File: ifprolog.pl

package info (click to toggle)
swi-prolog 8.0.2%2Bdfsg-3%2Bdeb10u1
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 72,036 kB
  • sloc: ansic: 349,612; perl: 306,654; java: 5,208; cpp: 4,436; sh: 3,042; ruby: 1,594; yacc: 845; makefile: 136; xml: 82; sed: 12; sql: 6
file content (1331 lines) | stat: -rw-r--r-- 36,785 bytes parent folder | download
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
/*  Part of SWI-Prolog

    Author:        Jan Wielemaker, Johan Romme
    E-mail:        J.Wielemaker@cs.vu.nl
    WWW:           http://www.swi-prolog.org
    Copyright (c)  2012-2016, VU University Amsterdam
    All rights reserved.

    Redistribution and use in source and binary forms, with or without
    modification, are permitted provided that the following conditions
    are met:

    1. Redistributions of source code must retain the above copyright
       notice, this list of conditions and the following disclaimer.

    2. Redistributions in binary form must reproduce the above copyright
       notice, this list of conditions and the following disclaimer in
       the documentation and/or other materials provided with the
       distribution.

    THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
    "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
    LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
    FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
    COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
    INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
    BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
    LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
    CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
    LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
    ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
    POSSIBILITY OF SUCH DAMAGE.
*/

:- module(ifprolog,
	  [ calling_context/1,			% -Module
	    context/2,				% :Goal, +Mapping
	    block/3,				% :Goal, +Tag, :Recovery
	    exit_block/1,			% +Tag
	    cut_block/1,			% +Tag

	    modify_mode/3,			% +PI, -Old, +New
	    debug_mode/3,			% +PI, -Old, +New
	    ifprolog_debug/1,			% :Goal,
	    debug_config/3,			% +Key, +Current, +Value
	    float_format/2,			% -Old, +New
	    program_parameters/1,		% -Argv
	    user_parameters/1,			% -Argv
	    match/2,				% +Mask, +Atom
	    match/3,				% +Mask, +Atom, ?Replacements
	    lower_upper/2,			% ?Lower, ?Upper
	    current_error/1,			% -Stream
	    writeq_atom/2,			% +Term, -Atom
	    write_atom/2,			% +Term, -Atom
	    write_formatted_atom/3,		% -Atom, +Format, +ArgList
	    write_formatted/2,			% +Format, +ArgList
	    write_formatted/3,			% +Stream, +Format, +ArgList
	    atom_part/4,			% +Atom, +Pos, +Len, -Sub
	    atom_prefix/3,			% +Atom, +Len, -Sub
	    atom_suffix/3,			% +Atom, +Len, -Sub
	    atom_split/3,			% +Atom, +Delimiter, ?Subatoms
	    if_concat_atom/2,			% +List, ?Atom
	    if_concat_atom/3,			% +List, +Delimiter, ?Atom
	    getchar/3,				% +Atom, +Pos, -Char
	    parse_atom/6,			% +Atom, +StartPos, ?EndPos,
						% ?Term, ?VarList, ?Error
	    index/3,				% +Atom, +String, -Position
	    list_length/2,			% +List, ?Length
	    load/1,				% :FileName
%	    unload/1,				% +Module
	    file_test/2,			% +File, +Mode
	    filepos/2,				% @Stream, -Line
	    filepos/3,				% @Stream, -Line, -Column
	    getcwd/1,				% -Dir
	    assign_alias/2,			% +Alias, @Stream
	    get_until/3,			% +SearchChar, ?Text, ?EndChar
	    get_until/4,			% @In, +SearchChar, ?Text, ?EndChar
	    for/3,				% +Start, ?Counter, +End
	    prolog_version/1,                   % -Atom
	    proroot/1,				% -Atom
	    system_name/1,			% -Atom
	    localtime/9,			% +Time, ?Year, ?Month,
						% ?Day, ?DoW, ?DoY,
						% ?Hour, ?Min, ?Sec

	    asserta_with_names/2,		% @Term, +VarNames
	    assertz_with_names/2,		% @Term, +VarNames
	    clause_with_names/3,		% ?Head, ?Body, ?VarNames
	    retract_with_names/2,		% ?Clause, ?VarNames
	    predicate_type/2,			% @Predicate, ?Type
	    current_visible/2,			% @Module, @Predicate
	    current_signal/2,			% ?Signal, ?Mode
	    digit/1,				% +Character
	    letter/1,				% +Character

	    current_global/1,			% +Name
	    get_global/2,			% +Name, ?Value
	    set_global/2,			% +Name, ?Value
	    unset_global/1,			% +Name

	    current_default_module/1,		% -Module
	    set_default_module/1,		% +Module

	    op(1150, fx, (meta)),
	    op(1150, fx, (export)),
	    op(100, xfx, @),
	    op(900, xfx, =>),
	    op(900,  fy, not)
	  ]).
:- use_module(library(debug)).
:- use_module(library(arithmetic)).
:- use_module(library(memfile)).
:- use_module(library(apply)).
:- set_prolog_flag(double_quotes, codes).

/** <module> IF/Prolog compatibility package

This library realises emulation of IF/Prolog.  As with all the emulation
layers in the dialect directory, the   emulation has been established on
`as needed' basis from porting programs. This implies that the emulation
is incomplete. Emumated directives, predicates   and libraries are often
not 100% compatible with the IF/Prolog version.

Note that this emulation layer targets primarily IF/Prolog version 5.

Please   help   extending   this   library   and   submit   patches   to
bugs@swi-prolog.org.
*/

:- module_transparent
	calling_context/1.

