aboutsummaryrefslogtreecommitdiff
path: root/src/boot/ast.boot
blob: 9bdd3e08f6210a65bb3a47d8de42a0a8d10ea1a1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
-- Copyright (c) 1991-2002, The Numerical Algorithms Group Ltd.
-- All rights reserved.
-- Copyright (C) 2007-2008, Gabriel Dos Reis.
-- All rights reserved.
--
-- Redistribution and use in source and binary forms, with or without
-- modification, are permitted provided that the following conditions are
-- met:
--
--     - Redistributions of source code must retain the above copyright
--       notice, this list of conditions and the following disclaimer.
--
--     - 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.
--
--     - Neither the name of The Numerical Algorithms Group Ltd. nor the
--       names of its contributors may be used to endorse or promote products
--       derived from this software without specific prior written permission.
--
-- 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.
--

--
-- Abstract:
--   This file defines the AST data structure and helper functions
--   for representing Boot programs.
--

import includer
namespace BOOTTRAN
module ast

++ True means that Boot functions should be translated to use
++ hash tables to remember values.  By default, functions are
++ translated with the obvious semantics, e.g. no caching.
$bfClamming := false

--% Basic types used in Boot codes.

%Thing <=> true

%Boolean <=> BOOLEAN

%String <=> STRING

%Symbol <=> SYMBOL

%Short <=> FIXNUM

++ Ideally, we would like to say that a List T if either nil or a 
++ cons of a T and List of T. 
%List <=> LIST

%Vector <=> VECTOR

%Sequence <=> SEQUENCE

++ Currently, the Boot processor uses Lisp symbol datatype for names.
++ That causes the BOOTTRAN package to contain more symbols than we would
++ like.  In the future, we want to intern `on demand'.  How that
++ interacts with renaming is to be worked out.
structure %Name == 
  %Name(%Symbol)

structure %Ast ==
  Command(%String)                      -- includer command
  %Module(%Name,%List)                  -- module declaration
  Import(%String)                       -- import module
  ImportSignature(Name, Signature)      -- import function declaration
  %TypeAlias(%Head, %List)              -- type alias definition
  Signature(Name, Mapping)              -- op: S -> T
  Mapping(Ast, %List)                   -- (S1, S2) -> T
  SuffixDot(Ast)                        -- x . 
  Quote(Ast)                            -- 'x
  EqualName(Name)                       -- =x        -- patterns
  Colon(Name)                           -- :x
  QualifiedName(Name, Name)             -- m::x
  %DefaultValue(%Name,%Ast)             -- opt. value for function param.
  Bracket(Ast)                          -- [x, y]
  UnboundedSegment(Ast)                 -- 3..
  BoundedSgement(Ast, Ast)              -- 2..4
  Tuple(List)                           -- comma-separated expression sequence
  ColonAppend(Ast, Ast)                 -- [:y] or [x, :y]
  Is(Ast, Ast)                          -- e is p    -- patterns
  Isnt(Ast, Ast)                        -- e isnt p  -- patterns
  Reduce(Ast, Ast)                      -- +/[...]
  PrefixExpr(Name, Ast)                 -- #v
  Call(Ast,%Sequence)                   -- f(x, y , z)
  InfixExpr(Name, Ast, Ast)             -- x + y
  ConstantDefinition(Name, Ast)         -- x == y
  Definition(Name, List, Ast, Ast)      -- f x == y
  Macro(Name, List, Ast)                -- m x ==> y
  SuchThat(Ast)                         -- | p
  %Assignment(Ast, Ast)                -- x := y
  While(Ast)                            -- while p           -- iterator
  Until(Ast)                            -- until p           -- iterator
  For(Ast, Ast, Ast)                    -- for x in e by k   -- iterator
  Exit(Ast, Ast)                        -- p => x
  Iterators(List)                       -- list of iterators
  Cross(List)                           -- iterator cross product
  Repeat(%Sequence,Ast)                 -- while p repeat s
  Pile(%Sequence)                       -- pile of expression sequence
  Append(%Sequence)                     -- concatenate lists
  Case(Ast,%Sequence)                   -- case x of ...
  Return(Ast)                           -- return x
  %Throw(Ast)                           -- throw OutOfRange 3
  %Catch(Ast)                           -- catch OutOfRange
  %Try(Ast,%Sequence)                   -- try x / y catch DivisionByZero
  Where(Ast,%Sequence)                  -- e where f x == y
  Structure(Ast,%Sequence)              -- structure Foo == ...

-- TRUE if we are currently building the syntax tree for an 'is' 
-- expression.
$inDefIS := false


++ returns a `quote' ast for x.
quote x ==
  ["QUOTE",x]

--%

bfGenSymbol: () -> %Symbol 
bfGenSymbol()==
    $GenVarCounter:=$GenVarCounter+1
    INTERN(CONCAT ('"bfVar#",STRINGIMAGE $GenVarCounter))

bfListOf: %List -> %List 
bfListOf x==
  x
 
bfColon: %Thing -> %List
bfColon x== 
  ["COLON",x]

bfColonColon: (%Symbol,%Symbol) -> %Symbol
bfColonColon(package, name) == 
  %hasFeature KEYWORD::CLISP and package in '(EXT FFI) =>
    FIND_-SYMBOL(SYMBOL_-NAME name,package)
  INTERN(SYMBOL_-NAME name, package)

bfSymbol: %Thing -> %Thing 
bfSymbol x==
   STRINGP x=> x
   ['QUOTE,x]

 
bfDot: () -> %Symbol
bfDot() == 
  "DOT"
 
bfSuffixDot: %Thing -> %List
bfSuffixDot x ==
  [x,"DOT"]

bfEqual: %Thing -> %List 
bfEqual(name) == 
  ["EQUAL",name]

bfBracket: %Thing -> %Thing 
bfBracket(part) == 
  part
 
bfPile: %List -> %List
bfPile(part) == 
  part
 
bfAppend: %List -> %List
bfAppend x== 
  APPLY(function APPEND,x)
 
