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ee6aac97 MD |
1 | /* srfi-1.c --- SRFI-1 procedures for Guile |
2 | * | |
d0a634de KR |
3 | * Copyright (C) 1995, 1996, 1997, 2000, 2001, 2002, 2003 Free Software |
4 | * Foundation, Inc. | |
ee6aac97 | 5 | * |
73be1d9e MV |
6 | * This library is free software; you can redistribute it and/or |
7 | * modify it under the terms of the GNU Lesser General Public | |
8 | * License as published by the Free Software Foundation; either | |
9 | * version 2.1 of the License, or (at your option) any later version. | |
ee6aac97 | 10 | * |
73be1d9e MV |
11 | * This library is distributed in the hope that it will be useful, |
12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
14 | * Lesser General Public License for more details. | |
ee6aac97 | 15 | * |
73be1d9e MV |
16 | * You should have received a copy of the GNU Lesser General Public |
17 | * License along with this library; if not, write to the Free Software | |
92205699 | 18 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
73be1d9e | 19 | */ |
ee6aac97 MD |
20 | |
21 | #include <libguile.h> | |
22 | #include <libguile/lang.h> | |
23 | ||
24 | #include "srfi-1.h" | |
25 | ||
26 | /* The intent of this file is to gradually replace those Scheme | |
27 | * procedures in srfi-1.scm which extends core primitive procedures, | |
28 | * so that using srfi-1 won't have performance penalties. | |
29 | * | |
30 | * Please feel free to contribute any new replacements! | |
31 | */ | |
32 | ||
33 | static long | |
34 | srfi1_ilength (SCM sx) | |
35 | { | |
36 | long i = 0; | |
37 | SCM tortoise = sx; | |
38 | SCM hare = sx; | |
39 | ||
40 | do { | |
41 | if (SCM_NULL_OR_NIL_P(hare)) return i; | |
896df2d5 | 42 | if (!scm_is_pair (hare)) return -2; |
ee6aac97 MD |
43 | hare = SCM_CDR(hare); |
44 | i++; | |
45 | if (SCM_NULL_OR_NIL_P(hare)) return i; | |
896df2d5 | 46 | if (!scm_is_pair (hare)) return -2; |
ee6aac97 MD |
47 | hare = SCM_CDR(hare); |
48 | i++; | |
49 | /* For every two steps the hare takes, the tortoise takes one. */ | |
50 | tortoise = SCM_CDR(tortoise); | |
51 | } | |
bc36d050 | 52 | while (! scm_is_eq (hare, tortoise)); |
ee6aac97 MD |
53 | |
54 | /* If the tortoise ever catches the hare, then the list must contain | |
55 | a cycle. */ | |
56 | return -1; | |
57 | } | |
58 | ||
d0a634de KR |
59 | static SCM |
60 | equal_trampoline (SCM proc, SCM arg1, SCM arg2) | |
61 | { | |
62 | return scm_equal_p (arg1, arg2); | |
63 | } | |
64 | ||
65 | ||
b1fff4e7 KR |
66 | SCM_DEFINE (scm_srfi1_alist_copy, "alist-copy", 1, 0, 0, |
67 | (SCM alist), | |
68 | "Return a copy of @var{alist}, copying both the pairs comprising\n" | |
69 | "the list and those making the associations.") | |
70 | #define FUNC_NAME s_scm_srfi1_alist_copy | |
71 | { | |
72 | SCM ret, *p, elem, c; | |
73 | ||
74 | /* ret is the list to return. p is where to append to it, initially &ret | |
75 | then SCM_CDRLOC of the last pair. */ | |
76 | ret = SCM_EOL; | |
77 | p = &ret; | |
78 | ||
79 | for ( ; scm_is_pair (alist); alist = SCM_CDR (alist)) | |
80 | { | |
81 | elem = SCM_CAR (alist); | |
82 | ||
83 | /* each element of alist must be a pair */ | |
84 | SCM_ASSERT_TYPE (scm_is_pair (elem), alist, SCM_ARG1, FUNC_NAME, | |
85 | "association list"); | |
86 | ||
87 | c = scm_cons (scm_cons (SCM_CAR (elem), SCM_CDR (elem)), SCM_EOL); | |
88 | *p = c; | |
89 | p = SCM_CDRLOC (c); | |
90 | } | |
91 | ||
92 | /* alist must be a proper list */ | |
93 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (alist), alist, SCM_ARG1, FUNC_NAME, | |
94 | "association list"); | |
95 | return ret; | |
96 | } | |
97 | #undef FUNC_NAME | |
98 | ||
99 | ||
6e9f3c26 KR |
100 | SCM_DEFINE (scm_srfi1_break, "break", 2, 0, 0, |
101 | (SCM pred, SCM lst), | |
102 | "Return two values, the longest initial prefix of @var{lst}\n" | |
103 | "whose elements all fail the predicate @var{pred}, and the\n" | |
104 | "remainder of @var{lst}.\n" | |
105 | "\n" | |
106 | "Note that the name @code{break} conflicts with the @code{break}\n" | |
107 | "binding established by @code{while}. Applications wanting to\n" | |
108 | "use @code{break} from within a @code{while} loop will need to\n" | |
109 | "make a new define under a different name.") | |
110 | #define FUNC_NAME s_scm_srfi1_break | |
111 | { | |
112 | scm_t_trampoline_1 pred_tramp; | |
113 | SCM ret, *p; | |
114 | ||
115 | pred_tramp = scm_trampoline_1 (pred); | |
116 | SCM_ASSERT (pred_tramp, pred, SCM_ARG1, FUNC_NAME); | |
117 | ||
118 | ret = SCM_EOL; | |
119 | p = &ret; | |
120 | for ( ; scm_is_pair (lst); lst = SCM_CDR (lst)) | |
121 | { | |
122 | SCM elem = SCM_CAR (lst); | |
123 | if (scm_is_true (pred_tramp (pred, elem))) | |
124 | goto done; | |
125 | ||
126 | /* want this elem, tack it onto the end of ret */ | |
127 | *p = scm_cons (elem, SCM_EOL); | |
128 | p = SCM_CDRLOC (*p); | |
129 | } | |
130 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, SCM_ARG2, FUNC_NAME, "list"); | |
131 | ||
132 | done: | |
133 | return scm_values (scm_list_2 (ret, lst)); | |
134 | } | |
135 | #undef FUNC_NAME | |
136 | ||
137 | ||
138 | SCM_DEFINE (scm_srfi1_break_x, "break!", 2, 0, 0, | |
139 | (SCM pred, SCM lst), | |
140 | "Return two values, the longest initial prefix of @var{lst}\n" | |
141 | "whose elements all fail the predicate @var{pred}, and the\n" | |
142 | "remainder of @var{lst}. @var{lst} may be modified to form the\n" | |
143 | "return.") | |
144 | #define FUNC_NAME s_scm_srfi1_break_x | |
145 | { | |
146 | SCM upto, *p; | |
147 | scm_t_trampoline_1 pred_tramp; | |
148 | ||
149 | pred_tramp = scm_trampoline_1 (pred); | |
150 | SCM_ASSERT (pred_tramp, pred, SCM_ARG1, FUNC_NAME); | |
151 | ||
152 | p = &lst; | |
153 | for (upto = lst; scm_is_pair (upto); upto = SCM_CDR (upto)) | |
154 | { | |
155 | if (scm_is_true (pred_tramp (pred, SCM_CAR (upto)))) | |
156 | goto done; | |
157 | ||
158 | /* want this element */ | |
159 | p = SCM_CDRLOC (upto); | |
160 | } | |
161 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (upto), lst, SCM_ARG2, FUNC_NAME, "list"); | |
162 | ||
163 | done: | |
164 | *p = SCM_EOL; | |
165 | return scm_values (scm_list_2 (lst, upto)); | |
166 | } | |
167 | #undef FUNC_NAME | |
168 | ||
169 | ||
e556f8c3 KR |
170 | SCM_DEFINE (scm_srfi1_car_plus_cdr, "car+cdr", 1, 0, 0, |
171 | (SCM pair), | |
172 | "Return two values, the @sc{car} and the @sc{cdr} of @var{pair}.") | |
173 | #define FUNC_NAME s_scm_srfi1_car_plus_cdr | |
174 | { | |
175 | SCM_VALIDATE_CONS (SCM_ARG1, pair); | |
176 | return scm_values (scm_list_2 (SCM_CAR (pair), SCM_CDR (pair))); | |
177 | } | |
178 | #undef FUNC_NAME | |
179 | ||
180 | ||
c66c6d53 KR |
181 | SCM_DEFINE (scm_srfi1_concatenate, "concatenate", 1, 0, 0, |
182 | (SCM lstlst), | |
183 | "Construct a list by appending all lists in @var{lstlst}.\n" | |
184 | "\n" | |
185 | "@code{concatenate} is the same as @code{(apply append\n" | |
186 | "@var{lstlst})}. It exists because some Scheme implementations\n" | |
187 | "have a limit on the number of arguments a function takes, which\n" | |
188 | "the @code{apply} might exceed. In Guile there is no such\n" | |
189 | "limit.") | |
190 | #define FUNC_NAME s_scm_srfi1_concatenate | |
191 | { | |
192 | SCM_VALIDATE_LIST (SCM_ARG1, lstlst); | |
193 | return scm_append (lstlst); | |
194 | } | |
195 | #undef FUNC_NAME | |
196 | ||
47f2726f | 197 | |
c66c6d53 KR |
198 | SCM_DEFINE (scm_srfi1_concatenate_x, "concatenate!", 1, 0, 0, |
199 | (SCM lstlst), | |
200 | "Construct a list by appending all lists in @var{lstlst}. Those\n" | |
201 | "lists may be modified to produce the result.\n" | |
202 | "\n" | |
203 | "@code{concatenate!} is the same as @code{(apply append!\n" | |
204 | "@var{lstlst})}. It exists because some Scheme implementations\n" | |
205 | "have a limit on the number of arguments a function takes, which\n" | |
206 | "the @code{apply} might exceed. In Guile there is no such\n" | |
207 | "limit.") | |
208 | #define FUNC_NAME s_scm_srfi1_concatenate | |
209 | { | |
210 | SCM_VALIDATE_LIST (SCM_ARG1, lstlst); | |
211 | return scm_append_x (lstlst); | |
212 | } | |
213 | #undef FUNC_NAME | |
47f2726f KR |
214 | |
215 | ||
110348ae | 216 | SCM_DEFINE (scm_srfi1_count, "count", 2, 0, 1, |
edea856c | 217 | (SCM pred, SCM list1, SCM rest), |
110348ae KR |
218 | "Return a count of the number of times @var{pred} returns true\n" |
219 | "when called on elements from the given lists.\n" | |
220 | "\n" | |
221 | "@var{pred} is called with @var{N} parameters @code{(@var{pred}\n" | |
222 | "@var{elem1} @dots{} @var{elemN})}, each element being from the\n" | |
edea856c | 223 | "corresponding @var{list1} @dots{} @var{lstN}. The first call is\n" |
110348ae KR |
224 | "with the first element of each list, the second with the second\n" |
225 | "element from each, and so on.\n" | |
226 | "\n" | |
227 | "Counting stops when the end of the shortest list is reached.\n" | |
228 | "At least one list must be non-circular.") | |
229 | #define FUNC_NAME s_scm_srfi1_count | |
230 | { | |
231 | long count; | |
5fc743b4 KR |
232 | SCM lst; |
233 | int argnum; | |
110348ae KR |
234 | SCM_VALIDATE_REST_ARGUMENT (rest); |
235 | ||
236 | count = 0; | |
237 | ||
896df2d5 | 238 | if (scm_is_null (rest)) |
110348ae KR |
239 | { |
240 | /* one list */ | |
241 | scm_t_trampoline_1 pred_tramp; | |
242 | pred_tramp = scm_trampoline_1 (pred); | |
243 | SCM_ASSERT (pred_tramp, pred, SCM_ARG1, FUNC_NAME); | |
244 | ||
896df2d5 | 245 | for ( ; scm_is_pair (list1); list1 = SCM_CDR (list1)) |
edea856c | 246 | count += scm_is_true (pred_tramp (pred, SCM_CAR (list1))); |
110348ae | 247 | |
5fc743b4 KR |
248 | /* check below that list1 is a proper list, and done */ |
249 | end_list1: | |
250 | lst = list1; | |
251 | argnum = 2; | |
110348ae | 252 | } |
896df2d5 | 253 | else if (scm_is_pair (rest) && scm_is_null (SCM_CDR (rest))) |
110348ae KR |
254 | { |
255 | /* two lists */ | |
256 | scm_t_trampoline_2 pred_tramp; | |