:- meta_predicate
	context(0, +),
	block(0, +, 0),
	modify_mode(:, -, +),
	debug_mode(:, -, +),
	ifprolog_debug(0),
	load(:),
	asserta_with_names(:, +),
	assertz_with_names(:, +),
	clause_with_names(:, -, -),
	retract_with_names(:, -),
	predicate_type(:, -),
	current_global(:),
	get_global(:, -),
	set_global(:, +),
	unset_global(:).


		 /*******************************
		 *	     EXPANSION		*
		 *******************************/

:- multifile
	user:goal_expansion/2,
	user:term_expansion/2,
	user:file_search_path/2,
	user:prolog_file_type/2,
	ifprolog_goal_expansion/2,
	ifprolog_term_expansion/2.
:- dynamic
	user:goal_expansion/2,
	user:term_expansion/2,
	user:file_search_path/2,
	user:prolog_file_type/2.

:- dynamic
	in_module_interface/1.

user:goal_expansion(In, Out) :-
	prolog_load_context(dialect, ifprolog),
	ifprolog_goal_expansion(In, Out).

user:term_expansion(In, Out) :-
	prolog_load_context(dialect, ifprolog),
	ifprolog_term_expansion(In, Out).

%%	ifprolog_goal_expansion(+In, +Out)
%
%	goal_expansion  rules  to   emulate    IF/Prolog   behaviour  in
%	SWI-Prolog. The expansions  below   maintain  optimization  from
%	compilation.   Defining   them   as   predicates   would   loose
%	compilation.

%%	context(:Goal, Handler)
%
%	Is  mapped  to  catch(Goal,  Error,    Recover)  is  Handler  is
%	=|error(_,_) => Recover|=. Other cases are   not  covered by the
%	emulation.

%%	asserta(Head,Body) is det.
%%	assertz(Head,Body) is det.
%%	retract(Head,Body) is det.
%
%	Mapped to asserta((Head:-Body)),  etc.  Note   that  this  masks
%	SWI-Prolog's asserta/2, etc.

ifprolog_goal_expansion(Module:Goal, Expanded) :-
	Module == system, nonvar(Goal), !,
	expand_goal(Goal, ExpandedGoal),
	head_pi(ExpandedGoal, PI),
	(   current_predicate(ifprolog:PI),
	    \+ predicate_property(ExpandedGoal, imported_from(_))
	->  Expanded = ifprolog:ExpandedGoal
	;   Expanded = ExpandedGoal
	).
ifprolog_goal_expansion(Goal, Expanded) :-
	if_goal_expansion(Goal, Expanded).

if_goal_expansion(context(Goal, [Error => Recover]),
		  catch(Goal, Error, Recover)) :-
	assertion(Error = error(_,_)).
if_goal_expansion(assertz(Head,Body),
		  assertz((Head:-Body))).
if_goal_expansion(asserta(Head,Body),
		  asserta((Head:-Body))).
if_goal_expansion(retract(Head,Body),
		  retract((Head:-Body))).
if_goal_expansion(Call@Module, call((Module:Goal)@Module)) :-
	nonvar(Call),
	Call = call(Goal).
if_goal_expansion(concat_atom(L,A), if_concat_atom(L,A)).
if_goal_expansion(concat_atom(L,D,A), if_concat_atom(L,D,A)).


head_pi(M:Head, M:PI) :- !,
	head_pi(Head, PI).
head_pi(Head, Name/Arity) :-
	functor(Head, Name, Arity).


%%	ifprolog_term_expansion(+In, +Out)
%
%	term_expansion  rules  to   emulate    IF/Prolog   behaviour  in
%	SWI-Prolog.

%%	meta(+ListOfPI)
%
%	Mapped  to  module_transparent/1.  Not  sure   whether  this  is
%	correct. It surely is not very elegant   to  map to a deprecated
%	feature.  Luckily,  although  the  module_transparent/1  API  is
%	deprecated, the underlying functionality is   still  core of the
%	module system.
%
%	Note that if :- meta  appears   inside  a  module interface, the
%	predicate is also exported.

%%	export(+ListOfPI) is det.
%%	discontiguous(+ListOfPI) is det.
%
%	Mapped to comma-lists

%%	module(+Name).
%%	begin_module(+Name).
%%	end_module(+Name).
%
%	These are emulated correctly,  provided   module/1  is the first
%	term of the file and the  implementation   is  part  of the same
%	file. Begin/end are ignored.

ifprolog_term_expansion((:- meta([])), []).
ifprolog_term_expansion((:- meta(List)),
			[ (:- module_transparent(Spec))
			| Export
			]) :-
	pi_list_to_pi_term(List, Spec),
	(   in_module_interface(_)
	->  Export = [(:- export(Spec))]
	;   Export = []
	).

ifprolog_term_expansion((:- export([])), []).
ifprolog_term_expansion((:- export(List)),
			(:- export(Spec))) :-
	is_list(List),
	pi_list_to_pi_term(List, Spec).

ifprolog_term_expansion((:- private(_)), []).

ifprolog_term_expansion((:- discontiguous([])), []).
ifprolog_term_expansion((:- discontiguous(List)),
			(:- discontiguous(Spec))) :-
	is_list(List),
	pi_list_to_pi_term(List, Spec).

ifprolog_term_expansion((:- multifile([])), []).
ifprolog_term_expansion((:- multifile(List)),
			(:- multifile(Spec))) :-
	is_list(List),
	pi_list_to_pi_term(List, Spec).

ifprolog_term_expansion((:- module(Name)),
			(:- module(Name, []))) :-
	asserta(in_module_interface(Name)).
ifprolog_term_expansion((:- begin_module(Name)), []) :-
	prolog_load_context(module, Loading),
	assertion(Name == Loading),
	retract(in_module_interface(Name)).
ifprolog_term_expansion((:- end_module(_)), []).
ifprolog_term_expansion((:- end_module), []).
ifprolog_term_expansion((:- nonotify), []).	% TBD: set verbosity


ifprolog_term_expansion((:- import(Module)),
			(:- use_module(File))) :-
	(   module_property(Module, file(File))
	->  true
	;   existence_error(module, Module)
	).
ifprolog_term_expansion((:- import(Module, ImportList)),
			(:- use_module(File, ImportList))) :-
	(   module_property(Module, file(File))
	->  true
	;   existence_error(module, Module)
	).

