This file is indexed.

/usr/share/lilypond/2.18.2/ly/music-functions-init.ly is in lilypond-data 2.18.2-4.1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

   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
%%%% -*- Mode: Scheme -*-

%%%% This file is part of LilyPond, the GNU music typesetter.
%%%%
%%%% Copyright (C) 2003--2012 Han-Wen Nienhuys <hanwen@xs4all.nl>
%%%%                          Jan Nieuwenhuizen <janneke@gnu.org>
%%%%
%%%% LilyPond is free software: you can redistribute it and/or modify
%%%% it under the terms of the GNU General Public License as published by
%%%% the Free Software Foundation, either version 3 of the License, or
%%%% (at your option) any later version.
%%%%
%%%% LilyPond is distributed in the hope that it will be useful,
%%%% but WITHOUT ANY WARRANTY; without even the implied warranty of
%%%% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
%%%% GNU General Public License for more details.
%%%%
%%%% You should have received a copy of the GNU General Public License
%%%% along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.

\version "2.17.11"


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% this file is alphabetically sorted.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%% need SRFI-1 for filter; optargs for lambda*
#(use-modules (srfi srfi-1)
	      (ice-9 optargs))

%% TODO: using define-music-function in a .scm causes crash.

absolute =
#(define-music-function (parser location music)
   (ly:music?)
   (_i "Make @var{music} absolute.  This does not actually change the
music itself but rather hides it from surrounding @code{\\relative}
commands.")
   (make-music 'RelativeOctaveMusic 'element music))

acciaccatura =
#(def-grace-function startAcciaccaturaMusic stopAcciaccaturaMusic
   (_i "Create an acciaccatura from the following music expression"))

%% keep these two together
instrument-definitions = #'()
addInstrumentDefinition =
#(define-void-function
   (parser location name lst) (string? list?)
   (_i "Create instrument @var{name} with properties @var{list}.")
   (set! instrument-definitions (acons name lst instrument-definitions)))

addQuote =
#(define-void-function (parser location name music) (string? ly:music?)
   (_i "Define @var{music} as a quotable music expression named
@var{name}")
   (add-quotable parser name music))

%% keep these two together
afterGraceFraction = #(cons 6 8)
afterGrace =
#(define-music-function (parser location main grace) (ly:music? ly:music?)
   (_i "Create @var{grace} note(s) after a @var{main} music expression.")
   (let ((main-length (ly:music-length main))
	 (fraction  (ly:parser-lookup parser 'afterGraceFraction)))
     (make-simultaneous-music
      (list
       main
       (make-sequential-music
	(list

	 (make-music 'SkipMusic
		     'duration (ly:make-duration
				0 0
				(* (ly:moment-main-numerator main-length)
				   (car fraction))
				(* (ly:moment-main-denominator main-length)
				   (cdr fraction))))
	 (make-music 'GraceMusic
		     'element grace)))))))


%% music identifiers not allowed at top-level,
%% so this is a music-function instead.
allowPageTurn =
#(define-music-function (location parser) ()
   (_i "Allow a page turn. May be used at toplevel (ie between scores or
markups), or inside a score.")
   (make-music 'EventChord
	       'page-marker #t
	       'page-turn-permission 'allow
	       'elements (list (make-music 'PageTurnEvent
					   'break-permission 'allow))))

alterBroken =
#(define-music-function (parser location property arg item)
  (symbol-list-or-symbol? list? symbol-list-or-music?)
  (_i "Override @var{property} for pieces of broken spanner @var{item}
with values @var{arg}.  @var{item} may either be music in the form of
a starting spanner event, or a symbol list in the form
@samp{Context.Grob} or just @samp{Grob}.  Iff @var{item} is in the
form of a spanner event, @var{property} may also have the form
@samp{Grob.property} for specifying a directed tweak.")
  (if (ly:music? item)
      (if (eq? (ly:music-property item 'span-direction) START)
          #{ \tweak #property #(value-for-spanner-piece arg) #item #}
          (begin
            (ly:music-warning item (_ "not a spanner"))
            item))
      (let* ((p (check-grob-path item parser location
                                 #:default 'Bottom
                                 #:min 2
                                 #:max 2))
             (name (and p (second p)))
             (description
              (and name (assoc-get name all-grob-descriptions))))
        (if (and description
                 (member 'spanner-interface
                         (assoc-get 'interfaces
                                    (assoc-get 'meta description))))
            #{
              \override #item . #property =
              #(value-for-spanner-piece arg)
            #}
            (begin
              (ly:input-warning location (_ "not a spanner name, `~a'") name)
              (make-music 'Music))))))

appendToTag =
#(define-music-function (parser location tag more music)
   (symbol? ly:music? ly:music?)
   (_i "Append @var{more} to the @code{elements} of all music
expressions in @var{music} that are tagged with @var{tag}.")
   (music-map (lambda (m)
		(if (memq tag (ly:music-property m 'tags))
		    (set! (ly:music-property m 'elements)
			  (append (ly:music-property m 'elements)
				  (list more))))
		m)
	      music))

applyContext =
#(define-music-function (parser location proc) (procedure?)
   (_i "Modify context properties with Scheme procedure @var{proc}.")
   (make-music 'ApplyContext
	       'procedure proc))

applyMusic =
#(define-music-function (parser location func music) (procedure? ly:music?)
   (_i"Apply procedure @var{func} to @var{music}.")
   (func music))

applyOutput =
#(define-music-function (parser location ctx proc) (symbol? procedure?)
   (_i "Apply function @code{proc} to every layout object in context @code{ctx}")
   (make-music 'ApplyOutputEvent
	       'procedure proc
	       'context-type ctx))

appoggiatura =
#(def-grace-function startAppoggiaturaMusic stopAppoggiaturaMusic
   (_i "Create an appoggiatura from @var{music}"))

% for regression testing purposes.
assertBeamQuant =
#(define-music-function (parser location l r) (pair? pair?)
   (_i "Testing function: check whether the beam quants @var{l} and @var{r} are correct")
   (make-grob-property-override 'Beam 'positions (check-quant-callbacks l r)))