edea856c | 257 | SCM list2; |
110348ae KR |
258 | |
259 | pred_tramp = scm_trampoline_2 (pred); | |
260 | SCM_ASSERT (pred_tramp, pred, SCM_ARG1, FUNC_NAME); | |
261 | ||
edea856c | 262 | list2 = SCM_CAR (rest); |
110348ae KR |
263 | for (;;) |
264 | { | |
896df2d5 | 265 | if (! scm_is_pair (list1)) |
5fc743b4 | 266 | goto end_list1; |
896df2d5 | 267 | if (! scm_is_pair (list2)) |
110348ae | 268 | { |
5fc743b4 KR |
269 | lst = list2; |
270 | argnum = 3; | |
110348ae KR |
271 | break; |
272 | } | |
00874d5f | 273 | count += scm_is_true (pred_tramp |
edea856c SJ |
274 | (pred, SCM_CAR (list1), SCM_CAR (list2))); |
275 | list1 = SCM_CDR (list1); | |
276 | list2 = SCM_CDR (list2); | |
110348ae KR |
277 | } |
278 | } | |
279 | else | |
280 | { | |
281 | /* three or more lists */ | |
eccd308a KR |
282 | SCM vec, args, a; |
283 | size_t len, i; | |
110348ae | 284 | |
eccd308a KR |
285 | /* vec is the list arguments */ |
286 | vec = scm_vector (scm_cons (list1, rest)); | |
287 | len = SCM_SIMPLE_VECTOR_LENGTH (vec); | |
110348ae | 288 | |
eccd308a | 289 | /* args is the argument list to pass to pred, same length as vec, |
110348ae | 290 | re-used for each call */ |
eccd308a | 291 | args = scm_make_list (SCM_I_MAKINUM (len), SCM_UNDEFINED); |
110348ae KR |
292 | |
293 | for (;;) | |
294 | { | |
eccd308a KR |
295 | /* first elem of each list in vec into args, and step those |
296 | vec entries onto their next element */ | |
297 | for (i = 0, a = args, argnum = 2; | |
298 | i < len; | |
299 | i++, a = SCM_CDR (a), argnum++) | |
110348ae | 300 | { |
eccd308a | 301 | lst = SCM_SIMPLE_VECTOR_REF (vec, i); /* list argument */ |
896df2d5 | 302 | if (! scm_is_pair (lst)) |
5fc743b4 | 303 | goto check_lst_and_done; |
110348ae | 304 | SCM_SETCAR (a, SCM_CAR (lst)); /* arg for pred */ |
eccd308a | 305 | SCM_SIMPLE_VECTOR_SET (vec, i, SCM_CDR (lst)); /* rest of lst */ |
110348ae KR |
306 | } |
307 | ||
00874d5f | 308 | count += scm_is_true (scm_apply (pred, args, SCM_EOL)); |
110348ae KR |
309 | } |
310 | } | |
5fc743b4 KR |
311 | |
312 | check_lst_and_done: | |
313 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, argnum, FUNC_NAME, "list"); | |
93ccaef0 | 314 | return scm_from_long (count); |
110348ae KR |
315 | } |
316 | #undef FUNC_NAME | |
317 | ||
318 | ||
d0a634de KR |
319 | SCM_DEFINE (scm_srfi1_delete, "delete", 2, 1, 0, |
320 | (SCM x, SCM lst, SCM pred), | |
321 | "Return a list containing the elements of @var{lst} but with\n" | |
322 | "those equal to @var{x} deleted. The returned elements will be\n" | |
323 | "in the same order as they were in @var{lst}.\n" | |
324 | "\n" | |
325 | "Equality is determined by @var{pred}, or @code{equal?} if not\n" | |
326 | "given. An equality call is made just once for each element,\n" | |
327 | "but the order in which the calls are made on the elements is\n" | |
328 | "unspecified.\n" | |
329 | "\n" | |
330 | "The equality calls are always @code{(pred x elem)}, ie.@: the\n" | |
331 | "given @var{x} is first. This means for instance elements\n" | |
332 | "greater than 5 can be deleted with @code{(delete 5 lst <)}.\n" | |
333 | "\n" | |
334 | "@var{lst} is not modified, but the returned list might share a\n" | |
335 | "common tail with @var{lst}.") | |
336 | #define FUNC_NAME s_scm_srfi1_delete | |
337 | { | |
338 | scm_t_trampoline_2 equal_p; | |
339 | SCM ret, *p, keeplst; | |
340 | ||
341 | if (SCM_UNBNDP (pred)) | |
342 | return scm_delete (x, lst); | |
343 | ||
344 | equal_p = scm_trampoline_2 (pred); | |
345 | SCM_ASSERT (equal_p, pred, SCM_ARG3, FUNC_NAME); | |
346 | ||
347 | /* ret is the return list being constructed. p is where to append to it, | |
348 | initially &ret then SCM_CDRLOC of the last pair. lst progresses as | |
349 | elements are considered. | |
350 | ||
351 | Elements to be retained are not immediately copied, instead keeplst is | |
352 | the last pair in lst which is to be retained but not yet copied. When | |
353 | there's no more deletions, *p can be set to keeplst to share the | |
354 | remainder of the original lst. (The entire original lst if there's no | |
355 | deletions at all.) */ | |
356 | ||
357 | keeplst = lst; | |
358 | ret = SCM_EOL; | |
359 | p = &ret; | |
360 | ||
896df2d5 | 361 | for ( ; scm_is_pair (lst); lst = SCM_CDR (lst)) |
d0a634de | 362 | { |
00874d5f | 363 | if (scm_is_true (equal_p (pred, x, SCM_CAR (lst)))) |
d0a634de KR |
364 | { |
365 | /* delete this element, so copy from keeplst (inclusive) to lst | |
366 | (exclusive) onto ret */ | |
bc36d050 | 367 | while (! scm_is_eq (keeplst, lst)) |
d0a634de KR |
368 | { |
369 | SCM c = scm_cons (SCM_CAR (keeplst), SCM_EOL); | |
370 | *p = c; | |
371 | p = SCM_CDRLOC (c); | |
372 | keeplst = SCM_CDR (keeplst); | |
373 | } | |
374 | ||
375 | keeplst = SCM_CDR (lst); | |
376 | } | |
377 | } | |
378 | ||
379 | /* final retained elements */ | |
380 | *p = keeplst; | |
381 | ||
382 | /* demand that lst was a proper list */ | |
383 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, SCM_ARG2, FUNC_NAME, "list"); | |
384 | ||
385 | return ret; | |
386 | } | |
387 | #undef FUNC_NAME | |
388 | ||
389 | ||
390 | SCM_DEFINE (scm_srfi1_delete_x, "delete!", 2, 1, 0, | |
391 | (SCM x, SCM lst, SCM pred), | |
392 | "Return a list containing the elements of @var{lst} but with\n" | |
393 | "those equal to @var{x} deleted. The returned elements will be\n" | |
394 | "in the same order as they were in @var{lst}.\n" | |
395 | "\n" | |
396 | "Equality is determined by @var{pred}, or @code{equal?} if not\n" | |
397 | "given. An equality call is made just once for each element,\n" | |
398 | "but the order in which the calls are made on the elements is\n" | |
399 | "unspecified.\n" | |
400 | "\n" | |
401 | "The equality calls are always @code{(pred x elem)}, ie.@: the\n" | |
402 | "given @var{x} is first. This means for instance elements\n" | |
403 | "greater than 5 can be deleted with @code{(delete 5 lst <)}.\n" | |
404 | "\n" | |
405 | "@var{lst} may be modified to construct the returned list.") | |
406 | #define FUNC_NAME s_scm_srfi1_delete_x | |
407 | { | |
408 | scm_t_trampoline_2 equal_p; | |
409 | SCM walk; | |
410 | SCM *prev; | |
411 | ||
412 | if (SCM_UNBNDP (pred)) | |
413 | return scm_delete_x (x, lst); | |
414 | ||
415 | equal_p = scm_trampoline_2 (pred); | |
416 | SCM_ASSERT (equal_p, pred, SCM_ARG3, FUNC_NAME); | |
417 | ||
418 | for (prev = &lst, walk = lst; | |
896df2d5 | 419 | scm_is_pair (walk); |
d0a634de KR |
420 | walk = SCM_CDR (walk)) |
421 | { | |
00874d5f | 422 | if (scm_is_true (equal_p (pred, x, SCM_CAR (walk)))) |
d0a634de KR |
423 | *prev = SCM_CDR (walk); |
424 | else | |
425 | prev = SCM_CDRLOC (walk); | |
426 | } | |
427 | ||
428 | /* demand the input was a proper list */ | |
429 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (walk), walk, SCM_ARG2, FUNC_NAME,"list"); | |
430 | return lst; | |
431 | } | |
432 | #undef FUNC_NAME | |
433 | ||
434 | ||
435 | SCM_DEFINE (scm_srfi1_delete_duplicates, "delete-duplicates", 1, 1, 0, | |
436 | (SCM lst, SCM pred), | |
437 | "Return a list containing the elements of @var{lst} but without\n" | |
438 | "duplicates.\n" | |
439 | "\n" | |
440 | "When elements are equal, only the first in @var{lst} is\n" | |
441 | "retained. Equal elements can be anywhere in @var{lst}, they\n" | |
442 | "don't have to be adjacent. The returned list will have the\n" | |
443 | "retained elements in the same order as they were in @var{lst}.\n" | |
444 | "\n" | |
445 | "Equality is determined by @var{pred}, or @code{equal?} if not\n" | |
446 | "given. Calls @code{(pred x y)} are made with element @var{x}\n" | |
447 | "being before @var{y} in @var{lst}. A call is made at most once\n" | |
448 | "for each combination, but the sequence of the calls across the\n" | |
449 | "elements is unspecified.\n" | |
450 | "\n" | |
451 | "@var{lst} is not modified, but the return might share a common\n" | |
452 | "tail with @var{lst}.\n" | |
453 | "\n" | |
454 | "In the worst case, this is an @math{O(N^2)} algorithm because\n" | |
455 | "it must check each element against all those preceding it. For\n" | |
456 | "long lists it is more efficient to sort and then compare only\n" | |
457 | "adjacent elements.") | |
458 | #define FUNC_NAME s_scm_srfi1_delete_duplicates | |
459 | { | |
460 | scm_t_trampoline_2 equal_p; | |
461 | SCM ret, *p, keeplst, item, l; | |
462 | ||
463 | /* ret is the new list constructed. p is where to append, initially &ret | |
464 | then SCM_CDRLOC of the last pair. lst is advanced as each element is | |
465 | considered. | |
466 | ||
467 | Elements retained are not immediately appended to ret, instead keeplst | |
468 | is the last pair in lst which is to be kept but is not yet copied. | |
469 | Initially this is the first pair of lst, since the first element is | |
470 | always retained. | |
471 | ||
472 | *p is kept set to keeplst, so ret (inclusive) to lst (exclusive) is all | |
473 | the elements retained, making the equality search loop easy. | |
474 | ||
475 | If an item must be deleted, elements from keeplst (inclusive) to lst | |
476 | (exclusive) must be copied and appended to ret. When there's no more | |
477 | deletions, *p is left set to keeplst, so ret shares structure with the | |
478 | original lst. (ret will be the entire original lst if there are no | |
479 | deletions.) */ | |
480 | ||
481 | /* skip to end if an empty list (or something invalid) */ | |
482 | ret = lst; | |
896df2d5 | 483 | if (scm_is_pair (lst)) |
d0a634de KR |
484 | { |
485 | if (SCM_UNBNDP (pred)) | |
486 | equal_p = equal_trampoline; | |
487 | else | |
488 | { | |
489 | equal_p = scm_trampoline_2 (pred); | |
490 | SCM_ASSERT (equal_p, pred, SCM_ARG2, FUNC_NAME); | |
491 | } | |
492 | ||
493 | keeplst = lst; | |
494 | p = &ret; | |
495 | ||
496 | /* loop over lst elements starting from second */ | |
497 | for (;;) | |
498 | { | |
499 | lst = SCM_CDR (lst); | |
896df2d5 | 500 | if (! scm_is_pair (lst)) |
d0a634de KR |
501 | break; |