%%	pi_list_to_pi_term(+List, -CommaList) is det.

pi_list_to_pi_term([PI], PI) :- !.
pi_list_to_pi_term([H|T], (H,CommaList)) :-
	pi_list_to_pi_term(T, CommaList).

                 /*******************************
                 *          LIBRARY SETUP       *
                 *******************************/

%%      push_ifprolog_library
%
%       Pushes searching for dialect/ifprolog in   front of every library
%       directory that contains such as sub-directory.

push_ifprolog_library :-
        (   absolute_file_name(library(dialect/ifprolog), Dir,
                               [ file_type(directory),
                                 access(read),
                                 solutions(all),
                                 file_errors(fail)
                               ]),
            asserta((user:file_search_path(library, Dir) :-
                    prolog_load_context(dialect, ifprolog))),
            fail
        ;   true
        ).

%%	push_ifprolog_file_extension
%
%	Looks for .pro files before looking for .pl files if the current
%	dialect is =pro=. If the dialect is   not active, the .pro files
%	are found as last resort.

push_ifprolog_file_extension :-
	asserta((user:prolog_file_type(pro, prolog) :-
		prolog_load_context(dialect, ifprolog))).

user:prolog_file_type(pro, prolog) :-
	\+ prolog_load_context(dialect, ifprolog).

:- push_ifprolog_library,
   push_ifprolog_file_extension.


		 /*******************************
		 *	    PREDICATES		*
		 *******************************/

%%	calling_context(-Context)
%
%	Mapped to context_module/1.

calling_context(Context) :-
	context_module(Context).

%%	context(:Goal, +Mapping)
%
%	IF/Prolog context/2 construct. This is  the true predicate. This
%	is normally mapped by goal-expansion.
%
%	@bug	Does not deal with IF/Prolog signal mapping

context(M:Goal, Mapping) :-
	member(Error => Action, Mapping),
	nonvar(Error),
	Error = error(_,_), !,
	catch(M:Goal, Error, Action).
context(M:Goal, _Mapping) :-
	M:Goal.

%%	block(:Goal, +Tag, :Recovery).
%%	exit_block(+Tag).
%%	cut_block(+Tag) is semidet.
%
%	The control construct block/3 runs Goal in a block labelled Tag.
%	If Goal calls exit_block/1 using a   matching Tag, the execution
%	of Goal is abandoned  using   exception  handling  and execution
%	continues by running Recovery.  Goal   can  call cut_block/1. If
%	there is a block with matching   Tag,  all choice points created
%	since the block was started are destroyed.
%
%	@bug	The block control structure is implemented on top of
%		catch/3 and throw/1.  If catch/3 is used inside Goal,
%		the user must ensure that either (1) the protected
%		goal does not call exit_block/1 or cut_block/1 or (2)
%		the _Catcher_ of the catch/3 call does *not* unify with
%		a term block(_,_).

block(Goal, Tag, Recovery) :-
	prolog_current_choice(Choice),
	catch(Goal, block(Tag, Choice), Recovery).

exit_block(Tag) :-
	throw(block(Tag, _)).

cut_block(Tag) :-
	prolog_current_frame(Frame),
	findall(Choice,			% use findall/3 to avoid binding
		prolog_frame_attribute(
		    Frame, parent_goal,
		    system:catch(_, block(Tag, Choice), _)),
		[Choice]),
	nonvar(Choice),
	prolog_cut_to(Choice).

%%	modify_mode(+PI, -OldMode, +NewMode) is det.
%
%	Switch between static and  dynamic   code.  Fully supported, but
%	notably changing static to dynamic code   is  not allowed if the
%	predicate has clauses.

modify_mode(PI, OldMode, NewMode) :-
	pi_head(PI, Head),
	old_mode(Head, OldMode),
	set_mode(PI, OldMode, NewMode).

old_mode(Head, Mode) :-
	(   predicate_property(Head, dynamic)
	->  Mode = on
	;   Mode = off
	).

set_mode(_, Old, Old) :- !.
set_mode(PI, _, on) :- !,
	dynamic(PI).
set_mode(PI, _, off) :-
	compile_predicates([PI]).

pi_head(M:PI, M:Head) :- !,
	pi_head(PI, Head).
pi_head(Name/Arity, Term) :-
	functor(Term, Name, Arity).

%%	debug_mode(:PI, -Old, +New)
%
%	Old is not unified.  Only  New  ==   off  is  mapped  to disable
%	debugging of a predicate.

debug_mode(PI, _, off) :- !,
	'$hide'(PI).
debug_mode(_, _, on).

%%	ifprolog_debug(:Goal)
%
%	Map IF/Prolog debug(Goal)@Module. This should  run Goal in debug
%	mode. We rarely needs this type of measures in SWI-Prolog.

ifprolog_debug(Goal) :-
	Goal.

