	:function! Div(a, b)
	:  call CheckRange(a:a, "Div")
	:  call CheckRange(a:b, "Div")
	:  if (a:b == 0)
	:    throw "EXCEPT:MATHERR:ZERODIV"
	:  endif
	:  return a:a / a:b
	:endfunction
	:
	:function! Write(file)
	:  try
	:    execute "write" fnameescape(a:file)
	:  catch /^Vim(write):/
	:    throw "EXCEPT:IO(" .. getcwd() .. ", " .. a:file .. "):WRITEERR"
	:  endtry
	:endfunction
	:
	:try
	:
	:  " something with arithmetic and I/O
	:
	:catch /^EXCEPT:MATHERR:RANGE/
	:  let function = substitute(v:exception, '.*(\(\a\+\)).*', '\1', "")
	:  echo "Range error in" function
	:
	:catch /^EXCEPT:MATHERR/	" catches OVERFLOW and ZERODIV
	:  echo "Math error"
	:
	:catch /^EXCEPT:IO/
	:  let dir = substitute(v:exception, '.*(\(.\+\),\s*.\+).*', '\1', "")
	:  let file = substitute(v:exception, '.*(.\+,\s*\(.\+\)).*', '\1', "")
	:  if file !~ '^/'
	:    let file = dir .. "/" .. file
	:  endif
	:  echo 'I/O error for "' .. file .. '"'
	:
	:catch /^EXCEPT/
	:  echo "Unspecified error"
	:
	:endtry

The exceptions raised by Vim itself (on error or when pressing CTRL-C) use
a flat hierarchy:  they are all in the "Vim" class.  You cannot throw yourself
exceptions with the "Vim" prefix; they are reserved for Vim.
   Vim error exceptions are parameterized with the name of the command that
failed, if known.  See |catch-errors|.


PECULIARITIES
							*except-compat*
The exception handling concept requires that the command sequence causing the
exception is aborted immediately and control is transferred to finally clauses
and/or a catch clause.

In the Vim script language there are cases where scripts and functions
continue after an error: in functions without the "abort" flag or in a command
after ":silent!", control flow goes to the following line, and outside
functions, control flow goes to the line following the outermost ":endwhile"
or ":endif".  On the other hand, errors should be catchable as exceptions
(thus, requiring the immediate abortion).

This problem has been solved by converting errors to exceptions and using
immediate abortion (if not suppressed by ":silent!") only when a try
conditional is active.  This is no restriction since an (error) exception can
be caught only from an active try conditional.  If you want an immediate
termination without catching the error, just use a try conditional without
catch clause.  (You can cause cleanup code being executed before termination
by specifying a finally clause.)

When no try conditional is active, the usual abortion and continuation
behavior is used instead of immediate abortion.  This ensures compatibility of
scripts written for Vim 6.1 and earlier.

However, when sourcing an existing script that does not use exception handling
commands (or when calling one of its functions) from inside an active try
conditional of a new script, you might change the control flow of the existing
script on error.  You get the immediate abortion on error and can catch the
error in the new script.  If however the sourced script suppresses error
messages by using the ":silent!" command (checking for errors by testing
|v:errmsg| if appropriate), its execution path is not changed.  The error is
not converted to an exception.  (See |:silent|.)  So the only remaining cause
where this happens is for scripts that don't care about errors and produce
error messages.  You probably won't want to use such code from your new
scripts.

							*except-syntax-err*
Syntax errors in the exception handling commands are never caught by any of
the ":catch" commands of the try conditional they belong to.  Its finally
clauses, however, is executed.
   Example: >

	:try
	:  try
	:    throw 4711
	:  catch /\(/
	:    echo "in catch with syntax error"
	:  catch
	:    echo "inner catch-all"
	:  finally
	:    echo "inner finally"
	:  endtry
	:catch
	:  echo 'outer catch-all caught "' .. v:exception .. '"'
	:  finally
	:    echo "outer finally"
	:endtry

This displays: >
    inner finally
    outer catch-all caught "Vim(catch):E54: Unmatched \("
    outer finally
The original exception is discarded and an error exception is raised, instead.

							*except-single-line*
The ":try", ":catch", ":finally", and ":endtry" commands can be put on
a single line, but then syntax errors may make it difficult to recognize the
"catch" line, thus you better avoid this.
   Example: >
	:try | unlet! foo # | catch | endtry
raises an error exception for the trailing characters after the ":unlet!"
argument, but does not see the ":catch" and ":endtry" commands, so that the
error exception is discarded and the "E488: Trailing characters" message gets
displayed.