502 | item = SCM_CAR (lst); | |
503 | ||
504 | /* loop searching ret upto lst */ | |
bc36d050 | 505 | for (l = ret; ! scm_is_eq (l, lst); l = SCM_CDR (l)) |
d0a634de | 506 | { |
00874d5f | 507 | if (scm_is_true (equal_p (pred, SCM_CAR (l), item))) |
d0a634de KR |
508 | { |
509 | /* duplicate, don't want this element, so copy keeplst | |
510 | (inclusive) to lst (exclusive) onto ret */ | |
bc36d050 | 511 | while (! scm_is_eq (keeplst, lst)) |
d0a634de KR |
512 | { |
513 | SCM c = scm_cons (SCM_CAR (keeplst), SCM_EOL); | |
514 | *p = c; | |
515 | p = SCM_CDRLOC (c); | |
516 | keeplst = SCM_CDR (keeplst); | |
517 | } | |
518 | ||
519 | keeplst = SCM_CDR (lst); /* elem after the one deleted */ | |
520 | *p = keeplst; | |
521 | break; | |
522 | } | |
523 | } | |
524 | } | |
525 | } | |
526 | ||
527 | /* demand that lst was a proper list */ | |
528 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, SCM_ARG1, FUNC_NAME, "list"); | |
529 | ||
530 | return ret; | |
531 | } | |
532 | #undef FUNC_NAME | |
533 | ||
534 | ||
535 | SCM_DEFINE (scm_srfi1_delete_duplicates_x, "delete-duplicates!", 1, 1, 0, | |
536 | (SCM lst, SCM pred), | |
537 | "Return a list containing the elements of @var{lst} but without\n" | |
538 | "duplicates.\n" | |
539 | "\n" | |
540 | "When elements are equal, only the first in @var{lst} is\n" | |
541 | "retained. Equal elements can be anywhere in @var{lst}, they\n" | |
542 | "don't have to be adjacent. The returned list will have the\n" | |
543 | "retained elements in the same order as they were in @var{lst}.\n" | |
544 | "\n" | |
545 | "Equality is determined by @var{pred}, or @code{equal?} if not\n" | |
546 | "given. Calls @code{(pred x y)} are made with element @var{x}\n" | |
547 | "being before @var{y} in @var{lst}. A call is made at most once\n" | |
548 | "for each combination, but the sequence of the calls across the\n" | |
549 | "elements is unspecified.\n" | |
550 | "\n" | |
551 | "@var{lst} may be modified to construct the returned list.\n" | |
552 | "\n" | |
553 | "In the worst case, this is an @math{O(N^2)} algorithm because\n" | |
554 | "it must check each element against all those preceding it. For\n" | |
555 | "long lists it is more efficient to sort and then compare only\n" | |
556 | "adjacent elements.") | |
557 | #define FUNC_NAME s_scm_srfi1_delete_duplicates_x | |
558 | { | |
559 | scm_t_trampoline_2 equal_p; | |
560 | SCM ret, endret, item, l; | |
561 | ||
562 | /* ret is the return list, constructed from the pairs in lst. endret is | |
563 | the last pair of ret, initially the first pair. lst is advanced as | |
564 | elements are considered. */ | |
565 | ||
566 | /* skip to end if an empty list (or something invalid) */ | |
567 | ret = lst; | |
896df2d5 | 568 | if (scm_is_pair (lst)) |
d0a634de KR |
569 | { |
570 | if (SCM_UNBNDP (pred)) | |
571 | equal_p = equal_trampoline; | |
572 | else | |
573 | { | |
574 | equal_p = scm_trampoline_2 (pred); | |
575 | SCM_ASSERT (equal_p, pred, SCM_ARG2, FUNC_NAME); | |
576 | } | |
577 | ||
578 | endret = ret; | |
579 | ||
580 | /* loop over lst elements starting from second */ | |
581 | for (;;) | |
582 | { | |
583 | lst = SCM_CDR (lst); | |
896df2d5 | 584 | if (! scm_is_pair (lst)) |
d0a634de KR |
585 | break; |
586 | item = SCM_CAR (lst); | |
587 | ||
588 | /* is item equal to any element from ret to endret (inclusive)? */ | |
589 | l = ret; | |
590 | for (;;) | |
591 | { | |
00874d5f | 592 | if (scm_is_true (equal_p (pred, SCM_CAR (l), item))) |
d0a634de KR |
593 | break; /* equal, forget this element */ |
594 | ||
bc36d050 | 595 | if (scm_is_eq (l, endret)) |
d0a634de KR |
596 | { |
597 | /* not equal to any, so append this pair */ | |
598 | SCM_SETCDR (endret, lst); | |
599 | endret = lst; | |
600 | break; | |
601 | } | |
602 | l = SCM_CDR (l); | |
603 | } | |
604 | } | |
605 | ||
606 | /* terminate, in case last element was deleted */ | |
607 | SCM_SETCDR (endret, SCM_EOL); | |
608 | } | |
609 | ||
610 | /* demand that lst was a proper list */ | |
611 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, SCM_ARG1, FUNC_NAME, "list"); | |
612 | ||
613 | return ret; | |
614 | } | |
615 | #undef FUNC_NAME | |
616 | ||
617 | ||
2b077051 KR |
618 | SCM_DEFINE (scm_srfi1_drop_right, "drop-right", 2, 0, 0, |
619 | (SCM lst, SCM n), | |
620 | "Return a new list containing all except the last @var{n}\n" | |
621 | "elements of @var{lst}.") | |
622 | #define FUNC_NAME s_scm_srfi1_drop_right | |
623 | { | |
624 | SCM tail = scm_list_tail (lst, n); | |
625 | SCM ret = SCM_EOL; | |
626 | SCM *rend = &ret; | |
627 | while (scm_is_pair (tail)) | |
628 | { | |
629 | *rend = scm_cons (SCM_CAR (lst), SCM_EOL); | |
630 | rend = SCM_CDRLOC (*rend); | |
631 | ||
632 | lst = SCM_CDR (lst); | |
633 | tail = SCM_CDR (tail); | |
634 | } | |
635 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P(tail), tail, SCM_ARG1, FUNC_NAME, "list"); | |
636 | return ret; | |
637 | } | |
638 | #undef FUNC_NAME | |
c1635946 KR |
639 | |
640 | ||
597dbd4e KR |
641 | SCM_DEFINE (scm_srfi1_drop_right_x, "drop-right!", 2, 0, 0, |
642 | (SCM lst, SCM n), | |
643 | "Return the a list containing the @var{n} last elements of\n" | |
644 | "@var{lst}. @var{lst} may be modified to build the return.") | |
645 | #define FUNC_NAME s_scm_srfi1_drop_right_x | |
646 | { | |
647 | SCM tail, *p; | |
648 | ||
649 | if (scm_is_eq (n, SCM_INUM0)) | |
650 | return lst; | |
651 | ||
652 | tail = scm_list_tail (lst, n); | |
653 | p = &lst; | |
654 | ||
655 | /* p and tail work along the list, p being the cdrloc of the cell n steps | |
656 | behind tail */ | |
657 | for ( ; scm_is_pair (tail); tail = SCM_CDR (tail)) | |
658 | p = SCM_CDRLOC (*p); | |
659 | ||
660 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P(tail), tail, SCM_ARG1, FUNC_NAME, "list"); | |
661 | ||
662 | *p = SCM_EOL; | |
663 | return lst; | |
664 | } | |
665 | #undef FUNC_NAME | |
666 | ||
667 | ||
668 | SCM_DEFINE (scm_srfi1_drop_while, "drop-while", 2, 0, 0, | |
669 | (SCM pred, SCM lst), | |
670 | "Drop the longest initial prefix of @var{lst} whose elements all\n" | |
671 | "satisfy the predicate @var{pred}.") | |
672 | #define FUNC_NAME s_scm_srfi1_drop_while | |
673 | { | |
674 | scm_t_trampoline_1 pred_tramp = scm_trampoline_1 (pred); | |
675 | SCM_ASSERT (pred_tramp, pred, SCM_ARG1, FUNC_NAME); | |
676 | ||
677 | for ( ; scm_is_pair (lst); lst = SCM_CDR (lst)) | |
678 | if (scm_is_false (pred_tramp (pred, SCM_CAR (lst)))) | |
679 | goto done; | |
680 | ||
681 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, SCM_ARG2, FUNC_NAME, "list"); | |
682 | done: | |
683 | return lst; | |
684 | } | |
685 | #undef FUNC_NAME | |
686 | ||
687 | ||
03731332 KR |
688 | SCM_DEFINE (scm_srfi1_eighth, "eighth", 1, 0, 0, |
689 | (SCM lst), | |
690 | "Return the eighth element of @var{lst}.") | |
691 | #define FUNC_NAME s_scm_srfi1_eighth | |
692 | { | |
693 | return scm_list_ref (lst, SCM_I_MAKINUM (7)); | |
694 | } | |
695 | #undef FUNC_NAME | |
696 | ||
697 | ||
698 | SCM_DEFINE (scm_srfi1_fifth, "fifth", 1, 0, 0, | |
699 | (SCM lst), | |
700 | "Return the fifth element of @var{lst}.") | |
701 | #define FUNC_NAME s_scm_srfi1_fifth | |
702 | { | |
703 | return scm_list_ref (lst, SCM_I_MAKINUM (4)); | |
704 | } | |
705 | #undef FUNC_NAME | |
706 | ||
707 | ||
c1635946 KR |
708 | SCM_DEFINE (scm_srfi1_filter_map, "filter-map", 2, 0, 1, |
709 | (SCM proc, SCM list1, SCM rest), | |
710 | "Apply @var{proc} to to the elements of @var{list1} @dots{} and\n" | |
711 | "return a list of the results as per SRFI-1 @code{map}, except\n" | |
712 | "that any @code{#f} results are omitted from the list returned.") | |
713 | #define FUNC_NAME s_scm_srfi1_filter_map | |
714 | { | |
715 | SCM ret, *loc, elem, newcell, lst; | |
716 | int argnum; | |
717 | ||
718 | SCM_VALIDATE_REST_ARGUMENT (rest); | |
719 | ||
720 | ret = SCM_EOL; | |
721 | loc = &ret; | |
722 | ||
3c55f6f1 | 723 | if (scm_is_null (rest)) |
c1635946 KR |
724 | { |
725 | /* one list */ | |
726 | scm_t_trampoline_1 proc_tramp = scm_trampoline_1 (proc); | |
727 | SCM_ASSERT (proc_tramp, proc, SCM_ARG1, FUNC_NAME); | |
728 | ||
729 | for ( ; scm_is_pair (list1); list1 = SCM_CDR (list1)) | |
730 | { | |
731 | elem = proc_tramp (proc, SCM_CAR (list1)); | |
732 | if (scm_is_true (elem)) | |
733 | { | |
734 | newcell = scm_cons (elem, SCM_EOL); | |
735 | *loc = newcell; | |
736 | loc = SCM_CDRLOC (newcell); | |
737 | } | |
738 | } | |
739 | ||
740 | /* check below that list1 is a proper list, and done */ | |
6507b831 | 741 | end_list1: |
c1635946 KR |
742 | lst = list1; |
743 | argnum = 2; | |
744 | } | |
3c55f6f1 | 745 | else if (scm_is_null (SCM_CDR (rest))) |
c1635946 KR |
746 | { |
747 | /* two lists */ | |
748 | scm_t_trampoline_2 proc_tramp = scm_trampoline_2 (proc); | |
749 | SCM list2 = SCM_CAR (rest); | |
750 | SCM_ASSERT (proc_tramp, proc, SCM_ARG1, FUNC_NAME); | |
751 | ||
752 | for (;;) | |
753 | { | |
754 | if (! scm_is_pair (list1)) | |
6507b831 | 755 | goto end_list1; |
c1635946 KR |
756 | if (! scm_is_pair (list2)) |
757 | { | |
758 | lst = list2; | |
759 | argnum = 3; | |
760 | goto check_lst_and_done; | |
761 | } | |
762 | elem = proc_tramp (proc, SCM_CAR (list1), SCM_CAR (list2)); | |
763 | if (scm_is_true (elem)) | |
764 | { | |
765 | newcell = scm_cons (elem, SCM_EOL); | |
766 | *loc = newcell; | |
767 | loc = SCM_CDRLOC (newcell); | |
768 | } | |
769 | list1 = SCM_CDR (list1); | |
770 | list2 = SCM_CDR (list2); | |
771 | } | |
772 | } | |
773 | else | |
774 | { | |
775 | /* three or more lists */ | |
eccd308a KR |
776 | SCM vec, args, a; |
777 | size_t len, i; | |
c1635946 | 778 | |
eccd308a KR |
779 | /* vec is the list arguments */ |
780 | vec = scm_vector (scm_cons (list1, rest)); | |
781 | len = SCM_SIMPLE_VECTOR_LENGTH (vec); | |
c1635946 | 782 | |
eccd308a | 783 | /* args is the argument list to pass to proc, same length as vec, |
c1635946 | 784 | re-used for each call */ |
