| 1 | /* Copyright (C) 1999,2000,2001,2002, 2004, 2006, 2007, 2008, 2009 Free Software Foundation, Inc. |
| 2 | * This library is free software; you can redistribute it and/or |
| 3 | * modify it under the terms of the GNU Lesser General Public License |
| 4 | * as published by the Free Software Foundation; either version 3 of |
| 5 | * the License, or (at your option) any later version. |
| 6 | * |
| 7 | * This library is distributed in the hope that it will be useful, but |
| 8 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 10 | * Lesser General Public License for more details. |
| 11 | * |
| 12 | * You should have received a copy of the GNU Lesser General Public |
| 13 | * License along with this library; if not, write to the Free Software |
| 14 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 15 | * 02110-1301 USA |
| 16 | */ |
| 17 | |
| 18 | |
| 19 | |
| 20 | /* Written in December 1998 by Roland Orre <orre@nada.kth.se> |
| 21 | * This implements the same sort interface as slib/sort.scm |
| 22 | * for lists and vectors where slib defines: |
| 23 | * sorted?, merge, merge!, sort, sort! |
| 24 | * For scsh compatibility sort-list and sort-list! are also defined. |
| 25 | * In cases where a stable-sort is required use stable-sort or |
| 26 | * stable-sort!. An additional feature is |
| 27 | * (restricted-vector-sort! vector less? startpos endpos) |
| 28 | * which allows you to sort part of a vector. |
| 29 | * Thanks to Aubrey Jaffer for the slib/sort.scm library. |
| 30 | * Thanks to Richard A. O'Keefe (based on Prolog code by D.H.D.Warren) |
| 31 | * for the merge sort inspiration. |
| 32 | * Thanks to Douglas C. Schmidt (schmidt@ics.uci.edu) for the |
| 33 | * quicksort code. |
| 34 | */ |
| 35 | |
| 36 | #ifdef HAVE_CONFIG_H |
| 37 | # include <config.h> |
| 38 | #endif |
| 39 | |
| 40 | #include "libguile/_scm.h" |
| 41 | #include "libguile/eval.h" |
| 42 | #include "libguile/arrays.h" |
| 43 | #include "libguile/array-map.h" |
| 44 | #include "libguile/feature.h" |
| 45 | #include "libguile/vectors.h" |
| 46 | #include "libguile/lang.h" |
| 47 | #include "libguile/async.h" |
| 48 | #include "libguile/dynwind.h" |
| 49 | |
| 50 | #include "libguile/validate.h" |
| 51 | #include "libguile/sort.h" |
| 52 | |
| 53 | /* We have two quicksort variants: one for contigous vectors and one |
| 54 | for vectors with arbitrary increments between elements. Note that |
| 55 | increments can be negative. |
| 56 | */ |
| 57 | |
| 58 | #define NAME quicksort1 |
| 59 | #define INC_PARAM /* empty */ |
| 60 | #define INC 1 |
| 61 | #include "libguile/quicksort.i.c" |
| 62 | |
| 63 | #define NAME quicksort |
| 64 | #define INC_PARAM ssize_t inc, |
| 65 | #define INC inc |
| 66 | #include "libguile/quicksort.i.c" |
| 67 | |
| 68 | static scm_t_trampoline_2 |
| 69 | compare_function (SCM less, unsigned int arg_nr, const char* fname) |
| 70 | { |
| 71 | const scm_t_trampoline_2 cmp = scm_trampoline_2 (less); |
| 72 | SCM_ASSERT_TYPE (cmp != NULL, less, arg_nr, fname, "less predicate"); |
| 73 | return cmp; |
| 74 | } |
| 75 | |
| 76 | |
| 77 | SCM_DEFINE (scm_restricted_vector_sort_x, "restricted-vector-sort!", 4, 0, 0, |