bfColonAppend: (%List,%Thing) -> %List
bfColonAppend(x,y) ==
     if null x
     then
      if y is ["BVQUOTE",:a]
      then ["&REST",["QUOTE",:a]]
      else ["&REST",y]
     else cons(first x,bfColonAppend(rest x,y))

bfDefinition: (%Thing,%Thing,%Thing) -> %List 
bfDefinition(bflhsitems, bfrhs,body) ==
       ['DEF,bflhsitems,bfrhs,body]
 
bfMDefinition: (%Thing,%Thing,%Thing) -> %List 
bfMDefinition(bflhsitems, bfrhs,body) ==
       bfMDef('MDEF,bflhsitems,bfrhs,body)

bfCompDef: %Thing -> %List 
bfCompDef x ==
  case x of
    ConstantDefinition(.,.) => x
    otherwise =>
      x is [def, op, args, body] =>
        bfDef(def,op,args,body)
      coreError '"invalid AST"

bfBeginsDollar: %Thing -> %Boolean 
bfBeginsDollar x ==  
  EQL('"$".0,(PNAME x).0)
 
compFluid id == 
  ["FLUID",id]
 
compFluidize x==
  IDENTP x and bfBeginsDollar x=>compFluid x
  atom x =>x
  EQCAR(x,"QUOTE")=>x
  cons(compFluidize(first x),compFluidize(rest x))
 
bfTuple x== ["TUPLE",:x]
 
bfTupleP x==EQCAR(x,"TUPLE")

++ If `bf' is a tuple return its elements; otherwise `bf'.
bfUntuple bf ==
  bfTupleP bf => cdr bf
  bf
 
bfTupleIf x==
  if bfTupleP x
  then x
  else bfTuple x
 
bfTupleConstruct b ==
  a:= if bfTupleP b
      then cdr b
      else [b]
  or/[x is ["COLON",.] for x in a] => bfMakeCons a
  ["LIST",:a]
 
bfConstruct b ==
  a:= if bfTupleP b
      then cdr b
      else [b]
  bfMakeCons a
 
bfMakeCons l ==
  null l => NIL
  l is [["COLON",a],:l1] =>
    l1 => ['APPEND,a,bfMakeCons l1]
    a
  ['CONS,first l,bfMakeCons rest l]
 
bfFor(bflhs,U,step) ==
     if EQCAR (U,'tails)
     then  bfForTree('ON, bflhs, second U)
     else
       if EQCAR(U,"SEGMENT")
       then  bfSTEP(bflhs,second U,step,third U)
       else  bfForTree('IN, bflhs, U)
 
bfForTree(OP,lhs,whole)==
         whole:=if bfTupleP whole then bfMakeCons cdr whole else whole
         atom lhs =>bfINON [OP,lhs,whole]
         lhs:=if bfTupleP lhs then second lhs else lhs
         EQCAR(lhs,"L%T") =>
             G:=second lhs
             [:bfINON [OP,G,whole],:bfSuchthat bfIS(G,third lhs)]
         G:=bfGenSymbol()
         [:bfINON [OP,G,whole],:bfSuchthat bfIS(G,lhs)]
 
 
bfSTEP(id,fst,step,lst)==
      initvar:=[id]
      initval:=[fst]
      inc:=if atom step
           then step
           else
               g1:=bfGenSymbol()
               initvar:=cons(g1,initvar)
               initval:=cons(step,initval)
               g1
      final:=if atom lst
             then lst
             else
               g2:=bfGenSymbol()
               initvar:=cons(g2,initvar)
               initval:=cons(lst,initval)
               g2
      ex:=
          null lst=> []
          INTEGERP inc =>
              pred:=if MINUSP inc then "<" else ">"
              [[pred,id,final]]
          [['COND,[['MINUSP,inc],
                ["<",id,final]],['T,[">",id,final]]]]
      suc:=[['SETQ,id,["+",id,inc]]]
      [[initvar,initval,suc,[],ex,[]]]
 
 
bfINON x==
    [op,id,whole]:=x
    if EQ(op,"ON")
    then bfON(id,whole)
    else bfIN(id,whole)
 
bfIN(x,E)==
    g:=bfGenSymbol()
    [[[g,x],[E,nil],[['SETQ,g,['CDR, g]]],[],
        [['OR,['ATOM,g],['PROGN,['SETQ,x,['CAR,g]] ,'NIL]]],[]]]
 
bfON(x,E)==
    [[[x],[E],[['SETQ,x,['CDR, x]]],[],
        [['ATOM,x]],[]]]
 
bfSuchthat p== [[[],[],[],[p],[],[]]]
 
bfWhile p== [[[],[],[],[],[bfNOT p],[]]]
 
bfUntil p==
     g:=bfGenSymbol()
     [[[g],[nil],[['SETQ,g,p]],[],[g],[]]]
 
bfIterators x==["ITERATORS",:x]
 
bfCross x== ["CROSS",:x]
 
bfLp(iters,body)==
     EQCAR (iters,"ITERATORS")=>bfLp1(rest iters,body)
     bfLpCross(rest iters,body)
 
bfLpCross(iters,body)==
     if null cdr iters
     then bfLp(first iters,body)
     else bfLp(first iters,bfLpCross(rest iters,body))
 
bfSep(iters)==
     if null iters
     then [[],[],[],[],[],[]]
     else
         f:=first iters
         r:=bfSep rest iters
         [append(i,j) for i in f for j in r]
 
bfReduce(op,y)==
     a:=if EQCAR(op,"QUOTE") then second op else op
     op:=bfReName a
     init:=GET(op,"SHOETHETA")
     g:=bfGenSymbol()
     g1:=bfGenSymbol()
     body:=['SETQ,g,[op,g,g1]]
     if null init
     then
        g2:=bfGenSymbol()
        init:=['CAR,g2]
        ny:=['CDR,g2]
        it:= ["ITERATORS",:[[[[g],[init],[],[],[],[g]]],bfIN(g1,ny)]]
        bfMKPROGN [['L%T,g2,y],bfLp(it,body)]
     else
        init:=car init
        it:= ["ITERATORS",:[[[[g],[init],[],[],[],[g]]],bfIN(g1,y)]]
        bfLp(it,body)
 
bfReduceCollect(op,y)==
   if EQCAR (y,"COLLECT")
   then
     body:=y.1
     itl:=y.2
     a:=if EQCAR(op,"QUOTE") then second op else op
     op:=bfReName a
     init:=GET(op,"SHOETHETA")
     bfOpReduce(op,init,body,itl)
   else
     a:=bfTupleConstruct (y.1)
     bfReduce(op,a)
 