eccd308a | 785 | args = scm_make_list (SCM_I_MAKINUM (len), SCM_UNDEFINED); |
c1635946 KR |
786 | |
787 | for (;;) | |
788 | { | |
eccd308a KR |
789 | /* first elem of each list in vec into args, and step those |
790 | vec entries onto their next element */ | |
791 | for (i = 0, a = args, argnum = 2; | |
792 | i < len; | |
793 | i++, a = SCM_CDR (a), argnum++) | |
c1635946 | 794 | { |
eccd308a | 795 | lst = SCM_SIMPLE_VECTOR_REF (vec, i); /* list argument */ |
c1635946 KR |
796 | if (! scm_is_pair (lst)) |
797 | goto check_lst_and_done; | |
798 | SCM_SETCAR (a, SCM_CAR (lst)); /* arg for proc */ | |
eccd308a | 799 | SCM_SIMPLE_VECTOR_SET (vec, i, SCM_CDR (lst)); /* rest of lst */ |
c1635946 KR |
800 | } |
801 | ||
802 | elem = scm_apply (proc, args, SCM_EOL); | |
803 | if (scm_is_true (elem)) | |
804 | { | |
805 | newcell = scm_cons (elem, SCM_EOL); | |
806 | *loc = newcell; | |
807 | loc = SCM_CDRLOC (newcell); | |
808 | } | |
809 | } | |
810 | } | |
811 | ||
812 | check_lst_and_done: | |
813 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, argnum, FUNC_NAME, "list"); | |
814 | return ret; | |
815 | } | |
816 | #undef FUNC_NAME | |
2b077051 KR |
817 | |
818 | ||
5df2ac97 KR |
819 | SCM_DEFINE (scm_srfi1_find, "find", 2, 0, 0, |
820 | (SCM pred, SCM lst), | |
821 | "Return the first element of @var{lst} which satisfies the\n" | |
822 | "predicate @var{pred}, or return @code{#f} if no such element is\n" | |
823 | "found.") | |
824 | #define FUNC_NAME s_scm_srfi1_find | |
825 | { | |
826 | scm_t_trampoline_1 pred_tramp = scm_trampoline_1 (pred); | |
827 | SCM_ASSERT (pred_tramp, pred, SCM_ARG1, FUNC_NAME); | |
828 | ||
829 | for ( ; scm_is_pair (lst); lst = SCM_CDR (lst)) | |
830 | { | |
831 | SCM elem = SCM_CAR (lst); | |
832 | if (scm_is_true (pred_tramp (pred, elem))) | |
833 | return elem; | |
834 | } | |
835 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, SCM_ARG2, FUNC_NAME, "list"); | |
836 | ||
837 | return SCM_BOOL_F; | |
838 | } | |
839 | #undef FUNC_NAME | |
840 | ||
841 | ||
842 | SCM_DEFINE (scm_srfi1_find_tail, "find-tail", 2, 0, 0, | |
843 | (SCM pred, SCM lst), | |
844 | "Return the first pair of @var{lst} whose @sc{car} satisfies the\n" | |
845 | "predicate @var{pred}, or return @code{#f} if no such element is\n" | |
846 | "found.") | |
847 | #define FUNC_NAME s_scm_srfi1_find_tail | |
848 | { | |
849 | scm_t_trampoline_1 pred_tramp = scm_trampoline_1 (pred); | |
850 | SCM_ASSERT (pred_tramp, pred, SCM_ARG1, FUNC_NAME); | |
851 | ||
852 | for ( ; scm_is_pair (lst); lst = SCM_CDR (lst)) | |
853 | if (scm_is_true (pred_tramp (pred, SCM_CAR (lst)))) | |
854 | return lst; | |
855 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, SCM_ARG2, FUNC_NAME, "list"); | |
856 | ||
857 | return SCM_BOOL_F; | |
858 | } | |
859 | #undef FUNC_NAME | |
860 | ||
861 | ||
e556f8c3 KR |
862 | SCM_DEFINE (scm_srfi1_fold, "fold", 3, 0, 1, |
863 | (SCM proc, SCM init, SCM list1, SCM rest), | |
864 | "Apply @var{proc} to the elements of @var{lst1} @dots{}\n" | |
865 | "@var{lstN} to build a result, and return that result.\n" | |
866 | "\n" | |
867 | "Each @var{proc} call is @code{(@var{proc} @var{elem1} @dots{}\n" | |
868 | "@var{elemN} @var{previous})}, where @var{elem1} is from\n" | |
869 | "@var{lst1}, through @var{elemN} from @var{lstN}.\n" | |
870 | "@var{previous} is the return from the previous call to\n" | |
871 | "@var{proc}, or the given @var{init} for the first call. If any\n" | |
872 | "list is empty, just @var{init} is returned.\n" | |
873 | "\n" | |
874 | "@code{fold} works through the list elements from first to last.\n" | |
875 | "The following shows a list reversal and the calls it makes,\n" | |
876 | "\n" | |
877 | "@example\n" | |
878 | "(fold cons '() '(1 2 3))\n" | |
879 | "\n" | |
880 | "(cons 1 '())\n" | |
881 | "(cons 2 '(1))\n" | |
882 | "(cons 3 '(2 1)\n" | |
883 | "@result{} (3 2 1)\n" | |
884 | "@end example\n" | |
885 | "\n" | |
886 | "If @var{lst1} through @var{lstN} have different lengths,\n" | |
887 | "@code{fold} stops when the end of the shortest is reached.\n" | |
888 | "Ie.@: elements past the length of the shortest are ignored in\n" | |
889 | "the other @var{lst}s. At least one @var{lst} must be\n" | |
890 | "non-circular.\n" | |
891 | "\n" | |
892 | "The way @code{fold} builds a result from iterating is quite\n" | |
893 | "general, it can do more than other iterations like say\n" | |
894 | "@code{map} or @code{filter}. The following for example removes\n" | |
895 | "adjacent duplicate elements from a list,\n" | |
896 | "\n" | |
897 | "@example\n" | |
898 | "(define (delete-adjacent-duplicates lst)\n" | |
899 | " (fold-right (lambda (elem ret)\n" | |
900 | " (if (equal? elem (first ret))\n" | |
901 | " ret\n" | |
902 | " (cons elem ret)))\n" | |
903 | " (list (last lst))\n" | |
904 | " lst))\n" | |
905 | "(delete-adjacent-duplicates '(1 2 3 3 4 4 4 5))\n" | |
906 | "@result{} (1 2 3 4 5)\n" | |
907 | "@end example\n" | |
908 | "\n" | |
909 | "Clearly the same sort of thing can be done with a\n" | |
910 | "@code{for-each} and a variable in which to build the result,\n" | |
911 | "but a self-contained @var{proc} can be re-used in multiple\n" | |
912 | "contexts, where a @code{for-each} would have to be written out\n" | |
913 | "each time.") | |
914 | #define FUNC_NAME s_scm_srfi1_fold | |
915 | { | |
916 | SCM lst; | |
917 | int argnum; | |
918 | SCM_VALIDATE_REST_ARGUMENT (rest); | |
919 | ||
920 | if (scm_is_null (rest)) | |
921 | { | |
922 | /* one list */ | |
923 | scm_t_trampoline_2 proc_tramp = scm_trampoline_2 (proc); | |
924 | SCM_ASSERT (proc_tramp, proc, SCM_ARG1, FUNC_NAME); | |
925 | ||
926 | for ( ; scm_is_pair (list1); list1 = SCM_CDR (list1)) | |
927 | init = proc_tramp (proc, SCM_CAR (list1), init); | |
928 | ||
929 | /* check below that list1 is a proper list, and done */ | |
930 | lst = list1; | |
931 | argnum = 2; | |
932 | } | |
933 | else | |
934 | { | |
935 | /* two or more lists */ | |
936 | SCM vec, args, a; | |
937 | size_t len, i; | |
938 | ||
939 | /* vec is the list arguments */ | |
940 | vec = scm_vector (scm_cons (list1, rest)); | |
941 | len = SCM_SIMPLE_VECTOR_LENGTH (vec); | |
942 | ||
943 | /* args is the argument list to pass to proc, same length as vec, | |
944 | re-used for each call */ | |
945 | args = scm_make_list (SCM_I_MAKINUM (len+1), SCM_UNDEFINED); | |
946 | ||
947 | for (;;) | |
948 | { | |
949 | /* first elem of each list in vec into args, and step those | |
950 | vec entries onto their next element */ | |
951 | for (i = 0, a = args, argnum = 2; | |
952 | i < len; | |
953 | i++, a = SCM_CDR (a), argnum++) | |
954 | { | |
955 | lst = SCM_SIMPLE_VECTOR_REF (vec, i); /* list argument */ | |
956 | if (! scm_is_pair (lst)) | |
957 | goto check_lst_and_done; | |
958 | SCM_SETCAR (a, SCM_CAR (lst)); /* arg for proc */ | |
959 | SCM_SIMPLE_VECTOR_SET (vec, i, SCM_CDR (lst)); /* rest of lst */ | |
960 | } | |
961 | SCM_SETCAR (a, init); | |
962 | ||
963 | init = scm_apply (proc, args, SCM_EOL); | |
964 | } | |
965 | } | |
966 | ||
967 | check_lst_and_done: | |
968 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, argnum, FUNC_NAME, "list"); | |
969 | return init; | |
970 | } | |
971 | #undef FUNC_NAME | |
972 | ||
973 | ||
974 | SCM_DEFINE (scm_srfi1_last, "last", 1, 0, 0, | |
975 | (SCM lst), | |
976 | "Like @code{cons}, but with interchanged arguments. Useful\n" | |
977 | "mostly when passed to higher-order procedures.") | |
978 | #define FUNC_NAME s_scm_srfi1_last | |
979 | { | |
980 | SCM pair = scm_last_pair (lst); | |
981 | /* scm_last_pair returns SCM_EOL for an empty list */ | |
982 | SCM_VALIDATE_CONS (SCM_ARG1, pair); | |
983 | return SCM_CAR (pair); | |
984 | } | |
985 | #undef FUNC_NAME | |
986 | ||
987 | ||
de51f595 KR |
988 | SCM_DEFINE (scm_srfi1_length_plus, "length+", 1, 0, 0, |
989 | (SCM lst), | |
990 | "Return the length of @var{lst}, or @code{#f} if @var{lst} is\n" | |
991 | "circular.") | |
992 | #define FUNC_NAME s_scm_srfi1_length_plus | |
993 | { | |
994 | long len = scm_ilength (lst); | |
93ccaef0 | 995 | return (len >= 0 ? SCM_I_MAKINUM (len) : SCM_BOOL_F); |
de51f595 KR |
996 | } |
997 | #undef FUNC_NAME | |
998 | ||
999 | ||
e556f8c3 KR |
1000 | SCM_DEFINE (scm_srfi1_list_index, "list-index", 2, 0, 1, |
1001 | (SCM pred, SCM list1, SCM rest), | |
1002 | "Return the index of the first set of elements, one from each of\n" | |
1003 | "@var{lst1}@dots{}@var{lstN}, which satisfies @var{pred}.\n" | |
1004 | "\n" | |
1005 | "@var{pred} is called as @code{(@var{pred} elem1 @dots{}\n" | |
1006 | "elemN)}. Searching stops when the end of the shortest\n" | |
1007 | "@var{lst} is reached. The return index starts from 0 for the\n" | |
1008 | "first set of elements. If no set of elements pass then the\n" | |
1009 | "return is @code{#f}.\n" | |
1010 | "\n" | |
1011 | "@example\n" | |
1012 | "(list-index odd? '(2 4 6 9)) @result{} 3\n" | |
1013 | "(list-index = '(1 2 3) '(3 1 2)) @result{} #f\n" | |
1014 | "@end example") | |
1015 | #define FUNC_NAME s_scm_srfi1_list_index | |
1016 | { | |
1017 | long n = 0; | |
1018 | SCM lst; | |
1019 | int argnum; | |
1020 | SCM_VALIDATE_REST_ARGUMENT (rest); | |
1021 | ||
1022 | if (scm_is_null (rest)) | |
1023 | { | |
1024 | /* one list */ | |
1025 | scm_t_trampoline_1 pred_tramp = scm_trampoline_1 (pred); | |
1026 | SCM_ASSERT (pred_tramp, pred, SCM_ARG1, FUNC_NAME); | |
1027 | ||
1028 | for ( ; scm_is_pair (list1); n++, list1 = SCM_CDR (list1)) | |
1029 | if (scm_is_true (pred_tramp (pred, SCM_CAR (list1)))) | |
1030 | return SCM_I_MAKINUM (n); | |
1031 | ||
1032 | /* not found, check below that list1 is a proper list */ | |
1033 | end_list1: | |
1034 | lst = list1; | |
1035 | argnum = 2; | |
1036 | } | |
1037 | else if (scm_is_pair (rest) && scm_is_null (SCM_CDR (rest))) | |
1038 | { | |
1039 | /* two lists */ | |
1040 | SCM list2 = SCM_CAR (rest); | |
1041 | scm_t_trampoline_2 pred_tramp = scm_trampoline_2 (pred); | |
1042 | SCM_ASSERT (pred_tramp, pred, SCM_ARG1, FUNC_NAME); | |