							*except-several-errors*
When several errors appear in a single command, the first error message is
usually the most specific one and therefore converted to the error exception.
   Example: >
	echo novar
causes >
	E121: Undefined variable: novar
	E15: Invalid expression: novar
The value of the error exception inside try conditionals is: >
	Vim(echo):E121: Undefined variable: novar
<							*except-syntax-error*
But when a syntax error is detected after a normal error in the same command,
the syntax error is used for the exception being thrown.
   Example: >
	unlet novar #
causes >
	E108: No such variable: "novar"
	E488: Trailing characters
The value of the error exception inside try conditionals is: >
	Vim(unlet):E488: Trailing characters
This is done because the syntax error might change the execution path in a way
not intended by the user.  Example: >
	try
	    try | unlet novar # | catch | echo v:exception | endtry
	catch /.*/
	    echo "outer catch:" v:exception
	endtry
This displays "outer catch: Vim(unlet):E488: Trailing characters", and then
a "E600: Missing :endtry" error message is given, see |except-single-line|.

==============================================================================
9. Examples						*eval-examples*

Printing in Binary ~
>
  :" The function Nr2Bin() returns the binary string representation of a number.
  :func Nr2Bin(nr)
  :  let n = a:nr
  :  let r = ""
  :  while n
  :    let r = '01'[n % 2] .. r
  :    let n = n / 2
  :  endwhile
  :  return r
  :endfunc

  :" The function String2Bin() converts each character in a string to a
  :" binary string, separated with dashes.
  :func String2Bin(str)
  :  let out = ''
  :  for ix in range(strlen(a:str))
  :    let out = out .. '-' .. Nr2Bin(char2nr(a:str[ix]))
  :  endfor
  :  return out[1:]
  :endfunc

Example of its use: >
  :echo Nr2Bin(32)
result: "100000" >
  :echo String2Bin("32")
result: "110011-110010"


Sorting lines ~

This example sorts lines with a specific compare function. >

  :func SortBuffer()
  :  let lines = getline(1, '$')
  :  call sort(lines, function("Strcmp"))
  :  call setline(1, lines)
  :endfunction

As a one-liner: >
  :call setline(1, sort(getline(1, '$'), function("Strcmp")))


scanf() replacement ~
							*sscanf*
There is no sscanf() function in Vim.  If you need to extract parts from a
line, you can use matchstr() and substitute() to do it.  This example shows
how to get the file name, line number and column number out of a line like
"foobar.txt, 123, 45". >
   :" Set up the match bit
   :let mx='\(\f\+\),\s*\(\d\+\),\s*\(\d\+\)'
   :"get the part matching the whole expression
   :let l = matchstr(line, mx)
   :"get each item out of the match
   :let file = substitute(l, mx, '\1', '')
   :let lnum = substitute(l, mx, '\2', '')
   :let col = substitute(l, mx, '\3', '')

The input is in the variable "line", the results in the variables "file",
"lnum" and "col". (idea from Michael Geddes)


getting the scriptnames in a Dictionary ~
						*scriptnames-dictionary*
The `:scriptnames` command can be used to get a list of all script files that
have been sourced.  There is also the `getscriptinfo()` function, but the
information returned is not exactly the same.  In case you need to manipulate
the list, this code can be used as a base: >

    # Create or update scripts dictionary, indexed by SNR, and return it.
    def Scripts(scripts: dict<string> = {}): dict<string>
      for info in getscriptinfo()
        if scripts->has_key(info.sid)
          continue
        endif
        scripts[info.sid] = info.name
      endfor
      return scripts
    enddef

==============================================================================
10. Vim script versions		*vimscript-version* *vimscript-versions*
							*scriptversion*
Over time many features have been added to Vim script.  This includes Ex
commands, functions, variable types, etc.  Each individual feature can be
checked with the |has()| and |exists()| functions.

Sometimes old syntax of functionality gets in the way of making Vim better.
When support is taken away this will break older Vim scripts.  To make this
explicit the |:scriptversion| command can be used.  When a Vim script is not
compatible with older versions of Vim this will give an explicit error,
instead of failing in mysterious ways.

When using a legacy function, defined with `:function`, in |Vim9| script then
scriptversion 4 is used.

							*scriptversion-1*  >
 :scriptversion 1
<	This is the original Vim script, same as not using a |:scriptversion|
	command.  Can be used to go back to old syntax for a range of lines.
	Test for support with: >
		has('vimscript-1')

<							*scriptversion-2*  >
 :scriptversion 2
<	String concatenation with "." is not supported, use ".." instead.
	This avoids the ambiguity using "." for Dict member access and
	floating point numbers.  Now ".5" means the number 0.5.

							*scriptversion-3*  >
 :scriptversion 3
<	All |vim-variable|s must be prefixed by "v:".  E.g. "version" doesn't
	work as |v:version| anymore, it can be used as a normal variable.
	Same for some obvious names as "count" and others.