-- delayed collect
 
bfDCollect(y,itl)== ["COLLECT",y,itl]
 
bfDTuple x== ["DTUPLE",x]
 
bfCollect(y,itl) ==
      y is ["COLON",a] => bf0APPEND(a,itl)
      y is ["TUPLE",:.] =>
        newBody:=bfConstruct y
        bf0APPEND(newBody,itl)
      bf0COLLECT(y,itl)
 
bf0COLLECT(y,itl)==bfListReduce('CONS,y,itl)
 
 
bf0APPEND(y,itl)==
     g:=bfGenSymbol()
     body:=['SETQ,g,['APPEND,['REVERSE,y],g]]
     extrait:= [[[g],[nil],[],[],[],[['NREVERSE,g]]]]
     bfLp2(extrait,itl,body)
 
bfListReduce(op,y,itl)==
     g:=bfGenSymbol()
     body:=['SETQ,g,[op,y,g]]
     extrait:= [[[g],[nil],[],[],[],[['NREVERSE,g]]]]
     bfLp2(extrait,itl,body)
 
bfLp1(iters,body)==
      [vars,inits,sucs,filters,exits,value]:=bfSep bfAppend iters
      nbody:=if null filters then body else bfAND [:filters,body]
      value:=if null value then "NIL" else first value
      exits:= ["COND",[bfOR exits,["RETURN",value]],
                  ['(QUOTE T),nbody]]
      loop := ["LOOP",exits,:sucs]
      if vars then loop := 
        ["LET",[[v, i] for v in vars for i in inits], loop]
      loop
 
bfLp2(extrait,itl,body)==
     EQCAR (itl,"ITERATORS")=>bfLp1(cons(extrait,rest itl),body)
     iters:=rest itl
     bfLpCross
          ([["ITERATORS",extrait,:CDAR iters],:rest iters],body)
 
bfOpReduce(op,init,y,itl)==
     g:=bfGenSymbol()
     body:=
         EQ(op,"AND")=>
                bfMKPROGN [["SETQ",g,y],
                    ['COND, [['NOT,g],['RETURN,'NIL]]]]
         EQ(op,"OR") =>
                bfMKPROGN [["SETQ",g,y],
                             ['COND, [g,['RETURN,g]]]]
         ['SETQ,g,[op,g,y]]
     if null init
     then
        g1:=bfGenSymbol()
        init:=['CAR,g1]
        y:=['CDR,g1]
        extrait:= [[[g],[init],[],[],[],[g]]]
        bfMKPROGN [['L%T,g1,y],bfLp2(extrait,itl,body)]
     else
        init:=first init
        extrait:= [[[g],[init],[],[],[],[g]]]
        bfLp2(extrait,itl,body)
 
bfLoop1 body == bfLp (bfIterators nil,body)
 
bfSegment1(lo)==     ["SEGMENT",lo,nil]
 
bfSegment2(lo,hi)==   ["SEGMENT",lo,hi]
 
bfForInBy(variable,collection,step)==
         bfFor(variable,collection,step)
 
bfForin(lhs,U)==bfFor(lhs,U,1)
 
bfLocal(a,b)==
         EQ(b,"FLUID")=>  compFluid a
         EQ(b,"fluid")=>  compFluid a
         EQ(b,"local") =>  compFluid a
    --   $typings:=cons(["TYPE",b,a],$typings)
         a
 
bfTake(n,x)==
     null x=>x
     n=0 => nil
     cons(first x,bfTake(n-1,rest x))
 
bfDrop(n,x)==
     null x or n=0 =>x
     bfDrop(n-1,rest x)
 
bfDefSequence l ==  
  ['SEQ,: l]
 
bfReturnNoName a ==
      ["RETURN",a]
 
bfSUBLIS(p,e)==
  atom e=>bfSUBLIS1(p,e)
  EQCAR(e,"QUOTE")=>e
  cons(bfSUBLIS(p,first e),bfSUBLIS(p,rest e))
 
+++ Returns e/p, where e is an atom.  We assume that the
+++ DEFs form a system admitting a fix point; otherwise we may
+++ loop forever.  That can happen only if nullary goats
+++ are recursive -- which they are not supposed to be.
+++ We don't enforce that restriction though.
bfSUBLIS1(p,e)==
   null p =>e
   f:=first p
   EQ(first f,e)=> bfSUBLIS(p, rest f)
   bfSUBLIS1(cdr p,e)
 
defSheepAndGoats(x)==
    EQCAR (x,"DEF") =>
        [def,op,args,body]:=x
        argl:=if bfTupleP args
              then rest args
              else [args]
        if null argl
        then
          opassoc:=[[op,:body]]
          [opassoc,[],[]]
        else
          op1:=INTERN CONCAT(PNAME $op,'",",PNAME op)
          opassoc:=[[op,:op1]]
          defstack:=[["DEF",op1,args,body]]
          [opassoc,defstack,[]]
    EQCAR (x,"SEQ") =>  defSheepAndGoatsList(rest x)
    [[],[],[x]]
 
defSheepAndGoatsList(x)==
     if null x
     then [[],[],[]]
     else
       [opassoc,defs,nondefs]    := defSheepAndGoats first x
       [opassoc1,defs1,nondefs1] := defSheepAndGoatsList rest x
       [append(opassoc,opassoc1),append(defs,defs1),
            append(nondefs,nondefs1)]
--% LET
 
