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6be07c52 TTN |
1 | ;;; srfi-1.scm --- List Library |
2 | ||
9e775af3 | 3 | ;; Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2009, 2010, 2011 Free Software Foundation, Inc. |
6be07c52 | 4 | ;; |
73be1d9e MV |
5 | ;; This library is free software; you can redistribute it and/or |
6 | ;; modify it under the terms of the GNU Lesser General Public | |
7 | ;; License as published by the Free Software Foundation; either | |
83ba2d37 | 8 | ;; version 3 of the License, or (at your option) any later version. |
73be1d9e MV |
9 | ;; |
10 | ;; This library is distributed in the hope that it will be useful, | |
6be07c52 TTN |
11 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
12 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
73be1d9e MV |
13 | ;; Lesser General Public License for more details. |
14 | ;; | |
15 | ;; You should have received a copy of the GNU Lesser General Public | |
16 | ;; License along with this library; if not, write to the Free Software | |
92205699 | 17 | ;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
e9680547 | 18 | |
9e775af3 AW |
19 | ;;; Some parts from the reference implementation, which is |
20 | ;;; Copyright (c) 1998, 1999 by Olin Shivers. You may do as you please with | |
21 | ;;; this code as long as you do not remove this copyright notice or | |
22 | ;;; hold me liable for its use. | |
23 | ||
e9680547 MG |
24 | ;;; Author: Martin Grabmueller <mgrabmue@cs.tu-berlin.de> |
25 | ;;; Date: 2001-06-06 | |
26 | ||
27 | ;;; Commentary: | |
28 | ||
6be07c52 TTN |
29 | ;; This is an implementation of SRFI-1 (List Library). |
30 | ;; | |
31 | ;; All procedures defined in SRFI-1, which are not already defined in | |
32 | ;; the Guile core library, are exported. The procedures in this | |
33 | ;; implementation work, but they have not been tuned for speed or | |
34 | ;; memory usage. | |
35 | ;; | |
36 | ;; This module is fully documented in the Guile Reference Manual. | |
e9680547 MG |
37 | |
38 | ;;; Code: | |
39 | ||
40 | (define-module (srfi srfi-1) | |
f595ccfe | 41 | :export ( |
e9680547 MG |
42 | ;;; Constructors |
43 | ;; cons <= in the core | |
44 | ;; list <= in the core | |
45 | xcons | |
46 | ;; cons* <= in the core | |
47 | ;; make-list <= in the core | |
48 | list-tabulate | |
d61261f0 | 49 | list-copy |
e9680547 | 50 | circular-list |
f595ccfe | 51 | ;; iota ; Extended. |
e9680547 MG |
52 | |
53 | ;;; Predicates | |
54 | proper-list? | |
55 | circular-list? | |
56 | dotted-list? | |
57 | ;; pair? <= in the core | |
58 | ;; null? <= in the core | |
59 | null-list? | |
60 | not-pair? | |
61 | list= | |
62 | ||
63 | ;;; Selectors | |
64 | ;; car <= in the core | |
65 | ;; cdr <= in the core | |
66 | ;; caar <= in the core | |
67 | ;; cadr <= in the core | |
68 | ;; cdar <= in the core | |
2a326497 | 69 | ;; cddr <= in the core |
e9680547 MG |
70 | ;; caaar <= in the core |
71 | ;; caadr <= in the core | |
72 | ;; cadar <= in the core | |
73 | ;; caddr <= in the core | |
74 | ;; cdaar <= in the core | |
75 | ;; cdadr <= in the core | |
76 | ;; cddar <= in the core | |
77 | ;; cdddr <= in the core | |
78 | ;; caaaar <= in the core | |
79 | ;; caaadr <= in the core | |
80 | ;; caadar <= in the core | |
81 | ;; caaddr <= in the core | |
82 | ;; cadaar <= in the core | |
83 | ;; cadadr <= in the core | |
84 | ;; caddar <= in the core | |
85 | ;; cadddr <= in the core | |
86 | ;; cdaaar <= in the core | |
87 | ;; cdaadr <= in the core | |
88 | ;; cdadar <= in the core | |
89 | ;; cdaddr <= in the core | |
90 | ;; cddaar <= in the core | |
91 | ;; cddadr <= in the core | |
92 | ;; cdddar <= in the core | |
93 | ;; cddddr <= in the core | |
94 | ;; list-ref <= in the core | |
95 | first | |
96 | second | |
97 | third | |
98 | fourth | |
99 | fifth | |
100 | sixth | |
101 | seventh | |
102 | eighth | |
103 | ninth | |
104 | tenth | |
105 | car+cdr | |
106 | take | |
107 | drop | |
108 | take-right | |
109 | drop-right | |
110 | take! | |
111 | drop-right! | |
112 | split-at | |
113 | split-at! | |
114 | last | |
115 | ;; last-pair <= in the core | |
116 | ||
117 | ;;; Miscelleneous: length, append, concatenate, reverse, zip & count | |