% for regression testing purposes.
assertBeamSlope =
#(define-music-function (parser location comp) (procedure?)
   (_i "Testing function: check whether the slope of the beam is the same as @code{comp}")
   (make-grob-property-override 'Beam 'positions (check-slope-callbacks comp)))

autochange =
#(define-music-function (parser location music) (ly:music?)
   (_i "Make voices that switch between staves automatically")
   (make-autochange-music parser music))



balloonGrobText =
#(define-music-function (parser location grob-name offset text)
   (symbol? number-pair? markup?)
   (_i "Attach @var{text} to @var{grob-name} at offset @var{offset}
 (use like @code{\\once})")
   (make-event-chord
    (list
     (make-music 'AnnotateOutputEvent
                 'symbol grob-name
                 'X-offset (car offset)
                 'Y-offset (cdr offset)
                 'text text))))

balloonText =
#(define-event-function (parser location offset text) (number-pair? markup?)
   (_i "Attach @var{text} at @var{offset} (use like @code{\\tweak})")
   (make-music 'AnnotateOutputEvent
	       'X-offset (car offset)
	       'Y-offset (cdr offset)
	       'text text))

bar =
#(define-music-function (parser location type) (string?)
   (_i "Insert a bar line of type @var{type}")
   (context-spec-music
    (make-property-set 'whichBar type)
    'Timing))

barNumberCheck =
#(define-music-function (parser location n) (integer?)
   (_i "Print a warning if the current bar number is not @var{n}.")
   (make-music 'ApplyContext
	       'procedure
	       (lambda (c)
		 (let ((cbn (ly:context-property c 'currentBarNumber)))
		   (if (and  (number? cbn) (not (= cbn n)))
		       (ly:input-warning location
					 "Barcheck failed got ~a expect ~a"
					 cbn n))))))

bendAfter =
#(define-event-function (parser location delta) (real?)
   (_i "Create a fall or doit of pitch interval @var{delta}.")
   (make-music 'BendAfterEvent
	       'delta-step delta))

bookOutputName =
#(define-void-function (parser location newfilename) (string?)
   (_i "Direct output for the current book block to @var{newfilename}.")
   (set! (paper-variable parser #f 'output-filename) newfilename))

bookOutputSuffix =
#(define-void-function (parser location newsuffix) (string?)
   (_i "Set the output filename suffix for the current book block to
@var{newsuffix}.")
   (set! (paper-variable parser #f 'output-suffix) newsuffix))

%% \breathe is defined as a music function rather than an event identifier to
%% ensure it gets useful input location information: as an event identifier,
%% it would have to be wrapped in an EventChord to prevent it from being
%% treated as a post_event by the parser
breathe =
#(define-music-function (parser location) ()
   (_i "Insert a breath mark.")
   (make-music 'BreathingEvent))

clef =
#(define-music-function (parser location type) (string?)
   (_i "Set the current clef to @var{type}.")
   (make-clef-set type))


compoundMeter =
#(define-music-function (parser location args) (pair?)
  (_i "Create compound time signatures. The argument is a Scheme list of
lists. Each list describes one fraction, with the last entry being the
denominator, while the first entries describe the summands in the
enumerator. If the time signature consists of just one fraction,
the list can be given directly, i.e. not as a list containing a single list.
For example, a time signature of (3+1)/8 + 2/4 would be created as
@code{\\compoundMeter #'((3 1 8) (2 4))}, and a time signature of (3+2)/8
as @code{\\compoundMeter #'((3 2 8))} or shorter
@code{\\compoundMeter #'(3 2 8)}.")
  (let* ((mlen (calculate-compound-measure-length args))
         (beat (calculate-compound-base-beat args))
         (beatGrouping (calculate-compound-beat-grouping args))
         (timesig (cons (ly:moment-main-numerator mlen)
                        (ly:moment-main-denominator mlen))))
  #{
    \once \override Staff.TimeSignature.stencil = #(lambda (grob)
      (grob-interpret-markup grob (format-compound-time args)))
    \set Timing.timeSignatureFraction = #timesig
    \set Timing.baseMoment = #beat
    \set Timing.beatStructure = #beatGrouping
    \set Timing.beamExceptions = #'()
    \set Timing.measureLength = #mlen
  #} ))

crossStaff =
#(define-music-function (parser location notes) (ly:music?)
  (_i "Create cross-staff stems")
  #{
  \temporary \override Stem.cross-staff = #cross-staff-connect
  \temporary \override Flag.style = #'no-flag
  #notes
  \revert Stem.cross-staff
  \revert Flag.style
#})

cueClef =
#(define-music-function (parser location type) (string?)
  (_i "Set the current cue clef to @var{type}.")
  (make-cue-clef-set type))

cueClefUnset =
#(define-music-function (parser location) ()
  (_i "Unset the current cue clef.")
  (make-cue-clef-unset))

cueDuring =
#(define-music-function
   (parser location what dir main-music) (string? ly:dir? ly:music?)
   (_i "Insert contents of quote @var{what} corresponding to @var{main-music},
in a CueVoice oriented by @var{dir}.")
   (make-music 'QuoteMusic
	       'element main-music
	       'quoted-context-type 'CueVoice
	       'quoted-context-id "cue"
	       'quoted-music-name what
	       'quoted-voice-direction dir))

cueDuringWithClef =
#(define-music-function
   (parser location what dir clef main-music) (string? ly:dir? string? ly:music?)
   (_i "Insert contents of quote @var{what} corresponding to @var{main-music},
in a CueVoice oriented by @var{dir}.")
   (make-music 'QuoteMusic
	       'element main-music
	       'quoted-context-type 'CueVoice
	       'quoted-context-id "cue"
	       'quoted-music-name what
	       'quoted-music-clef clef
	       'quoted-voice-direction dir))



displayLilyMusic =
#(define-music-function (parser location music) (ly:music?)
   (_i "Display the LilyPond input representation of @var{music}
to the console.")
   (newline)
   (display-lily-music music parser)
   music)

displayMusic =
#(define-music-function (parser location music) (ly:music?)
   (_i "Display the internal representation of @var{music} to the console.")
   (newline)
   (display-scheme-music music)
   music)

displayScheme =
#(define-scheme-function (parser location expr) (scheme?)
   (_i "Display the internal representation of @var{expr} to the console.")
   (newline)
   (display-scheme-music expr)
   expr)



endSpanners =
#(define-music-function (parser location music) (ly:music?)
   (_i "Terminate the next spanner prematurely after exactly one note
without the need of a specific end spanner.")
   (let* ((start-span-evs (filter (lambda (ev)
				    (equal? (ly:music-property ev 'span-direction)
					    START))
				  (extract-typed-music music 'span-event)))
	  (stop-span-evs
	   (map (lambda (m)
		  (music-clone m 'span-direction STOP))
                start-span-evs))
	  (end-ev-chord (make-music 'EventChord
				    'elements stop-span-evs))
	  (total (make-music 'SequentialMusic
			     'elements (list music
					     end-ev-chord))))
     total))

eventChords =
#(define-music-function (parser location music) (ly:music?)
   (_i "Compatibility function wrapping @code{EventChord} around
isolated rhythmic events occuring since version 2.15.28, after
expanding repeat chords @samp{q}.")
   (event-chord-wrap! music parser))

featherDurations=
#(define-music-function (parser location factor argument) (ly:moment? ly:music?)
   (_i "Adjust durations of music in @var{argument} by rational @var{factor}.")
   (let ((orig-duration (ly:music-length argument))
	 (multiplier (ly:make-moment 1 1)))

     (for-each
      (lambda (mus)
	(if (< 0 (ly:moment-main-denominator (ly:music-length mus)))
	    (begin
	      (ly:music-compress mus multiplier)
	      (set! multiplier (ly:moment-mul factor multiplier)))))
      (extract-named-music argument '(EventChord NoteEvent RestEvent SkipEvent)))
     (ly:music-compress
      argument
      (ly:moment-div orig-duration (ly:music-length argument)))

     argument))

finger =
#(define-event-function (parser location finger) (number-or-markup?)
   (_i "Apply @var{finger} as a fingering indication.")