1043 | ||
1044 | for ( ; ; n++) | |
1045 | { | |
1046 | if (! scm_is_pair (list1)) | |
1047 | goto end_list1; | |
1048 | if (! scm_is_pair (list2)) | |
1049 | { | |
1050 | lst = list2; | |
1051 | argnum = 3; | |
1052 | break; | |
1053 | } | |
1054 | if (scm_is_true (pred_tramp (pred, | |
1055 | SCM_CAR (list1), SCM_CAR (list2)))) | |
1056 | return SCM_I_MAKINUM (n); | |
1057 | ||
1058 | list1 = SCM_CDR (list1); | |
1059 | list2 = SCM_CDR (list2); | |
1060 | } | |
1061 | } | |
1062 | else | |
1063 | { | |
1064 | /* three or more lists */ | |
1065 | SCM vec, args, a; | |
1066 | size_t len, i; | |
1067 | ||
1068 | /* vec is the list arguments */ | |
1069 | vec = scm_vector (scm_cons (list1, rest)); | |
1070 | len = SCM_SIMPLE_VECTOR_LENGTH (vec); | |
1071 | ||
1072 | /* args is the argument list to pass to pred, same length as vec, | |
1073 | re-used for each call */ | |
1074 | args = scm_make_list (SCM_I_MAKINUM (len), SCM_UNDEFINED); | |
1075 | ||
1076 | for ( ; ; n++) | |
1077 | { | |
1078 | /* first elem of each list in vec into args, and step those | |
1079 | vec entries onto their next element */ | |
1080 | for (i = 0, a = args, argnum = 2; | |
1081 | i < len; | |
1082 | i++, a = SCM_CDR (a), argnum++) | |
1083 | { | |
1084 | lst = SCM_SIMPLE_VECTOR_REF (vec, i); /* list argument */ | |
1085 | if (! scm_is_pair (lst)) | |
1086 | goto not_found_check_lst; | |
1087 | SCM_SETCAR (a, SCM_CAR (lst)); /* arg for pred */ | |
1088 | SCM_SIMPLE_VECTOR_SET (vec, i, SCM_CDR (lst)); /* rest of lst */ | |
1089 | } | |
1090 | ||
1091 | if (scm_is_true (scm_apply (pred, args, SCM_EOL))) | |
1092 | return SCM_I_MAKINUM (n); | |
1093 | } | |
1094 | } | |
1095 | ||
1096 | not_found_check_lst: | |
1097 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, argnum, FUNC_NAME, "list"); | |
1098 | return SCM_BOOL_F; | |
1099 | } | |
1100 | #undef FUNC_NAME | |
1101 | ||
1102 | ||
d61261f0 KR |
1103 | /* This routine differs from the core list-copy in allowing improper lists. |
1104 | Maybe the core could allow them similarly. */ | |
1105 | ||
1106 | SCM_DEFINE (scm_srfi1_list_copy, "list-copy", 1, 0, 0, | |
1107 | (SCM lst), | |
1108 | "Return a copy of the given list @var{lst}.\n" | |
1109 | "\n" | |
1110 | "@var{lst} can be a proper or improper list. And if @var{lst}\n" | |
1111 | "is not a pair then it's treated as the final tail of an\n" | |
1112 | "improper list and simply returned.") | |
1113 | #define FUNC_NAME s_scm_srfi1_list_copy | |
1114 | { | |
1115 | SCM newlst; | |
1116 | SCM * fill_here; | |
1117 | SCM from_here; | |
1118 | ||
1119 | newlst = lst; | |
1120 | fill_here = &newlst; | |
1121 | from_here = lst; | |
1122 | ||
896df2d5 | 1123 | while (scm_is_pair (from_here)) |
d61261f0 KR |
1124 | { |
1125 | SCM c; | |
1126 | c = scm_cons (SCM_CAR (from_here), SCM_CDR (from_here)); | |
1127 | *fill_here = c; | |
1128 | fill_here = SCM_CDRLOC (c); | |
1129 | from_here = SCM_CDR (from_here); | |
1130 | } | |
1131 | return newlst; | |
1132 | } | |
1133 | #undef FUNC_NAME | |
1134 | ||
1135 | ||
e556f8c3 KR |
1136 | SCM_DEFINE (scm_srfi1_list_tabulate, "list-tabulate", 2, 0, 0, |
1137 | (SCM n, SCM proc), | |
1138 | "Return an @var{n}-element list, where each list element is\n" | |
1139 | "produced by applying the procedure @var{init-proc} to the\n" | |
1140 | "corresponding list index. The order in which @var{init-proc}\n" | |
1141 | "is applied to the indices is not specified.") | |
1142 | #define FUNC_NAME s_scm_srfi1_list_tabulate | |
1143 | { | |
1144 | long i, nn; | |
1145 | scm_t_trampoline_1 proc_tramp = scm_trampoline_1 (proc); | |
1146 | SCM ret = SCM_EOL; | |
1147 | ||
b730fbf1 | 1148 | nn = scm_to_signed_integer (n, 0, LONG_MAX); |
e556f8c3 KR |
1149 | SCM_ASSERT (proc_tramp, proc, SCM_ARG2, FUNC_NAME); |
1150 | ||
1151 | for (i = nn-1; i >= 0; i--) | |
b730fbf1 | 1152 | ret = scm_cons (proc_tramp (proc, scm_from_long (i)), ret); |
e556f8c3 KR |
1153 | |
1154 | return ret; | |
1155 | } | |
1156 | #undef FUNC_NAME | |
1157 | ||
1158 | ||
597dbd4e KR |
1159 | SCM_DEFINE (scm_srfi1_lset_adjoin, "lset-adjoin", 2, 0, 1, |
1160 | (SCM equal, SCM lst, SCM rest), | |
1161 | "Add to @var{list} any of the given @var{elem}s not already in\n" | |
1162 | "the list. @var{elem}s are @code{cons}ed onto the start of\n" | |
1163 | "@var{list} (so the return shares a common tail with\n" | |
1164 | "@var{list}), but the order they're added is unspecified.\n" | |
1165 | "\n" | |
1166 | "The given @var{=} procedure is used for comparing elements,\n" | |
1167 | "called as @code{(@var{=} listelem elem)}, ie.@: the second\n" | |
1168 | "argument is one of the given @var{elem} parameters.\n" | |
1169 | "\n" | |
1170 | "@example\n" | |
1171 | "(lset-adjoin eqv? '(1 2 3) 4 1 5) @result{} (5 4 1 2 3)\n" | |
1172 | "@end example") | |
1173 | #define FUNC_NAME s_scm_srfi1_lset_adjoin | |
1174 | { | |
1175 | scm_t_trampoline_2 equal_tramp; | |
1176 | SCM l, elem; | |
1177 | ||
1178 | equal_tramp = scm_trampoline_2 (equal); | |
1179 | SCM_ASSERT (equal_tramp, equal, SCM_ARG1, FUNC_NAME); | |
1180 | SCM_VALIDATE_REST_ARGUMENT (rest); | |
1181 | ||
1182 | /* It's not clear if duplicates among the `rest' elements are meant to be | |
1183 | cast out. The spec says `=' is called as (= list-elem rest-elem), | |
1184 | suggesting perhaps not, but the reference implementation shows the | |
1185 | "list" at each stage as including those "rest" elements already added. | |
1186 | The latter corresponds to what's described for lset-union, so that's | |
1187 | what's done here. */ | |
1188 | ||
1189 | for ( ; scm_is_pair (rest); rest = SCM_CDR (rest)) | |
1190 | { | |
1191 | elem = SCM_CAR (rest); | |
1192 | ||
1193 | for (l = lst; scm_is_pair (l); l = SCM_CDR (l)) | |
1194 | if (scm_is_true (equal_tramp (equal, SCM_CAR (l), elem))) | |
1195 | goto next_elem; /* elem already in lst, don't add */ | |
1196 | ||
1197 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P(l), lst, SCM_ARG2, FUNC_NAME, "list"); | |
1198 | ||
1199 | /* elem is not equal to anything already in lst, add it */ | |
1200 | lst = scm_cons (elem, lst); | |
1201 | ||
1202 | next_elem: | |
1203 | ; | |
1204 | } | |
1205 | ||
1206 | return lst; | |
1207 | } | |
1208 | #undef FUNC_NAME | |
1209 | ||
1210 | ||
ee6aac97 MD |
1211 | /* Typechecking for multi-argument MAP and FOR-EACH. |
1212 | ||
1213 | Verify that each element of the vector ARGV, except for the first, | |
1214 | is a list and return minimum length. Attribute errors to WHO, | |
1215 | and claim that the i'th element of ARGV is WHO's i+2'th argument. */ | |
1216 | static inline int | |
1217 | check_map_args (SCM argv, | |
1218 | long len, | |
1219 | SCM gf, | |
1220 | SCM proc, | |
1221 | SCM args, | |
1222 | const char *who) | |
1223 | { | |
ee6aac97 | 1224 | long i; |
705f4f57 | 1225 | SCM elt; |
ee6aac97 | 1226 | |
3c4ce91b | 1227 | for (i = SCM_SIMPLE_VECTOR_LENGTH (argv) - 1; i >= 1; i--) |
ee6aac97 MD |
1228 | { |
1229 | long elt_len; | |
705f4f57 | 1230 | elt = SCM_SIMPLE_VECTOR_REF (argv, i); |
ee6aac97 | 1231 | |
896df2d5 | 1232 | if (!(scm_is_null (elt) || scm_is_pair (elt))) |
705f4f57 | 1233 | goto check_map_error; |
ee6aac97 | 1234 | |
3c4ce91b | 1235 | elt_len = srfi1_ilength (elt); |
ee6aac97 MD |
1236 | if (elt_len < -1) |
1237 | goto check_map_error; | |
1238 | ||
1239 | if (len < 0 || (elt_len >= 0 && elt_len < len)) | |
1240 | len = elt_len; | |
1241 | } | |
705f4f57 | 1242 | |
ee6aac97 | 1243 | if (len < 0) |
705f4f57 MV |
1244 | { |
1245 | /* i == 0 */ | |
1246 | elt = SCM_EOL; | |
1247 | check_map_error: | |
1248 | if (gf) | |
1249 | scm_apply_generic (gf, scm_cons (proc, args)); | |
1250 | else | |
1251 | scm_wrong_type_arg (who, i + 2, elt); | |
1252 | } | |
1253 | ||
ee6aac97 MD |
1254 | scm_remember_upto_here_1 (argv); |
1255 | return len; | |
1256 | } | |
1257 | ||
1258 | ||
1259 | SCM_GPROC (s_srfi1_map, "map", 2, 0, 1, scm_srfi1_map, g_srfi1_map); | |
1260 | ||
1261 | /* Note: Currently, scm_srfi1_map applies PROC to the argument list(s) | |
1262 | sequentially, starting with the first element(s). This is used in | |
1263 | the Scheme procedure `map-in-order', which guarantees sequential | |
1264 | behaviour, is implemented using scm_map. If the behaviour changes, | |
1265 | we need to update `map-in-order'. | |
1266 | */ | |
1267 | ||
1268 | SCM | |
1269 | scm_srfi1_map (SCM proc, SCM arg1, SCM args) | |
1270 | #define FUNC_NAME s_srfi1_map | |
1271 | { | |
1272 | long i, len; | |
1273 | SCM res = SCM_EOL; | |
1274 | SCM *pres = &res; | |
ee6aac97 MD |
1275 | |
1276 | len = srfi1_ilength (arg1); | |
896df2d5 | 1277 | SCM_GASSERTn ((scm_is_null (arg1) || scm_is_pair (arg1)) && len >= -1, |
ee6aac97 MD |
1278 | g_srfi1_map, |
1279 | scm_cons2 (proc, arg1, args), SCM_ARG2, s_srfi1_map); | |
1280 | SCM_VALIDATE_REST_ARGUMENT (args); | |
896df2d5 | 1281 | if (scm_is_null (args)) |
ee6aac97 MD |
1282 | { |
1283 | scm_t_trampoline_1 call = scm_trampoline_1 (proc); | |
1284 | SCM_GASSERT2 (call, g_srfi1_map, proc, arg1, SCM_ARG1, s_srfi1_map); | |
1285 | SCM_GASSERT2 (len >= 0, g_srfi1_map, proc, arg1, SCM_ARG2, s_srfi1_map); | |
1286 | while (SCM_NIMP (arg1)) | |
1287 | { | |
1288 | *pres = scm_list_1 (call (proc, SCM_CAR (arg1))); | |
1289 | pres = SCM_CDRLOC (*pres); | |
1290 | arg1 = SCM_CDR (arg1); | |
1291 | } | |
1292 | return res; | |
1293 | } | |
896df2d5 | 1294 | if (scm_is_null (SCM_CDR (args))) |
ee6aac97 MD |
1295 | { |
1296 | SCM arg2 = SCM_CAR (args); | |
1297 | int len2 = srfi1_ilength (arg2); | |
1298 | scm_t_trampoline_2 call = scm_trampoline_2 (proc); | |
1299 | SCM_GASSERTn (call, g_srfi1_map, | |
1300 | scm_cons2 (proc, arg1, args), SCM_ARG1, s_srfi1_map); | |
1301 | if (len < 0 || (len2 >= 0 && len2 < len)) | |
1302 | len = len2; | |
896df2d5 | 1303 | SCM_GASSERTn ((scm_is_null (arg2) || scm_is_pair (arg2)) |
ee6aac97 MD |
1304 | && len >= 0 && len2 >= -1, |
1305 | g_srfi1_map, | |
1306 | scm_cons2 (proc, arg1, args), | |