%%	debug_config(+Key, -Current, +Value)
%
%	Ignored.  Prints a message.

debug_config(Key,Current,Value) :-
	print_message(informational, ignored(debug_config(Key,Current,Value))).

%%	float_format(-Old, +New)
%
%	Ignored. Prints a message. Cannot   be emulated. Printing floats
%	with a specified precision can only be done using format/2.

float_format(Old, New) :-
	print_message(informational, ignored(float_format(Old, New))).

%%	program_parameters(-List:atom)
%
%	All command-line argument, including the executable,

program_parameters(Argv) :-
	current_prolog_flag(os_argv, Argv).

%%	user_parameters(-List:atom)
%
%	Parameters after =|--|=.

user_parameters(Argv) :-
	current_prolog_flag(argv, Argv).

%%	match(+Mask, +Atom) is semidet.
%
%	Same as once(match(Mask, Atom, _Replacements)).

match(Mask, Atom) :-
	match(Mask, Atom, _), !.

%%	match(+Mask, +Atom, ?Replacements) is nondet.
%
%	Pattern matching. This emulation  should   be  complete.  Can be
%	optimized using caching of  the   pattern-analysis  or doing the
%	analysis at compile-time.

match(Mask, Atom, Replacements) :-
	atom_codes(Mask, MaskCodes),
	atom_codes(Atom, Codes),
	phrase(match_pattern(Pattern), MaskCodes), !,
	pattern_goal(Pattern, Codes, Replacements, Goal),
	Goal.

pattern_goal([], [], [], true).
pattern_goal([string(String)|T], Codes, Replacements, Goal) :- !,
	append(String, Rest, Codes),
	pattern_goal(T, Rest, Replacements, Goal).
pattern_goal([star|T], Codes, [Atom|Replacements], Goal) :-
	append(Replacement, Rest, Codes),
	Goal = (atom_codes(Atom, Replacement),Goal2),
	pattern_goal(T, Rest, Replacements, Goal2).
pattern_goal([set(S)|T], [C|Rest], [Atom|Replacements], Goal) :-
	memberchk(C, S), !,
	Goal = (char_code(Atom, C),Goal2),
	pattern_goal(T, Rest, Replacements, Goal2).
pattern_goal([any|T], [C|Rest], [Atom|Replacements], Goal) :-
	Goal = (char_code(Atom, C),Goal2),
	pattern_goal(T, Rest, Replacements, Goal2).

match_pattern([set(S)|T]) -->
	"[",
	match_set(S), !,
	match_pattern(T).
match_pattern([string(List)|T]) -->
	non_special(List),
	{ List \== [] }, !,
	match_pattern(T).
match_pattern([star|T]) -->
	"*", !,
	match_pattern(T).
match_pattern([any|T]) -->
	"?", !,
	match_pattern(T).
match_pattern([]) --> [].

match_set([]) --> "]", !.
match_set(L) -->
	[C0], "-", [C1],
	{ C1 \= 0'],
	  C0 =< C1,
	  numlist(C0, C1, Range),
	  append(Range, T, L)
	},
	match_set(T).
match_set([C|L]) -->
	[C],
	match_set(L).

non_special([H|T]) -->
	[H],
	{ \+ special(H) }, !,
	non_special(T).
non_special([]) --> [].

special(0'*).
special(0'?).
special(0'[).

%%	lower_upper(+Lower, -Upper) is det.
%%	lower_upper(-Lower, +Upper) is det.
%
%	Multi-moded combination of upcase_atom/2 and downcase_atom/2.


lower_upper(Lower, Upper) :-
	nonvar(Lower), !,
	upcase_atom(Lower, Upper).
lower_upper(Lower, Upper) :-
	downcase_atom(Upper, Lower).

%%	load(File)
%
%	Mapped to consult.  I think that the compatible version should
%	only load .qlf (compiled) code.

load(File) :-
	consult(File).

%%	unload(+Module) is det.
%
%	Unload the named module.
%
%	@bug: What to do with modules that are not associated to a
%	file?

unload(Module) :-
	module_property(Module, file(File)), !,
	unload_file(File).
unload(_Module) :-
	assertion(fail).

%%	file_test(+File, +Mode)
%
%	Mapped to access_file/2 (which understand more modes). Note that
%	this predicate is defined in the   module  =system= to allow for
%	direct calling.

file_test(File, Mode) :-
	access_file(File, Mode).

%%	filepos(@Stream, -Line)
%
%	from  the  IF/Prolog  documentation    The  predicate  filepos/2
%	determines the current line  position   of  the  specified input
%	stream and unifies the  result  with   Line.  The  current  line
%	position is the number of line processed + 1

filepos(Stream, Line) :-
	line_count(Stream, L),
	Line is L + 1.


%%	getcwd(-Dir)
%
%	The predicate getcwd/1 unifies Dir with the full pathname of the
%	current working directory.

getcwd(Dir) :-
	working_directory(Dir, Dir).

%%	filepos(@Stream, -Line, -Column)
%
%	from  the  IF/Prolog  documentation    The  predicate  filepos/2
%	determines the current line  position   of  the  specified input
%	stream and unifies the  result  with   Line.  The  current  line
%	position is the number of line processed + 1

filepos(Stream, Line, Column) :-
	line_count(Stream, L),
	line_position(Stream, C),
	Line is L + 1,
	Column is C + 1.

%%	assign_alias(+Alias, @Stream) is det.
%

assign_alias(Alias, Stream) :-
	set_stream(Stream, alias(Alias)).