   (make-music
            'FingeringEvent
            (if (number? finger) 'digit 'text)
            finger))

footnote =
#(define-music-function (parser location mark offset footnote item)
   ((markup?) number-pair? markup? symbol-list-or-music?)
   (_i "Make the markup @var{footnote} a footnote on @var{item}.  The
footnote is marked with a markup @var{mark} moved by @var{offset} with
respect to the marked music.

If @var{mark} is not given or specified as @var{\\default}, it is
replaced by an automatically generated sequence number.  If @var{item}
is a symbol list of form @samp{Grob} or @samp{Context.Grob}, then
grobs of that type will be marked at the current time step in the
given context (default @code{Bottom}).

If @var{item} is music, the music will get a footnote attached to a
grob immediately attached to the event, like @var{\\tweak} does.  For
attaching a footnote to an @emph{indirectly} caused grob, write
@code{\\single\\footnote}, use @var{item} to specify the grob, and
follow it with the music to annotate.

Like with @code{\\tweak}, if you use a footnote on a following
post-event, the @code{\\footnote} command itself needs to be attached
to the preceding note or rest as a post-event with @code{-}.")
   (let ((mus (make-music
	       'FootnoteEvent
	       'X-offset (car offset)
	       'Y-offset (cdr offset)
	       'automatically-numbered (not mark)
	       'text (or mark (make-null-markup))
	       'footnote-text footnote)))
     #{ \once \tweak footnote-music #mus #item #}))

grace =
#(def-grace-function startGraceMusic stopGraceMusic
   (_i "Insert @var{music} as grace notes."))

grobdescriptions =
#(define-scheme-function (parser location descriptions) (list?)
   (_i "Create a context modification from @var{descriptions}, a list
in the format of @code{all-grob-descriptions}.")
   (ly:make-context-mod
    (map (lambda (p)
	   (list 'assign (car p) (list (cdr p))))
	 descriptions)))

harmonicByFret = #(define-music-function (parser location fret music) (number? ly:music?)
  (_i "Convert @var{music} into mixed harmonics; the resulting notes resemble
harmonics played on a fretted instrument by touching the strings at @var{fret}.")
  #{
    \set harmonicDots = ##t
    \temporary \override TabNoteHead.stencil = #(tab-note-head::print-custom-fret-label (number->string fret))
    \temporary \override NoteHead.Y-extent = #grob::always-Y-extent-from-stencil
    \temporary \override NoteHead.stencil = #(lambda (grob) (ly:grob-set-property! grob 'style 'harmonic-mixed)
                                            (ly:note-head::print grob))
    #(make-harmonic
       (calc-harmonic-pitch (fret->pitch (number->string fret)) music))
    \unset harmonicDots
    \revert TabNoteHead.stencil
    \revert NoteHead.Y-extent
    \revert NoteHead.stencil
  #})

harmonicByRatio = #(define-music-function (parser location ratio music) (number? ly:music?)
    (_i "Convert @var{music} into mixed harmonics; the resulting notes resemble
harmonics played on a fretted instrument by touching the strings at the point
given through @var{ratio}.")
  #{
    \set harmonicDots = ##t
    \temporary \override TabNoteHead.stencil = #(tab-note-head::print-custom-fret-label (ratio->fret ratio))
    \temporary \override NoteHead.Y-extent = #(ly:make-unpure-pure-container ly:grob::stencil-height
                                       (lambda (grob start end)
                                               (ly:grob::stencil-height grob)))
    \temporary \override NoteHead.stencil = #(lambda (grob) (ly:grob-set-property! grob 'style 'harmonic-mixed)
                                            (ly:note-head::print grob))
    #(make-harmonic
      (calc-harmonic-pitch (ratio->pitch ratio) music))
    \unset harmonicDots
    \revert TabNoteHead.stencil
    \revert NoteHead.Y-extent
    \revert NoteHead.stencil
  #})

hide =
#(define-music-function (parser location item) (symbol-list-or-music?)
   (_i "Set @var{item}'s @samp{transparent} property to @code{#t},
making it invisible while still retaining its dimensions.

If @var{item} is a symbol list of form @code{GrobName} or
@code{Context.GrobName}, the result is an override for the grob name
specified by it.  If @var{item} is a music expression, the result is
the same music expression with an appropriate tweak applied to it.")
   #{ \tweak transparent ##t #item #})

inStaffSegno =
#(define-music-function (parser location) ()
   (_i "Put the segno variant 'varsegno' at this position into the staff,
compatible with the repeat command.")
   (make-music 'ApplyContext
               'procedure
               (lambda (ctx)
                 (let ((score-ctx (ly:context-find ctx 'Score)))
                   (if (ly:context? score-ctx)
                     (let ((old-rc (ly:context-property score-ctx 'repeatCommands '())))
                       (if (eq? (memq 'segno-display old-rc) #f)
                         (ly:context-set-property! score-ctx 'repeatCommands (cons 'segno-display old-rc)))))))))

instrumentSwitch =
#(define-music-function
   (parser location name) (string?)
   (_i "Switch instrument to @var{name}, which must be predefined with
@code{\\addInstrumentDefinition}.")
   (let* ((handle (assoc name instrument-definitions))
	  (instrument-def (if handle (cdr handle) '())))

     (if (not handle)
	 (ly:input-warning location "No such instrument: ~a" name))
     (context-spec-music
      (make-music 'SimultaneousMusic
		  'elements
		  (map (lambda (kv)
			 (make-property-set
			  (car kv)
			  (cdr kv)))
		       instrument-def))
      'Staff)))



keepWithTag =
#(define-music-function (parser location tag music)
   (symbol-list-or-symbol? ly:music?)
   (_i "Include only elements of @var{music} that are either untagged
or tagged with one of the tags in @var{tag}.  @var{tag} may be either
a single symbol or a list of symbols.")
   (music-filter
    (if (symbol? tag)
        (lambda (m)
          (let ((music-tags (ly:music-property m 'tags)))
            (or (null? music-tags)
                (memq tag music-tags))))
        (lambda (m)
          (let ((music-tags (ly:music-property m 'tags)))
            (or (null? music-tags)
                (any (lambda (t) (memq t music-tags)) tag)))))
    music))

key =
#(define-music-function (parser location tonic pitch-alist)
   ((ly:pitch? '()) (list? '()))
   (_i "Set key to @var{tonic} and scale @var{pitch-alist}.
If both are null, just generate @code{KeyChangeEvent}.")
   (cond ((null? tonic) (make-music 'KeyChangeEvent))
	 ((null? pitch-alist)
	  (ly:parser-error parser (_ "second argument must be pitch list")
			   location)
	  (make-music 'SequentialMusic 'void #t))
	 (else
	  (ly:music-transpose
	   (make-music 'KeyChangeEvent
		'tonic (ly:make-pitch 0 0 0)
		'pitch-alist pitch-alist)
	   tonic))))

killCues =
#(define-music-function (parser location music) (ly:music?)
   (_i "Remove cue notes from @var{music}.")
   (music-map
    (lambda (mus)
      (if (and (string? (ly:music-property mus 'quoted-music-name))
	       (string=? (ly:music-property mus 'quoted-context-id "") "cue"))
	  (ly:music-property mus 'element)
	  mus))
    music))



label =
#(define-music-function (parser location label) (symbol?)
   (_i "Create @var{label} as a bookmarking label.")
   (make-music 'EventChord
	       'page-marker #t
	       'page-label label
	       'elements (list (make-music 'LabelEvent
					   'page-label label))))


language =
#(define-void-function (parser location language) (string?)
   (_i "Set note names for language @var{language}.")
   (note-names-language parser language))

languageSaveAndChange =
#(define-void-function (parser location language) (string?)
  (_i "Store the previous pitchnames alist, and set a new one.")
  (set! previous-pitchnames pitchnames)
  (note-names-language parser language))

languageRestore =
#(define-void-function (parser location) ()
   (_i "Restore a previously-saved pitchnames alist.")
   (if previous-pitchnames
       (begin
        (set! pitchnames previous-pitchnames)
        (ly:parser-set-note-names parser pitchnames))
      (ly:input-warning location (_ "No other language was defined previously. Ignoring."))))