f9ac1c2d | 1307 | len2 >= 0 ? SCM_ARG2 : SCM_ARG3, |
ee6aac97 MD |
1308 | s_srfi1_map); |
1309 | while (len > 0) | |
1310 | { | |
1311 | *pres = scm_list_1 (call (proc, SCM_CAR (arg1), SCM_CAR (arg2))); | |
1312 | pres = SCM_CDRLOC (*pres); | |
1313 | arg1 = SCM_CDR (arg1); | |
1314 | arg2 = SCM_CDR (arg2); | |
1315 | --len; | |
1316 | } | |
1317 | return res; | |
1318 | } | |
1319 | args = scm_vector (arg1 = scm_cons (arg1, args)); | |
ee6aac97 MD |
1320 | len = check_map_args (args, len, g_srfi1_map, proc, arg1, s_srfi1_map); |
1321 | while (len > 0) | |
1322 | { | |
1323 | arg1 = SCM_EOL; | |
3c4ce91b | 1324 | for (i = SCM_SIMPLE_VECTOR_LENGTH (args) - 1; i >= 0; i--) |
ee6aac97 | 1325 | { |
3c4ce91b MV |
1326 | SCM elt = SCM_SIMPLE_VECTOR_REF (args, i); |
1327 | arg1 = scm_cons (SCM_CAR (elt), arg1); | |
1328 | SCM_SIMPLE_VECTOR_SET (args, i, SCM_CDR (elt)); | |
ee6aac97 MD |
1329 | } |
1330 | *pres = scm_list_1 (scm_apply (proc, arg1, SCM_EOL)); | |
1331 | pres = SCM_CDRLOC (*pres); | |
1332 | --len; | |
1333 | } | |
1334 | return res; | |
1335 | } | |
1336 | #undef FUNC_NAME | |
1337 | ||
1338 | SCM_REGISTER_PROC (s_srfi1_map_in_order, "map-in-order", 2, 0, 1, scm_srfi1_map); | |
1339 | ||
1340 | SCM_GPROC (s_srfi1_for_each, "for-each", 2, 0, 1, scm_srfi1_for_each, g_srfi1_for_each); | |
1341 | ||
1342 | SCM | |
1343 | scm_srfi1_for_each (SCM proc, SCM arg1, SCM args) | |
1344 | #define FUNC_NAME s_srfi1_for_each | |
1345 | { | |
ee6aac97 MD |
1346 | long i, len; |
1347 | len = srfi1_ilength (arg1); | |
896df2d5 | 1348 | SCM_GASSERTn ((scm_is_null (arg1) || scm_is_pair (arg1)) && len >= -1, |
ee6aac97 MD |
1349 | g_srfi1_for_each, scm_cons2 (proc, arg1, args), |
1350 | SCM_ARG2, s_srfi1_for_each); | |
1351 | SCM_VALIDATE_REST_ARGUMENT (args); | |
896df2d5 | 1352 | if (scm_is_null (args)) |
ee6aac97 MD |
1353 | { |
1354 | scm_t_trampoline_1 call = scm_trampoline_1 (proc); | |
1355 | SCM_GASSERT2 (call, g_srfi1_for_each, proc, arg1, | |
1356 | SCM_ARG1, s_srfi1_for_each); | |
1357 | SCM_GASSERT2 (len >= 0, g_srfi1_for_each, proc, arg1, | |
1358 | SCM_ARG2, s_srfi1_map); | |
1359 | while (SCM_NIMP (arg1)) | |
1360 | { | |
1361 | call (proc, SCM_CAR (arg1)); | |
1362 | arg1 = SCM_CDR (arg1); | |
1363 | } | |
1364 | return SCM_UNSPECIFIED; | |
1365 | } | |
896df2d5 | 1366 | if (scm_is_null (SCM_CDR (args))) |
ee6aac97 MD |
1367 | { |
1368 | SCM arg2 = SCM_CAR (args); | |
1369 | int len2 = srfi1_ilength (arg2); | |
1370 | scm_t_trampoline_2 call = scm_trampoline_2 (proc); | |
1371 | SCM_GASSERTn (call, g_srfi1_for_each, | |
1372 | scm_cons2 (proc, arg1, args), SCM_ARG1, s_srfi1_for_each); | |
1373 | if (len < 0 || (len2 >= 0 && len2 < len)) | |
1374 | len = len2; | |
896df2d5 | 1375 | SCM_GASSERTn ((scm_is_null (arg2) || scm_is_pair (arg2)) |
f9ac1c2d | 1376 | && len >= 0 && len2 >= -1, |
ee6aac97 MD |
1377 | g_srfi1_for_each, |
1378 | scm_cons2 (proc, arg1, args), | |
f9ac1c2d | 1379 | len2 >= 0 ? SCM_ARG2 : SCM_ARG3, |
ee6aac97 MD |
1380 | s_srfi1_for_each); |
1381 | while (len > 0) | |
1382 | { | |
1383 | call (proc, SCM_CAR (arg1), SCM_CAR (arg2)); | |
1384 | arg1 = SCM_CDR (arg1); | |
1385 | arg2 = SCM_CDR (arg2); | |
1386 | --len; | |
1387 | } | |
1388 | return SCM_UNSPECIFIED; | |
1389 | } | |
1390 | args = scm_vector (arg1 = scm_cons (arg1, args)); | |
ee6aac97 MD |
1391 | len = check_map_args (args, len, g_srfi1_for_each, proc, arg1, |
1392 | s_srfi1_for_each); | |
1393 | while (len > 0) | |
1394 | { | |
1395 | arg1 = SCM_EOL; | |
3c4ce91b | 1396 | for (i = SCM_SIMPLE_VECTOR_LENGTH (args) - 1; i >= 0; i--) |
ee6aac97 | 1397 | { |
3c4ce91b MV |
1398 | SCM elt = SCM_SIMPLE_VECTOR_REF (args, i); |
1399 | arg1 = scm_cons (SCM_CAR (elt), arg1); | |
1400 | SCM_SIMPLE_VECTOR_SET (args, i, SCM_CDR (elt)); | |
ee6aac97 MD |
1401 | } |
1402 | scm_apply (proc, arg1, SCM_EOL); | |
1403 | --len; | |
1404 | } | |
1405 | return SCM_UNSPECIFIED; | |
1406 | } | |
1407 | #undef FUNC_NAME | |
1408 | ||
1409 | ||
ee6aac97 MD |
1410 | SCM_DEFINE (scm_srfi1_member, "member", 2, 1, 0, |
1411 | (SCM x, SCM lst, SCM pred), | |
4e3cc389 KR |
1412 | "Return the first sublist of @var{lst} whose @sc{car} is equal\n" |
1413 | "to @var{x}. If @var{x} does not appear in @var{lst}, return\n" | |
1414 | "@code{#f}.\n" | |
1415 | "\n" | |
1416 | "Equality is determined by @code{equal?}, or by the equality\n" | |
1417 | "predicate @var{=} if given. @var{=} is called @code{(= @var{x}\n" | |
1418 | "elem)}, ie.@: with the given @var{x} first, so for example to\n" | |
1419 | "find the first element greater than 5,\n" | |
1420 | "\n" | |
1421 | "@example\n" | |
1422 | "(member 5 '(3 5 1 7 2 9) <) @result{} (7 2 9)\n" | |
1423 | "@end example\n" | |
1424 | "\n" | |
1425 | "This version of @code{member} extends the core @code{member} by\n" | |
1426 | "accepting an equality predicate.") | |
ee6aac97 MD |
1427 | #define FUNC_NAME s_scm_srfi1_member |
1428 | { | |
1429 | scm_t_trampoline_2 equal_p; | |
1430 | SCM_VALIDATE_LIST (2, lst); | |
1431 | if (SCM_UNBNDP (pred)) | |
1432 | equal_p = equal_trampoline; | |
1433 | else | |
1434 | { | |
1435 | equal_p = scm_trampoline_2 (pred); | |
1436 | SCM_ASSERT (equal_p, pred, 3, FUNC_NAME); | |
1437 | } | |
1438 | for (; !SCM_NULL_OR_NIL_P (lst); lst = SCM_CDR (lst)) | |
1439 | { | |
2796304a | 1440 | if (scm_is_true (equal_p (pred, x, SCM_CAR (lst)))) |
ee6aac97 MD |
1441 | return lst; |
1442 | } | |
1443 | return SCM_BOOL_F; | |
1444 | } | |
1445 | #undef FUNC_NAME | |
1446 | ||
7692d26b MD |
1447 | SCM_DEFINE (scm_srfi1_assoc, "assoc", 2, 1, 0, |
1448 | (SCM key, SCM alist, SCM pred), | |
1449 | "Behaves like @code{assq} but uses third argument @var{pred?}\n" | |
1450 | "for key comparison. If @var{pred?} is not supplied,\n" | |
1451 | "@code{equal?} is used. (Extended from R5RS.)\n") | |
1452 | #define FUNC_NAME s_scm_srfi1_assoc | |
1453 | { | |
1454 | SCM ls = alist; | |
1455 | scm_t_trampoline_2 equal_p; | |
1456 | if (SCM_UNBNDP (pred)) | |
1457 | equal_p = equal_trampoline; | |
1458 | else | |
1459 | { | |
1460 | equal_p = scm_trampoline_2 (pred); | |
1461 | SCM_ASSERT (equal_p, pred, 3, FUNC_NAME); | |
1462 | } | |
896df2d5 | 1463 | for(; scm_is_pair (ls); ls = SCM_CDR (ls)) |
7692d26b MD |
1464 | { |
1465 | SCM tmp = SCM_CAR (ls); | |
896df2d5 | 1466 | SCM_ASSERT_TYPE (scm_is_pair (tmp), alist, SCM_ARG2, FUNC_NAME, |
7692d26b | 1467 | "association list"); |
00874d5f | 1468 | if (scm_is_true (equal_p (pred, SCM_CAR (tmp), key))) |
7692d26b MD |
1469 | return tmp; |
1470 | } | |
1471 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (ls), alist, SCM_ARG2, FUNC_NAME, | |
1472 | "association list"); | |
1473 | return SCM_BOOL_F; | |
1474 | } | |
1475 | #undef FUNC_NAME | |
1476 | ||
03731332 KR |
1477 | |
1478 | SCM_DEFINE (scm_srfi1_ninth, "ninth", 1, 0, 0, | |
1479 | (SCM lst), | |
1480 | "Return the ninth element of @var{lst}.") | |
1481 | #define FUNC_NAME s_scm_srfi1_ninth | |
1482 | { | |
b730fbf1 | 1483 | return scm_list_ref (lst, scm_from_int (8)); |
03731332 KR |
1484 | } |
1485 | #undef FUNC_NAME | |
1486 | ||
1487 | ||
e556f8c3 KR |
1488 | SCM_DEFINE (scm_srfi1_not_pair_p, "not-pair?", 1, 0, 0, |
1489 | (SCM obj), | |
1490 | "Return @code{#t} is @var{obj} is not a pair, @code{#f}\n" | |
1491 | "otherwise.\n" | |
1492 | "\n" | |
1493 | "This is shorthand notation @code{(not (pair? @var{obj}))} and\n" | |
1494 | "is supposed to be used for end-of-list checking in contexts\n" | |
1495 | "where dotted lists are allowed.") | |
1496 | #define FUNC_NAME s_scm_srfi1_not_pair_p | |
1497 | { | |
1498 | return scm_from_bool (! scm_is_pair (obj)); | |
1499 | } | |
1500 | #undef FUNC_NAME | |
1501 | ||
1502 | ||
65978fb2 KR |
1503 | SCM_DEFINE (scm_srfi1_partition, "partition", 2, 0, 0, |
1504 | (SCM pred, SCM list), | |
1505 | "Partition the elements of @var{list} with predicate @var{pred}.\n" | |
1506 | "Return two values: the list of elements satifying @var{pred} and\n" | |
1507 | "the list of elements @emph{not} satisfying @var{pred}. The order\n" | |
1508 | "of the output lists follows the order of @var{list}. @var{list}\n" | |
1509 | "is not mutated. One of the output lists may share memory with @var{list}.\n") | |
1510 | #define FUNC_NAME s_scm_srfi1_partition | |
1511 | { | |
1512 | /* In this implementation, the output lists don't share memory with | |
1513 | list, because it's probably not worth the effort. */ | |
1514 | scm_t_trampoline_1 call = scm_trampoline_1(pred); | |
1515 | SCM kept = scm_cons(SCM_EOL, SCM_EOL); | |
1516 | SCM kept_tail = kept; | |
1517 | SCM dropped = scm_cons(SCM_EOL, SCM_EOL); | |
1518 | SCM dropped_tail = dropped; | |
1519 | ||
1520 | SCM_ASSERT(call, pred, 2, FUNC_NAME); | |
1521 | ||
1522 | for (; !SCM_NULL_OR_NIL_P (list); list = SCM_CDR(list)) { | |
1523 | SCM elt = SCM_CAR(list); | |
1524 | SCM new_tail = scm_cons(SCM_CAR(list), SCM_EOL); | |
00874d5f | 1525 | if (scm_is_true (call (pred, elt))) { |
65978fb2 KR |
1526 | SCM_SETCDR(kept_tail, new_tail); |
1527 | kept_tail = new_tail; | |
1528 | } | |
1529 | else { | |
1530 | SCM_SETCDR(dropped_tail, new_tail); | |
1531 | dropped_tail = new_tail; | |
1532 | } | |
1533 | } | |
1534 | /* re-use the initial conses for the values list */ | |
1535 | SCM_SETCAR(kept, SCM_CDR(kept)); | |
1536 | SCM_SETCDR(kept, dropped); | |
1537 | SCM_SETCAR(dropped, SCM_CDR(dropped)); | |
1538 | SCM_SETCDR(dropped, SCM_EOL); | |
1539 | return scm_values(kept); | |
1540 | } | |
1541 | #undef FUNC_NAME | |
1542 | ||
2b077051 KR |
1543 | |
1544 | SCM_DEFINE (scm_srfi1_partition_x, "partition!", 2, 0, 0, | |
1545 | (SCM pred, SCM lst), | |
1546 | "Split @var{lst} into those elements which do and don't satisfy\n" | |
1547 | "the predicate @var{pred}.\n" | |
1548 | "\n" | |
1549 | "The return is two values (@pxref{Multiple Values}), the first\n" | |
1550 | "being a list of all elements from @var{lst} which satisfy\n" | |
1551 | "@var{pred}, the second a list of those which do not.\n" | |