bfLetForm(lhs,rhs) ==   
  ['L%T,lhs,rhs]
 
bfLET1(lhs,rhs) ==
  IDENTP lhs         => bfLetForm(lhs,rhs)
  lhs is ['FLUID,.] => bfLetForm(lhs,rhs)
  IDENTP rhs and not bfCONTAINED(rhs,lhs) =>
    rhs1 := bfLET2(lhs,rhs)
    EQCAR(rhs1,'L%T) => bfMKPROGN [rhs1,rhs]
    EQCAR(rhs1,'PROGN) => APPEND(rhs1,[rhs])
    if IDENTP first rhs1 then rhs1 := CONS(rhs1,NIL)
    bfMKPROGN [:rhs1,rhs]
  CONSP(rhs) and EQCAR(rhs,'L%T) and IDENTP(name := second rhs) =>
    -- handle things like [a] := x := foo
    l1 := bfLET1(name,third rhs)
    l2 := bfLET1(lhs,name)
    EQCAR(l2,'PROGN) => bfMKPROGN [l1,:rest l2]
    if IDENTP first l2 then l2 := cons(l2,nil)
    bfMKPROGN [l1,:l2,name]
  g := INTERN CONCAT('"LETTMP#",STRINGIMAGE $letGenVarCounter)
  $letGenVarCounter := $letGenVarCounter + 1
  rhs1 := ['L%T,g,rhs]
  let1 := bfLET1(lhs,g)
  EQCAR(let1,'PROGN) => bfMKPROGN [rhs1,:rest let1]
  if IDENTP first let1 then let1 := CONS(let1,NIL)
  bfMKPROGN [rhs1,:let1,g]
 
bfCONTAINED(x,y)==
    EQ(x,y) => true
    atom y=> false
    bfCONTAINED(x,car y) or bfCONTAINED(x,cdr y)
 
bfLET2(lhs,rhs) ==
  IDENTP lhs => bfLetForm(lhs,rhs)
  NULL lhs   => NIL
  lhs is ['FLUID,.] => bfLetForm(lhs,rhs)
  lhs is ['L%T,a,b] =>
    a := bfLET2(a,rhs)
    null (b := bfLET2(b,rhs)) => a
    atom b => [a,b]
    CONSP first b => CONS(a,b)
    [a,b]
  lhs is ['CONS,var1,var2] =>
    var1 = "DOT" or (CONSP(var1) and EQCAR(var1,'QUOTE)) =>
      bfLET2(var2,addCARorCDR('CDR,rhs))
    l1 := bfLET2(var1,addCARorCDR('CAR,rhs))
    null var2 or EQ(var2,"DOT") =>l1
    if CONSP l1 and atom first l1 then l1 := cons(l1,nil)
    IDENTP var2 =>
      [:l1,bfLetForm(var2,addCARorCDR('CDR,rhs))]
    l2 := bfLET2(var2,addCARorCDR('CDR,rhs))
    if CONSP l2 and atom first l2 then l2 := cons(l2,nil)
    APPEND(l1,l2)
  lhs is ['APPEND,var1,var2] =>
    patrev := bfISReverse(var2,var1)
    rev := ['REVERSE,rhs]
    g := INTERN CONCAT('"LETTMP#", STRINGIMAGE $letGenVarCounter)
    $letGenVarCounter := $letGenVarCounter + 1
    l2 := bfLET2(patrev,g)
    if CONSP l2 and atom first l2 then l2 := cons(l2,nil)
    var1 = "DOT" => [['L%T,g,rev],:l2]
    last l2 is ['L%T, =var1, val1] =>
      [['L%T,g,rev],:REVERSE rest REVERSE l2,
       bfLetForm(var1,['NREVERSE,val1])]
    [['L%T,g,rev],:l2,bfLetForm(var1,['NREVERSE,var1])]
  lhs is ["EQUAL",var1] =>
    ['COND,[["EQUAL",var1,rhs],var1]]
  -- The original expression may be one that involves literals as 
  -- sub-patterns, e.g.
  --      ['SEQ, :l, ['exit, 1, x]] := item
  -- We continue the processing as if that expression had been written
  --      item is ['SEQ, :l, ['exit, 1, x]]
  -- and generate appropriate codes.
  --                  -- gdr/2007-04-02.
  isPred :=
    $inDefIS => bfIS1(rhs,lhs)
    bfIS(rhs,lhs)
  ['COND,[isPred,rhs]]
 
 
bfLET(lhs,rhs) ==
  $letGenVarCounter : local := 1
--  $inbfLet : local := true
  bfLET1(lhs,rhs)
 
addCARorCDR(acc,expr) ==
  NULL CONSP expr => [acc,expr]
  acc = 'CAR and EQCAR(expr,'REVERSE) =>
      ["CAR",["LAST",:rest expr]]
 --   cons('last,rest expr)
  funs := '(CAR CDR CAAR CDAR CADR CDDR CAAAR CADAR CAADR CADDR
            CDAAR CDDAR CDADR CDDDR)
  p := bfPosition(first expr,funs)
  p = -1 => [acc,expr]
  funsA := '(CAAR CADR CAAAR CADAR CAADR CADDR CAAAAR CAADAR CAAADR
             CAADDR CADAAR CADDAR CADADR CADDDR)
  funsR := '(CDAR CDDR CDAAR CDDAR CDADR CDDDR CDAAAR CDADAR CDAADR
             CDADDR CDDAAR CDDDAR CDDADR CDDDDR)
  if acc = 'CAR then CONS(funsA.p,rest expr)
  else               CONS(funsR.p,rest expr)
 
bfPosition(x,l) ==  bfPosn(x,l,0)
bfPosn(x,l,n) ==
      null l => -1
      x=first l => n
      bfPosn(x,rest l,n+1)
 