| 78 | (SCM vec, SCM less, SCM startpos, SCM endpos), |
| 79 | "Sort the vector @var{vec}, using @var{less} for comparing\n" |
| 80 | "the vector elements. @var{startpos} (inclusively) and\n" |
| 81 | "@var{endpos} (exclusively) delimit\n" |
| 82 | "the range of the vector which gets sorted. The return value\n" |
| 83 | "is not specified.") |
| 84 | #define FUNC_NAME s_scm_restricted_vector_sort_x |
| 85 | { |
| 86 | const scm_t_trampoline_2 cmp = compare_function (less, 2, FUNC_NAME); |
| 87 | size_t vlen, spos, len; |
| 88 | ssize_t vinc; |
| 89 | scm_t_array_handle handle; |
| 90 | SCM *velts; |
| 91 | |
| 92 | velts = scm_vector_writable_elements (vec, &handle, &vlen, &vinc); |
| 93 | spos = scm_to_unsigned_integer (startpos, 0, vlen); |
| 94 | len = scm_to_unsigned_integer (endpos, spos, vlen) - spos; |
| 95 | |
| 96 | if (vinc == 1) |
| 97 | quicksort1 (velts + spos*vinc, len, cmp, less); |
| 98 | else |
| 99 | quicksort (velts + spos*vinc, len, vinc, cmp, less); |
| 100 | |
| 101 | scm_array_handle_release (&handle); |
| 102 | |
| 103 | return SCM_UNSPECIFIED; |
| 104 | } |
| 105 | #undef FUNC_NAME |
| 106 | |
| 107 | |
| 108 | /* (sorted? sequence less?) |
| 109 | * is true when sequence is a list (x0 x1 ... xm) or a vector #(x0 ... xm) |
| 110 | * such that for all 1 <= i <= m, |
| 111 | * (not (less? (list-ref list i) (list-ref list (- i 1)))). */ |
| 112 | SCM_DEFINE (scm_sorted_p, "sorted?", 2, 0, 0, |
| 113 | (SCM items, SCM less), |
| 114 | "Return @code{#t} iff @var{items} is a list or a vector such that\n" |
| 115 | "for all 1 <= i <= m, the predicate @var{less} returns true when\n" |
| 116 | "applied to all elements i - 1 and i") |
| 117 | #define FUNC_NAME s_scm_sorted_p |
| 118 | { |
| 119 | const scm_t_trampoline_2 cmp = compare_function (less, 2, FUNC_NAME); |
| 120 | long len, j; /* list/vector length, temp j */ |
| 121 | SCM item, rest; /* rest of items loop variable */ |
| 122 | |
| 123 | if (SCM_NULL_OR_NIL_P (items)) |
| 124 | return SCM_BOOL_T; |
| 125 | |
| 126 | if (scm_is_pair (items)) |
| 127 | { |
| 128 | len = scm_ilength (items); /* also checks that it's a pure list */ |
| 129 | SCM_ASSERT_RANGE (1, items, len >= 0); |
| 130 | if (len <= 1) |
| 131 | return SCM_BOOL_T; |
| 132 | |
| 133 | item = SCM_CAR (items); |
| 134 | rest = SCM_CDR (items); |
| 135 | j = len - 1; |
| 136 | while (j > 0) |
| 137 | { |
| 138 | if (scm_is_true ((*cmp) (less, SCM_CAR (rest), item))) |
| 139 | return SCM_BOOL_F; |
| 140 | else |
| 141 | { |
| 142 | item = SCM_CAR (rest); |
| 143 | rest = SCM_CDR (rest); |
| 144 | j--; |
| 145 | } |
| 146 | } |
| 147 | return SCM_BOOL_T; |
| 148 | } |
| 149 | else |
| 150 | { |
| 151 | scm_t_array_handle handle; |
| 152 | size_t i, len; |
| 153 | ssize_t inc; |
| 154 | const SCM *elts; |
| 155 | SCM result = SCM_BOOL_T; |
| 156 | |
| 157 | elts = scm_vector_elements (items, &handle, &len, &inc); |
| 158 | |
| 159 | for (i = 1; i < len; i++, elts += inc) |
| 160 | { |
| 161 | if (scm_is_true ((*cmp) (less, elts[inc], elts[0]))) |
| 162 | { |
| 163 | result = SCM_BOOL_F; |
| 164 | break; |
| 165 | } |