1552 | "\n" | |
1553 | "The elements in the result lists are in the same order as in\n" | |
1554 | "@var{lst} but the order in which the calls @code{(@var{pred}\n" | |
1555 | "elem)} are made on the list elements is unspecified.\n" | |
1556 | "\n" | |
1557 | "@var{lst} may be modified to construct the return lists.") | |
1558 | #define FUNC_NAME s_scm_srfi1_partition_x | |
1559 | { | |
1560 | SCM tlst, flst, *tp, *fp; | |
1561 | scm_t_trampoline_1 pred_tramp; | |
1562 | ||
1563 | pred_tramp = scm_trampoline_1 (pred); | |
1564 | SCM_ASSERT (pred_tramp, pred, SCM_ARG1, FUNC_NAME); | |
1565 | ||
1566 | /* tlst and flst are the lists of true and false elements. tp and fp are | |
1567 | where to store to append to them, initially &tlst and &flst, then | |
1568 | SCM_CDRLOC of the last pair in the respective lists. */ | |
1569 | ||
1570 | tlst = SCM_EOL; | |
1571 | flst = SCM_EOL; | |
1572 | tp = &tlst; | |
1573 | fp = &flst; | |
1574 | ||
1575 | for ( ; scm_is_pair (lst); lst = SCM_CDR (lst)) | |
1576 | { | |
1577 | if (scm_is_true (pred_tramp (pred, SCM_CAR (lst)))) | |
1578 | { | |
1579 | *tp = lst; | |
1580 | tp = SCM_CDRLOC (lst); | |
1581 | } | |
1582 | else | |
1583 | { | |
1584 | *fp = lst; | |
1585 | fp = SCM_CDRLOC (lst); | |
1586 | } | |
1587 | } | |
1588 | ||
1589 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, SCM_ARG2, FUNC_NAME, "list"); | |
1590 | ||
1591 | /* terminate whichever didn't get the last element(s) */ | |
1592 | *tp = SCM_EOL; | |
1593 | *fp = SCM_EOL; | |
1594 | ||
1595 | return scm_values (scm_list_2 (tlst, flst)); | |
1596 | } | |
1597 | #undef FUNC_NAME | |
1598 | ||
1599 | ||
597dbd4e KR |
1600 | SCM_DEFINE (scm_srfi1_reduce, "reduce", 3, 0, 0, |
1601 | (SCM proc, SCM def, SCM lst), | |
1602 | "@code{reduce} is a variant of @code{fold}, where the first call\n" | |
1603 | "to @var{proc} is on two elements from @var{lst}, rather than\n" | |
1604 | "one element and a given initial value.\n" | |
1605 | "\n" | |
1606 | "If @var{lst} is empty, @code{reduce} returns @var{def} (this is\n" | |
1607 | "the only use for @var{def}). If @var{lst} has just one element\n" | |
1608 | "then that's the return value. Otherwise @var{proc} is called\n" | |
1609 | "on the elements of @var{lst}.\n" | |
1610 | "\n" | |
1611 | "Each @var{proc} call is @code{(@var{proc} @var{elem}\n" | |
1612 | "@var{previous})}, where @var{elem} is from @var{lst} (the\n" | |
1613 | "second and subsequent elements of @var{lst}), and\n" | |
1614 | "@var{previous} is the return from the previous call to\n" | |
1615 | "@var{proc}. The first element of @var{lst} is the\n" | |
1616 | "@var{previous} for the first call to @var{proc}.\n" | |
1617 | "\n" | |
1618 | "For example, the following adds a list of numbers, the calls\n" | |
1619 | "made to @code{+} are shown. (Of course @code{+} accepts\n" | |
1620 | "multiple arguments and can add a list directly, with\n" | |
1621 | "@code{apply}.)\n" | |
1622 | "\n" | |
1623 | "@example\n" | |
1624 | "(reduce + 0 '(5 6 7)) @result{} 18\n" | |
1625 | "\n" | |
1626 | "(+ 6 5) @result{} 11\n" | |
1627 | "(+ 7 11) @result{} 18\n" | |
1628 | "@end example\n" | |
1629 | "\n" | |
1630 | "@code{reduce} can be used instead of @code{fold} where the\n" | |
1631 | "@var{init} value is an ``identity'', meaning a value which\n" | |
1632 | "under @var{proc} doesn't change the result, in this case 0 is\n" | |
1633 | "an identity since @code{(+ 5 0)} is just 5. @code{reduce}\n" | |
1634 | "avoids that unnecessary call.") | |
1635 | #define FUNC_NAME s_scm_srfi1_reduce | |
1636 | { | |
1637 | scm_t_trampoline_2 proc_tramp = scm_trampoline_2 (proc); | |
1638 | SCM ret; | |
1639 | ||
1640 | SCM_ASSERT (proc_tramp, proc, SCM_ARG1, FUNC_NAME); | |
1641 | ||
1642 | ret = def; /* if lst is empty */ | |
1643 | if (scm_is_pair (lst)) | |
1644 | { | |
1645 | ret = SCM_CAR (lst); /* if lst has one element */ | |
1646 | ||
1647 | for (lst = SCM_CDR (lst); scm_is_pair (lst); lst = SCM_CDR (lst)) | |
1648 | ret = proc_tramp (proc, SCM_CAR (lst), ret); | |
1649 | } | |
1650 | ||
1651 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, SCM_ARG3, FUNC_NAME, "list"); | |
1652 | return ret; | |
1653 | } | |
1654 | #undef FUNC_NAME | |
1655 | ||
1656 | ||
1657 | SCM_DEFINE (scm_srfi1_reduce_right, "reduce-right", 3, 0, 0, | |
1658 | (SCM proc, SCM def, SCM lst), | |
1659 | "@code{reduce-right} is a variant of @code{fold-right}, where\n" | |
1660 | "the first call to @var{proc} is on two elements from @var{lst},\n" | |
1661 | "rather than one element and a given initial value.\n" | |
1662 | "\n" | |
1663 | "If @var{lst} is empty, @code{reduce-right} returns @var{def}\n" | |
1664 | "(this is the only use for @var{def}). If @var{lst} has just\n" | |
1665 | "one element then that's the return value. Otherwise @var{proc}\n" | |
1666 | "is called on the elements of @var{lst}.\n" | |
1667 | "\n" | |
1668 | "Each @var{proc} call is @code{(@var{proc} @var{elem}\n" | |
1669 | "@var{previous})}, where @var{elem} is from @var{lst} (the\n" | |
1670 | "second last and then working back to the first element of\n" | |
1671 | "@var{lst}), and @var{previous} is the return from the previous\n" | |
1672 | "call to @var{proc}. The last element of @var{lst} is the\n" | |
1673 | "@var{previous} for the first call to @var{proc}.\n" | |
1674 | "\n" | |
1675 | "For example, the following adds a list of numbers, the calls\n" | |
1676 | "made to @code{+} are shown. (Of course @code{+} accepts\n" | |
1677 | "multiple arguments and can add a list directly, with\n" | |
1678 | "@code{apply}.)\n" | |
1679 | "\n" | |
1680 | "@example\n" | |
1681 | "(reduce-right + 0 '(5 6 7)) @result{} 18\n" | |
1682 | "\n" | |
1683 | "(+ 6 7) @result{} 13\n" | |
1684 | "(+ 5 13) @result{} 18\n" | |
1685 | "@end example\n" | |
1686 | "\n" | |
1687 | "@code{reduce-right} can be used instead of @code{fold-right}\n" | |
1688 | "where the @var{init} value is an ``identity'', meaning a value\n" | |
1689 | "which under @var{proc} doesn't change the result, in this case\n" | |
1690 | "0 is an identity since @code{(+ 7 0)} is just 5.\n" | |
1691 | "@code{reduce-right} avoids that unnecessary call.\n" | |
1692 | "\n" | |
1693 | "@code{reduce} should be preferred over @code{reduce-right} if\n" | |
1694 | "the order of processing doesn't matter, or can be arranged\n" | |
1695 | "either way, since @code{reduce} is a little more efficient.") | |
1696 | #define FUNC_NAME s_scm_srfi1_reduce_right | |
1697 | { | |
1698 | /* To work backwards across a list requires either repeatedly traversing | |
1699 | to get each previous element, or using some memory for a reversed or | |
1700 | random-access form. Repeated traversal might not be too terrible, but | |
1701 | is of course quadratic complexity and hence to be avoided in case LST | |
1702 | is long. A vector is preferred over a reversed list since it's more | |
1703 | compact and is less work for the gc to collect. */ | |
1704 | ||
1705 | scm_t_trampoline_2 proc_tramp = scm_trampoline_2 (proc); | |
1706 | SCM ret, vec; | |
1707 | long len, i; | |
1708 | ||
1709 | SCM_ASSERT (proc_tramp, proc, SCM_ARG1, FUNC_NAME); | |
1710 | ||
1711 | if (SCM_NULL_OR_NIL_P (lst)) | |
1712 | return def; | |
1713 | ||
1714 | vec = scm_vector (lst); | |
1715 | len = SCM_SIMPLE_VECTOR_LENGTH (vec); | |
1716 | ||
1717 | ret = SCM_SIMPLE_VECTOR_REF (vec, len-1); | |
1718 | for (i = len-2; i >= 0; i--) | |
1719 | ret = proc_tramp (proc, SCM_SIMPLE_VECTOR_REF (vec, i), ret); | |
1720 | ||
1721 | return ret; | |
1722 | } | |
1723 | #undef FUNC_NAME | |
1724 | ||
1725 | ||
59747b8d KR |
1726 | SCM_DEFINE (scm_srfi1_remove, "remove", 2, 0, 0, |
1727 | (SCM pred, SCM list), | |
1728 | "Return a list containing all elements from @var{lst} which do\n" | |
1729 | "not satisfy the predicate @var{pred}. The elements in the\n" | |
1730 | "result list have the same order as in @var{lst}. The order in\n" | |
1731 | "which @var{pred} is applied to the list elements is not\n" | |
1732 | "specified.") | |
1733 | #define FUNC_NAME s_scm_srfi1_remove | |
1734 | { | |
1735 | scm_t_trampoline_1 call = scm_trampoline_1 (pred); | |
1736 | SCM walk; | |
1737 | SCM *prev; | |
1738 | SCM res = SCM_EOL; | |
1739 | SCM_ASSERT (call, pred, 1, FUNC_NAME); | |
1740 | SCM_VALIDATE_LIST (2, list); | |
1741 | ||
1742 | for (prev = &res, walk = list; | |
1743 | scm_is_pair (walk); | |
1744 | walk = SCM_CDR (walk)) | |
1745 | { | |
1746 | if (scm_is_false (call (pred, SCM_CAR (walk)))) | |
1747 | { | |
1748 | *prev = scm_cons (SCM_CAR (walk), SCM_EOL); | |
1749 | prev = SCM_CDRLOC (*prev); | |
1750 | } | |
1751 | } | |
1752 | ||
1753 | return res; | |
1754 | } | |
1755 | #undef FUNC_NAME | |
1756 | ||
2b077051 KR |
1757 | |
1758 | SCM_DEFINE (scm_srfi1_remove_x, "remove!", 2, 0, 0, | |
1759 | (SCM pred, SCM list), | |
1760 | "Return a list containing all elements from @var{list} which do\n" | |
1761 | "not satisfy the predicate @var{pred}. The elements in the\n" | |
1762 | "result list have the same order as in @var{list}. The order in\n" | |
1763 | "which @var{pred} is applied to the list elements is not\n" | |
1764 | "specified. @var{list} may be modified to build the return\n" | |
1765 | "list.") | |
1766 | #define FUNC_NAME s_scm_srfi1_remove_x | |
1767 | { | |
1768 | scm_t_trampoline_1 call = scm_trampoline_1 (pred); | |
1769 | SCM walk; | |
1770 | SCM *prev; | |
1771 | SCM_ASSERT (call, pred, 1, FUNC_NAME); | |
1772 | SCM_VALIDATE_LIST (2, list); | |
1773 | ||
1774 | for (prev = &list, walk = list; | |
1775 | scm_is_pair (walk); | |
1776 | walk = SCM_CDR (walk)) | |
1777 | { | |
1778 | if (scm_is_false (call (pred, SCM_CAR (walk)))) | |
1779 | prev = SCM_CDRLOC (walk); | |
1780 | else | |
1781 | *prev = SCM_CDR (walk); | |
1782 | } | |
1783 | ||
1784 | return list; | |
1785 | } | |
1786 | #undef FUNC_NAME | |
1787 | ||
1788 | ||
03731332 KR |
1789 | SCM_DEFINE (scm_srfi1_seventh, "seventh", 1, 0, 0, |
1790 | (SCM lst), | |