--% IS
 
bfISApplication(op,left,right)==
   EQ(op ,"IS")      => bfIS(left,right)
   EQ(op ,"ISNT")    => bfNOT bfIS(left,right)
   [op ,left,right]
 
bfIS(left,right)==
    $isGenVarCounter:local :=1
    $inDefIS :local :=true
    bfIS1(left,right)
 
bfISReverse(x,a) ==
  x is ['CONS,:.] =>
    null third x => ['CONS,second x, a]
    y := bfISReverse(third x, NIL)
    RPLACA(CDDR y,['CONS,second x,a])
    y
  bpSpecificErrorHere '"Error in bfISReverse"
  bpTrap()
 
bfIS1(lhs,rhs) ==
  null rhs =>
    ['NULL,lhs]
  STRINGP rhs =>
    ['EQ,lhs,['QUOTE,INTERN rhs]]
  NUMBERP rhs =>
    ["EQUAL",lhs,rhs]
  atom rhs =>
    ['PROGN,bfLetForm(rhs,lhs),''T]
  rhs is ['QUOTE,a] =>
    IDENTP a => ['EQ,lhs,rhs]
    ["EQUAL",lhs,rhs]
  rhs is ['L%T,c,d] =>
    l :=
      bfLET(c,lhs)
--    $inbfLet => bfLET1(c,lhs)
--    bfLET(c,lhs)
    bfAND [bfIS1(lhs,d),bfMKPROGN [l,''T]]
  rhs is ["EQUAL",a] =>
    ["EQUAL",lhs,a]
  CONSP lhs =>
    g := INTERN CONCAT('"ISTMP#",STRINGIMAGE $isGenVarCounter)
    $isGenVarCounter := $isGenVarCounter + 1
    bfMKPROGN [['L%T,g,lhs],bfIS1(g,rhs)]
  rhs is ['CONS,a,b] =>
    a = "DOT" =>
      NULL b =>
        bfAND [['CONSP,lhs],
               ['EQ,['CDR,lhs],'NIL]]
      bfAND [['CONSP,lhs],
             bfIS1(['CDR,lhs],b)]
    NULL b =>
      bfAND [['CONSP,lhs],
             ['EQ,['CDR,lhs],'NIL],_
             bfIS1(['CAR,lhs],a)]
    b = "DOT" =>
      bfAND [['CONSP,lhs],bfIS1(['CAR,lhs],a)]
    a1 := bfIS1(['CAR,lhs],a)
    b1 := bfIS1(['CDR,lhs],b)
    a1 is ['PROGN,c,''T] and b1 is ['PROGN,:cls] =>
      bfAND [['CONSP,lhs],bfMKPROGN [c,:cls]]
    bfAND [['CONSP,lhs],a1,b1]
  rhs is ['APPEND,a,b] =>
    patrev := bfISReverse(b,a)
    g := INTERN CONCAT('"ISTMP#",STRINGIMAGE $isGenVarCounter)
    $isGenVarCounter := $isGenVarCounter + 1
    rev := bfAND [['CONSP,lhs],['PROGN,['L%T,g,['REVERSE,lhs]],''T]]
    l2 := bfIS1(g,patrev)
    if CONSP l2 and atom first l2 then l2 := cons(l2,nil)
    a = "DOT" => bfAND [rev,:l2]
    bfAND [rev,:l2,['PROGN,bfLetForm(a,['NREVERSE,a]),''T]]
  bpSpecificErrorHere '"bad IS code is generated"
  bpTrap()
 
bfApplication(bfop, bfarg) ==
         if bfTupleP bfarg
         then cons(bfop,rest bfarg)
         else cons(bfop,[bfarg])
 

++ Token renaming.  New Boot and Old Boot differs in the set of
++ tokens they rename.  When converting code written in Old Boot
++ to New Boot, it is helpful to have some noise about potential
++ divergence in semantics.  So, when compiling with --boot=old,
++ we compute the renaming in both Old Boot and New Boot and compare
++ the results.  If they differ, we prefer the old meaning, with some
++ warnings.  Notice that the task is compounded by the fact the
++ tokens in both language do not always agreee.
++ However, to minimize the flood of false positive, we
++ keep a list of symbols which apparently differ in meanings, but
++ which have been verified to agree.  
++ This is a valuable automated tool during the transition period.

-- return the meaning of the x in Old Boot.
bfGetOldBootName x ==
  a := GET(x, "OLD-BOOT") => first a
  x

-- returns true if x has same meaning in both Old Boot and New Boot.
bfSameMeaning x ==
  GET(x, 'RENAME_-OK)
 
-- returns the meaning of x in the appropriate Boot dialect.
bfReName x==
  newName :=
    a := GET(x,"SHOERENAME") => first a
    x
  $translatingOldBoot and not bfSameMeaning x =>
    oldName := bfGetOldBootName x
    if newName ^= oldName then
       warn [PNAME x, '" as `", PNAME newName, _
             '"_' differs from Old Boot `", PNAME oldName,_
             '"_' at ", diagnosticLocation $stok]
    oldName
  newName

 
bfInfApplication(op,left,right)==
   EQ(op,"EQUAL") => bfQ(left,right)
   EQ(op,"/=")    => bfNOT bfQ(left,right)
   EQ(op,">")     => bfLessp(right,left)
   EQ(op,"<")     => bfLessp(left,right)
   EQ(op,"<=")    => bfNOT bfLessp(right,left)
   EQ(op,">=")    => bfNOT bfLessp(left,right)
   EQ(op,"OR")    => bfOR [left,right]
   EQ(op,"AND")   => bfAND [left,right]
   [op,left,right]
 
bfNOT x==
   x is ["NOT",a]=> a
   x is ["NULL",a]=> a
   ["NOT",x]
 
bfFlatten(op, x) ==
      EQCAR(x,op) => rest x
      [x]
 
bfOR l  ==
       null l => NIL
       null rest l => first l
       ["OR",:[:bfFlatten("OR",c) for c in l]]
 
bfAND l ==
       null l=> 'T
       null rest l => first l
       ["AND",:[:bfFlatten("AND",c) for c in l]]
 
 
defQuoteId x==  EQCAR(x,"QUOTE") and IDENTP second x
 
bfSmintable x==
  INTEGERP x or CONSP x and
      first x in '(SIZE LENGTH char)
 
