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
|
;;;; "printf.scm" Implementation of standard C functions for Scheme
;;; Copyright (C) 1991-1993, 1996 Aubrey Jaffer.
;
;Permission to copy this software, to redistribute it, and to use it
;for any purpose is granted, subject to the following restrictions and
;understandings.
;
;1. Any copy made of this software must include this copyright notice
;in full.
;
;2. I have made no warrantee or representation that the operation of
;this software will be error-free, and I am under no obligation to
;provide any services, by way of maintenance, update, or otherwise.
;
;3. In conjunction with products arising from the use of this
;material, there shall be no use of my name in any advertising,
;promotional, or sales literature without prior written consent in
;each case.
(require 'string-case)
;; Parse the output of NUMBER->STRING.
;; Returns a list: (sign-character digit-string exponent-integer)
;; SIGN-CHAR will be either #\+ or #\-, DIGIT-STRING will always begin
;; with a "0", after which a decimal point should be understood.
;; If STR denotes a non-real number, 3 additional elements for the
;; complex part are appended.
(define (stdio:parse-float str)
(let ((n (string-length str))
(iend 0))
(letrec ((prefix
(lambda (i rest)
(if (and (< i (- n 1))
(char=? #\# (string-ref str i)))
(case (string-ref str (+ i 1))
((#\d #\i #\e) (prefix (+ i 2) rest))
((#\.) (rest i))
(else (parse-error)))
(rest i))))
(sign
(lambda (i rest)
(if (< i n)
(let ((c (string-ref str i)))
(case c
((#\- #\+) (cons c (rest (+ i 1))))
(else (cons #\+ (rest i))))))))
(digits
(lambda (i rest)
(do ((j i (+ j 1)))
((or (>= j n)
(not (or (char-numeric? (string-ref str j))
(char=? #\# (string-ref str j)))))
(cons
(if (= i j) "0" (substring str i j))
(rest j))))))
(point
(lambda (i rest)
(if (and (< i n)
(char=? #\. (string-ref str i)))
(rest (+ i 1))
(rest i))))
(exp
(lambda (i)
(if (< i n)
(case (string-ref str i)
((#\e #\s #\f #\d #\l #\E #\S #\F #\D #\L)
(let ((s (sign (+ i 1) (lambda (i) (digits i end!)))))
(list
(if (char=? #\- (car s))
(- (string->number (cadr s)))
(string->number (cadr s))))))
(else (end! i)
'(0)))
(begin (end! i)
'(0)))))
(end!
(lambda (i)
(set! iend i)
'()))
(real
(lambda (i)
(let ((parsed
(prefix
i
(lambda (i)
(sign
i
(lambda (i)
(digits
i
(lambda (i)
(point
i
(lambda (i)
(digits i exp)))))))))))
(and (list? parsed)
(apply
(lambda (sgn idigs fdigs exp)
(let* ((digs (string-append "0" idigs fdigs))
(n (string-length digs)))
(let loop ((i 1)
(exp (+ exp (string-length idigs))))
(if (and (< i n)
(char=? #\0 (string-ref digs i)))
(loop (+ i 1) (- exp 1))
(list sgn (substring digs (- i 1) n) exp)))))
parsed)))))
(parse-error
(lambda () #f)))
(let ((realpart (real 0)))
(cond ((= iend n) realpart)
((memv (string-ref str iend) '(#\+ #\-))
(let ((complexpart (real iend)))
(and (= iend (- n 1))
(char-ci=? #\i (string-ref str iend))
(append realpart complexpart))))
((eqv? (string-ref str iend) #\@)
;; Polar form: No point in parsing the angle ourselves,
;; since some transcendental approximation is unavoidable.
(let ((num (string->number str)))
(and num
(let ((realpart
(stdio:parse-float
(number->string (real-part num))))
(imagpart
(if (real? num)
'()
(stdio:parse-float
(number->string (imag-part num))))))
(and realpart imagpart
(append realpart imagpart))))))
(else #f))))))
;; STR is a digit string representing a floating point mantissa, STR must
;; begin with "0", after which a decimal point is understood.
;; The output is a digit string rounded to NDIGS digits after the decimal
;; point implied between chars 0 and 1.
;; If STRIP-0S is not #F then trailing zeros will be stripped from the result.
;; In this case, STRIP-0S should be the minimum number of digits required
;; after the implied decimal point.
(define (stdio:round-string str ndigs strip-0s)
(let* ((n (- (string-length str) 1))
(res
(cond ((< ndigs 0) "")
((= n ndigs) str)
((< n ndigs)
(let ((zeropad (make-string
(max 0 (- (or strip-0s ndigs) n))
(if (char-numeric? (string-ref str n))
#\0 #\#))))
(if (zero? (string-length zeropad))
str
(string-append str zeropad))))
(else
(let ((res (substring str 0 (+ ndigs 1)))
(dig (lambda (i)
(let ((c (string-ref str i)))
(if (char-numeric? c)
(string->number (string c))
0)))))
(let ((ldig (dig (+ 1 ndigs))))
(if (or (> ldig 5)
(and (= ldig 5)
(let loop ((i (+ 2 ndigs)))
(if (> i n) (odd? (dig ndigs))
(if (zero? (dig i))
(loop (+ i 1))
#t)))))
(let inc! ((i ndigs))
(let ((d (dig i)))
(if (< d 9)
(string-set! res i
(string-ref
(number->string (+ d 1)) 0))
(begin
(string-set! res i #\0)
(inc! (- i 1))))))))
res)))))
(if strip-0s
(let loop ((i (- (string-length res) 1)))
(if (or (<= i strip-0s)
(not (char=? #\0 (string-ref res i))))
(substring res 0 (+ i 1))
(loop (- i 1))))
res)))
(define (stdio:iprintf out format-string . args)
(cond
((not (equal? "" format-string))
(let ((pos -1)
(fl (string-length format-string))
(fc (string-ref format-string 0)))
(define (advance)
(set! pos (+ 1 pos))
(cond ((>= pos fl) (set! fc #f))
(else (set! fc (string-ref format-string pos)))))
(define (must-advance)
(set! pos (+ 1 pos))
(cond ((>= pos fl) (incomplete))
(else (set! fc (string-ref format-string pos)))))
(define (end-of-format?)
(>= pos fl))
(define (incomplete)
(slib:error 'printf "conversion specification incomplete"
format-string))
(define (wna)
(slib:error 'printf "wrong number of arguments"
(length args)
format-string))
(let loop ((args args))
(advance)
(cond
((end-of-format?)
;;(or (null? args) (wna)) ;Extra arguments are *not* a bug.
)
((eqv? #\\ fc);;Emulating C strings may not be a good idea.
(must-advance)
(and (case fc
((#\n #\N) (out #\newline))
((#\t #\T) (out slib:tab))
;;((#\r #\R) (out #\return))
((#\f #\F) (out slib:form-feed))
((#\newline) #t)
(else (out fc)))
(loop args)))
((eqv? #\% fc)
(must-advance)
(let ((left-adjust #f) ;-
(signed #f) ;+
(blank #f)
(alternate-form #f) ;#
(leading-0s #f) ;0
(width 0)
(precision -1)
(type-modifier #f)
(read-format-number
(lambda ()
(cond
((eqv? #\* fc) ; GNU extension
(must-advance)
(let ((ans (car args)))
(set! args (cdr args))
ans))
(else
(do ((c fc fc)
(accum 0 (+ (* accum 10)
(string->number (string c)))))
((not (char-numeric? fc)) accum)
(must-advance)))))))
(define (pad pre . strs)
(let loop ((len (string-length pre))
(ss strs))
(cond ((>= len width) (apply string-append pre strs))
((null? ss)
(cond (left-adjust
(apply string-append
pre
(append strs
(list (make-string
(- width len) #\space)))))
(leading-0s
(apply string-append
pre
(make-string (- width len) #\0)
strs))
(else
(apply string-append
(make-string (- width len) #\space)
pre strs))))
(else
(loop (+ len (string-length (car ss))) (cdr ss))))))
(define integer-convert
(lambda (s radix)
(cond ((not (negative? precision))
(set! leading-0s #f)
(if (and (zero? precision)
(eqv? 0 s))
(set! s ""))))
(set! s (cond ((symbol? s) (symbol->string s))
((number? s) (number->string s radix))
((or (not s) (null? s)) "0")
((string? s) s)
(else "1")))
(let ((pre (cond ((equal? "" s) "")
((eqv? #\- (string-ref s 0))
(set! s (substring s 1 (string-length s)))
"-")
(signed "+")
(blank " ")
(alternate-form
(case radix
((8) "0")
((16) "0x")
(else "")))
(else ""))))
(pad pre
(if (< (string-length s) precision)
(make-string
(- precision (string-length s)) #\0)
"")
s))))
(define (float-convert num fc)
(define (f digs exp strip-0s)
(let ((digs (stdio:round-string
digs (+ exp precision) (and strip-0s exp))))
(cond ((>= exp 0)
(let* ((i0 (cond ((zero? exp) 0)
((char=? #\0 (string-ref digs 0)) 1)
(else 0)))
(i1 (max 1 (+ 1 exp)))
(idigs (substring digs i0 i1))
(fdigs (substring digs i1
(string-length digs))))
(cons idigs
(if (and (string=? fdigs "")
(not alternate-form))
'()
(list "." fdigs)))))
((zero? precision)
(list (if alternate-form "0." "0")))
((and strip-0s (string=? digs "") (list "0")))
(else
(list "0."
(make-string (min precision (- -1 exp)) #\0)
digs)))))
(define (e digs exp strip-0s)
(let* ((digs (stdio:round-string
digs (+ 1 precision) (and strip-0s 0)))
(istrt (if (char=? #\0 (string-ref digs 0)) 1 0))
(fdigs (substring
digs (+ 1 istrt) (string-length digs)))
(exp (if (zero? istrt) exp (- exp 1))))
(list
(substring digs istrt (+ 1 istrt))
(if (and (string=? fdigs "") (not alternate-form))
"" ".")
fdigs
(if (char-upper-case? fc) "E" "e")
(if (negative? exp) "-" "+")
(if (< -10 exp 10) "0" "")
(number->string (abs exp)))))
(define (g digs exp)
(let ((strip-0s (not alternate-form)))
(set! alternate-form #f)
(cond ((<= (- 1 precision) exp precision)
(set! precision (- precision exp))
(f digs exp strip-0s))
(else
(set! precision (- precision 1))
(e digs exp strip-0s)))))
(define (k digs exp sep)
(let* ((units '#("y" "z" "a" "f" "p" "n" "u" "m" ""
"k" "M" "G" "T" "P" "E" "Z" "Y"))
(base 8) ;index of ""
(uind (let ((i (if (negative? exp)
(quotient (- exp 3) 3)
(quotient (- exp 1) 3))))
(and
(< -1 (+ i base) (vector-length units))
i))))
(cond (uind
(set! exp (- exp (* 3 uind)))
(set! precision (max 0 (- precision exp)))
(append
(f digs exp #f)
(list sep
(vector-ref units (+ uind base)))))
(else
(g digs exp)))))
(cond ((negative? precision)
(set! precision 6))
((and (zero? precision)
(char-ci=? fc #\g))
(set! precision 1)))
(let* ((str
(cond ((number? num)
(number->string (exact->inexact num)))
((string? num) num)
((symbol? num) (symbol->string num))
(else "???")))
(parsed (stdio:parse-float str)))
(letrec ((format-real
(lambda (signed? sgn digs exp . rest)
(if (null? rest)
(cons
(if (char=? #\- sgn) "-"
(if signed? "+" (if blank " " "")))
(case fc
((#\e #\E) (e digs exp #f))
((#\f #\F) (f digs exp #f))
((#\g #\G) (g digs exp))
((#\k) (k digs exp ""))
((#\K) (k digs exp " "))))
(append (format-real signed? sgn digs exp)
(apply format-real #t rest)
'("i"))))))
(if parsed
(apply pad (apply format-real signed parsed))
(pad "???")))))
(do ()
((case fc
((#\-) (set! left-adjust #t) #f)
((#\+) (set! signed #t) #f)
((#\ ) (set! blank #t) #f)
((#\#) (set! alternate-form #t) #f)
((#\0) (set! leading-0s #t) #f)
(else #t)))
(must-advance))
(cond (left-adjust (set! leading-0s #f)))
(cond (signed (set! blank #f)))
(set! width (read-format-number))
(cond ((negative? width)
(set! left-adjust #t)
(set! width (- width))))
(cond ((eqv? #\. fc)
(must-advance)
(set! precision (read-format-number))))
(case fc ;Ignore these specifiers
((#\l #\L #\h)
(set! type-modifier fc)
(must-advance)))
;;At this point fc completely determines the format to use.
(if (null? args)
(if (memv (char-downcase fc)
'(#\c #\s #\a #\d #\i #\u #\o #\x #\b
#\f #\e #\g #\k))
(wna)))
(case fc
;; only - is allowed between % and c
((#\c #\C) ; C is enhancement
(and (out (string (car args))) (loop (cdr args))))
;; only - flag, no type-modifiers
((#\s #\S) ; S is enhancement
(let ((s (cond
((symbol? (car args)) (symbol->string (car args)))
((not (car args)) "(NULL)")
(else (car args)))))
(cond ((not (or (negative? precision)
(>= precision (string-length s))))
(set! s (substring s 0 precision))))
(and (out (cond
((<= width (string-length s)) s)
(left-adjust
(string-append
s (make-string (- width (string-length s)) #\ )))
(else
(string-append
(make-string (- width (string-length s))
(if leading-0s #\0 #\ )) s))))
(loop (cdr args)))))
;; SLIB extension
((#\a #\A) ;#\a #\A are pretty-print
(require 'generic-write)
(let ((os "") (pr precision))
(generic-write
(car args) (not alternate-form) #f
(cond ((and left-adjust (negative? pr))
(set! pr 0)
(lambda (s)
(set! pr (+ pr (string-length s)))
(out s)))
(left-adjust
(lambda (s)
(define sl (- pr (string-length s)))
(set! pr (cond ((negative? sl)
(out (substring s 0 pr)) 0)
(else (out s) sl)))
(positive? sl)))
((negative? pr)
(set! pr width)
(lambda (s)
(set! pr (- pr (string-length s)))
(cond ((not os) (out s))
((negative? pr)
(out os)
(set! os #f)
(out s))
(else (set! os (string-append os s))))
#t))
(else
(lambda (s)
(define sl (- pr (string-length s)))
(cond ((negative? sl)
(set! os (string-append
os (substring s 0 pr))))
(else (set! os (string-append os s))))
(set! pr sl)
(positive? sl)))))
(cond ((and left-adjust (negative? precision))
(cond
((> width pr) (out (make-string (- width pr) #\ )))))
(left-adjust
(cond
((> width (- precision pr))
(out (make-string (- width (- precision pr)) #\ )))))
((not os))
((<= width (string-length os)) (out os))
(else (and (out (make-string
(- width (string-length os)) #\ ))
(out os)))))
(loop (cdr args)))
((#\d #\D #\i #\I #\u #\U)
(and (out (integer-convert (car args) 10)) (loop (cdr args))))
((#\o #\O)
(and (out (integer-convert (car args) 8)) (loop (cdr args))))
((#\x #\X)
(and (out ((if (char-upper-case? fc)
string-upcase string-downcase)
(integer-convert (car args) 16)))
(loop (cdr args))))
((#\b #\B)
(and (out (integer-convert (car args) 2)) (loop (cdr args))))
((#\%) (and (out #\%) (loop args)))
((#\f #\F #\e #\E #\g #\G #\k #\K)
(and (out (float-convert (car args) fc)) (loop (cdr args))))
(else
(cond ((end-of-format?) (incomplete))
(else (and (out #\%) (out fc) (out #\?) (loop args))))))))
(else (and (out fc) (loop args)))))))))
(define (stdio:fprintf port format . args)
(let ((cnt 0))
(apply stdio:iprintf
(lambda (x)
(cond ((string? x)
(set! cnt (+ (string-length x) cnt)) (display x port) #t)
(else (set! cnt (+ 1 cnt)) (display x port) #t)))
format args)
cnt))
(define (stdio:printf format . args)
(apply stdio:fprintf (current-output-port) format args))
(define (stdio:sprintf str format . args)
(let* ((cnt 0)
(s (cond ((string? str) str)
((number? str) (make-string str))
((not str) (make-string 100))
(else (slib:error 'sprintf "first argument not understood"
str))))
(end (string-length s)))
(apply stdio:iprintf
(lambda (x)
(cond ((string? x)
(if (or str (>= (- end cnt) (string-length x)))
(do ((lend (min (string-length x) (- end cnt)))
(i 0 (+ i 1)))
((>= i lend))
(string-set! s cnt (string-ref x i))
(set! cnt (+ cnt 1)))
(let ()
(set! s (string-append (substring s 0 cnt) x))
(set! cnt (string-length s))
(set! end cnt))))
((and str (>= cnt end)))
(else (cond ((and (not str) (>= cnt end))
(set! s (string-append s (make-string 100)))
(set! end (string-length s))))
(string-set! s cnt (if (char? x) x #\?))
(set! cnt (+ cnt 1))))
(not (and str (>= cnt end))))
format
args)
(cond ((string? str) cnt)
((eqv? end cnt) s)
(else (substring s 0 cnt)))))
(define printf stdio:printf)
(define fprintf stdio:fprintf)
(define sprintf stdio:sprintf)
;;(do ((i 0 (+ 1 i))) ((> i 50)) (printf "%s\n" (sprintf i "%#-13a:%#13a:%-13.8a:" "123456789" "123456789" "123456789")))
|