makeClusters =
#(define-music-function (parser location arg) (ly:music?)
   (_i "Display chords in @var{arg} as clusters.")
   (music-map note-to-cluster arg))

modalInversion =
#(define-music-function (parser location around to scale music)
    (ly:pitch? ly:pitch? ly:music? ly:music?)
    (_i "Invert @var{music} about @var{around} using @var{scale} and
transpose from @var{around} to @var{to}.")
    (let ((inverter (make-modal-inverter around to scale)))
      (change-pitches music inverter)
      music))

modalTranspose =
#(define-music-function (parser location from to scale music)
    (ly:pitch? ly:pitch? ly:music? ly:music?)
    (_i "Transpose @var{music} from pitch @var{from} to pitch @var{to}
using @var{scale}.")
    (let ((transposer (make-modal-transposer from to scale)))
      (change-pitches music transposer)
      music))

inversion =
#(define-music-function
   (parser location around to music) (ly:pitch? ly:pitch? ly:music?)
   (_i "Invert @var{music} about @var{around} and
transpose from @var{around} to @var{to}.")
   (music-invert around to music))

mark =
#(define-music-function
   (parser location label) ((scheme? '()))
  "Make the music for the \\mark command."
  (let* ((set (and (integer? label)
		   (context-spec-music (make-property-set 'rehearsalMark label)
				      'Score)))
	 (ev (make-music 'MarkEvent
			 'origin location)))

    (if set
	(make-sequential-music (list set ev))
	(begin
	  (set! (ly:music-property ev 'label) label)
	  ev))))

musicMap =
#(define-music-function (parser location proc mus) (procedure? ly:music?)
   (_i "Apply @var{proc} to @var{mus} and all of the music it contains.")
   (music-map proc mus))

%% noPageBreak and noPageTurn are music functions (not music indentifiers),
%% because music identifiers are not allowed at top-level.
noPageBreak =
#(define-music-function (location parser) ()
   (_i "Forbid a page break.  May be used at toplevel (i.e., between scores or
markups), or inside a score.")
   (make-music 'EventChord
	       'page-marker #t
	       'page-break-permission 'forbid
	       'elements (list (make-music 'PageBreakEvent
					   'break-permission '()))))

noPageTurn =
#(define-music-function (location parser) ()
   (_i "Forbid a page turn.  May be used at toplevel (i.e., between scores or
markups), or inside a score.")
   (make-music 'EventChord
	       'page-marker #t
	       'page-turn-permission 'forbid
	       'elements (list (make-music 'PageTurnEvent
					   'break-permission '()))))



octaveCheck =
#(define-music-function (parser location pitch) (ly:pitch?)
   (_i "Octave check.")
   (make-music 'RelativeOctaveCheck
               'pitch pitch))

offset =
#(define-music-function (parser location property offsets item)
  (symbol-list-or-symbol? scheme? symbol-list-or-music?)
   (_i "Offset the default value of @var{property} of @var{item} by
@var{offsets}.  If @var{item} is a string, the result is
@code{\\override} for the specified grob type.  If @var{item} is
a music expression, the result is the same music expression with an
appropriate tweak applied.")
  (if (ly:music? item)
      ; In case of a tweak, grob property path is Grob.property
      (let ((prop-path (check-grob-path
                         (if (symbol? property)
                             (list property)
                             property)
                         parser location
                         #:start 1 #:default #t #:min 2 #:max 2)))
        (if prop-path
            ; If the head of the grob property path is a symbol--i.e.,
            ; a grob name, produce a directed tweak.  Otherwise, create
            ; an ordinary tweak.
            (if (symbol? (car prop-path))
                #{
                  \tweak #prop-path #(offsetter (second prop-path) offsets) #item
                #}
                #{
                  \tweak #(second prop-path) #(offsetter (second prop-path) offsets) #item
                #})
            item))
      ; In case of an override, grob property path is Context.Grob.property.
      (let ((prop-path (check-grob-path
                         (append item
                                 (if (symbol? property)
                                     (list property)
                                     property))
                         parser location
                         #:default 'Bottom #:min 3 #:max 3)))
        (if prop-path
            #{
              \override #prop-path = #(offsetter (third prop-path) offsets)
            #}
            (make-music 'Music)))))
 
omit =
#(define-music-function (parser location item) (symbol-list-or-music?)
   (_i "Set @var{item}'s @samp{stencil} property to @code{#f},
effectively omitting it without taking up space.

If @var{item} is a symbol list of form @code{GrobName} or
@code{Context.GrobName}, the result is an override for the grob name
specified by it.  If @var{item} is a music expression, the result is
the same music expression with an appropriate tweak applied to it.")
   #{ \tweak stencil ##f #item #})

once =
#(define-music-function (parser location music) (ly:music?)
   (_i "Set @code{once} to @code{#t} on all layout instruction events
in @var{music}.  This will complain about music with an actual
duration.  As a special exception, if @var{music} contains
@samp{tweaks} it will be silently ignored in order to allow for
@code{\\once \\tweak} to work as both one-time override and proper
tweak.")
   (if (not (pair? (ly:music-property music 'tweaks)))
       (for-some-music
        (lambda (m)
          (cond ((music-is-of-type? m 'layout-instruction-event)
                 (set! (ly:music-property m 'once) #t)
                 #t)
                ((ly:duration? (ly:music-property m 'duration))
                 (ly:music-warning m (_ "Cannot apply \\once to timed music"))
                 #t)
                (else #f)))
        music))
   music)

ottava =
#(define-music-function (parser location octave) (integer?)
   (_i "Set the octavation.")
   (make-music 'OttavaMusic
	       'ottava-number octave))

overrideTimeSignatureSettings =
#(define-music-function
   (parser location time-signature base-moment beat-structure beam-exceptions)
   (fraction? fraction? list? list?)

   (_i "Override @code{timeSignatureSettings}
for time signatures of @var{time-signature} to have settings
of @var{base-moment}, @var{beat-structure}, and @var{beam-exceptions}.")