118 | ;; length <= in the core | |
119 | length+ | |
120 | ;; append <= in the core | |
121 | ;; append! <= in the core | |
122 | concatenate | |
123 | concatenate! | |
124 | ;; reverse <= in the core | |
125 | ;; reverse! <= in the core | |
126 | append-reverse | |
127 | append-reverse! | |
128 | zip | |
129 | unzip1 | |
130 | unzip2 | |
131 | unzip3 | |
132 | unzip4 | |
133 | unzip5 | |
134 | count | |
135 | ||
136 | ;;; Fold, unfold & map | |
137 | fold | |
138 | fold-right | |
139 | pair-fold | |
140 | pair-fold-right | |
141 | reduce | |
142 | reduce-right | |
143 | unfold | |
144 | unfold-right | |
f595ccfe MD |
145 | ;; map ; Extended. |
146 | ;; for-each ; Extended. | |
e9680547 MG |
147 | append-map |
148 | append-map! | |
149 | map! | |
f595ccfe | 150 | ;; map-in-order ; Extended. |
e9680547 MG |
151 | pair-for-each |
152 | filter-map | |
153 | ||
154 | ;;; Filtering & partitioning | |
c614a00b | 155 | ;; filter <= in the core |
e9680547 MG |
156 | partition |
157 | remove | |
c614a00b | 158 | ;; filter! <= in the core |
e9680547 MG |
159 | partition! |
160 | remove! | |
161 | ||
162 | ;;; Searching | |
163 | find | |
164 | find-tail | |
165 | take-while | |
166 | take-while! | |
167 | drop-while | |
168 | span | |
169 | span! | |
170 | break | |
171 | break! | |
172 | any | |
173 | every | |
f595ccfe MD |
174 | ;; list-index ; Extended. |
175 | ;; member ; Extended. | |
e9680547 MG |
176 | ;; memq <= in the core |
177 | ;; memv <= in the core | |
178 | ||
179 | ;;; Deletion | |
f595ccfe MD |
180 | ;; delete ; Extended. |
181 | ;; delete! ; Extended. | |
e9680547 MG |
182 | delete-duplicates |
183 | delete-duplicates! | |
184 | ||
185 | ;;; Association lists | |
f595ccfe | 186 | ;; assoc ; Extended. |
e9680547 MG |
187 | ;; assq <= in the core |
188 | ;; assv <= in the core | |
189 | alist-cons | |
190 | alist-copy | |
191 | alist-delete | |
192 | alist-delete! | |
193 | ||
194 | ;;; Set operations on lists | |
195 | lset<= | |
196 | lset= | |
197 | lset-adjoin | |
198 | lset-union | |
199 | lset-intersection | |
200 | lset-difference | |
201 | lset-xor | |
202 | lset-diff+intersection | |
203 | lset-union! | |
204 | lset-intersection! | |
205 | lset-difference! | |
206 | lset-xor! | |
207 | lset-diff+intersection! | |
208 | ||
209 | ;;; Primitive side-effects | |
210 | ;; set-car! <= in the core | |
211 | ;; set-cdr! <= in the core | |
212 | ) | |
d61261f0 | 213 | :re-export (cons list cons* make-list pair? null? |
b8b0abf0 MD |
214 | car cdr caar cadr cdar cddr |
215 | caaar caadr cadar caddr cdaar cdadr cddar cdddr | |
216 | caaaar caaadr caadar caaddr cadaar cadadr caddar cadddr | |
217 | cdaaar cdaadr cdadar cdaddr cddaar cddadr cdddar cddddr | |
218 | list-ref last-pair length append append! reverse reverse! | |
219 | filter filter! memq memv assq assv set-car! set-cdr!) | |
d61261f0 | 220 | :replace (iota map for-each map-in-order list-copy list-index member |
f595ccfe MD |
221 | delete delete! assoc) |
222 | ) | |
e9680547 MG |
223 | |
224 | (cond-expand-provide (current-module) '(srfi-1)) | |
225 | ||
ee6aac97 MD |
226 | ;; Load the compiled primitives from the shared library. |
227 | ;; | |
37710f7e AW |
228 | (load-extension (string-append "libguile-" (effective-version)) |
229 | "scm_init_srfi_1") | |
ee6aac97 MD |
230 | |
231 | ||
e9680547 MG |
232 | ;;; Constructors |
233 | ||
0b7f2eb8 LC |
234 | (define (xcons d a) |
235 | "Like `cons', but with interchanged arguments. Useful mostly when passed to | |
236 | higher-order procedures." | |
237 | (cons a d)) | |
238 | ||
5753f02f GH |
239 | ;; internal helper, similar to (scsh utilities) check-arg. |
240 | (define (check-arg-type pred arg caller) | |
241 | (if (pred arg) | |
242 | arg | |
243 | (scm-error 'wrong-type-arg caller | |
244 | "Wrong type argument: ~S" (list arg) '()))) | |
245 | ||
7f593bc7 LC |
246 | (define (out-of-range proc arg) |
247 | (scm-error 'out-of-range proc | |
248 | "Value out of range: ~A" (list arg) (list arg))) | |
249 | ||
5753f02f GH |
250 | ;; the srfi spec doesn't seem to forbid inexact integers. |
251 | (define (non-negative-integer? x) (and (integer? x) (>= x 0))) | |
252 | ||
0b7f2eb8 LC |