%%	writeq_atom(+Term, -Atom)
%
%	Use writeq/1 to write Term to Atom.

writeq_atom(Term, Atom) :-
	with_output_to(atom(Atom), writeq(Term)).

%%	write_atom(+Term, -Atom)
%
%	Use write/1 to write Term to Atom.

write_atom(Term, Atom) :-
	with_output_to(atom(Atom), write(Term)).

%%	current_error(-Stream)
%
%	Doesn't exist in SWI-Prolog, but =user_error= is always an alias
%	to the current error stream.

current_error(user_error).


		 /*******************************
		 *	  FORMATTED WRITE	*
		 *******************************/

%%	write_formatted_atom(-Atom, +Format, +ArgList) is det.
%%	write_formatted(+Format, +ArgList) is det.
%%	write_formatted(@Stream, +Format, +ArgList) is det.
%
%	Emulation of IF/Prolog formatted write.   The  emulation is very
%	incomplete. Notable asks for dealing with aligned fields, etc.
%
%	@bug	Not all format characters are processed
%	@bug    Incomplete processing of modifiers, fieldwidth and precision
%	@tbd	This should become goal-expansion based to process
%		format specifiers at compile-time.

write_formatted_atom(Atom, Format, ArgList) :-
	with_output_to(atom(Atom), write_formatted(Format, ArgList)).

write_formatted(Format, ArgList) :-
	write_formatted(current_output, Format, ArgList).

write_formatted(Out, Format, ArgList) :-
	atom_codes(Format, Codes),
	phrase(format_string(FormatCodes), Codes), !,
	string_codes(FormatString, FormatCodes),
	format(Out, FormatString, ArgList).

format_string([]) --> [].
format_string(Fmt) -->
	"%", format_modifiers(Flags, FieldLen, Precision), [IFC], !,
	{   map_format([IFC], Flags, FieldLen, Precision, Repl)
	->  append(Repl, T, Fmt)
	;   print_message(warning, ifprolog_format(IFC)),
	    %backtrace(20),
	    T = Fmt
	},
	format_string(T).
format_string([H|T]) -->
	[H],
	format_string(T).

map_format(Format, [], default, default, Mapped) :- !,
	map_format(Format, Mapped).
map_format(Format, Flags, Width, Precision, Mapped) :-
	integer(Width), !,			% left/right aligned in Width
	map_format(Format, Field),
	format_precision(Precision, Field, PrecField),
	fill_code(Flags, [Fill]),
	(   memberchk(-, Flags)			% left aligned
	->  format(codes(Mapped), '~~|~s~~`~ct~~~d+', [PrecField, Fill, Width])
	;   format(codes(Mapped), '~~|~~`~ct~s~~~d+', [Fill, PrecField, Width])
	).
map_format(Format, Flags, _, _, Mapped) :-
	memberchk(#, Flags),
	can_format(Format, Mapped), !.
map_format(Format, _, _, Precision, Mapped) :-
	map_format(Format, Field),
	format_precision(Precision, Field, Mapped).

can_format("o", "0~8r").
can_format("x", "0x~16r").
can_format("X", "0x~16R").
can_format("w", "~k").

map_format("t", "~w").
map_format("q", "~q").
map_format("s", "~a").
map_format("f", "~f").
map_format("e", "~e").
map_format("E", "~E").
map_format("g", "~G").
map_format("d", "~d").
map_format("x", "~16r").
map_format("o", "~8r").
map_format("X", "~16R").
map_format("O", "~8R").
map_format("c", "~c").
map_format("%", "%").

have_precision("d").
have_precision("D").
have_precision("e").
have_precision("E").
have_precision("f").
have_precision("g").
have_precision("G").

format_precision(N, [0'~|C], [0'~|Field]) :-
    integer(N),
    have_precision(C),
    !,
    format(codes(Field), '~d~s', [N, C]).
format_precision(_, Field, Field).

fill_code(Flags, "0") :- memberchk(0, Flags), !.
fill_code(_,     " ").

%%	format_modifiers(-Flags, -FieldLength, -Precision) is det.
%
%	Read the IF/Prolog format modifiers. We currently do not process
%	any of the modifiers! Some code seems to be using e.g. %07lx. We
%	assume this is the same as -07x (assuming l=left).

format_modifiers(Flags, FieldLength, Precision) -->
	format_flags(Flags0),
	digits(FieldLengthDigits),
	{   FieldLengthDigits == []
	->  FieldLength = default
	;   number_codes(FieldLength, FieldLengthDigits)
	},
	(   "."
	->  digits(PrecisionDigits),
	    { number_codes(Precision, PrecisionDigits) }
	;   { Precision = default }
	),
	opt_alignment(Flags0, Flags).

format_flags([H|T]) -->
	format_flag(H), !,
	format_flags(T).
format_flags([]) --> [].

format_flag(+) --> "+".		% Always prefix number with a sign
format_flag(-) --> "-".		% Left-justify
format_flag(space) --> " ".	% Space before positive numbers
format_flag(#) --> "#".		% Canonical output
format_flag(0) --> "0".		% Use leading 0 for integers

digits([D0|T]) -->
	digit(D0), !,
	digits(T).
digits([]) --> [].

digit(D) --> [D], {between(0'0, 0'9, D)}.

opt_alignment(L, [-|L]) --> "l", !.
opt_alignment(L, L) --> [].


%%	get_until(+SearchChar, -Text, -EndChar) is det.
%%	get_until(@Stream, +SearchChar, -Text, -EndChar) is det.
%
%	Read input from Stream  until   SearchChar.  Unify  EndChar with
%	either SearchChar or the atom =end_of_file=.

get_until(SearchChar, Text, EndChar) :-
	get_until(current_input, SearchChar, Text, EndChar).

get_until(In, SearchChar, Text, EndChar) :-
	get_char(In, C0),
	get_until(C0, In, SearchChar, Codes, EndChar),
	atom_chars(Text, Codes).

get_until(C0, _, C0, [], C0) :- !.
get_until(end_of_file, _, _,  [], end_of_file) :- !.
get_until(C0, In, Search, [C0|T], End) :-
	get_char(In, C1),
	get_until(C1, In, Search, T, End).


		 /*******************************
		 *	      PARSE		*
		 *******************************/

%%	atom_part(+Atom, +Pos, +Len, -Sub) is det.
%
%	True when Sub is part  of   the  atom [Pos,Pos+Len). Unifies Sub
%	with '' if Pos or Len is out of range!?

atom_part(_, Pos, _, Sub) :-
	Pos < 1, !,
	Sub = ''.
atom_part(_, _, Len, Sub) :-
	Len < 1, !,
	Sub = ''.
atom_part(Atom, Pos, _, Sub) :-
	atom_length(Atom, Len),
	Pos > Len, !,
	Sub = ''.
atom_part(Atom, Pos, Len, Sub) :-
	Pos >= 1,
	Pos0 is Pos - 1,
	atom_length(Atom, ALen),
	Len0 is min(Len, ALen-Pos0),
	sub_atom(Atom, Pos0, Len0, _, Sub).

%%	atom_prefix(+Atom, +Len, -Sub) is det.
%
%	Unifies Sub with the atom formed by  the first Len characters in
%	atom.
%
%	 - If Len < 1, Sub is unified with the null atom ''.
%	 - If Len > length of Atom, Sub is unified with Atom.

atom_prefix(_, Len, Sub) :-
	Len < 1, !,
	Sub = ''.
atom_prefix(Atom, Len, Sub) :-
	atom_length(Atom, AtomLen),
	Len > AtomLen, !,
	Sub = Atom.
atom_prefix(Atom, Len, Sub) :-
	sub_atom(Atom, 0, Len, _, Sub).

%%	atom_suffix(+Atom, +Len, -Sub) is det.
%
%	Unifies Sub with the atom formed by   the last Len characters in
%	atom.
%
%	  - If Len < 1, Sub is unified with the null atom ''.
%	  - If Len > length of Atom, Sub is unified with Atom.

atom_suffix(_, Len, Sub) :-
	Len < 1, !,
	Sub = ''.
atom_suffix(Atom, Len, Sub) :-
	atom_length(Atom, AtomLen),
	Len > AtomLen, !,
	Sub = Atom.
atom_suffix(Atom, Len, Sub) :-
	atom_length(Atom, AtomLen),
	Pos is AtomLen - Len,
	sub_atom(Atom, Pos, Len, _, Sub).

%%	atom_split( +Atom, +Delimiter, ?Subatoms )
%
%	Split Atom over Delimiter and unify the parts with Subatoms.

atom_split(Atom, Delimiter, Subatoms)  :-
	atomic_list_concat(Subatoms, Delimiter, Atom).

%%	if_concat_atom(+List, +Delimiter, -Atom) is det.
%
%	True when Atom is the concatenation of   the lexical form of all
%	elements from List, using Delimiter to delimit the elements.
%
%	The behavior of this  ifprolog   predicate  is  different w.r.t.
%	SWI-Prolog in two respect: it supports   arbitrary terms in List
%	rather than only atomic and it does _not_ work in mode -,+,+.

if_concat_atom(List, Delimiter, Atom) :-
	maplist(write_term_to_atom, List, AtomList),
	atomic_list_concat(AtomList, Delimiter, Atom).

write_term_to_atom(Term, Atom) :-
	(   atomic(Term)
	->  Atom = Term
	;   with_output_to(string(Atom), write(Term))
	).

%%	if_concat_atom(+List, -Atom) is det.
%
%	True when Atom is the concatenation of   the lexical form of all
%	elements  from  List.  Same  as  if_concat_atom/3  using  ''  as
%	delimiter.

if_concat_atom(List, Atom) :-
	maplist(write_term_to_atom, List, AtomList),
	atomic_list_concat(AtomList, Atom).

%%	getchar(+Atom, +Pos, -Char)
%
%	Unifies Char with the Position-th character in Atom
%	If Pos < 1 or Pos > length of Atom, then fail.

getchar(_, Pos, _) :-
	Pos < 1, !,
	fail.
getchar(Atom, Pos, _) :-
	atom_length(Atom, Len),
	Pos > Len, !,
	fail.
getchar(Atom, Pos, Char) :-
	P is Pos - 1,
	sub_atom(Atom, P, 1, _, Char).


%%	parse_atom(+Atom, +StartPos, ?EndPos, ?Term, ?VarList, ?Error)
%
%	Read from an atom.
%
%	@param StartPos is 1-based position to start reading
%	@param Error is the 1-based position of a syntax error or 0 if
%	       there is no error.

parse_atom(Atom, StartPos, EndPos, Term, VarList, Error) :-
	setup_call_cleanup(
	    ( atom_to_memory_file(Atom, MemF),
	      open_memory_file(MemF, read, In)
	    ),
	    ( StartPos0 is StartPos-1,
	      seek(In, StartPos0, bof, _),
	      catch(read_term(In, Term, [variable_names(VarList)]), E, true),
	      parse_atom_error(E, Error),
	      character_count(In, EndPos0),
	      EndPos is EndPos0+1
	    ),
	    ( close(In),
	      free_memory_file(MemF)
	    )).

parse_atom_error(Var, Pos) :-
	var(Var), !, Pos = 0.
parse_atom_error(error(_, stream(_Stream, _, _, Pos)), Pos1) :-
	Pos1 is Pos+1.


%%	index(+Atom, +String, -Position) is semidet.
%
%	True when Position is the first   occurrence  of String in Atom.
%	Position is 1-based.

index(Atom, String, Position) :-
	sub_string(Atom, Pos0, _, _, String), !,
        Position is Pos0 + 1.

%%	list_length(+List, ?Length) is det.
%
%	Deterministic version of length/2. Current implementation simply
%	calls length/2.

list_length(List, Length) :-
	length(List, Length).


		 /*******************************
		 *	      MISC		*
		 *******************************/

%%	for(+Start, ?Count, +End) is nondet.
%
%	Similar to between/3, but can count down if Start > End.

for(Start, Count, End) :-
	Start =< End, !,
	between(Start, End, Count).
for(Start, Count, End) :-
	nonvar(Count), !,
	between(End, Start, Count).
for(Start, Count, End) :-
	Range is Start-End,
	between(0, Range, X),
	Count is Start-X.

%%	prolog_version(-Version)
%
%	Return IF/Prolog simulated version string

prolog_version(Version) :-
	current_prolog_flag(version_data, swi(Major, Minor, Patch, _)),
	atomic_list_concat([Major, Minor, Patch], '.', Version).

%%	proroot(-Path)
%
%	True when Path is  the  installation   location  of  the  Prolog
%	system.

proroot(Path) :-
	current_prolog_flag(home, Path).

%%	system_name(-SystemName)
%
%	True when SystemName identifies the  operating system. Note that
%	this returns the SWI-Prolog =arch= flag,   and not the IF/Prolog
%	identifiers.

system_name(SystemName) :-
	current_prolog_flag(arch, SystemName).

%%	localtime(+Time, ?Year, ?Month, ?Day, ?DoW, ?DoY, ?Hour, ?Min, ?Sec)
%
%	Break system time into its components.  Deefines components:
%
%	  | Year    | Year number    | 4 digits        |
%	  | Month   | Month number   | 1..12           |
%	  | Day	    | Day of month   | 1..31           |
%	  | DoW	    | Day of week    | 1..7 (Mon-Sun)  |
%	  | DoY	    | Day in year    | 1..366          |
%	  | Hour    | Hours	     | 0..23           |
%	  | Min	    | Minutes	     | 0..59           |
%	  | Sec	    | Seconds	     | 0..59           |
%
%	Note that in IF/Prolog  V4,  Year  is   0..99,  while  it  is  a
%	four-digit number in IF/Prolog V5.  We emulate IF/Prolog V5.

localtime(TimeExpr, Year, Month, Day, DoW, DoY, Hour, Min, Sec) :-
	arithmetic_expression_value(TimeExpr, Time),
        stamp_date_time(Time, date(Year, Month, Day,
				   Hour, Min, SecFloat,
				   _Off, _TZ, _DST), local),
        Sec is floor(SecFloat),
	Date = date(Year,Month,Day),
	day_of_the_year(Date, DoY),
        day_of_the_week(Date, DoW).


%%	current_global(+Name) is semidet.
%%	get_global(+Name, ?Value) is det.
%%	set_global(+Name, ?Value) is det.
%%	unset_global(+Name) is det.
%
%	IF/Prolog  global  variables,  mapped    to   SWI-Prolog's  nb_*
%	predicates.

current_global(Name) :-
	gvar_name(Name, GName),
	nb_current(GName, _).

get_global(Name, Value) :-
	gvar_name(Name, GName),
	nb_getval(GName, Value).

set_global(Name, Value) :-
	gvar_name(Name, GName),
	nb_setval(GName, Value).

unset_global(Name) :-
	gvar_name(Name, GName),
	nb_delete(GName).

gvar_name(Module:Name, GName) :-
	atomic_list_concat([Module, :, Name], GName).


%%	current_default_module(-Module) is det.
%
%	Name of the toplevel typein module.

current_default_module(Module) :-
	'$current_typein_module'(Module).

%%	set_default_module(+Module) is det.
%
%	Set the default toplevel module.

set_default_module(Module) :-
	module(Module).


		 /*******************************
		 *	      DATABASE		*
		 *******************************/

:- dynamic
	names/2.

%%	asserta_with_names(@Clause, +VarNames) is det.
%%	assertz_with_names(@Clause, +VarNames) is det.
%%	clause_with_names(?Head, ?Body, -VarNames) is det.
%%	retract_with_names(?Clause, -VarNames) is det.
%
%	Predicates that manage  the  database   while  keeping  track of
%	variable names.

asserta_with_names(M:Clause, VarNames) :-
	term_varnames(Clause, VarNames, VarTerm),
	system:asserta(M:Clause, Ref),
	asserta(names(Ref, VarTerm)).
assertz_with_names(M:Clause, VarNames) :-
	term_varnames(Clause, VarNames, VarTerm),
	system:assertz(M:Clause, Ref),
	asserta(names(Ref, VarTerm)).

term_varnames(Term, VarNames, VarTerm) :-
	findall(Vars,
		( term_variables(Term, Vars),
		  bind_names(VarNames)
		),
		[ VarList ]),
	VarTerm =.. [ v | VarList ].

bind_names([]).
bind_names([Name=Var|T]) :-
	Name=Var,
	bind_names(T).


clause_with_names(M:Head, Body, VarNames) :-
	clause(M:Head, Body, Ref),
	(   names(Ref, VarTerm)
	->  term_variables((Head:-Body), Vars),
	    VarTerm =.. [v|NameList],
	    make_bindings(NameList, Vars, VarNames)
	;   VarNames = []
	).

retract_with_names(M:Term, VarNames) :-
	clause(M:Term, Ref),
	erase(Ref),
	(   retract(names(Ref, VarTerm))
	->  term_variables((Term), Vars),
	    VarTerm =.. [v|NameList],
	    make_bindings(NameList, Vars, VarNames)
	;   VarNames = []
	).

make_bindings([], [], []).
make_bindings([Name|NT], [Var|VT], [Name=Var|BT]) :-
	make_bindings(NT, VT, BT).