| 166 | } |
| 167 | |
| 168 | scm_array_handle_release (&handle); |
| 169 | |
| 170 | return result; |
| 171 | } |
| 172 | |
| 173 | return SCM_BOOL_F; |
| 174 | } |
| 175 | #undef FUNC_NAME |
| 176 | |
| 177 | |
| 178 | /* (merge a b less?) |
| 179 | takes two lists a and b such that (sorted? a less?) and (sorted? b less?) |
| 180 | and returns a new list in which the elements of a and b have been stably |
| 181 | interleaved so that (sorted? (merge a b less?) less?). |
| 182 | Note: this does _not_ accept vectors. */ |
| 183 | SCM_DEFINE (scm_merge, "merge", 3, 0, 0, |
| 184 | (SCM alist, SCM blist, SCM less), |
| 185 | "Merge two already sorted lists into one.\n" |
| 186 | "Given two lists @var{alist} and @var{blist}, such that\n" |
| 187 | "@code{(sorted? alist less?)} and @code{(sorted? blist less?)},\n" |
| 188 | "return a new list in which the elements of @var{alist} and\n" |
| 189 | "@var{blist} have been stably interleaved so that\n" |
| 190 | "@code{(sorted? (merge alist blist less?) less?)}.\n" |
| 191 | "Note: this does _not_ accept vectors.") |
| 192 | #define FUNC_NAME s_scm_merge |
| 193 | { |
| 194 | SCM build; |
| 195 | |
| 196 | if (SCM_NULL_OR_NIL_P (alist)) |
| 197 | return blist; |
| 198 | else if (SCM_NULL_OR_NIL_P (blist)) |
| 199 | return alist; |
| 200 | else |
| 201 | { |
| 202 | const scm_t_trampoline_2 cmp = compare_function (less, 3, FUNC_NAME); |
| 203 | long alen, blen; /* list lengths */ |
| 204 | SCM last; |
| 205 | |
| 206 | SCM_VALIDATE_NONEMPTYLIST_COPYLEN (1, alist, alen); |
| 207 | SCM_VALIDATE_NONEMPTYLIST_COPYLEN (2, blist, blen); |
| 208 | if (scm_is_true ((*cmp) (less, SCM_CAR (blist), SCM_CAR (alist)))) |
| 209 | { |
| 210 | build = scm_cons (SCM_CAR (blist), SCM_EOL); |
| 211 | blist = SCM_CDR (blist); |
| 212 | blen--; |
| 213 | } |
| 214 | else |
| 215 | { |
| 216 | build = scm_cons (SCM_CAR (alist), SCM_EOL); |
| 217 | alist = SCM_CDR (alist); |
| 218 | alen--; |
| 219 | } |
| 220 | last = build; |
| 221 | while ((alen > 0) && (blen > 0)) |
| 222 | { |
| 223 | SCM_TICK; |
| 224 | if (scm_is_true ((*cmp) (less, SCM_CAR (blist), SCM_CAR (alist)))) |
| 225 | { |
| 226 | SCM_SETCDR (last, scm_cons (SCM_CAR (blist), SCM_EOL)); |
| 227 | blist = SCM_CDR (blist); |
| 228 | blen--; |
| 229 | } |
| 230 | else |
| 231 | { |
| 232 | SCM_SETCDR (last, scm_cons (SCM_CAR (alist), SCM_EOL)); |
| 233 | alist = SCM_CDR (alist); |
| 234 | alen--; |
| 235 | } |
| 236 | last = SCM_CDR (last); |
| 237 | } |
| 238 | if ((alen > 0) && (blen == 0)) |
| 239 | SCM_SETCDR (last, alist); |
| 240 | else if ((alen == 0) && (blen > 0)) |
| 241 | SCM_SETCDR (last, blist); |
| 242 | } |
| 243 | return build; |
| 244 | } |
| 245 | #undef FUNC_NAME |
| 246 | |
| 247 | |
| 248 | static SCM |
| 249 | scm_merge_list_x (SCM alist, SCM blist, |
| 250 | long alen, long blen, |
| 251 | scm_t_trampoline_2 cmp, SCM less) |
| 252 | { |
| 253 | SCM build, last; |
| 254 | |
| 255 | if (SCM_NULL_OR_NIL_P (alist)) |
| 256 | return blist; |
| 257 | else if (SCM_NULL_OR_NIL_P (blist)) |
| 258 | return alist; |
| 259 | else |
| 260 | { |
| 261 | if (scm_is_true ((*cmp) (less, SCM_CAR (blist), SCM_CAR (alist)))) |