	Test for support with: >
		has('vimscript-3')
<
							*scriptversion-4*  >
 :scriptversion 4
<	Numbers with a leading zero are not recognized as octal.  "0o" or "0O"
	is still recognized as octal.  With the
	previous version you get: >
		echo 017   " displays 15 (octal)
		echo 0o17  " displays 15 (octal)
		echo 018   " displays 18 (decimal)
<	with script version 4: >
		echo 017   " displays 17 (decimal)
		echo 0o17  " displays 15 (octal)
		echo 018   " displays 18 (decimal)
<	Also, it is possible to use single quotes inside numbers to make them
	easier to read: >
		echo 1'000'000
<	The quotes must be surrounded by digits.

	Test for support with: >
		has('vimscript-4')

==============================================================================
11. No +eval feature				*no-eval-feature*

When the |+eval| feature was disabled at compile time, none of the expression
evaluation commands are available.  To prevent this from causing Vim scripts
to generate all kinds of errors, the ":if" and ":endif" commands are still
recognized, though the argument of the ":if" and everything between the ":if"
and the matching ":endif" is ignored.  Nesting of ":if" blocks is allowed, but
only if the commands are at the start of the line.  The ":else" command is not
recognized.

Example of how to avoid executing commands when the |+eval| feature is
missing: >

	:if 1
	:  echo "Expression evaluation is compiled in"
	:else
	:  echo "You will _never_ see this message"
	:endif

To execute a command only when the |+eval| feature is disabled can be done in
two ways.  The simplest is to exit the script (or Vim) prematurely: >
	if 1
	   echo "commands executed with +eval"
	   finish
	endif
	args  " command executed without +eval

If you do not want to abort loading the script you can use a trick, as this
example shows: >

	silent! while 0
	  set history=111
	silent! endwhile

When the |+eval| feature is available the command is skipped because of the
"while 0".  Without the |+eval| feature the "while 0" is an error, which is
silently ignored, and the command is executed.

==============================================================================
12. The sandbox					*eval-sandbox* *sandbox*

The 'foldexpr', 'formatexpr', 'includeexpr', 'indentexpr', 'statusline' and
'foldtext' options may be evaluated in a sandbox.  This means that you are
protected from these expressions having nasty side effects.  This gives some
safety for when these options are set from a modeline.  It is also used when
the command from a tags file is executed and for CTRL-R = in the command line.
The sandbox is also used for the |:sandbox| command.
								*E48*
These items are not allowed in the sandbox:
	- changing the buffer text
	- defining or changing mapping, autocommands, user commands
	- setting certain options (see |option-summary|)
	- setting certain v: variables (see |v:var|)  *E794*
	- executing a shell command
	- reading or writing a file
	- jumping to another buffer or editing a file
	- executing Python, Perl, etc. commands
This is not guaranteed 100% secure, but it should block most attacks.

							*:san* *:sandbox*
:san[dbox] {cmd}	Execute {cmd} in the sandbox.  Useful to evaluate an
			option that may have been set from a modeline, e.g.
			'foldexpr'.

							*sandbox-option*
A few options contain an expression.  When this expression is evaluated it may
have to be done in the sandbox to avoid a security risk.  But the sandbox is
restrictive, thus this only happens when the option was set from an insecure
location.  Insecure in this context are:
- sourcing a .vimrc or .exrc in the current directory
- while executing in the sandbox
- value coming from a modeline
- executing a function that was defined in the sandbox

Note that when in the sandbox and saving an option value and restoring it, the
option will still be marked as it was set in the sandbox.

==============================================================================
13. Textlock							*textlock*

In a few situations it is not allowed to change the text in the buffer, jump
to another window and some other things that might confuse or break what Vim
is currently doing.  This mostly applies to things that happen when Vim is
actually doing something else.  For example, evaluating the 'balloonexpr' may
happen any moment the mouse cursor is resting at some position.

This is not allowed when the textlock is active:
	- changing the buffer text
	- jumping to another buffer or window
	- editing another file
	- closing a window or quitting Vim
	- etc.

==============================================================================
14. Vim script library					*vim-script-library*

Vim comes bundled with a Vim script library, that can be used by runtime,
script authors.  Currently, it only includes very few functions, but it may
grow over time.

The functions are available as |Vim9-script| as well as using legacy Vim
script (to be used for non Vim 9.0 versions and Neovim).

							*dist#vim* *dist#vim9*
The functions make use of the autoloaded prefix "dist#vim" (for legacy Vim
script and Neovim) and "dist#vim9" for Vim9 script.

The following functions are available:

dist#vim#IsSafeExecutable(filetype, executable) ~
dist#vim9#IsSafeExecutable(filetype:string, executable:string): bool ~

This function takes a filetype and an executable and checks whether it is safe
to execute the given executable.  For security reasons users may not want to
have Vim execute random executables or may have forbidden to do so for
specific filetypes by setting the "<filetype>_exec" variable (|plugin_exec|).

It returns |true| or |false| to indicate whether the plugin should run the given
executable.  It takes the following arguments:

	argument	type ~

	filetype	string
	executable	string


 vim:tw=78:ts=8:noet:ft=help:norl: