This file is indexed.

/usr/share/scsh-0.6/srfi/srfi-14.scm is in scsh-common-0.6 0.6.7-8.

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
;;; SRFI-14 character-sets library				-*- Scheme -*-
;;;
;;; - Ported from MIT Scheme runtime by Brian D. Carlstrom.
;;; - Massively rehacked & extended by Olin Shivers 6/98.
;;; - Massively redesigned and rehacked 5/2000 during SRFI process.
;;; At this point, the code bears the following relationship to the
;;; MIT Scheme code: "This is my grandfather's axe. My father replaced
;;; the head, and I have replaced the handle." Nonetheless, we preserve
;;; the MIT Scheme copyright:
;;;     Copyright (c) 1988-1995 Massachusetts Institute of Technology
;;; The MIT Scheme license is a "free software" license. See the end of
;;; this file for the tedious details. 
;;;
;;;
;;; On 16 Dec 2003, Olin added the following comment in a private email
;;; to Mike Sperber, Jonathan Rees and Martin Gasbichler:
;;;
;;; This code has nothing in common w/the MIT code. Just check it out.
;;; The only connection is (1) some of the API design and (2) the basic
;;; data-structure (a 256-elt string of \000 & non-\000 chars), which is
;;; obvious art. I was being overly generous when I included the MIT copyright.
;;; The system was completely rewritten for the 2000 SRFI reference version;
;;; I should have removed the MIT notices then. In particular, as a casual
;;; examination will show, the implementation of the common API is *quite* 
;;; different -- I don't even mean at the in-the-small level, but at the
;;; medium-level architectural/structural details.



;;; Exports:
;;; char-set? char-set= char-set<=
;;; char-set-hash 
;;; char-set-cursor char-set-ref char-set-cursor-next end-of-char-set?
;;; char-set-fold char-set-unfold char-set-unfold!
;;; char-set-for-each char-set-map
;;; char-set-copy char-set
;;;
;;; list->char-set  string->char-set 
;;; list->char-set! string->char-set! 
;;;
;;; filterchar-set  ucs-range->char-set  ->char-set
;;; filterchar-set! ucs-range->char-set!
;;;
;;; char-set->list char-set->string
;;;
;;; char-set-size char-set-count char-set-contains?
;;; char-set-every char-set-any
;;;
;;; char-set-adjoin  char-set-delete 
;;; char-set-adjoin! char-set-delete!
;;; 

;;; char-set-complement  char-set-union  char-set-intersection  
;;; char-set-complement! char-set-union! char-set-intersection! 
;;;
;;; char-set-difference  char-set-xor  char-set-diff+intersection
;;; char-set-difference! char-set-xor! char-set-diff+intersection!
;;;
;;; char-set:lower-case		char-set:upper-case	char-set:title-case
;;; char-set:letter		char-set:digit		char-set:letter+digit
;;; char-set:graphic		char-set:printing	char-set:whitespace
;;; char-set:iso-control	char-set:punctuation	char-set:symbol
;;; char-set:hex-digit		char-set:blank		char-set:ascii
;;; char-set:empty		char-set:full

;;; Imports
;;; This code has the following non-R5RS dependencies:
;;; - ERROR
;;; - %LATIN1->CHAR %CHAR->LATIN1
;;; - LET-OPTIONALS* and :OPTIONAL macros for parsing, checking & defaulting
;;;   optional arguments from rest lists.
;;; - BITWISE-AND for CHAR-SET-HASH
;;; - The SRFI-19 DEFINE-RECORD-TYPE record macro
;;; - A simple CHECK-ARG procedure: 
;;;   (lambda (pred val caller) (if (not (pred val)) (error val caller)))

;;; This is simple code, not great code. Char sets are represented as 256-char
;;; strings. If char I is ASCII/Latin-1 0, then it isn't in the set; if char I
;;; is ASCII/Latin-1 1, then it is in the set.
;;; - Should be rewritten to use bit strings or byte vecs.
;;; - Is Latin-1 specific. Would certainly have to be rewritten for Unicode.

;;; See the end of the file for porting and performance-tuning notes.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

; Start S48 additions

(define (check-arg pred val caller)
  (if (not (pred val))
      (error val caller))
  val)

(define-syntax :optional
  (syntax-rules ()
    ((:optional rest default-exp)
     (let ((maybe-arg rest))
       (if (pair? maybe-arg)
	   (if (null? (cdr maybe-arg)) (car maybe-arg)
	       (error "too many optional arguments" maybe-arg))
	   default-exp)))

    ((:optional rest default-exp arg-test)
     (let ((maybe-arg rest))
       (if (pair? maybe-arg)
	   (if (null? (cdr maybe-arg))
	       (let ((val (car maybe-arg)))
		 (if (arg-test val) val
		     (error "Optional argument failed test"
			    'arg-test val)))
	       (error "too many optional arguments" maybe-arg))
	   default-exp)))))

(define-syntax let-optionals*
  (syntax-rules ()
    ((let-optionals* arg (opt-clause ...) body ...)
     (let ((rest arg))
       (%let-optionals* rest (opt-clause ...) body ...)))))

(define-syntax %let-optionals*
  (syntax-rules ()
    ((%let-optionals* arg (((var ...) xparser) opt-clause ...) body ...)
     (call-with-values (lambda () (xparser arg))
       (lambda (rest var ...)
         (%let-optionals* rest (opt-clause ...) body ...))))
    
    ((%let-optionals* arg ((var default) opt-clause ...) body ...)
     (call-with-values (lambda () (if (null? arg) (values default '())
				      (values (car arg) (cdr arg))))
       (lambda (var rest)
	 (%let-optionals* rest (opt-clause ...) body ...))))

    ((%let-optionals* arg ((var default test) opt-clause ...) body ...)
     (call-with-values (lambda ()
			 (if (null? arg) (values default '())
			     (let ((var (car arg)))
			       (if test (values var (cdr arg))
				   (error "arg failed LET-OPT test" var)))))
       (lambda (var rest)
	 (%let-optionals* rest (opt-clause ...) body ...))))

    ((%let-optionals* arg ((var default test supplied?) opt-clause ...) body ...)
     (call-with-values (lambda ()
			 (if (null? arg) (values default #f '())
			     (let ((var (car arg)))
			       (if test (values var #t (cdr arg))
				   (error "arg failed LET-OPT test" var)))))
       (lambda (var supplied? rest)
	 (%let-optionals* rest (opt-clause ...) body ...))))

    ((%let-optionals* arg (rest) body ...)
     (let ((rest arg)) body ...))

    ((%let-optionals* arg () body ...)
     (if (null? arg) (begin body ...)
	 (error "Too many arguments in let-opt" arg)))))

; End S48 additions

(define-record-type :char-set
  (make-char-set s)
  char-set?
  (s char-set:s))

(define (%string-copy s) (substring s 0 (string-length s)))

;;; Parse, type-check & default a final optional BASE-CS parameter from
;;; a rest argument. Return a *fresh copy* of the underlying string.
;;; The default is the empty set. The PROC argument is to help us
;;; generate informative error exceptions.

(define (%default-base maybe-base proc)
  (if (pair? maybe-base)
      (let ((bcs  (car maybe-base))
	    (tail (cdr maybe-base)))
	(if (null? tail)
	    (if (char-set? bcs) (%string-copy (char-set:s bcs))
		(error "BASE-CS parameter not a char-set" proc bcs))
	    (error "Expected final base char set -- too many parameters"
		   proc maybe-base)))
      (make-string 256 (%latin1->char 0))))

;;; If CS is really a char-set, do CHAR-SET:S, otw report an error msg on
;;; behalf of our caller, PROC. This procedure exists basically to provide
;;; explicit error-checking & reporting.

(define (%char-set:s/check cs proc)
  (let lp ((cs cs))
    (if (char-set? cs) (char-set:s cs)
	(lp (error "Not a char-set" cs proc)))))



;;; These internal functions hide a lot of the dependency on the
;;; underlying string representation of char sets. They should be
;;; inlined if possible.

(define (si=0? s i) (zero? (%char->latin1 (string-ref s i))))
(define (si=1? s i) (not (si=0? s i)))
(define c0 (%latin1->char 0))
(define c1 (%latin1->char 1))
(define (si s i) (%char->latin1 (string-ref s i)))
(define (%set0! s i) (string-set! s i c0))
(define (%set1! s i) (string-set! s i c1))

;;; These do various "s[i] := s[i] op val" operations -- see 
;;; %CHAR-SET-ALGEBRA. They are used to implement the various
;;; set-algebra procedures.
(define (setv!   s i v) (string-set! s i (%latin1->char v))) ; SET to a Value.
(define (%not!   s i v) (setv! s i (- 1 v)))
(define (%and!   s i v) (if (zero? v) (%set0! s i)))
(define (%or!    s i v) (if (not (zero? v)) (%set1! s i)))
(define (%minus! s i v) (if (not (zero? v)) (%set0! s i)))
(define (%xor!   s i v) (if (not (zero? v)) (setv! s i (- 1 (si s i)))))


(define (char-set-copy cs)
  (make-char-set (%string-copy (%char-set:s/check cs char-set-copy))))

(define (char-set= . rest)
  (or (null? rest)
      (let* ((cs1  (car rest))
	     (rest (cdr rest))
	     (s1 (%char-set:s/check cs1 char-set=)))
	(let lp ((rest rest))
	  (or (not (pair? rest))
	      (and (string=? s1 (%char-set:s/check (car rest) char-set=))
		   (lp (cdr rest))))))))

(define (char-set<= . rest)
  (or (null? rest)
      (let ((cs1  (car rest))
	    (rest (cdr rest)))
	(let lp ((s1 (%char-set:s/check cs1 char-set<=))  (rest rest))
	  (or (not (pair? rest))
	      (let ((s2 (%char-set:s/check (car rest) char-set<=))
		    (rest (cdr rest)))
		(if (eq? s1 s2) (lp s2 rest)	; Fast path
		    (let lp2 ((i 255))		; Real test
		      (if (< i 0) (lp s2 rest)
			  (and (<= (si s1 i) (si s2 i))
			       (lp2 (- i 1))))))))))))

;;; Hash
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Compute (c + 37 c + 37^2 c + ...) modulo BOUND, with sleaze thrown in
;;; to keep the intermediate values small. (We do the calculation with just
;;; enough bits to represent BOUND, masking off high bits at each step in
;;; calculation. If this screws up any important properties of the hash
;;; function I'd like to hear about it. -Olin)
;;;
;;; If you keep BOUND small enough, the intermediate calculations will 
;;; always be fixnums. How small is dependent on the underlying Scheme system; 
;;; we use a default BOUND of 2^22 = 4194304, which should hack it in
;;; Schemes that give you at least 29 signed bits for fixnums. The core 
;;; calculation that you don't want to overflow is, worst case,
;;;     (+ 65535 (* 37 (- bound 1)))
;;; where 65535 is the max character code. Choose the default BOUND to be the
;;; biggest power of two that won't cause this expression to fixnum overflow, 
;;; and everything will be copacetic.

(define (char-set-hash cs . maybe-bound)
  (let* ((bound (:optional maybe-bound 4194304 (lambda (n) (and (integer? n)
								(exact? n)
								(<= 0 n)))))
	 (bound (if (zero? bound) 4194304 bound))	; 0 means default.
	 (s (%char-set:s/check cs char-set-hash))
	 ;; Compute a 111...1 mask that will cover BOUND-1:
	 (mask (let lp ((i #x10000)) ; Let's skip first 16 iterations, eh?
		 (if (>= i bound) (- i 1) (lp (+ i i))))))

      (let lp ((i 255) (ans 0))
	(if (< i 0) (modulo ans bound)
	    (lp (- i 1)
		(if (si=0? s i) ans
		    (bitwise-and mask (+ (* 37 ans) i))))))))


(define (char-set-contains? cs char)
  (si=1? (%char-set:s/check cs char-set-contains?)
	 (%char->latin1 (check-arg char? char char-set-contains?))))

(define (char-set-size cs)
  (let ((s (%char-set:s/check cs char-set-size)))
    (let lp ((i 255) (size 0))
      (if (< i 0) size
	  (lp (- i 1) (+ size (si s i)))))))

(define (char-set-count pred cset)
  (check-arg procedure? pred char-set-count)
  (let ((s (%char-set:s/check cset char-set-count)))
    (let lp ((i 255) (count 0))
      (if (< i 0) count
	  (lp (- i 1)
	      (if (and (si=1? s i) (pred (%latin1->char i)))
		  (+ count 1)
		  count))))))


;;; -- Adjoin & delete

(define (%set-char-set set proc cs chars)
  (let ((s (%string-copy (%char-set:s/check cs proc))))
    (for-each (lambda (c) (set s (%char->latin1 c)))
	      chars)
    (make-char-set s)))

(define (%set-char-set! set proc cs chars)
  (let ((s (%char-set:s/check cs proc)))
    (for-each (lambda (c) (set s (%char->latin1 c)))
	      chars))
  cs)

(define (char-set-adjoin cs . chars)
  (%set-char-set  %set1! char-set-adjoin cs chars))
(define (char-set-adjoin! cs . chars)
  (%set-char-set! %set1! char-set-adjoin! cs chars))
(define (char-set-delete cs . chars)
  (%set-char-set  %set0! char-set-delete cs chars))
(define (char-set-delete! cs . chars)
  (%set-char-set! %set0! char-set-delete! cs chars))


;;; Cursors
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; Simple implementation. A cursors is an integer index into the
;;; mark vector, and -1 for the end-of-char-set cursor.
;;;
;;; If we represented char sets as a bit set, we could do the following
;;; trick to pick the lowest bit out of the set: 
;;;   (count-bits (xor (- cset 1) cset))
;;; (But first mask out the bits already scanned by the cursor first.)

(define (char-set-cursor cset)
  (%char-set-cursor-next cset 256 char-set-cursor))
  
(define (end-of-char-set? cursor) (< cursor 0))

(define (char-set-ref cset cursor) (%latin1->char cursor))

(define (char-set-cursor-next cset cursor)
  (check-arg (lambda (i) (and (integer? i) (exact? i) (<= 0 i 255))) cursor
	     char-set-cursor-next)
  (%char-set-cursor-next cset cursor char-set-cursor-next))

(define (%char-set-cursor-next cset cursor proc)	; Internal
  (let ((s (%char-set:s/check cset proc)))
    (let lp ((cur cursor))
      (let ((cur (- cur 1)))
	(if (or (< cur 0) (si=1? s cur)) cur
	    (lp cur))))))


;;; -- for-each map fold unfold every any

(define (char-set-for-each proc cs)
  (check-arg procedure? proc char-set-for-each)
  (let ((s (%char-set:s/check cs char-set-for-each)))
    (let lp ((i 255))
      (cond ((>= i 0)
	     (if (si=1? s i) (proc (%latin1->char i)))
	     (lp (- i 1)))))))

(define (char-set-map proc cs)
  (check-arg procedure? proc char-set-map)
  (let ((s (%char-set:s/check cs char-set-map))
	(ans (make-string 256 c0)))
    (let lp ((i 255))
      (cond ((>= i 0)
	     (if (si=1? s i)
		 (%set1! ans (%char->latin1 (proc (%latin1->char i)))))
	     (lp (- i 1)))))
    (make-char-set ans)))

(define (char-set-fold kons knil cs)
  (check-arg procedure? kons char-set-fold)
  (let ((s (%char-set:s/check cs char-set-fold)))
    (let lp ((i 255) (ans knil))
      (if (< i 0) ans
	  (lp (- i 1)
	      (if (si=0? s i) ans
		  (kons (%latin1->char i) ans)))))))

(define (char-set-every pred cs)
  (check-arg procedure? pred char-set-every)
  (let ((s (%char-set:s/check cs char-set-every)))
    (let lp ((i 255))
      (or (< i 0)
	  (and (or (si=0? s i) (pred (%latin1->char i)))
	       (lp (- i 1)))))))

(define (char-set-any pred cs)
  (check-arg procedure? pred char-set-any)
  (let ((s (%char-set:s/check cs char-set-any)))
    (let lp ((i 255))
      (and (>= i 0)
	   (or (and (si=1? s i) (pred (%latin1->char i)))
	       (lp (- i 1)))))))


(define (%char-set-unfold! proc p f g s seed)
  (check-arg procedure? p proc)
  (check-arg procedure? f proc)
  (check-arg procedure? g proc)
  (let lp ((seed seed))
    (cond ((not (p seed))			; P says we are done.
	   (%set1! s (%char->latin1 (f seed)))	; Add (F SEED) to set.
	   (lp (g seed))))))			; Loop on (G SEED).

(define (char-set-unfold p f g seed . maybe-base)
  (let ((bs (%default-base maybe-base char-set-unfold)))
    (%char-set-unfold! char-set-unfold p f g bs seed)
    (make-char-set bs)))

(define (char-set-unfold! p f g seed base-cset)
  (%char-set-unfold! char-set-unfold! p f g
		     (%char-set:s/check base-cset char-set-unfold!)
		     seed)
  base-cset)



;;; list <--> char-set

(define (%list->char-set! chars s)
  (for-each (lambda (char) (%set1! s (%char->latin1 char)))
	    chars))

(define (char-set . chars)
  (let ((s (make-string 256 c0)))
    (%list->char-set! chars s)
    (make-char-set s)))

(define (list->char-set chars . maybe-base)
  (let ((bs (%default-base maybe-base list->char-set)))
    (%list->char-set! chars bs)
    (make-char-set bs)))

(define (list->char-set! chars base-cs)
  (%list->char-set! chars (%char-set:s/check base-cs list->char-set!))
  base-cs)


(define (char-set->list cs)
  (let ((s (%char-set:s/check cs char-set->list)))
    (let lp ((i 255) (ans '()))
      (if (< i 0) ans
	  (lp (- i 1)
	      (if (si=0? s i) ans
		  (cons (%latin1->char i) ans)))))))



;;; string <--> char-set

(define (%string->char-set! str bs proc)
  (check-arg string? str proc)
  (do ((i (- (string-length str) 1) (- i 1)))
      ((< i 0))
    (%set1! bs (%char->latin1 (string-ref str i)))))

(define (string->char-set str . maybe-base)
  (let ((bs (%default-base maybe-base string->char-set)))
    (%string->char-set! str bs string->char-set)
    (make-char-set bs)))

(define (string->char-set! str base-cs)
  (%string->char-set! str (%char-set:s/check base-cs string->char-set!)
		      string->char-set!)
  base-cs)


(define (char-set->string cs)
  (let* ((s (%char-set:s/check cs char-set->string))
	 (ans (make-string (char-set-size cs))))
    (let lp ((i 255) (j 0))
      (if (< i 0) ans
	  (let ((j (if (si=0? s i) j
		       (begin (string-set! ans j (%latin1->char i))
			      (+ j 1)))))
	    (lp (- i 1) j))))))


;;; -- UCS-range -> char-set

(define (%ucs-range->char-set! lower upper error? bs proc)
  (check-arg (lambda (x) (and (integer? x) (exact? x) (<= 0 x))) lower proc)
  (check-arg (lambda (x) (and (integer? x) (exact? x) (<= lower x))) upper proc)

  (if (and (< lower upper) (< 256 upper) error?)
      (error "Requested UCS range contains unavailable characters -- this implementation only supports Latin-1"
	     proc lower upper))

  (let lp ((i (- (min upper 256) 1)))
    (cond ((<= lower i) (%set1! bs i) (lp (- i 1))))))

(define (ucs-range->char-set lower upper . rest)
  (let-optionals* rest ((error? #f) rest)
    (let ((bs (%default-base rest ucs-range->char-set)))
      (%ucs-range->char-set! lower upper error? bs ucs-range->char-set)
      (make-char-set bs))))

(define (ucs-range->char-set! lower upper error? base-cs)
  (%ucs-range->char-set! lower upper error?
			 (%char-set:s/check base-cs ucs-range->char-set!)
			 ucs-range->char-set)
  base-cs)


;;; -- predicate -> char-set

(define (%char-set-filter! pred ds bs proc)
  (check-arg procedure? pred proc)
  (let lp ((i 255))
    (cond ((>= i 0)
	   (if (and (si=1? ds i) (pred (%latin1->char i)))
	       (%set1! bs i))
	   (lp (- i 1))))))

(define (char-set-filter predicate domain . maybe-base)
  (let ((bs (%default-base maybe-base char-set-filter)))
    (%char-set-filter! predicate
		       (%char-set:s/check domain char-set-filter!)
		       bs
		       char-set-filter)
    (make-char-set bs)))

(define (char-set-filter! predicate domain base-cs)
  (%char-set-filter! predicate
		     (%char-set:s/check domain char-set-filter!)
		     (%char-set:s/check base-cs char-set-filter!)
		     char-set-filter!)
  base-cs)


;;; {string, char, char-set} -> char-set

(define (x->char-set x)
  (cond ((char-set? x) x)
	((string? x) (string->char-set x))
	((char? x) (char-set x))
	(else (error "->char-set: Not a charset, string or char." x))))



;;; Set algebra
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; The exported ! procs are "linear update" -- allowed, but not required, to
;;; side-effect their first argument when computing their result. In other
;;; words, you must use them as if they were completely functional, just like
;;; their non-! counterparts, and you must additionally ensure that their
;;; first arguments are "dead" at the point of call. In return, we promise a
;;; more efficient result, plus allowing you to always assume char-sets are
;;; unchangeable values.

;;; Apply P to each index and its char code in S: (P I VAL).
;;; Used by the set-algebra ops.

(define (%string-iter p s)
  (let lp ((i (- (string-length s) 1)))
    (cond ((>= i 0)
	   (p i (%char->latin1 (string-ref s i)))
	   (lp (- i 1))))))

;;; String S represents some initial char-set. (OP s i val) does some
;;; kind of s[i] := s[i] op val update. Do
;;;     S := S OP CSETi
;;; for all the char-sets in the list CSETS. The n-ary set-algebra ops
;;; all use this internal proc.

(define (%char-set-algebra s csets op proc)
  (for-each (lambda (cset)
	      (let ((s2 (%char-set:s/check cset proc)))
		(let lp ((i 255))
		  (cond ((>= i 0)
			 (op s i (si s2 i))
			 (lp (- i 1)))))))
	    csets))


;;; -- Complement

(define (char-set-complement cs)
  (let ((s (%char-set:s/check cs char-set-complement))
	(ans (make-string 256)))
    (%string-iter (lambda (i v) (%not! ans i v)) s)
    (make-char-set ans)))

(define (char-set-complement! cset)
  (let ((s (%char-set:s/check cset char-set-complement!)))
    (%string-iter (lambda (i v) (%not! s i v)) s))
  cset)


;;; -- Union

(define (char-set-union! cset1 . csets)
  (%char-set-algebra (%char-set:s/check cset1 char-set-union!)
		     csets %or! char-set-union!)
  cset1)

(define (char-set-union . csets)
  (if (pair? csets)
      (let ((s (%string-copy (%char-set:s/check (car csets) char-set-union))))
	(%char-set-algebra s (cdr csets) %or! char-set-union)
	(make-char-set s))
      (char-set-copy char-set:empty)))


;;; -- Intersection

(define (char-set-intersection! cset1 . csets)
  (%char-set-algebra (%char-set:s/check cset1 char-set-intersection!)
		     csets %and! char-set-intersection!)
  cset1)

(define (char-set-intersection . csets)
  (if (pair? csets)
      (let ((s (%string-copy (%char-set:s/check (car csets) char-set-intersection))))
	(%char-set-algebra s (cdr csets) %and! char-set-intersection)
	(make-char-set s))
      (char-set-copy char-set:full)))


;;; -- Difference

(define (char-set-difference! cset1 . csets)
  (%char-set-algebra (%char-set:s/check cset1 char-set-difference!)
		     csets %minus! char-set-difference!)
  cset1)

(define (char-set-difference cs1 . csets)
  (if (pair? csets)
      (let ((s (%string-copy (%char-set:s/check cs1 char-set-difference))))
	(%char-set-algebra s csets %minus! char-set-difference)
	(make-char-set s))
      (char-set-copy cs1)))


;;; -- Xor

(define (char-set-xor! cset1 . csets)
  (%char-set-algebra (%char-set:s/check cset1 char-set-xor!)
		      csets %xor! char-set-xor!)
  cset1)

(define (char-set-xor . csets)
  (if (pair? csets)
      (let ((s (%string-copy (%char-set:s/check (car csets) char-set-xor))))
	(%char-set-algebra s (cdr csets) %xor! char-set-xor)
	(make-char-set s))
      (char-set-copy char-set:empty)))


;;; -- Difference & intersection

(define (%char-set-diff+intersection! diff int csets proc)
  (for-each (lambda (cs)
	      (%string-iter (lambda (i v)
			      (if (not (zero? v))
				  (cond ((si=1? diff i)
					 (%set0! diff i)
					 (%set1! int  i)))))
			    (%char-set:s/check cs proc)))
	    csets))

(define (char-set-diff+intersection! cs1 cs2 . csets)
  (let ((s1 (%char-set:s/check cs1 char-set-diff+intersection!))
	(s2 (%char-set:s/check cs2 char-set-diff+intersection!)))
    (%string-iter (lambda (i v) (if (zero? v)
				    (%set0! s2 i)
				    (if (si=1? s2 i) (%set0! s1 i))))
		  s1)
    (%char-set-diff+intersection! s1 s2 csets char-set-diff+intersection!))
  (values cs1 cs2))

(define (char-set-diff+intersection cs1 . csets)
  (let ((diff (string-copy (%char-set:s/check cs1 char-set-diff+intersection)))
	(int  (make-string 256 c0)))
    (%char-set-diff+intersection! diff int csets char-set-diff+intersection)
    (values (make-char-set diff) (make-char-set int))))


;;;; System character sets
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; These definitions are for Latin-1.
;;;
;;; If your Scheme implementation allows you to mark the underlying strings
;;; as immutable, you should do so -- it would be very, very bad if a client's
;;; buggy code corrupted these constants.

(define char-set:empty (char-set))
(define char-set:full (char-set-complement char-set:empty))

(define char-set:lower-case
  (let* ((a-z (ucs-range->char-set #x61 #x7B))
	 (latin1 (ucs-range->char-set! #xdf #xf7  #t a-z))
	 (latin2 (ucs-range->char-set! #xf8 #x100 #t latin1)))
    (char-set-adjoin! latin2 (%latin1->char #xb5))))

(define char-set:upper-case
  (let ((A-Z (ucs-range->char-set #x41 #x5B)))
    ;; Add in the Latin-1 upper-case chars.
    (ucs-range->char-set! #xd8 #xdf #t
			  (ucs-range->char-set! #xc0 #xd7 #t A-Z))))

(define char-set:title-case char-set:empty)

(define char-set:letter
  (let ((u/l (char-set-union char-set:upper-case char-set:lower-case)))
    (char-set-adjoin! u/l
		      (%latin1->char #xaa)	; FEMININE ORDINAL INDICATOR
		      (%latin1->char #xba))))	; MASCULINE ORDINAL INDICATOR

(define char-set:digit     (string->char-set "0123456789"))
(define char-set:hex-digit (string->char-set "0123456789abcdefABCDEF"))

(define char-set:letter+digit
  (char-set-union char-set:letter char-set:digit))

(define char-set:punctuation
  (let ((ascii (string->char-set "!\"#%&'()*,-./:;?@[\\]_{}"))
	(latin-1-chars (map %latin1->char '(#xA1 ; INVERTED EXCLAMATION MARK
					    #xAB ; LEFT-POINTING DOUBLE ANGLE QUOTATION MARK
					    #xAD ; SOFT HYPHEN
					    #xB7 ; MIDDLE DOT
					    #xBB ; RIGHT-POINTING DOUBLE ANGLE QUOTATION MARK
					    #xBF)))) ; INVERTED QUESTION MARK
    (list->char-set! latin-1-chars ascii)))

(define char-set:symbol
  (let ((ascii (string->char-set "$+<=>^`|~"))
	(latin-1-chars (map %latin1->char '(#x00A2 ; CENT SIGN
					    #x00A3 ; POUND SIGN
					    #x00A4 ; CURRENCY SIGN
					    #x00A5 ; YEN SIGN
					    #x00A6 ; BROKEN BAR
					    #x00A7 ; SECTION SIGN
					    #x00A8 ; DIAERESIS
					    #x00A9 ; COPYRIGHT SIGN
					    #x00AC ; NOT SIGN
					    #x00AE ; REGISTERED SIGN
					    #x00AF ; MACRON
					    #x00B0 ; DEGREE SIGN
					    #x00B1 ; PLUS-MINUS SIGN
					    #x00B4 ; ACUTE ACCENT
					    #x00B6 ; PILCROW SIGN
					    #x00B8 ; CEDILLA
					    #x00D7 ; MULTIPLICATION SIGN
					    #x00F7)))) ; DIVISION SIGN
    (list->char-set! latin-1-chars ascii)))
  

(define char-set:graphic
  (char-set-union char-set:letter+digit char-set:punctuation char-set:symbol))

(define char-set:whitespace
  (list->char-set (map %latin1->char '(#x09 ; HORIZONTAL TABULATION
				       #x0A ; LINE FEED		
				       #x0B ; VERTICAL TABULATION
				       #x0C ; FORM FEED
				       #x0D ; CARRIAGE RETURN
				       #x20 ; SPACE
				       #xA0))))

(define char-set:printing (char-set-union char-set:whitespace char-set:graphic)) ; NO-BREAK SPACE

(define char-set:blank
  (list->char-set (map %latin1->char '(#x09 ; HORIZONTAL TABULATION
				       #x20 ; SPACE
				       #xA0)))) ; NO-BREAK SPACE


(define char-set:iso-control
  (ucs-range->char-set! #x7F #xA0 #t (ucs-range->char-set 0 32)))

(define char-set:ascii (ucs-range->char-set 0 128))

; Begin S48 additions

(define (make-char-set-immutable! char-set)
  (make-immutable! char-set)
  (make-immutable! (char-set:s char-set)))

(make-char-set-immutable! char-set:empty)
(make-char-set-immutable! char-set:full)
(make-char-set-immutable! char-set:lower-case)
(make-char-set-immutable! char-set:upper-case)
(make-char-set-immutable! char-set:letter)
(make-char-set-immutable! char-set:digit)
(make-char-set-immutable! char-set:hex-digit)
(make-char-set-immutable! char-set:letter+digit)
(make-char-set-immutable! char-set:punctuation)
(make-char-set-immutable! char-set:symbol)
(make-char-set-immutable! char-set:graphic)
(make-char-set-immutable! char-set:whitespace)
(make-char-set-immutable! char-set:printing)
(make-char-set-immutable! char-set:blank)
(make-char-set-immutable! char-set:iso-control)
(make-char-set-immutable! char-set:ascii)

; End S48 additions


;;; Porting & performance-tuning notes
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;; See the section at the beginning of this file on external dependencies.
;;;
;;; First and foremost, rewrite this code to use bit vectors of some sort.
;;; This will give big speedup and memory savings.
;;;
;;; - LET-OPTIONALS* macro.
;;; This is only used once. You can rewrite the use, port the hairy macro
;;; definition (which is implemented using a Clinger-Rees low-level
;;; explicit-renaming macro system), or port the simple, high-level
;;; definition, which is less efficient.
;;;
;;; - :OPTIONAL macro
;;; Very simply defined using an R5RS high-level macro.
;;;
;;; Implementations that can arrange for the base char sets to be immutable
;;; should do so. (E.g., Scheme 48 allows one to mark a string as immutable,
;;; which can be used to protect the underlying strings.) It would be very,
;;; very bad if a client's buggy code corrupted these constants.
;;;
;;; There is a fair amount of argument checking. This is, strictly speaking,
;;; unnecessary -- the actual body of the procedures will blow up if an
;;; illegal value is passed in. However, the error message will not be as good
;;; as if the error were caught at the "higher level." Also, a very, very
;;; smart Scheme compiler may be able to exploit having the type checks done
;;; early, so that the actual body of the procedures can assume proper values.
;;; This isn't likely; this kind of compiler technology isn't common any
;;; longer.
;;; 
;;; The overhead of optional-argument parsing is irritating. The optional
;;; arguments must be consed into a rest list on entry, and then parsed out.
;;; Function call should be a matter of a few register moves and a jump; it
;;; should not involve heap allocation! Your Scheme system may have a superior
;;; non-R5RS optional-argument system that can eliminate this overhead. If so,
;;; then this is a prime candidate for optimising these procedures,
;;; *especially* the many optional BASE-CS parameters.
;;;
;;; Note that optional arguments are also a barrier to procedure integration.
;;; If your Scheme system permits you to specify alternate entry points
;;; for a call when the number of optional arguments is known in a manner
;;; that enables inlining/integration, this can provide performance 
;;; improvements.
;;;
;;; There is enough *explicit* error checking that *all* internal operations
;;; should *never* produce a type or index-range error. Period. Feel like
;;; living dangerously? *Big* performance win to be had by replacing string
;;; and record-field accessors and setters with unsafe equivalents in the
;;; code. Similarly, fixnum-specific operators can speed up the arithmetic
;;; done on the index values in the inner loops. The only arguments that are
;;; not completely error checked are
;;;   - string lists (complete checking requires time proportional to the
;;;     length of the list)
;;;   - procedure arguments, such as char->char maps & predicates.
;;;     There is no way to check the range & domain of procedures in Scheme.
;;; Procedures that take these parameters cannot fully check their
;;; arguments. But all other types to all other procedures are fully
;;; checked.
;;;
;;; This does open up the alternate possibility of simply *removing* these 
;;; checks, and letting the safe primitives raise the errors. On a dumb
;;; Scheme system, this would provide speed (by eliminating the redundant
;;; error checks) at the cost of error-message clarity.
;;;
;;; In an interpreted Scheme, some of these procedures, or the internal
;;; routines with % prefixes, are excellent candidates for being rewritten
;;; in C.
;;;
;;; It would also be nice to have the ability to mark some of these
;;; routines as candidates for inlining/integration.
;;; 
;;; See the comments preceding the hash function code for notes on tuning
;;; the default bound so that the code never overflows your implementation's
;;; fixnum size into bignum calculation.
;;;
;;; All the %-prefixed routines in this source code are written
;;; to be called internally to this library. They do *not* perform
;;; friendly error checks on the inputs; they assume everything is
;;; proper. They also do not take optional arguments. These two properties
;;; save calling overhead and enable procedure integration -- but they
;;; are not appropriate for exported routines.


;;; The MIT Scheme project gave Olin Shivers the permission to use the
;;; code from this SRFI under the following license:
;;; 
;;; 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.
;;; 
;;;    3. The name of the author may not be used to endorse or promote
;;;       products derived from this software without specific prior
;;;       written permission.
;;; 
;;; THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.