253 | (define (list-tabulate n init-proc) |
254 | "Return an N-element list, where each list element is produced by applying the | |
255 | procedure INIT-PROC to the corresponding list index. The order in which | |
256 | INIT-PROC is applied to the indices is not specified." | |
257 | (check-arg-type non-negative-integer? n "list-tabulate") | |
258 | (let lp ((n n) (acc '())) | |
259 | (if (<= n 0) | |
260 | acc | |
261 | (lp (- n 1) (cons (init-proc (- n 1)) acc))))) | |
e9680547 | 262 | |
2d411b05 KR |
263 | (define (circular-list elt1 . elts) |
264 | (set! elts (cons elt1 elts)) | |
265 | (set-cdr! (last-pair elts) elts) | |
266 | elts) | |
e9680547 | 267 | |
2cf7ff2e | 268 | (define* (iota count #:optional (start 0) (step 1)) |
5753f02f | 269 | (check-arg-type non-negative-integer? count "iota") |
2cf7ff2e LC |
270 | (let lp ((n 0) (acc '())) |
271 | (if (= n count) | |
e9680547 | 272 | (reverse! acc) |
2cf7ff2e | 273 | (lp (+ n 1) (cons (+ start (* n step)) acc))))) |
e9680547 MG |
274 | |
275 | ;;; Predicates | |
276 | ||
277 | (define (proper-list? x) | |
278 | (list? x)) | |
279 | ||
280 | (define (circular-list? x) | |
281 | (if (not-pair? x) | |
282 | #f | |
283 | (let lp ((hare (cdr x)) (tortoise x)) | |
284 | (if (not-pair? hare) | |
285 | #f | |
286 | (let ((hare (cdr hare))) | |
287 | (if (not-pair? hare) | |
288 | #f | |
289 | (if (eq? hare tortoise) | |
290 | #t | |
291 | (lp (cdr hare) (cdr tortoise))))))))) | |
292 | ||
293 | (define (dotted-list? x) | |
294 | (cond | |
295 | ((null? x) #f) | |
296 | ((not-pair? x) #t) | |
297 | (else | |
298 | (let lp ((hare (cdr x)) (tortoise x)) | |
299 | (cond | |
300 | ((null? hare) #f) | |
301 | ((not-pair? hare) #t) | |
302 | (else | |
303 | (let ((hare (cdr hare))) | |
513a3bd7 | 304 | (cond |
e9680547 MG |
305 | ((null? hare) #f) |
306 | ((not-pair? hare) #t) | |
307 | ((eq? hare tortoise) #f) | |
308 | (else | |
309 | (lp (cdr hare) (cdr tortoise))))))))))) | |
310 | ||
311 | (define (null-list? x) | |
312 | (cond | |
513a3bd7 | 313 | ((proper-list? x) |
e9680547 MG |
314 | (null? x)) |
315 | ((circular-list? x) | |
316 | #f) | |
317 | (else | |
318 | (error "not a proper list in null-list?")))) | |
319 | ||
0b7f2eb8 LC |
320 | (define (not-pair? x) |
321 | "Return #t if X is not a pair, #f otherwise. | |
322 | ||
323 | This is shorthand notation `(not (pair? X))' and is supposed to be used for | |
324 | end-of-list checking in contexts where dotted lists are allowed." | |
325 | (not (pair? x))) | |
326 | ||
e9680547 MG |
327 | (define (list= elt= . rest) |
328 | (define (lists-equal a b) | |
329 | (let lp ((a a) (b b)) | |
330 | (cond ((null? a) | |
331 | (null? b)) | |
332 | ((null? b) | |
333 | #f) | |
334 | (else | |
335 | (and (elt= (car a) (car b)) | |
336 | (lp (cdr a) (cdr b))))))) | |
337 | (or (null? rest) | |
1bc8745f KR |
338 | (let lp ((lists rest)) |
339 | (or (null? (cdr lists)) | |
340 | (and (lists-equal (car lists) (cadr lists)) | |
341 | (lp (cdr lists))))))) | |
e9680547 MG |
342 | |
343 | ;;; Selectors | |
344 | ||
345 | (define first car) | |
346 | (define second cadr) | |
347 | (define third caddr) | |
348 | (define fourth cadddr) | |
d7418e60 LC |
349 | (define (fifth x) (car (cddddr x))) |
350 | (define (sixth x) (cadr (cddddr x))) | |
351 | (define (seventh x) (caddr (cddddr x))) | |
352 | (define (eighth x) (cadddr (cddddr x))) | |
353 | (define (ninth x) (car (cddddr (cddddr x)))) | |
354 | (define (tenth x) (cadr (cddddr (cddddr x)))) | |
e9680547 | 355 | |
0b7f2eb8 LC |
356 | (define (car+cdr x) |
357 | "Return two values, the `car' and the `cdr' of PAIR." | |
358 | (values (car x) (cdr x))) | |
359 | ||
4dd6bd84 KR |
360 | (define take list-head) |
361 | (define drop list-tail) | |
362 | ||
dcde4386 LC |
363 | (define (take! lst i) |
364 | "Linear-update variant of `take'." | |
365 | (if (= i 0) | |
366 | '() | |
367 | (let ((tail (drop lst (- i 1)))) | |
368 | (set-cdr! tail '()) | |
369 | lst))) | |
370 | ||
371 | (define (drop-right! lst i) | |
372 | "Linear-update variant of `drop-right'." | |
373 | (let ((tail (drop lst i))) | |
374 | (if (null? tail) | |
375 | '() | |
376 | (let loop ((prev lst) | |
377 | (tail (cdr tail))) | |
378 | (if (null? tail) | |
379 | (if (pair? prev) | |
380 | (begin | |
381 | (set-cdr! prev '()) | |
382 | lst) | |
383 | lst) | |
384 | (loop (cdr prev) | |
385 | (cdr tail))))))) | |
386 | ||
7f593bc7 LC |
387 | (define (split-at lst i) |
388 | "Return two values, a list of the elements before index I in LST, and | |
389 | a list of those after." | |
390 | (if (< i 0) | |
391 | (out-of-range 'split-at i) | |
392 | (let lp ((l lst) (n i) (acc '())) | |
393 | (if (<= n 0) | |
394 | (values (reverse! acc) l) | |
395 | (lp (cdr l) (- n 1) (cons (car l) acc)))))) | |
396 | ||
397 | (define (split-at! lst i) | |
398 | "Linear-update variant of `split-at'." | |
399 | (cond ((< i 0) | |
400 | (out-of-range 'split-at! i)) | |
401 | ((= i 0) | |
402 | (values '() lst)) | |
403 | (else | |
404 | (let lp ((l lst) (n (- i 1))) | |
405 | (if (<= n 0) | |
406 | (let ((tmp (cdr l))) | |
407 | (set-cdr! l '()) | |
408 | (values lst tmp)) | |
409 | (lp (cdr l) (- n 1))))))) | |
410 | ||
0b7f2eb8 LC |
411 | (define (last pair) |
412 | "Return the last element of the non-empty, finite list PAIR." | |
413 | (car (last-pair pair))) | |
414 | ||
e9680547 MG |
415 | ;;; Miscelleneous: length, append, concatenate, reverse, zip & count |
416 | ||
e9680547 MG |
417 | (define (zip clist1 . rest) |
418 | (let lp ((l (cons clist1 rest)) (acc '())) | |
419 | (if (any null? l) | |
420 | (reverse! acc) | |
a2230b65 | 421 | (lp (map cdr l) (cons (map car l) acc))))) |
513a3bd7 | 422 | |
e9680547 MG |
423 | |
424 | (define (unzip1 l) | |
a2230b65 | 425 | (map first l)) |
e9680547 | 426 | (define (unzip2 l) |
a2230b65 | 427 | (values (map first l) (map second l))) |
e9680547 | 428 | (define (unzip3 l) |
a2230b65 | 429 | (values (map first l) (map second l) (map third l))) |
e9680547 | 430 | (define (unzip4 l) |
a2230b65 | 431 | (values (map first l) (map second l) (map third l) (map fourth l))) |
e9680547 | 432 | (define (unzip5 l) |
a2230b65 AW |
433 | (values (map first l) (map second l) (map third l) (map fourth l) |
434 | (map fifth l))) | |
e9680547 | 435 | |
e9680547 MG |
436 | ;;; Fold, unfold & map |
437 | ||
0b7f2eb8 LC |
438 | (define (fold kons knil list1 . rest) |
439 | "Apply PROC to the elements of LIST1 ... LISTN to build a result, and return | |
440 | that result. See the manual for details." | |
441 | (if (null? rest) | |
442 | (let f ((knil knil) (list1 list1)) | |
443 | (if (null? list1) | |
444 | knil | |
445 | (f (kons (car list1) knil) (cdr list1)))) | |
446 | (let f ((knil knil) (lists (cons list1 rest))) | |
447 | (if (any null? lists) | |
448 | knil | |
a2230b65 AW |
449 | (let ((cars (map car lists)) |
450 | (cdrs (map cdr lists))) | |
0b7f2eb8 LC |
451 | (f (apply kons (append! cars (list knil))) cdrs)))))) |
452 | ||
e9680547 MG |
453 | (define (fold-right kons knil clist1 . rest) |
454 | (if (null? rest) | |
a6505cb4 LC |
455 | (let loop ((lst (reverse clist1)) |
456 | (result knil)) | |
457 | (if (null? lst) | |
458 | result | |
459 | (loop (cdr lst) | |
460 | (kons (car lst) result)))) | |
a2230b65 | 461 | (let loop ((lists (map reverse (cons clist1 rest))) |
a6505cb4 LC |
462 | (result knil)) |
463 | (if (any1 null? lists) | |
464 | result | |
a2230b65 AW |
465 | (loop (map cdr lists) |
466 | (apply kons (append! (map car lists) (list result)))))))) | |
e9680547 MG |
467 | |
468 | (define (pair-fold kons knil clist1 . rest) | |
469 | (if (null? rest) | |
470 | (let f ((knil knil) (list1 clist1)) | |
471 | (if (null? list1) | |
472 | knil | |
473 | (let ((tail (cdr list1))) | |
474 | (f (kons list1 knil) tail)))) | |
475 | (let f ((knil knil) (lists (cons clist1 rest))) | |
476 | (if (any null? lists) | |
477 | knil | |
a2230b65 | 478 | (let ((tails (map cdr lists))) |
563058ef | 479 | (f (apply kons (append! lists (list knil))) tails)))))) |
e9680547 MG |
480 | |
481 | ||
482 | (define (pair-fold-right kons knil clist1 . rest) | |
483 | (if (null? rest) | |
484 | (let f ((list1 clist1)) | |
485 | (if (null? list1) | |
486 | knil | |
487 | (kons list1 (f (cdr list1))))) | |
488 | (let f ((lists (cons clist1 rest))) | |
489 | (if (any null? lists) | |
490 | knil | |
a2230b65 | 491 | (apply kons (append! lists (list (f (map cdr lists))))))))) |
e9680547 | 492 | |
2cf7ff2e | 493 | (define* (unfold p f g seed #:optional (tail-gen (lambda (x) '()))) |
07076c1e LC |
494 | (define (reverse+tail lst seed) |
495 | (let loop ((lst lst) | |
496 | (result (tail-gen seed))) | |
497 | (if (null? lst) | |
498 | result | |
499 | (loop (cdr lst) | |
500 | (cons (car lst) result))))) | |
501 | ||
502 | (let loop ((seed seed) | |
503 | (result '())) | |
2cf7ff2e | 504 | (if (p seed) |
07076c1e LC |
505 | (reverse+tail result seed) |
506 | (loop (g seed) | |
507 | (cons (f seed) result))))) | |
2cf7ff2e LC |
508 | |
509 | (define* (unfold-right p f g seed #:optional (tail '())) | |
510 | (let uf ((seed seed) (lis tail)) | |
511 | (if (p seed) | |
512 | lis | |
513 | (uf (g seed) (cons (f seed) lis))))) | |
e9680547 | 514 | |
dcde4386 LC |
515 | (define (reduce f ridentity lst) |
516 | "`reduce' is a variant of `fold', where the first call to F is on two | |
517 | elements from LST, rather than one element and a given initial value. | |
518 | If LST is empty, RIDENTITY is returned. If LST has just one element | |
519 | then that's the return value." | |
520 | (if (null? lst) | |
521 | ridentity | |
522 | (fold f (car lst) (cdr lst)))) | |
523 | ||
524 | (define (reduce-right f ridentity lst) | |
525 | "`reduce-right' is a variant of `fold-right', where the first call to | |
526 | F is on two elements from LST, rather than one element and a given | |
527 | initial value. If LST is empty, RIDENTITY is returned. If LST | |
528 | has just one element then that's the return value." | |
529 | (if (null? lst) | |
530 | ridentity | |
531 | (fold-right f (last lst) (drop-right lst 1)))) | |
532 | ||
a2230b65 AW |
533 | (define map |
534 | (case-lambda | |
535 | ((f l) | |
536 | (let map1 ((hare l) (tortoise l) (move? #f) (out '())) | |
537 | (if (pair? hare) | |
538 | (if move? | |
539 | (if (eq? tortoise hare) | |
540 | (scm-error 'wrong-type-arg "map" "Circular list: ~S" | |
541 | (list l) #f) | |
542 | (map1 (cdr hare) (cdr tortoise) #f | |
543 | (cons (f (car hare)) out))) | |
544 | (map1 (cdr hare) tortoise #t | |
545 | (cons (f (car hare)) out))) | |
546 | (if (null? hare) | |
547 | (reverse! out) | |
548 | (scm-error 'wrong-type-arg "map" "Not a list: ~S" | |
549 | (list l) #f))))) | |
550 | ||
551 | ((f l1 . rest) | |
552 | (let ((len (fold (lambda (ls len) | |
553 | (let ((ls-len (length+ ls))) | |
554 | (if len | |
555 | (if ls-len (min ls-len len) len) | |
556 | ls-len))) | |
557 | (length+ l1) | |
558 | rest))) | |
559 | (if (not len) | |
560 | (scm-error 'wrong-type-arg "map" | |
561 | "Args do not contain a proper (finite) list: ~S" | |
562 | (list (cons l1 rest)) #f)) | |
563 | (let mapn ((l1 l1) (rest rest) (len len) (out '())) | |
564 | (if (zero? len) | |
565 | (reverse! out) | |
566 | (mapn (cdr l1) (map cdr rest) (1- len) | |
567 | (cons (apply f (car l1) (map car rest)) out)))))))) | |
568 | ||
b706a011 AW |
569 | (define map-in-order map) |
570 | ||
a2230b65 AW |
571 | (define for-each |
572 | (case-lambda | |
573 | ((f l) | |
574 | (let for-each1 ((hare l) (tortoise l) (move? #f)) | |
575 | (if (pair? hare) | |
576 | (if move? | |
577 | (if (eq? tortoise hare) | |
578 | (scm-error 'wrong-type-arg "for-each" "Circular list: ~S" | |
579 | (list l) #f) | |
580 | (begin | |
581 | (f (car hare)) | |
582 | (for-each1 (cdr hare) (cdr tortoise) #f))) | |
583 | (begin | |
584 | (f (car hare)) | |
585 | (for-each1 (cdr hare) tortoise #t))) | |
586 | ||
587 | (if (not (null? hare)) | |
588 | (scm-error 'wrong-type-arg "for-each" "Not a list: ~S" | |
589 | (list l) #f))))) | |
590 | ||
591 | ((f l1 . rest) | |
592 | (let ((len (fold (lambda (ls len) | |
593 | (let ((ls-len (length+ ls))) | |
594 | (if len | |
595 | (if ls-len (min ls-len len) len) | |
596 | ls-len))) | |
597 | (length+ l1) | |
598 | rest))) | |
599 | (if (not len) | |
600 | (scm-error 'wrong-type-arg "for-each" | |
601 | "Args do not contain a proper (finite) list: ~S" | |
602 | (list (cons l1 rest)) #f)) | |
603 | (let for-eachn ((l1 l1) (rest rest) (len len)) | |
604 | (if (> len 0) | |
605 | (begin | |
606 | (apply f (car l1) (map car rest)) | |
607 | (for-eachn (cdr l1) (map cdr rest) (1- len))))))))) | |
cef248dd | 608 | |
e9680547 | 609 | (define (append-map f clist1 . rest) |
8b981efd | 610 | (concatenate (apply map f clist1 rest))) |
558d5c03 | 611 | |
e9680547 | 612 | (define (append-map! f clist1 . rest) |
8b981efd | 613 | (concatenate! (apply map f clist1 rest))) |
e9680547 | 614 | |
c6424115 KR |
615 | ;; OPTIMIZE-ME: Re-use cons cells of list1 |
616 | (define map! map) | |
e9680547 | 617 | |
58ee1bea LC |
618 | (define (filter-map proc list1 . rest) |
619 | "Apply PROC to to the elements of LIST1... and return a list of the | |
620 | results as per SRFI-1 `map', except that any #f results are omitted from | |
621 | the list returned." | |
622 | (if (null? rest) | |
623 | (let lp ((l list1) | |
624 | (rl '())) | |
625 | (if (null? l) | |
626 | (reverse! rl) | |
627 | (let ((res (proc (car l)))) | |
628 | (if res | |
629 | (lp (cdr l) (cons res rl)) | |
630 | (lp (cdr l) rl))))) | |
631 | (let lp ((l (cons list1 rest)) | |
632 | (rl '())) | |
633 | (if (any1 null? l) | |
634 | (reverse! rl) | |
a2230b65 | 635 | (let ((res (apply proc (map car l)))) |
58ee1bea | 636 | (if res |
a2230b65 AW |
637 | (lp (map cdr l) (cons res rl)) |
638 | (lp (map cdr l) rl))))))) | |
58ee1bea | 639 | |
e9680547 MG |
640 | (define (pair-for-each f clist1 . rest) |
641 | (if (null? rest) | |
642 | (let lp ((l clist1)) | |
643 | (if (null? l) | |
644 | (if #f #f) | |
645 | (begin | |
646 | (f l) | |
647 | (lp (cdr l))))) | |
648 | (let lp ((l (cons clist1 rest))) | |
649 | (if (any1 null? l) | |
650 | (if #f #f) | |
651 | (begin | |
652 | (apply f l) | |
a2230b65 | 653 | (lp (map cdr l))))))) |
e9680547 | 654 | |
dcde4386 | 655 | \f |
e9680547 MG |
656 | ;;; Searching |
657 | ||
dcde4386 LC |
658 | (define (take-while pred ls) |
659 | "Return a new list which is the longest initial prefix of LS whose | |
660 | elements all satisfy the predicate PRED." | |
661 | (cond ((null? ls) '()) | |
662 | ((not (pred (car ls))) '()) | |
663 | (else | |
664 | (let ((result (list (car ls)))) | |
665 | (let lp ((ls (cdr ls)) (p result)) | |
666 | (cond ((null? ls) result) | |
667 | ((not (pred (car ls))) result) | |
668 | (else | |
669 | (set-cdr! p (list (car ls))) | |
670 | (lp (cdr ls) (cdr p))))))))) | |
671 | ||
672 | (define (take-while! pred lst) | |
673 | "Linear-update variant of `take-while'." | |
674 | (let loop ((prev #f) | |
675 | (rest lst)) | |
676 | (cond ((null? rest) | |
677 | lst) | |
678 | ((pred (car rest)) | |
679 | (loop rest (cdr rest))) | |
680 | (else | |
681 | (if (pair? prev) | |
682 | (begin | |
683 | (set-cdr! prev '()) | |
684 | lst) | |
685 | '()))))) | |
686 | ||
687 | (define (drop-while pred lst) | |
688 | "Drop the longest initial prefix of LST whose elements all satisfy the | |
689 | predicate PRED." | |
690 | (let loop ((lst lst)) | |
691 | (cond ((null? lst) | |
692 | '()) | |
693 | ((pred (car lst)) | |
694 | (loop (cdr lst))) | |
695 | (else lst)))) | |
696 | ||
697 | (define (span pred lst) | |
698 | "Return two values, the longest initial prefix of LST whose elements | |
699 | all satisfy the predicate PRED, and the remainder of LST." | |
700 | (let lp ((lst lst) (rl '())) | |
701 | (if (and (not (null? lst)) | |
702 | (pred (car lst))) | |
703 | (lp (cdr lst) (cons (car lst) rl)) | |
704 | (values (reverse! rl) lst)))) | |
705 | ||
706 | (define (span! pred list) | |
707 | "Linear-update variant of `span'." | |
708 | (let loop ((prev #f) | |
709 | (rest list)) | |
710 | (cond ((null? rest) | |
711 | (values list '())) | |
712 | ((pred (car rest)) | |
713 | (loop rest (cdr rest))) | |
714 | (else | |
715 | (if (pair? prev) | |
716 | (begin | |
717 | (set-cdr! prev '()) | |
718 | (values list rest)) | |
719 | (values '() list)))))) | |
720 | ||
b86d2309 LC |
721 | (define (break pred clist) |
722 | "Return two values, the longest initial prefix of LST whose elements | |
723 | all fail the predicate PRED, and the remainder of LST." | |
724 | (let lp ((clist clist) (rl '())) | |
725 | (if (or (null? clist) | |
726 | (pred (car clist))) | |
727 | (values (reverse! rl) clist) | |
728 | (lp (cdr clist) (cons (car clist) rl))))) | |
729 | ||
730 | (define (break! pred list) | |
731 | "Linear-update variant of `break'." | |
732 | (let loop ((l list) | |
733 | (prev #f)) | |
734 | (cond ((null? l) | |
735 | (values list '())) | |
736 | ((pred (car l)) | |
737 | (if (pair? prev) | |
738 | (begin | |
739 | (set-cdr! prev '()) | |
740 | (values list l)) | |
741 | (values '() list))) | |
742 | (else | |
743 | (loop (cdr l) l))))) | |
744 | ||
e9680547 MG |
745 | (define (any pred ls . lists) |
746 | (if (null? lists) | |
747 | (any1 pred ls) | |
748 | (let lp ((lists (cons ls lists))) | |
749 | (cond ((any1 null? lists) | |
750 | #f) | |
a2230b65 AW |
751 | ((any1 null? (map cdr lists)) |
752 | (apply pred (map car lists))) | |
e9680547 | 753 | (else |
a2230b65 | 754 | (or (apply pred (map car lists)) (lp (map cdr lists)))))))) |
e9680547 MG |
755 | |
756 | (define (any1 pred ls) | |
757 | (let lp ((ls ls)) | |
758 | (cond ((null? ls) | |
759 | #f) | |
760 | ((null? (cdr ls)) | |
761 | (pred (car ls))) | |
762 | (else | |
763 | (or (pred (car ls)) (lp (cdr ls))))))) | |
764 | ||
765 | (define (every pred ls . lists) | |
766 | (if (null? lists) | |
767 | (every1 pred ls) | |
768 | (let lp ((lists (cons ls lists))) | |
769 | (cond ((any1 null? lists) | |
770 | #t) | |
a2230b65 AW |
771 | ((any1 null? (map cdr lists)) |
772 | (apply pred (map car lists))) | |
e9680547 | 773 | (else |
a2230b65 | 774 | (and (apply pred (map car lists)) (lp (map cdr lists)))))))) |
e9680547 MG |
775 | |
776 | (define (every1 pred ls) | |
777 | (let lp ((ls ls)) | |
778 | (cond ((null? ls) | |
779 | #t) | |
780 | ((null? (cdr ls)) | |
781 | (pred (car ls))) | |
782 | (else | |
783 | (and (pred (car ls)) (lp (cdr ls))))))) | |
784 | ||
0b7f2eb8 LC |
785 | (define (list-index pred clist1 . rest) |
786 | "Return the index of the first set of elements, one from each of | |
787 | CLIST1 ... CLISTN, that satisfies PRED." | |
788 | (if (null? rest) | |
789 | (let lp ((l clist1) (i 0)) | |
790 | (if (null? l) | |
791 | #f | |
792 | (if (pred (car l)) | |
793 | i | |
794 | (lp (cdr l) (+ i 1))))) | |
795 | (let lp ((lists (cons clist1 rest)) (i 0)) | |
796 | (cond ((any1 null? lists) | |
797 | #f) | |
a2230b65 | 798 | ((apply pred (map car lists)) i) |
0b7f2eb8 | 799 | (else |
a2230b65 | 800 | (lp (map cdr lists) (+ i 1))))))) |
0b7f2eb8 | 801 | |
e9680547 MG |
802 | ;;; Association lists |
803 | ||
0b5adedd | 804 | (define alist-cons acons) |
e9680547 | 805 | |
194865d2 LC |
806 | (define (alist-copy alist) |
807 | "Return a copy of ALIST, copying both the pairs comprising the list | |
808 | and those making the associations." | |
809 | (let lp ((a alist) | |
810 | (rl '())) | |
811 | (if (null? a) | |
812 | (reverse! rl) | |
813 | (lp (cdr a) (alist-cons (caar a) (cdar a) rl))))) | |
814 | ||
2cf7ff2e LC |
815 | (define* (alist-delete key alist #:optional (k= equal?)) |
816 | (let lp ((a alist) (rl '())) | |
817 | (if (null? a) | |
49ae1e25 | 818 | (reverse! rl) |
41ab236c | 819 | (if (k= key (caar a)) |
2cf7ff2e LC |
820 | (lp (cdr a) rl) |
821 | (lp (cdr a) (cons (car a) rl)))))) | |
e9680547 | 822 | |
2cf7ff2e LC |
823 | (define* (alist-delete! key alist #:optional (k= equal?)) |
824 | (alist-delete key alist k=)) ; XXX:optimize | |
e9680547 | 825 | |
9e775af3 AW |
826 | ;;; Delete / assoc / member |
827 | ||
828 | (define* (member x ls #:optional (= equal?)) | |
829 | (cond | |
830 | ((eq? = eq?) (memq x ls)) | |
831 | ((eq? = eqv?) (memv x ls)) | |
832 | (else (find-tail (lambda (y) (= x y)) ls)))) | |
833 | ||
e9680547 MG |
834 | ;;; Set operations on lists |
835 | ||
836 | (define (lset<= = . rest) | |
837 | (if (null? rest) | |
9e775af3 AW |
838 | #t |
839 | (let lp ((f (car rest)) (r (cdr rest))) | |
840 | (or (null? r) | |
841 | (and (every (lambda (el) (member el (car r) =)) f) | |
842 | (lp (car r) (cdr r))))))) | |
e9680547 | 843 | |
9d494a73 | 844 | (define (lset= = . rest) |
e9680547 MG |
845 | (if (null? rest) |
846 | #t | |
9d494a73 | 847 | (let lp ((f (car rest)) (r (cdr rest))) |
e9680547 MG |
848 | (or (null? r) |
849 | (and (every (lambda (el) (member el (car r) =)) f) | |
600af2ed | 850 | (every (lambda (el) (member el f (lambda (x y) (= y x)))) (car r)) |
e9680547 MG |
851 | (lp (car r) (cdr r))))))) |
852 | ||
dcde4386 LC |