1791 | "Return the seventh element of @var{lst}.") | |
1792 | #define FUNC_NAME s_scm_srfi1_seventh | |
1793 | { | |
b730fbf1 | 1794 | return scm_list_ref (lst, scm_from_int (6)); |
03731332 KR |
1795 | } |
1796 | #undef FUNC_NAME | |
1797 | ||
1798 | ||
1799 | SCM_DEFINE (scm_srfi1_sixth, "sixth", 1, 0, 0, | |
1800 | (SCM lst), | |
1801 | "Return the sixth element of @var{lst}.") | |
1802 | #define FUNC_NAME s_scm_srfi1_sixth | |
1803 | { | |
b730fbf1 | 1804 | return scm_list_ref (lst, scm_from_int (5)); |
03731332 KR |
1805 | } |
1806 | #undef FUNC_NAME | |
1807 | ||
1808 | ||
597dbd4e KR |
1809 | SCM_DEFINE (scm_srfi1_span, "span", 2, 0, 0, |
1810 | (SCM pred, SCM lst), | |
1811 | "Return two values, the longest initial prefix of @var{lst}\n" | |
1812 | "whose elements all satisfy the predicate @var{pred}, and the\n" | |
1813 | "remainder of @var{lst}.") | |
1814 | #define FUNC_NAME s_scm_srfi1_span | |
1815 | { | |
1816 | scm_t_trampoline_1 pred_tramp; | |
1817 | SCM ret, *p; | |
1818 | ||
1819 | pred_tramp = scm_trampoline_1 (pred); | |
1820 | SCM_ASSERT (pred_tramp, pred, SCM_ARG1, FUNC_NAME); | |
1821 | ||
1822 | ret = SCM_EOL; | |
1823 | p = &ret; | |
1824 | for ( ; scm_is_pair (lst); lst = SCM_CDR (lst)) | |
1825 | { | |
1826 | SCM elem = SCM_CAR (lst); | |
1827 | if (scm_is_false (pred_tramp (pred, elem))) | |
1828 | goto done; | |
1829 | ||
1830 | /* want this elem, tack it onto the end of ret */ | |
1831 | *p = scm_cons (elem, SCM_EOL); | |
1832 | p = SCM_CDRLOC (*p); | |
1833 | } | |
1834 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, SCM_ARG2, FUNC_NAME, "list"); | |
1835 | ||
1836 | done: | |
1837 | return scm_values (scm_list_2 (ret, lst)); | |
1838 | } | |
1839 | #undef FUNC_NAME | |
1840 | ||
1841 | ||
1842 | SCM_DEFINE (scm_srfi1_span_x, "span!", 2, 0, 0, | |
1843 | (SCM pred, SCM lst), | |
1844 | "Return two values, the longest initial prefix of @var{lst}\n" | |
1845 | "whose elements all satisfy the predicate @var{pred}, and the\n" | |
1846 | "remainder of @var{lst}. @var{lst} may be modified to form the\n" | |
1847 | "return.") | |
1848 | #define FUNC_NAME s_scm_srfi1_span_x | |
1849 | { | |
1850 | SCM upto, *p; | |
1851 | scm_t_trampoline_1 pred_tramp; | |
1852 | ||
1853 | pred_tramp = scm_trampoline_1 (pred); | |
1854 | SCM_ASSERT (pred_tramp, pred, SCM_ARG1, FUNC_NAME); | |
1855 | ||
1856 | p = &lst; | |
1857 | for (upto = lst; scm_is_pair (upto); upto = SCM_CDR (upto)) | |
1858 | { | |
1859 | if (scm_is_false (pred_tramp (pred, SCM_CAR (upto)))) | |
1860 | goto done; | |
1861 | ||
1862 | /* want this element */ | |
1863 | p = SCM_CDRLOC (upto); | |
1864 | } | |
1865 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (upto), lst, SCM_ARG2, FUNC_NAME, "list"); | |
1866 | ||
1867 | done: | |
1868 | *p = SCM_EOL; | |
1869 | return scm_values (scm_list_2 (lst, upto)); | |
1870 | } | |
1871 | #undef FUNC_NAME | |
1872 | ||
1873 | ||
d2f57ee0 KR |
1874 | SCM_DEFINE (scm_srfi1_split_at, "split-at", 2, 0, 0, |
1875 | (SCM lst, SCM n), | |
1876 | "Return two values (multiple values), being a list of the\n" | |
1877 | "elements before index @var{n} in @var{lst}, and a list of those\n" | |
1878 | "after.") | |
1879 | #define FUNC_NAME s_scm_srfi1_split_at | |
1880 | { | |
1881 | size_t nn; | |
1882 | /* pre is a list of elements before the i split point, loc is the CDRLOC | |
1883 | of the last cell, ie. where to store to append to it */ | |
1884 | SCM pre = SCM_EOL; | |
1885 | SCM *loc = ⪯ | |
1886 | ||
1887 | for (nn = scm_to_size_t (n); nn != 0; nn--) | |
1888 | { | |
1889 | SCM_VALIDATE_CONS (SCM_ARG1, lst); | |
1890 | ||
1891 | *loc = scm_cons (SCM_CAR (lst), SCM_EOL); | |
1892 | loc = SCM_CDRLOC (*loc); | |
1893 | lst = SCM_CDR(lst); | |
1894 | } | |
1895 | return scm_values (scm_list_2 (pre, lst)); | |
1896 | } | |
1897 | #undef FUNC_NAME | |
1898 | ||
1899 | ||
1900 | SCM_DEFINE (scm_srfi1_split_at_x, "split-at!", 2, 0, 0, | |
1901 | (SCM lst, SCM n), | |
1902 | "Return two values (multiple values), being a list of the\n" | |
1903 | "elements before index @var{n} in @var{lst}, and a list of those\n" | |
1904 | "after. @var{lst} is modified to form those values.") | |
1905 | #define FUNC_NAME s_scm_srfi1_split_at | |
1906 | { | |
1907 | size_t nn; | |
1908 | SCM upto = lst; | |
1909 | SCM *loc = &lst; | |
1910 | ||
1911 | for (nn = scm_to_size_t (n); nn != 0; nn--) | |
1912 | { | |
1913 | SCM_VALIDATE_CONS (SCM_ARG1, upto); | |
1914 | ||
1915 | loc = SCM_CDRLOC (upto); | |
1916 | upto = SCM_CDR (upto); | |
1917 | } | |
1918 | ||
1919 | *loc = SCM_EOL; | |
1920 | return scm_values (scm_list_2 (lst, upto)); | |
1921 | } | |
1922 | #undef FUNC_NAME | |
1923 | ||
1924 | ||
597dbd4e KR |
1925 | SCM_DEFINE (scm_srfi1_take_x, "take!", 2, 0, 0, |
1926 | (SCM lst, SCM n), | |
1927 | "Return a list containing the first @var{n} elements of\n" | |
1928 | "@var{lst}.") | |
1929 | #define FUNC_NAME s_scm_srfi1_take_x | |
1930 | { | |
1931 | long nn; | |
1932 | SCM pos; | |
1933 | ||
b730fbf1 | 1934 | nn = scm_to_signed_integer (n, 0, LONG_MAX); |
597dbd4e KR |
1935 | if (nn == 0) |
1936 | return SCM_EOL; | |
1937 | ||
b730fbf1 | 1938 | pos = scm_list_tail (lst, scm_from_long (nn - 1)); |
597dbd4e KR |
1939 | |
1940 | /* Must have at least one cell left, mustn't have reached the end of an | |
1941 | n-1 element list. SCM_VALIDATE_CONS here gives the same error as | |
1942 | scm_list_tail does on say an n-2 element list, though perhaps a range | |
1943 | error would make more sense (for both). */ | |
1944 | SCM_VALIDATE_CONS (SCM_ARG1, pos); | |
1945 | ||
1946 | SCM_SETCDR (pos, SCM_EOL); | |
1947 | return lst; | |
1948 | } | |
1949 | #undef FUNC_NAME | |
1950 | ||
1951 | ||
2b077051 KR |
1952 | SCM_DEFINE (scm_srfi1_take_right, "take-right", 2, 0, 0, |
1953 | (SCM lst, SCM n), | |
1954 | "Return the a list containing the @var{n} last elements of\n" | |
1955 | "@var{lst}.") | |
1956 | #define FUNC_NAME s_scm_srfi1_take_right | |
1957 | { | |
1958 | SCM tail = scm_list_tail (lst, n); | |
1959 | while (scm_is_pair (tail)) | |
1960 | { | |
1961 | lst = SCM_CDR (lst); | |
1962 | tail = SCM_CDR (tail); | |
1963 | } | |
1964 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P(tail), tail, SCM_ARG1, FUNC_NAME, "list"); | |
1965 | return lst; | |
1966 | } | |
1967 | #undef FUNC_NAME | |
1968 | ||
1969 | ||
597dbd4e KR |
1970 | SCM_DEFINE (scm_srfi1_take_while, "take-while", 2, 0, 0, |
1971 | (SCM pred, SCM lst), | |
1972 | "Return a new list which is the longest initial prefix of\n" | |
1973 | "@var{lst} whose elements all satisfy the predicate @var{pred}.") | |
1974 | #define FUNC_NAME s_scm_srfi1_take_while | |
1975 | { | |
1976 | scm_t_trampoline_1 pred_tramp; | |
1977 | SCM ret, *p; | |
1978 | ||
1979 | pred_tramp = scm_trampoline_1 (pred); | |
1980 | SCM_ASSERT (pred_tramp, pred, SCM_ARG1, FUNC_NAME); | |
1981 | ||
1982 | ret = SCM_EOL; | |
1983 | p = &ret; | |
1984 | for ( ; scm_is_pair (lst); lst = SCM_CDR (lst)) | |
1985 | { | |
1986 | SCM elem = SCM_CAR (lst); | |
1987 | if (scm_is_false (pred_tramp (pred, elem))) | |
1988 | goto done; | |
1989 | ||
1990 | /* want this elem, tack it onto the end of ret */ | |
1991 | *p = scm_cons (elem, SCM_EOL); | |
1992 | p = SCM_CDRLOC (*p); | |
1993 | } | |
1994 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (lst), lst, SCM_ARG2, FUNC_NAME, "list"); | |
1995 | ||
1996 | done: | |
1997 | return ret; | |
1998 | } | |
1999 | #undef FUNC_NAME | |
2000 | ||
2001 | ||
2002 | SCM_DEFINE (scm_srfi1_take_while_x, "take-while!", 2, 0, 0, | |
2003 | (SCM pred, SCM lst), | |
2004 | "Return the longest initial prefix of @var{lst} whose elements\n" | |
2005 | "all satisfy the predicate @var{pred}. @var{lst} may be\n" | |
2006 | "modified to form the return.") | |
2007 | #define FUNC_NAME s_scm_srfi1_take_while_x | |
2008 | { | |
2009 | SCM upto, *p; | |
2010 | scm_t_trampoline_1 pred_tramp; | |
2011 | ||
2012 | pred_tramp = scm_trampoline_1 (pred); | |
2013 | SCM_ASSERT (pred_tramp, pred, SCM_ARG1, FUNC_NAME); | |
2014 | ||
2015 | p = &lst; | |
2016 | for (upto = lst; scm_is_pair (upto); upto = SCM_CDR (upto)) | |
2017 | { | |
2018 | if (scm_is_false (pred_tramp (pred, SCM_CAR (upto)))) | |
2019 | goto done; | |
2020 | ||
2021 | /* want this element */ | |
2022 | p = SCM_CDRLOC (upto); | |
2023 | } | |
2024 | SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (upto), lst, SCM_ARG2, FUNC_NAME, "list"); | |
2025 | ||
2026 | done: | |
2027 | *p = SCM_EOL; | |
2028 | return lst; | |
2029 | } | |
2030 | #undef FUNC_NAME | |
2031 | ||
2032 | ||
03731332 KR |
2033 | SCM_DEFINE (scm_srfi1_tenth, "tenth", 1, 0, 0, |
2034 | (SCM lst), | |
2035 | "Return the tenth element of @var{lst}.") | |
2036 | #define FUNC_NAME s_scm_srfi1_tenth | |
2037 | { | |
b730fbf1 | 2038 | return scm_list_ref (lst, scm_from_int (9)); |
03731332 KR |
2039 | } |
2040 | #undef FUNC_NAME | |
2041 | ||
2042 | ||
e556f8c3 KR |
2043 | SCM_DEFINE (scm_srfi1_xcons, "xcons", 2, 0, 0, |
2044 | (SCM d, SCM a), | |
2045 | "Like @code{cons}, but with interchanged arguments. Useful\n" | |
2046 | "mostly when passed to higher-order procedures.") | |
2047 | #define FUNC_NAME s_scm_srfi1_xcons | |
2048 | { | |
2049 | return scm_cons (a, d); | |
2050 | } | |
2051 | #undef FUNC_NAME | |
2052 | ||
2053 | ||
ee6aac97 MD |
2054 | void |
2055 | scm_init_srfi_1 (void) | |
2056 | { | |
a48d60b1 | 2057 | SCM the_root_module = scm_lookup_closure_module (SCM_BOOL_F); |
ee6aac97 MD |
2058 | #ifndef SCM_MAGIC_SNARFER |
2059 | #include "srfi/srfi-1.x" | |
2060 | #endif | |
a48d60b1 MD |
2061 | scm_c_extend_primitive_generic |
2062 | (SCM_VARIABLE_REF (scm_c_module_lookup (the_root_module, "map")), | |
2063 | SCM_VARIABLE_REF (scm_c_lookup ("map"))); | |
2064 | scm_c_extend_primitive_generic | |
2065 | (SCM_VARIABLE_REF (scm_c_module_lookup (the_root_module, "for-each")), | |
2066 | SCM_VARIABLE_REF (scm_c_lookup ("for-each"))); | |
ee6aac97 MD |
2067 | } |
2068 | ||
2069 | /* End of srfi-1.c. */ |