bfQ(l,r)==
       if bfSmintable l or bfSmintable r
       then  ["EQL",l,r]
       else if defQuoteId l or defQuoteId r
            then  ["EQ",l,r]
            else
              if null l
              then ["NULL",r]
              else if null r
                   then ["NULL",l]
                   else ["EQUAL",l,r]
 
bfLessp(l,r)==
      if r=0
      then ["MINUSP", l]
      else ["<",l,r]
 
bfMDef (defOp,op,args,body) ==
  argl:=if bfTupleP args then cdr args else [args]
  [gargl,sgargl,nargl,largl]:=bfGargl argl
  sb:=[cons(i,j) for i in nargl for j in sgargl]
  body:= SUBLIS(sb,body)
  sb2 := [["CONS",["QUOTE",i],j] for i in sgargl for j in largl]
  body := ["SUBLIS",["LIST",:sb2],["QUOTE",body]]
  lamex:= ["MLAMBDA",gargl,body]
  def:= [op,lamex]
  bfTuple
     cons(shoeComp def,[:shoeComps bfDef1 d for d in $wheredefs])
 
bfGargl argl==
      if null argl
      then [[],[],[],[]]
      else
        [a,b,c,d]:=bfGargl rest argl
        if first argl="&REST"
        then [cons(first argl,b),b,c,
             cons(["CONS",["QUOTE","LIST"],first d],rest d)]
        else
            f:=bfGenSymbol()
            [cons(f,a),cons(f,b),cons(first argl,c),cons(f,d)]
 
bfDef1 [defOp,op,args,body] ==
  argl:=if bfTupleP args then rest args else [args]
  [quotes,control,arglp,body]:=bfInsertLet (argl,body)
  quotes=>shoeLAM(op,arglp,control,body)
  [[op,["LAMBDA",arglp,body]]]
 
shoeLAM (op,args,control,body)==
  margs :=bfGenSymbol()
  innerfunc:=INTERN(CONCAT(PNAME op,",LAM"))
  [[innerfunc,["LAMBDA",args,body]],
     [op,["MLAMBDA",["&REST",margs],["CONS",["QUOTE", innerfunc],
                    ["WRAP",margs, ["QUOTE", control]]]]]]
 
bfDef(defOp,op,args,body) ==
 $bfClamming =>
          [.,op1,arg1,:body1]:=shoeComp first bfDef1 [defOp,op,args,body]
          bfCompHash(op1,arg1,body1)
 bfTuple
  [:shoeComps bfDef1 d for d in  cons([defOp,op,args,body],$wheredefs)]
 
shoeComps  x==
  [shoeComp def for def in x]

shoeComp x==
     a:=shoeCompTran second x
     if EQCAR(a,"LAMBDA")
     then ["DEFUN",first x,second a,:CDDR a]
     else ["DEFMACRO",first x,second a,:CDDR a]


++ Translate function parameter list to Lisp.
++ We are processing a function definition.  `p2' is the list of
++ parameters we have seen so far, and we are about to add a 
++ parameter `p1'.  Check that the new specification is coherent
++ with the previous one.  In particular, check that restrictions
++ on parameters with default values are satisfied.  Return the
++ new augmented parameter list.
bfParameterList(p1,p2) ==
  p2=nil and not atom p1 => p1
  p1 is ["&OPTIONAL",:.] =>
    p2 isnt ["&OPTIONAL",:.] => bpSpecificErrorHere '"default value required"
    [first p1,:rest p1,:rest p2]
  p2 is ["&OPTIONAL",:.] =>   [p1,first p2,:rest p2]
  [p1,:p2]
 
bfInsertLet(x,body)==
   if null x
   then [false,nil,x,body]
   else
      if x is ["&REST",a]
      then if a is ["QUOTE",b]
           then [true,"QUOTE",["&REST",b],body]
           else [false,nil,x,body]
      else
       [b,norq,name1,body1]:=  bfInsertLet1 (first x,body)
       [b1,norq1,name2,body2]:=  bfInsertLet (rest x,body1)
       [b or b1,cons(norq,norq1),bfParameterList(name1,name2),body2]
 
bfInsertLet1(y,body)==
   y is ["L%T",l,r] => [false,nil,l,bfMKPROGN [bfLET(r,l),body]]
   IDENTP y => [false,nil,y,body]
   y is ["BVQUOTE",b] => [true,"QUOTE",b,body]
   g:=bfGenSymbol()
   atom y => [false,nil,g,body]
   case y of
     %DefaultValue(p,v) => [false,nil,["&OPTIONAL",[p,v]],body]
     otherwise => [false,nil,g,bfMKPROGN [bfLET(compFluidize y,g),body]]
 
shoeCompTran x==
   lamtype:=first x
   args   :=second x
   body   :=CDDR x
   $fluidVars:local:=nil
   $locVars:local:=nil
   $dollarVars:local:=nil
   shoeCompTran1 body
   $locVars:=SETDIFFERENCE(SETDIFFERENCE($locVars,
                                  $fluidVars),shoeATOMs args)
   body:=
     lvars:=append($fluidVars,$locVars)
     $fluidVars:=UNION($fluidVars,$dollarVars)
     body' := body
     if $typings then body' := [["DECLARE",:$typings],:body']
     if $fluidVars then
       fvars:=["DECLARE",["SPECIAL",:$fluidVars]]
       body' := [fvars,:body']
     if lvars or needsPROG body then shoePROG(lvars,body') else body'
   fl:=shoeFluids args
   body:=if fl
         then
           fvs:=["DECLARE",["SPECIAL",:fl]]
           cons(fvs,body)
         else body
   [lamtype,args, :body]

needsPROG body ==
  atom body => false
  [op,:args] := body
  op in '(RETURN RETURN_-FROM) => true
  op in '(LET PROG LOOP BLOCK DECLARE LAMBDA) => false
  or/[needsPROG t for t in body] => true
  false