853 | ;; It's not quite clear if duplicates among the `rest' elements are meant to |
854 | ;; be cast out. The spec says `=' is called as (= lstelem restelem), | |
855 | ;; suggesting perhaps not, but the reference implementation shows the "list" | |
856 | ;; at each stage as including those elements already added. The latter | |
857 | ;; corresponds to what's described for lset-union, so that's what's done. | |
858 | ;; | |
859 | (define (lset-adjoin = list . rest) | |
860 | "Add to LIST any of the elements of REST not already in the list. | |
861 | These elements are `cons'ed onto the start of LIST (so the return shares | |
862 | a common tail with LIST), but the order they're added is unspecified. | |
863 | ||
864 | The given `=' procedure is used for comparing elements, called | |
865 | as `(@var{=} listelem elem)', i.e., the second argument is one of the | |
866 | given REST parameters." | |
9e775af3 AW |
867 | ;; If `=' is `eq?' or `eqv?', users won't be able to tell which arg is |
868 | ;; first, so we can pass the raw procedure through to `member', | |
869 | ;; allowing `memq' / `memv' to be selected. | |
870 | (define pred | |
871 | (if (or (eq? = eq?) (eq? = eqv?)) | |
872 | = | |
873 | (lambda (x y) (= y x)))) | |
874 | ||
875 | (let lp ((ans list) (rest rest)) | |
876 | (if (null? rest) | |
877 | ans | |
878 | (lp (if (member (car rest) ans pred) | |
879 | ans | |
880 | (cons (car rest) ans)) | |
881 | (cdr rest))))) | |
dcde4386 | 882 | |
e9680547 | 883 | (define (lset-union = . rest) |
9e775af3 AW |
884 | ;; Likewise, allow memq / memv to be used if possible. |
885 | (define pred | |
886 | (if (or (eq? = eq?) (eq? = eqv?)) | |
887 | = | |
888 | (lambda (x y) (= y x)))) | |
889 | ||
890 | (fold (lambda (lis ans) ; Compute ANS + LIS. | |
891 | (cond ((null? lis) ans) ; Don't copy any lists | |
892 | ((null? ans) lis) ; if we don't have to. | |
893 | ((eq? lis ans) ans) | |
894 | (else | |
895 | (fold (lambda (elt ans) | |
896 | (if (member elt ans pred) | |
897 | ans | |
898 | (cons elt ans))) | |
899 | ans lis)))) | |
900 | '() | |
901 | rest)) | |
e9680547 MG |
902 | |
903 | (define (lset-intersection = list1 . rest) | |
904 | (let lp ((l list1) (acc '())) | |
905 | (if (null? l) | |
906 | (reverse! acc) | |
907 | (if (every (lambda (ll) (member (car l) ll =)) rest) | |
908 | (lp (cdr l) (cons (car l) acc)) | |
909 | (lp (cdr l) acc))))) | |
910 | ||
911 | (define (lset-difference = list1 . rest) | |
912 | (if (null? rest) | |
913 | list1 | |
914 | (let lp ((l list1) (acc '())) | |
915 | (if (null? l) | |
916 | (reverse! acc) | |
917 | (if (any (lambda (ll) (member (car l) ll =)) rest) | |
918 | (lp (cdr l) acc) | |
919 | (lp (cdr l) (cons (car l) acc))))))) | |
920 | ||
921 | ;(define (fold kons knil list1 . rest) | |
922 | ||
923 | (define (lset-xor = . rest) | |
924 | (fold (lambda (lst res) | |
925 | (let lp ((l lst) (acc '())) | |
926 | (if (null? l) | |
927 | (let lp0 ((r res) (acc acc)) | |
928 | (if (null? r) | |
929 | (reverse! acc) | |
930 | (if (member (car r) lst =) | |
931 | (lp0 (cdr r) acc) | |
932 | (lp0 (cdr r) (cons (car r) acc))))) | |
933 | (if (member (car l) res =) | |
934 | (lp (cdr l) acc) | |
935 | (lp (cdr l) (cons (car l) acc)))))) | |
936 | '() | |
937 | rest)) | |
938 | ||
939 | (define (lset-diff+intersection = list1 . rest) | |
940 | (let lp ((l list1) (accd '()) (acci '())) | |
941 | (if (null? l) | |
942 | (values (reverse! accd) (reverse! acci)) | |
943 | (let ((appears (every (lambda (ll) (member (car l) ll =)) rest))) | |
944 | (if appears | |
945 | (lp (cdr l) accd (cons (car l) acci)) | |
946 | (lp (cdr l) (cons (car l) accd) acci)))))) | |
947 | ||
948 | ||
949 | (define (lset-union! = . rest) | |
950 | (apply lset-union = rest)) ; XXX:optimize | |
951 | ||
952 | (define (lset-intersection! = list1 . rest) | |
953 | (apply lset-intersection = list1 rest)) ; XXX:optimize | |
954 | ||
e9680547 MG |
955 | (define (lset-xor! = . rest) |
956 | (apply lset-xor = rest)) ; XXX:optimize | |
957 | ||
958 | (define (lset-diff+intersection! = list1 . rest) | |
959 | (apply lset-diff+intersection = list1 rest)) ; XXX:optimize | |
6be07c52 TTN |
960 | |
961 | ;;; srfi-1.scm ends here |