%%	predicate_type(:PI, -Type) is det.
%
%	True when Type describes the type  of   PI.  Note that the value
%	=linear= seems to mean you can use clause/2 on it, which is true
%	for any SWI-Prolog predicate that is  defined. Therefore, we use
%	it for any predicate that is defined.

predicate_type(M:Name/Arity, Type) :-
	functor(Head, Name, Arity),
	Pred = M:Head,
	(   (   predicate_property(Pred, built_in)
	    ;	predicate_property(Pred, foreign)
	    )
	->  Type = builtin
	;   predicate_property(Pred, imported_from(_))
	->  Type = imported
	;   predicate_property(Pred, dynamic)
	->  Type = linear
	;   control(Head)
	->  Type = control
	;   Name == call
	->  Type = control
	;   current_predicate(M:Name/Arity)
	->  Type = linear
	;   Type = undefined
	).

control((_,_)).
control((_;_)).
control((_->_)).
control((_*->_)).
control((!)).

%%	current_visible(@Module, @PredicateIndicator).
%
%	FIXME check with documentation

current_visible(Module, Name/Arity) :-
	atom(Name), integer(Arity), !,
	functor(Head, Name, Arity),
	predicate_property(Module:Head, visible).
current_visible(Module, Name/Arity) :-
	predicate_property(Module:Head, visible),
	functor(Head, Name, Arity).

%%	current_signal(?Signal, ?Mode) is nondet.
%
%	True when Mode is the current   mode  for handling Signal. Modes
%	are =on=, =off=,  =default=,  =ignore=.   Signals  are  =abort=,
%	=alarm=, =interrupt=, =pipe=, =quit=,   =termination=,  =user_1=
%	and =user_2=.
%
%	@tbd	Implement

current_signal(_,_) :- fail.


%%	digit(+A).
%
%	Is the character A a digit [0-9]
digit(A) :-
	char_type(A, digit).

%%	letter(+A).
%
%	Is the character A a letter [A-Za-z]
letter(A) :-
	char_type(A, alpha).

		 /*******************************
		 *	    ARITHMETIC		*
		 *******************************/

:- arithmetic_function(system:time/0).
:- arithmetic_function(system:trunc/1).
:- arithmetic_function(system:ln/1).
:- arithmetic_function(system:minint/0).
:- arithmetic_function(system:maxint/0).
:- arithmetic_function(system:dbsize/0).
:- arithmetic_function(system:dbused/0).
:- arithmetic_function(system:ssize/0).
:- arithmetic_function(system:gused/0).
:- arithmetic_function(system:lused/0).
:- arithmetic_function(system:tused/0).
:- arithmetic_function(system:sinh/1).
:- arithmetic_function(system:cosh/1).

system:time(Time) :-
	get_time(GetTime),
	Time is round(GetTime).  % Time in seconds since 1970-01-01 00:00:00 UTC
system:trunc(Val, Trunc) :-
	Trunc is truncate(Val).
system:ln(Val, Log) :-
	Log is log(Val).
system:minint(MinInt) :-
	MinInt is -1<<31.
system:maxint(MaxInt) :-
	MaxInt is 1<<31 - 1.
system:dbsize(0).
system:dbused(0).
system:ssize(Size) :-
	statistics(globallimit, Size).
system:gused(Size) :-
	statistics(globalused, Size).
system:lused(Size) :-
	statistics(localused, Size).
system:tused(Size) :-
	statistics(trailused, Size).

%%	sinh(Val)
%
%	Hyperbolic sine: sinh = (e^x - e^-x) / 2
system:sinh(Val, Sinh) :-
	Sinh is ((exp(Val) - exp(-Val)) / 2).

%%	cosh(Val)
%
%	Hyperbolic cosine: cosh = (e^x + e^-x) / 2
system:cosh(Val, Cosh) :-
	Cosh is ((exp(Val) + exp(-Val)) / 2).


		 /*******************************
		 *	       MESSAGES		*
		 *******************************/

prolog:message(ifprolog_format(IFC)) -->
	[ 'Unknown specifier for write_formatted/3: ~c'-[IFC] ].


		 /*******************************
		 *	  COLOUR SUPPORT	*
		 *******************************/

:- multifile
	prolog_colour:style/2,
	prolog_colour:goal_colours/2.

prolog_colour:goal_colours(meta(_),
			   ifprolog-[predicates]).
prolog_colour:goal_colours(private(_),
			   ifprolog-[predicates]).
prolog_colour:goal_colours(import(Module,_),
			   ifprolog-[module(Module),predicates]).
prolog_colour:goal_colours(begin_module(Module),
			   ifprolog-[module(Module)]).
prolog_colour:goal_colours(end_module(Module),
			   ifprolog-[module(Module)]).
prolog_colour:goal_colours(end_module,
			   ifprolog-[]).
prolog_colour:goal_colours(nonotify,
			   ifprolog-[]).

prolog_colour:style(goal(ifprolog,_), [ colour(blue), background(lightcyan) ]).