   ;; TODO -- add warning if largest value of grouping is
   ;;	    greater than time-signature.
  (let ((setting (make-setting base-moment beat-structure beam-exceptions)))
    (override-time-signature-setting time-signature setting)))

overrideProperty =
#(define-music-function (parser location grob-property-path value)
   (symbol-list? scheme?)

   (_i "Set the grob property specified by @var{grob-property-path} to
@var{value}.  @var{grob-property-path} is a symbol list of the form
@code{Context.GrobName.property} or @code{GrobName.property}, possibly
with subproperties given as well.")
   (let ((p (check-grob-path grob-property-path parser location
                             #:default 'Bottom
                             #:min 3)))
     (if p
         (make-music 'ApplyOutputEvent
                     'context-type (first p)
                     'procedure
                     (lambda (grob orig-context context)
                       (if (equal?
                            (cdr (assoc 'name (ly:grob-property grob 'meta)))
                            (second p))
                           (ly:grob-set-nested-property!
                            grob (cddr p) value))))
         (make-music 'Music))))






%% pageBreak and pageTurn are music functions (iso music indentifiers),
%% because music identifiers are not allowed at top-level.
pageBreak =
#(define-music-function (location parser) ()
   (_i "Force a page break.  May be used at toplevel (i.e., between scores or
markups), or inside a score.")
   (make-music 'EventChord
	       'page-marker #t
	       'line-break-permission 'force
	       'page-break-permission 'force
	       'elements (list (make-music 'LineBreakEvent
					   'break-permission 'force)
			       (make-music 'PageBreakEvent
					   'break-permission 'force))))

pageTurn =
#(define-music-function (location parser) ()
   (_i "Force a page turn between two scores or top-level markups.")
   (make-music 'EventChord
	       'page-marker #t
	       'line-break-permission 'force
	       'page-break-permission 'force
	       'page-turn-permission 'force
	       'elements (list (make-music 'LineBreakEvent
					   'break-permission 'force)
			       (make-music 'PageBreakEvent
					   'break-permission 'force)
			       (make-music 'PageTurnEvent
					   'break-permission 'force))))

parallelMusic =
#(define-void-function (parser location voice-ids music) (list? ly:music?)
   (_i "Define parallel music sequences, separated by '|' (bar check signs),
and assign them to the identifiers provided in @var{voice-ids}.

@var{voice-ids}: a list of music identifiers (symbols containing only letters)

@var{music}: a music sequence, containing BarChecks as limiting expressions.

Example:

@verbatim
  \\parallelMusic #'(A B C) {
    c c | d d | e e |
    d d | e e | f f |
  }
<==>
  A = { c c | d d | }
  B = { d d | e e | }
  C = { e e | f f | }
@end verbatim
")
   (define (bar-check? m)
     "Checks whether m is a bar check."
     (eq? (ly:music-property m 'name) 'BarCheck))
   (define (recurse-and-split music)
     "This returns either a list of music split along barchecks, or
@code{#f}."
     (let ((elt (ly:music-property music 'element))
           (elts (ly:music-property music 'elements)))
       (cond ((ly:music? elt)
              (let ((lst (recurse-and-split elt)))
                (and lst
                     (map
                      (lambda (x)
                        (let ((res (music-clone music 'element x)))
                          (if (ly:input-location?
                               (ly:music-property x 'origin))
                              (set! (ly:music-property res 'origin)
                                    (ly:music-property x 'origin)))
                          res))
                      lst))))
             ((any bar-check? elts)
              (let* ((voices (apply circular-list
                                    (make-list (length voice-ids)
                                               '())))
                     (current-voices voices)
                     (current-sequence '()))
                ;;
                ;; utilities
                (define (push-music m)
                  "Push the music expression into the current sequence"
                  (set! current-sequence (cons m current-sequence)))
                (define (change-voice)
                  "Stores the previously built sequence into the current voice and
       change to the following voice."
                  (set-car! current-voices
                            (cons (reverse! current-sequence)
                                  (car current-voices)))
                  (set! current-sequence '())
                  (set! current-voices (cdr current-voices)))
                (for-each (lambda (m)
                            (let ((split? (recurse-and-split m)))
                              (if split?
                                  (for-each
                                   (lambda (m)
                                     (push-music m)
                                     (change-voice))
                                   split?)
                                  (begin
                                    (push-music m)
                                    (if (bar-check? m) (change-voice))))))
                          elts)
                (if (pair? current-sequence) (change-voice))
                ;; un-circularize `voices' and reorder the voices

                (set! voices (map reverse!
                                  (list-head voices (length voice-ids))))

                ;; check sequence length
                (apply for-each (lambda seqs
                                  (define (seq-len seq)
                                    (reduce ly:moment-add
                                            (ly:make-moment 0)
                                            (map ly:music-length seq)))
                                  (let ((moment-reference (seq-len (car seqs))))
                                    (for-each (lambda (seq)
                                                (if (not (equal? (seq-len seq)
                                                                 moment-reference))
                                                    (ly:music-warning
                                                     (if (pair? seq)
                                                         (last seq)
                                                         (caar seqs))
                                                     (_ "Bars in parallel music don't have the same length"))))
                                              seqs)))
                       voices)
                (map
                 (lambda (lst)
                   (set! lst (concatenate! lst))
                   (let ((res (music-clone music 'elements lst)))
                     (if (and (pair? lst)
                              (ly:input-location? (ly:music-property
                                                   (car lst)
                                                   'origin)))
                         (set! (ly:music-property res 'origin)
                               (ly:music-property (car lst) 'origin)))
                     res))
                 voices)))
             (else #f))))
   (let ((voices (recurse-and-split music)))
     (if voices
         ;;
         ;; bind voice identifiers to the voices
         (for-each (lambda (voice-id voice)
                     (ly:parser-define! parser voice-id voice))
	  voice-ids voices)
         (ly:music-warning music
                           (_ "ignoring parallel music without barchecks")))))

parenthesize =
#(define-music-function (parser loc arg) (ly:music?)
   (_i "Tag @var{arg} to be parenthesized.")

   (if (memq 'event-chord (ly:music-property arg 'types))
       ;; arg is an EventChord -> set the parenthesize property
       ;; on all child notes and rests
       (for-each
	(lambda (ev)
	  (if (or (memq 'note-event (ly:music-property ev 'types))
		  (memq 'rest-event (ly:music-property ev 'types)))
	      (set! (ly:music-property ev 'parenthesize) #t)))
	(ly:music-property arg 'elements))
       ;; No chord, simply set property for this expression:
       (set! (ly:music-property arg 'parenthesize) #t))
   arg)

partcombine =
#(define-music-function (parser location part1 part2) (ly:music? ly:music?)
   (_i "Take the music in @var{part1} and @var{part2} and typeset so
that they share a staff.")
   (make-part-combine-music parser
                            (list part1 part2) #f))

partcombineUp =
#(define-music-function (parser location part1 part2) (ly:music? ly:music?)
   (_i "Take the music in @var{part1} and @var{part2} and typeset so
that they share a staff with stems directed upward.")
   (make-part-combine-music parser
                            (list part1 part2) UP))

partcombineDown =
#(define-music-function (parser location part1 part2) (ly:music? ly:music?)
   (_i "Take the music in @var{part1} and @var{part2} and typeset so
that they share a staff with stems directed downward.")
   (make-part-combine-music parser
                            (list part1 part2) DOWN))