shoePROG(v,b)==
    null b => [["PROG", v]]
    [:blist,blast] := b
    [["PROG",v,:blist,["RETURN", blast]]]

shoeFluids x==
         if null x
         then nil
         else if IDENTP x and bfBeginsDollar x
              then [x]
              else
                if EQCAR(x,"QUOTE")
                then []
                else
                  if atom x
                  then nil
                  else  append(shoeFluids first x,shoeFluids rest x)
shoeATOMs x==
         if null x
         then nil
         else if atom x
              then [x]
              else append(shoeATOMs first x,shoeATOMs rest x)
 
shoeCompTran1 x==
    atom x=>
                IDENTP x and bfBeginsDollar x=>
                    $dollarVars:=
                          MEMQ(x,$dollarVars)=>$dollarVars
                          cons(x,$dollarVars)
                nil
    U:=car x
    EQ(U,"QUOTE")=>nil
    x is ["L%T",l,r]=>
                RPLACA (x,"SETQ")
                shoeCompTran1 r
                IDENTP l =>
                  not bfBeginsDollar l=>
                    $locVars:=
                          MEMQ(l,$locVars)=>$locVars
                          cons(l,$locVars)
                  $dollarVars:=
                          MEMQ(l,$dollarVars)=>$dollarVars
                          cons(l,$dollarVars)
                EQCAR(l,"FLUID")=>
                    $fluidVars:=
                         MEMQ(second l,$fluidVars)=>$fluidVars
                         cons(second l,$fluidVars)
                    RPLACA (rest x,second l)
    MEMQ(U,'(PROG LAMBDA))=>
         newbindings:=nil
         for y in second x repeat
             not MEMQ(y,$locVars)=>
                  $locVars:=cons(y,$locVars)
                  newbindings:=cons(y,newbindings)
         res:=shoeCompTran1 CDDR x
         $locVars:=[y for y in $locVars | not MEMQ(y,newbindings)]
    shoeCompTran1 first x
    shoeCompTran1 rest x
 
bfTagged(a,b)==
  null $op => Signature(a,b)        -- surely a toplevel decl
  IDENTP a =>
    EQ(b,"FLUID") =>  bfLET(compFluid a,NIL)
    EQ(b,"fluid") =>  bfLET(compFluid a,NIL)
    EQ(b,"local") =>  bfLET(compFluid a,NIL)
    $typings:=cons(["TYPE",b,a],$typings)
    a
  ["THE",b,a]
 
bfAssign(l,r)==
   if bfTupleP l then bfSetelt(second l,CDDR l ,r) else bfLET(l,r)
 
bfSetelt(e,l,r)==
    if null rest l
    then defSETELT(e,car l,r)
    else bfSetelt(bfElt(e,first l),rest l,r)
 
bfElt(expr,sel)==
      y:=SYMBOLP sel and GET(sel,"SHOESELFUNCTION")
      y=>
         INTEGERP y => ["ELT",expr,y]
         [y,expr]
      ["ELT",expr,sel]
 
defSETELT(var,sel,expr)==
      y:=SYMBOLP sel and GET(sel,"SHOESELFUNCTION")
      y=>
         INTEGERP y => ["SETF",["ELT",var,y],expr]
         ["SETF",[y,var],expr]
      ["SETF",["ELT",var,sel],expr]
 
bfIfThenOnly(a,b)==
    b1:=if EQCAR (b,"PROGN") then rest b else [b]
    ["COND",[a,:b1]]
 
bfIf(a,b,c)==
    b1:=if EQCAR (b,"PROGN") then rest b else [b]
    EQCAR (c,"COND") => ["COND",[a,:b1],:rest c]
    c1:=if EQCAR (c,"PROGN") then rest c else [c]
    ["COND",[a,:b1],['(QUOTE T),:c1]]
 
bfExit(a,b)==  
  ["COND",[a,["IDENTITY",b]]]
 
bfMKPROGN l==
    a:=[:bfFlattenSeq c for c in tails l]
    null a=> nil
    null rest a=> first a
    ["PROGN",:a]
 
bfFlattenSeq x ==
      null x=>NIL
      f:=first x
      atom f =>if rest x then nil else [f]
      EQCAR(f,"PROGN") =>
              rest x=>  [i for i in rest f| not atom i]
              rest f
      [f]
 
bfSequence l ==
      null l=> NIL
      transform:= [[a,b] for x in l while
              x is ["COND",[a,["IDENTITY",b]]]]
      no:=#transform
      before:= bfTake(no,l)
      aft   := bfDrop(no,l)
      null before =>
              null rest l =>
                   f:=first l
                   if EQCAR(f,"PROGN")
                   then bfSequence rest f
                   else f
              bfMKPROGN [first l,bfSequence rest l]
      null aft => ["COND",:transform]
      ["COND",:transform,['(QUOTE T),bfSequence aft]]
 
bfWhere (context,expr)==
  [opassoc,defs,nondefs] := defSheepAndGoats context
  a:=[[def,op,args,bfSUBLIS(opassoc,body)]
               for d in defs  |d is [def,op,args,body]]
  $wheredefs:=append(a,$wheredefs)
  bfMKPROGN bfSUBLIS(opassoc,NCONC(nondefs,[expr]))
 
--shoeReadLispString(s,n)==
--    n>= # s => nil
--    [exp,ind]:=shoeReadLisp(s,n)
--    null exp => nil
--    cons(exp,shoeReadLispString(s,ind))
 
bfReadLisp string ==
  bfTuple shoeReadLispString (string,0)

bfCompHash(op,argl,body) ==
  auxfn:= INTERN CONCAT (PNAME op,'";")
  computeFunction:= ["DEFUN",auxfn,argl,:body]
  bfTuple [computeFunction,:bfMain(auxfn,op)]
 
shoeCompileTimeEvaluation x ==
  ["EVAL-WHEN", [KEYWORD::COMPILE_-TOPLEVEL], x]

shoeEVALANDFILEACTQ x==  
  ["EVAL-WHEN", [KEYWORD::EXECUTE, KEYWORD::LOAD_-TOPLEVEL], x]
 
bfMain(auxfn,op)==
  g1:= bfGenSymbol()
  arg:=["&REST",g1]
  computeValue := ['APPLY,["FUNCTION",auxfn],g1]
  cacheName:= INTERN CONCAT (PNAME op,'";AL")
  g2:= bfGenSymbol()
  getCode:=   ['GETHASH,g1,cacheName]
  secondPredPair:= [['SETQ,g2,getCode],g2]
  putCode:=   ['SETF ,getCode,computeValue]
  thirdPredPair:= ['(QUOTE T),putCode]
  codeBody:= ['PROG,[g2],
               ['RETURN,['COND,secondPredPair,thirdPredPair]]]
  mainFunction:= ["DEFUN",op,arg,codeBody]
 
  cacheType:=     'hash_-table
  cacheResetCode:=   ['SETQ,cacheName,['MAKE_-HASHTABLE,
                        ["QUOTE","UEQUAL"]]]
  cacheCountCode:= ['hashCount,cacheName]
  cacheVector:=
      [op,cacheName,cacheType,cacheResetCode,cacheCountCode]
  defCode := ["DEFPARAMETER",cacheName,
                ['MAKE_-HASHTABLE,["QUOTE","UEQUAL"]]]
  [defCode,mainFunction,
    shoeEVALANDFILEACTQ
      ["SETF",["GET",
           ["QUOTE", op],["QUOTE",'cacheInfo]],["QUOTE", cacheVector]]]


bfNameOnly: %Thing -> %List 
bfNameOnly x==
      if x="t"
      then ["T"]
      else  [x]

bfNameArgs: (%Thing,%Thing) -> %List 
bfNameArgs (x,y)==
    y:=if EQCAR(y,"TUPLE") then rest y else [y]
    cons(x,y)
 
bfStruct: (%Thing,%List) -> %List
bfStruct(name,arglist)==
  bfTuple [bfCreateDef i for i in arglist]

bfCreateDef: %Thing -> %List
bfCreateDef x==
     if null rest x
     then
       f:=first x
       ["DEFCONSTANT",f,["LIST",["QUOTE",f]]]
     else
       a:=[bfGenSymbol() for i in rest x]
       ["DEFUN",first x,a,["CONS",["QUOTE",first x],["LIST",:a]]]

bfCaseItem: (%Thing,%Thing) -> %List 
bfCaseItem(x,y) ==
  [x,y]

bfCase: (%Thing,%Thing) -> %List
bfCase(x,y)==
         g:=bfGenSymbol()
         g1:=bfGenSymbol()
         a:=bfLET(g,x)
         b:=bfLET(g1,["CDR",g])
         c:=bfCaseItems (g1,y)
         bfMKPROGN [a,b,["CASE",["CAR", g],:c]]

bfCaseItems: (%Thing,%List) -> %List 
bfCaseItems(g,x) ==  
  [bfCI(g,i,j) for [i,j] in x]

bfCI: (%Thing,%Thing,%Thing) -> %List 
bfCI(g,x,y)==
    a:=rest x
    if null a
    then [first x,y]
    else
       b:=[[i,bfCARCDR(j,g)] for i in a for j in 0.. | i ^= "DOT"]
       null b => [first x,y]
       [first x,["LET",b,y]]

bfCARCDR: (%Short,%Thing) -> %List 
bfCARCDR(n,g) ==
  [INTERN CONCAT ('"CA",bfDs n,'"R"),g]

bfDs: %Short -> %String 
bfDs n== 
  if n=0 then '"" else CONCAT('"D",bfDs(n-1))


++ Generate code for try-catch expressions.
bfTry: (%Thing,%List) -> %Thing
bfTry(e,cs) ==
  null cs => e
  case first cs of
    %Catch(tag) => 
      atom tag => bfTry(["CATCH",["QUOTE",tag],e],rest cs)
      bpTrap()  -- sorry
    otherwise => bpTrap()

++ Generate code for `throw'-expressions
bfThrow e ==
  atom e => ["THROW",["QUOTE",e],nil]
  not atom first e => bpTrap()
  ["THROW",["QUOTE",first e],:rest e]

--% Type alias definition

backquote(form,params) ==
  null params => quote  form
  atom form =>
    form in params => form
    quote form
  ["LIST",:[backquote(t,params) for t in form]]

genTypeAlias(head,body) ==
  [op,:args] := head
  ["DEFTYPE",op,args,backquote(body,args)]

--% Native datatype translation
coreSymbol: %Symbol -> %Symbol
coreSymbol s ==
  INTERN(SYMBOL_-NAME s, "AxiomCore")

bootSymbol: %Symbol -> %Symbol
bootSymbol s ==
  INTERN SYMBOL_-NAME s


unknownNativeTypeError t ==
  fatalError CONCAT('"unsupported native type: ", SYMBOL_-NAME t)


nativeType t ==
  null t => t
  -- for the time being, approximate `data buffer' by `pointer to data'
  t = "buffer" or t = "pointer" =>
    %hasFeature KEYWORD::GCL => "FIXNUM"
    %hasFeature KEYWORD::ECL => KEYWORD::POINTER_-VOID
    %hasFeature KEYWORD::SBCL => ["*",true]
    %hasFeature KEYWORD::CLISP => bfColonColon("FFI","C-POINTER")
    unknownNativeTypeError t
  t' := rest ASSOC(coreSymbol t,$NativeTypeTable) => 
    t' := 
      %hasFeature KEYWORD::SBCL => bfColonColon("SB-ALIEN", t')
      %hasFeature KEYWORD::CLISP => bfColonColon("FFI",t')
      t'
    -- ??? decree we have not discovered Unicode yet.
    t = "string" and %hasFeature KEYWORD::SBCL =>
      [t',KEYWORD::EXTERNAL_-FORMAT,KEYWORD::ASCII,
         KEYWORD::ELEMENT_-TYPE, "BASE-CHAR"]
    t'
  unknownNativeTypeError t