partcombineForce =
#(define-music-function (location parser type once) (symbol-or-boolean? boolean?)
   (_i "Override the part-combiner.")
   (make-music 'EventChord
	       'elements (list (make-music 'PartCombineForceEvent
					   'forced-type type
					   'once once))))
partcombineApart = \partcombineForce #'apart ##f
partcombineApartOnce = \partcombineForce #'apart ##t
partcombineChords = \partcombineForce #'chords ##f
partcombineChordsOnce = \partcombineForce #'chords ##t
partcombineUnisono = \partcombineForce #'unisono ##f
partcombineUnisonoOnce = \partcombineForce #'unisono ##t
partcombineSoloI = \partcombineForce #'solo1 ##f
partcombineSoloIOnce = \partcombineForce #'solo1 ##t
partcombineSoloII = \partcombineForce #'solo2 ##f
partcombineSoloIIOnce = \partcombineForce #'solo2 ##t
partcombineAutomatic = \partcombineForce ##f ##f
partcombineAutomaticOnce = \partcombineForce ##f ##t

partial =
#(define-music-function (parser location dur) (ly:duration?)
  (_i "Make a partial measure.")

  ;; We use `descend-to-context' here instead of `context-spec-music' to
  ;; ensure \partial still works if the Timing_translator is moved
    (descend-to-context
     (context-spec-music (make-music 'PartialSet
				     'origin location
				     'duration dur)
			 'Timing)
     'Score))

pitchedTrill =
#(define-music-function
   (parser location main-note secondary-note)
   (ly:music? ly:music?)
   (_i "Print a trill with @var{main-note} as the main note of the trill and
print @var{secondary-note} as a stemless note head in parentheses.")
   (let* ((get-notes (lambda (ev-chord)
		       (extract-named-music ev-chord 'NoteEvent)))
          (sec-note-events (get-notes secondary-note))
          (trill-events (extract-named-music main-note 'TrillSpanEvent)))
     (if (pair? sec-note-events)
         (begin
           (let* ((trill-pitch (ly:music-property (car sec-note-events) 'pitch))
                  (forced (ly:music-property (car sec-note-events) 'force-accidental)))

             (if (ly:pitch? trill-pitch)
                 (for-each (lambda (m)
                             (ly:music-set-property! m 'pitch trill-pitch)) trill-events)
                 (begin
                   (ly:input-warning location (_ "Second argument of \\pitchedTrill should be single note: "))
                   (display sec-note-events)))

             (if (eq? forced #t)
                 (for-each (lambda (m)
                             (ly:music-set-property! m 'force-accidental forced))
                           trill-events)))))
     main-note))

pushToTag =
#(define-music-function (parser location tag more music)
   (symbol? ly:music? ly:music?)
   (_i "Add @var{more} to the front of @code{elements} of all music
expressions in @var{music} that are tagged with @var{tag}.")
   (music-map (lambda (m)
		(if (memq tag (ly:music-property m 'tags))
		    (set! (ly:music-property m 'elements)
			  (cons more (ly:music-property m 'elements))))
		m)
	      music))

quoteDuring =
#(define-music-function (parser location what main-music) (string? ly:music?)
   (_i "Indicate a section of music to be quoted.  @var{what} indicates the name
of the quoted voice, as specified in an @code{\\addQuote} command.
@var{main-music} is used to indicate the length of music to be quoted;
usually contains spacers or multi-measure rests.")
   (make-music 'QuoteMusic
               'element main-music
               'quoted-music-name what))

relative =
#(define-music-function (parser location pitch music)
   ((ly:pitch?) ly:music?)
   (_i "Make @var{music} relative to @var{pitch}.  If @var{pitch} is
omitted, the first note in @var{music} is given in absolute pitch.")
   ;; When \relative has no clear decision (can only happen with
   ;; scales with an even number of steps), it goes down (see
   ;; pitch.cc).  The following formula puts out f for both the normal
   ;; 7-step scale as well as for a "shortened" scale missing the
   ;; final b.  In either case, a first note of c will end up as c,
   ;; namely pitch (-1, 0, 0).
   (ly:make-music-relative! music
                            (or pitch
                                (ly:make-pitch
                                 -1
                                 (quotient
                                  ;; size of current scale:
                                  (ly:pitch-steps (ly:make-pitch 1 0))
                                  2))))
   (make-music 'RelativeOctaveMusic
	       'element music))

removeWithTag =
#(define-music-function (parser location tag music)
   (symbol-list-or-symbol? ly:music?)
   (_i "Remove elements of @var{music} that are tagged with one of the
tags in @var{tag}.  @var{tag} may be either a single symbol or a list
of symbols.")
   (music-filter
    (if (symbol? tag)
        (lambda (m)
          (not (memq tag (ly:music-property m 'tags))))
        (lambda (m)
          (let ((music-tags (ly:music-property m 'tags)))
            (or (null? music-tags)
                (not (any (lambda (t) (memq t music-tags)) tag))))))
    music))

resetRelativeOctave =
#(define-music-function (parser location pitch) (ly:pitch?)
   (_i "Set the octave inside a \\relative section.")

   (make-music 'SequentialMusic
               'to-relative-callback
               (lambda (music last-pitch) pitch)))

retrograde =
#(define-music-function (parser location music)
    (ly:music?)
    (_i "Return @var{music} in reverse order.")
    (retrograde-music music))

revertTimeSignatureSettings =
#(define-music-function
   (parser location time-signature)
   (pair?)

   (_i "Revert @code{timeSignatureSettings}
for time signatures of @var{time-signature}.")
   (revert-time-signature-setting time-signature))

rightHandFinger =
#(define-event-function (parser location finger) (number-or-markup?)
   (_i "Apply @var{finger} as a fingering indication.")

   (make-music
            'StrokeFingerEvent
            (if (number? finger) 'digit 'text)
            finger))

scaleDurations =
#(define-music-function (parser location fraction music)
   (fraction? ly:music?)
   (_i "Multiply the duration of events in @var{music} by @var{fraction}.")
   (ly:music-compress music
		      (ly:make-moment (car fraction) (cdr fraction))))

settingsFrom =
#(define-scheme-function (parser location ctx music)
   ((symbol?) ly:music?)
   (_i "Take the layout instruction events from @var{music}, optionally
restricted to those applying to context type @var{ctx}, and return
a context modification duplicating their effect.")
   (let ((mods (ly:make-context-mod)))
     (define (musicop m)
       (if (music-is-of-type? m 'layout-instruction-event)
	   (ly:add-context-mod
	    mods
	    (case (ly:music-property m 'name)
	      ((PropertySet)
	       (list 'assign
		     (ly:music-property m 'symbol)
		     (ly:music-property m 'value)))
	      ((PropertyUnset)
	       (list 'unset
		     (ly:music-property m 'symbol)))
	      ((OverrideProperty)
	       (cons* 'push
		      (ly:music-property m 'symbol)
		      (ly:music-property m 'grob-value)
                      (cond
                       ((ly:music-property m 'grob-property #f) => list)
                       (else
                        (ly:music-property m 'grob-property-path)))))
	      ((RevertProperty)
	       (cons* 'pop
		      (ly:music-property m 'symbol)
                      (cond
                       ((ly:music-property m 'grob-property #f) => list)
                       (else
                        (ly:music-property m 'grob-property-path)))))))
	   (case (ly:music-property m 'name)
	     ((ApplyContext)
	      (ly:add-context-mod mods
				  (list 'apply
					(ly:music-property m 'procedure))))
	     ((ContextSpeccedMusic)
	      (if (or (not ctx)
		      (eq? ctx (ly:music-property m 'context-type)))
		  (musicop (ly:music-property m 'element))))
	     (else
	      (let ((callback (ly:music-property m 'elements-callback)))
		(if (procedure? callback)
		    (for-each musicop (callback m))))))))
     (musicop music)
     mods))

shape =
#(define-music-function (parser location offsets item)
   (list? symbol-list-or-music?)
   (_i "Offset control-points of @var{item} by @var{offsets}.  The
argument is a list of number pairs or list of such lists.  Each
element of a pair represents an offset to one of the coordinates of a
control-point.  If @var{item} is a string, the result is
@code{\\once\\override} for the specified grob type.  If @var{item} is
a music expression, the result is the same music expression with an
appropriate tweak applied.")
   (define (shape-curve grob)
     (let* ((orig (ly:grob-original grob))
            (siblings (if (ly:spanner? grob)
                          (ly:spanner-broken-into orig) '()))
            (total-found (length siblings))
            (function (assoc-get 'control-points
                                 (reverse (ly:grob-basic-properties grob))))
            (coords (function grob)))

       (define (offset-control-points offsets)
         (if (null? offsets)
             coords
             (map
               (lambda (x y) (coord-translate x y))
               coords offsets)))

       (define (helper sibs offs)
         (if (pair? offs)
             (if (eq? (car sibs) grob)
                 (offset-control-points (car offs))
                 (helper (cdr sibs) (cdr offs)))
             coords))

       ;; we work with lists of lists
       (if (or (null? offsets)
               (not (list? (car offsets))))
           (set! offsets (list offsets)))

       (if (>= total-found 2)
           (helper siblings offsets)
           (offset-control-points (car offsets)))))
   #{ \once \tweak control-points #shape-curve #item #})

shiftDurations =
#(define-music-function (parser location dur dots arg)
   (integer? integer? ly:music?)
   (_i "Change the duration of @var{arg} by adding @var{dur} to the
@code{durlog} of @var{arg} and @var{dots} to the @code{dots} of @var{arg}.")

   (music-map
    (lambda (x)
      (shift-one-duration-log x dur dots)) arg))

single =
#(define-music-function (parser location overrides music)
   (ly:music? ly:music?)
   (_i "Convert @var{overrides} to tweaks and apply them to @var{music}.
This does not convert @code{\\revert}, @code{\\set} or @code{\\unset}.")
   (set! (ly:music-property music 'tweaks)
         (fold-some-music
          (lambda (m) (eq? (ly:music-property m 'name)
                           'OverrideProperty))
          (lambda (m tweaks)
            (let ((p (cond
                      ((ly:music-property m 'grob-property #f) => list)
                      (else
                       (ly:music-property m 'grob-property-path)))))
              (acons (cons (ly:music-property m 'symbol) ;grob name
                           (if (pair? (cdr p))
                               p ;grob property path
                               (car p))) ;grob property
                     (ly:music-property m 'grob-value)
                     tweaks)))
          (ly:music-property music 'tweaks)
          overrides))
   music)

skip =
#(define-music-function (parser location dur) (ly:duration?)
  (_i "Skip forward by @var{dur}.")
  (make-music 'SkipMusic
	      'duration dur))


slashedGrace =
#(def-grace-function startSlashedGraceMusic stopSlashedGraceMusic
   (_i "Create slashed graces (slashes through stems, but no slur) from
the following music expression"))

spacingTweaks =
#(define-music-function (parser location parameters) (list?)
   (_i "Set the system stretch, by reading the 'system-stretch property of
the `parameters' assoc list.")
   #{
     \overrideProperty Score.NonMusicalPaperColumn.line-break-system-details
     #(list (cons 'alignment-extra-space (cdr (assoc 'system-stretch parameters)))
	     (cons 'system-Y-extent (cdr (assoc 'system-Y-extent parameters))))
   #})

styledNoteHeads =
#(define-music-function (parser location style heads music)
   (symbol? symbol-list-or-symbol? ly:music?)
   (_i "Set @var{heads} in @var{music} to @var{style}.")
   (style-note-heads heads style music))

tag =
#(define-music-function (parser location tag music) (symbol-list-or-symbol? ly:music?)
   (_i "Tag the following @var{music} with @var{tag} and return the
result, by adding the single symbol or symbol list @var{tag} to the
@code{tags} property of @var{music}.")

   (set!
    (ly:music-property music 'tags)
    ((if (symbol? tag) cons append)
     tag
     (ly:music-property music 'tags)))
   music)

temporary =
#(define-music-function (parser location music)
   (ly:music?)
   (_i "Make any @code{\\override} in @var{music} replace an existing
grob property value only temporarily, restoring the old value when a
corresponding @code{\\revert} is executed.  This is achieved by
clearing the @samp{pop-first} property normally set on
@code{\\override}s.

An @code{\\override}/@/@code{\\revert} sequence created by using
@code{\\temporary} and @code{\\undo} on the same music containing
overrides will cancel out perfectly or cause a@tie{}warning.

Non-property-related music is ignored, warnings are generated for any
property-changing music that isn't an @code{\\override}.")
   (define warned #f)
   (for-some-music
    (lambda (m)
      (and (or (music-is-of-type? m 'layout-instruction-event)
               (music-is-of-type? m 'context-specification)
               (music-is-of-type? m 'apply-context)
               (music-is-of-type? m 'time-signature-music))
           (case (ly:music-property m 'name)
             ((OverrideProperty)
              (if (ly:music-property m 'pop-first #f)
                  (set! (ly:music-property m 'pop-first) '()))
              (if (ly:music-property m 'once #f)
                  (set! (ly:music-property m 'once) '()))
              #t)
             ((ContextSpeccedMusic)
              #f)
             (else
              (if (not warned)
                  (begin
                    (ly:input-warning location (_ "Cannot make ~a revertible")
                                      (ly:music-property m 'name))
                    (set! warned #t)))
              #t))))
    music)
   music)

time =
#(define-music-function (parser location beat-structure fraction)
   ((number-list? '()) fraction?)
   (_i "Set @var{fraction} as time signature, with optional
number list @var{beat-structure} before it.")
  (make-music 'TimeSignatureMusic
              'numerator (car fraction)
              'denominator (cdr fraction)
              'beat-structure beat-structure))

times =
#(define-music-function (parser location fraction music)
   (fraction? ly:music?)
   (_i "Scale @var{music} in time by @var{fraction}.")
  (make-music 'TimeScaledMusic
  	      'element (ly:music-compress music (ly:make-moment (car fraction) (cdr fraction)))
  	      'numerator (car fraction)
  	      'denominator (cdr fraction)))

transpose =
#(define-music-function
   (parser location from to music)
   (ly:pitch? ly:pitch? ly:music?)

   (_i "Transpose @var{music} from pitch @var{from} to pitch @var{to}.")
   (make-music 'TransposedMusic
               'element (ly:music-transpose music (ly:pitch-diff to from))))

transposedCueDuring =
#(define-music-function
   (parser location what dir pitch main-music)
   (string? ly:dir? ly:pitch? ly:music?)

   (_i "Insert notes from the part @var{what} into a voice called @code{cue},
using the transposition defined by @var{pitch}.  This happens
simultaneously with @var{main-music}, which is usually a rest.	The
argument @var{dir} determines whether the cue notes should be notated
as a first or second voice.")

   (make-music 'QuoteMusic
	       'element main-music
	       'quoted-context-type 'CueVoice
	       'quoted-context-id "cue"
	       'quoted-music-name what
	       'quoted-voice-direction dir
               ;; following is inverse of instrumentTransposition for
               ;; historical reasons
	       'quoted-transposition pitch))

transposition =
#(define-music-function (parser location pitch) (ly:pitch?)
   (_i "Set instrument transposition")

   (context-spec-music
    (make-property-set 'instrumentTransposition pitch)
    'Staff))

tuplet =
#(define-music-function (parser location ratio tuplet-span music)
   (fraction? (ly:duration? '()) ly:music?)
   (_i "Scale the given @var{music} to tuplets.  @var{ratio} is a
fraction that specifies how many notes are played in place of the
nominal value: it will be @samp{3/2} for triplets, namely three notes
being played in place of two.  If the optional duration
@var{tuplet-span} is specified, it is used instead of
@code{tupletSpannerDuration} for grouping the tuplets.
For example,
@example
\\tuplet 3/2 4 @{ c8 c c c c c @}
@end example
will result in two groups of three tuplets, each group lasting for a
quarter note.")
   (make-music 'TimeScaledMusic
               'element (ly:music-compress
                         music
                         (ly:make-moment (cdr ratio) (car ratio)))
               'numerator (cdr ratio)
               'denominator (car ratio)
               'duration tuplet-span))

tupletSpan =
#(define-music-function (parser location tuplet-span)
   ((ly:duration?))
   (_i "Set @code{tupletSpannerDuration}, the length into which
@code{\\tuplet} without an explicit @samp{tuplet-span} argument of its
own will group its tuplets, to the duration @var{tuplet-span}.  To
revert to the default of not subdividing the contents of a @code{\\tuplet}
command without explicit @samp{tuplet-span}, use
@example
\\tupletSpan \\default
@end example
")
   (if tuplet-span
       #{ \set tupletSpannerDuration = #(ly:duration-length tuplet-span) #}
       #{ \unset tupletSpannerDuration #}))

tweak =
#(define-music-function (parser location prop value item)
   (symbol-list-or-symbol? scheme? symbol-list-or-music?)
   (_i "Add a tweak to the following @var{item}, usually music.
Layout objects created by @var{item} get their property @var{prop}
set to @var{value}.  If @var{prop} has the form @samp{Grob.property}, like with
@example
\\tweak Accidental.color #red cis'
@end example
an indirectly created grob (@samp{Accidental} is caused by
@samp{NoteHead}) can be tweaked; otherwise only directly created grobs
are affected.

As a special case, @var{item} may be a symbol list specifying a grob
path, in which case @code{\\override} is called on it instead of
creating tweaked music.  This is mainly useful when using
@code{\\tweak} as as a component for building other functions.

If this use case would call for @code{\\once \\override} rather than a
plain @code{\\override}, writing @code{\\once \\tweak @dots{}} can be
convenient.

@var{prop} can contain additional elements in which case a nested
property (inside of an alist) is tweaked.")
   (if (ly:music? item)
       (let ((p (check-grob-path prop parser location
                                 #:start 1
                                 #:default #t
                                 #:min 2)))
         (if p
             (set! (ly:music-property item 'tweaks)
                   (acons (cond ((pair? (cddr p)) p)
                                ((symbol? (car p))
                                 (cons (car p) (cadr p)))
                                (else (cadr p)))
                          value
                          (ly:music-property item 'tweaks))))
         item)
       ;; We could just throw this at \override and let it sort this
       ;; out on its own, but this way we should get better error
       ;; diagnostics.
       (let ((p (check-grob-path
                 (append item (if (symbol? prop) (list prop) prop))
                 parser location
                 #:default 'Bottom #:min 3)))
         (if p
             #{ \override #p = #value #}
             (make-music 'Music)))))

undo =
#(define-music-function (parser location music)
   (ly:music?)
   (_i "Convert @code{\\override} and @code{\\set} in @var{music} to
@code{\\revert} and @code{\\unset}, respectively.  Any reverts and
unsets already in @var{music} cause a warning.  Non-property-related music is ignored.")
   (define warned #f)
   (let loop
       ((music music))
     (let
         ((lst
           (fold-some-music
            (lambda (m) (or (music-is-of-type? m 'layout-instruction-event)
                            (music-is-of-type? m 'context-specification)
                            (music-is-of-type? m 'apply-context)
                            (music-is-of-type? m 'time-signature-music)))
            (lambda (m overrides)
              (case (ly:music-property m 'name)
                ((OverrideProperty)
                 (cons
                  (make-music 'RevertProperty
                              'symbol (ly:music-property m 'symbol)
                              'grob-property-path
                              (cond
                               ((ly:music-property m 'grob-property #f) => list)
                               (else
                                (ly:music-property m 'grob-property-path))))
                  overrides))
                ((PropertySet)
                 (cons
                  (make-music 'PropertyUnset
                              'symbol (ly:music-property m 'symbol))
                  overrides))
                ((ContextSpeccedMusic)
                 (cons
                  (make-music 'ContextSpeccedMusic
                              'element (loop (ly:music-property m 'element))
                              'context-type (ly:music-property m 'context-type))
                  overrides))
                (else
                 (if (not warned)
                     (begin
                       (ly:input-warning location (_ "Cannot revert ~a")
                                         (ly:music-property m 'name))
                       (set! warned #t)))
                 overrides)))
            '()
            music)))
       (cond
        ((null? lst) (make-music 'Music))
        ((null? (cdr lst)) (car lst))
        (else (make-sequential-music lst))))))

unfoldRepeats =
#(define-music-function (parser location music) (ly:music?)
   (_i "Force any @code{\\repeat volta}, @code{\\repeat tremolo} or
@code{\\repeat percent} commands in @var{music} to be interpreted
as @code{\\repeat unfold}.")
   (unfold-repeats music))

void =
#(define-void-function (parser location arg) (scheme?)
   (_i "Accept a scheme argument, return a void expression.
Use this if you want to have a scheme expression evaluated
because of its side-effects, but its value ignored."))

withMusicProperty =
#(define-music-function (parser location sym val music)
   (symbol? scheme? ly:music?)
   (_i "Set @var{sym} to @var{val} in @var{music}.")

   (set! (ly:music-property music sym) val)
   music)