| 262 | { |
| 263 | build = blist; |
| 264 | blist = SCM_CDR (blist); |
| 265 | blen--; |
| 266 | } |
| 267 | else |
| 268 | { |
| 269 | build = alist; |
| 270 | alist = SCM_CDR (alist); |
| 271 | alen--; |
| 272 | } |
| 273 | last = build; |
| 274 | while ((alen > 0) && (blen > 0)) |
| 275 | { |
| 276 | SCM_TICK; |
| 277 | if (scm_is_true ((*cmp) (less, SCM_CAR (blist), SCM_CAR (alist)))) |
| 278 | { |
| 279 | SCM_SETCDR (last, blist); |
| 280 | blist = SCM_CDR (blist); |
| 281 | blen--; |
| 282 | } |
| 283 | else |
| 284 | { |
| 285 | SCM_SETCDR (last, alist); |
| 286 | alist = SCM_CDR (alist); |
| 287 | alen--; |
| 288 | } |
| 289 | last = SCM_CDR (last); |
| 290 | } |
| 291 | if ((alen > 0) && (blen == 0)) |
| 292 | SCM_SETCDR (last, alist); |
| 293 | else if ((alen == 0) && (blen > 0)) |
| 294 | SCM_SETCDR (last, blist); |
| 295 | } |
| 296 | return build; |
| 297 | } /* scm_merge_list_x */ |
| 298 | |
| 299 | |
| 300 | SCM_DEFINE (scm_merge_x, "merge!", 3, 0, 0, |
| 301 | (SCM alist, SCM blist, SCM less), |
| 302 | "Takes two lists @var{alist} and @var{blist} such that\n" |
| 303 | "@code{(sorted? alist less?)} and @code{(sorted? blist less?)} and\n" |
| 304 | "returns a new list in which the elements of @var{alist} and\n" |
| 305 | "@var{blist} have been stably interleaved so that\n" |
| 306 | " @code{(sorted? (merge alist blist less?) less?)}.\n" |
| 307 | "This is the destructive variant of @code{merge}\n" |
| 308 | "Note: this does _not_ accept vectors.") |
| 309 | #define FUNC_NAME s_scm_merge_x |
| 310 | { |
| 311 | if (SCM_NULL_OR_NIL_P (alist)) |
| 312 | return blist; |
| 313 | else if (SCM_NULL_OR_NIL_P (blist)) |
| 314 | return alist; |
| 315 | else |
| 316 | { |
| 317 | const scm_t_trampoline_2 cmp = compare_function (less, 3, FUNC_NAME); |
| 318 | long alen, blen; /* list lengths */ |
| 319 | SCM_VALIDATE_NONEMPTYLIST_COPYLEN (1, alist, alen); |
| 320 | SCM_VALIDATE_NONEMPTYLIST_COPYLEN (2, blist, blen); |
| 321 | return scm_merge_list_x (alist, blist, alen, blen, cmp, less); |
| 322 | } |
| 323 | } |
| 324 | #undef FUNC_NAME |
| 325 | |
| 326 | |
| 327 | /* This merge sort algorithm is same as slib's by Richard A. O'Keefe. |
| 328 | The algorithm is stable. We also tried to use the algorithm used by |
| 329 | scsh's merge-sort but that algorithm showed to not be stable, even |
| 330 | though it claimed to be. |
| 331 | */ |
| 332 | static SCM |
| 333 | scm_merge_list_step (SCM * seq, scm_t_trampoline_2 cmp, SCM less, long n) |
| 334 | { |
| 335 | SCM a, b; |
| 336 | |
| 337 | if (n > 2) |
| 338 | { |
| 339 | long mid = n / 2; |
| 340 | SCM_TICK; |
| 341 | a = scm_merge_list_step (seq, cmp, less, mid); |
| 342 | b = scm_merge_list_step (seq, cmp, less, n - mid); |
| 343 | return scm_merge_list_x (a, b, mid, n - mid, cmp, less); |
| 344 | } |
| 345 | else if (n == 2) |
| 346 | { |
| 347 | SCM p = *seq; |
| 348 | SCM rest = SCM_CDR (*seq); |
| 349 | SCM x = SCM_CAR (*seq); |
| 350 | SCM y = SCM_CAR (SCM_CDR (*seq)); |
| 351 | *seq = SCM_CDR (rest); |
| 352 | SCM_SETCDR (rest, SCM_EOL); |
| 353 | if (scm_is_true ((*cmp) (less, y, x))) |
| 354 | { |
| 355 | SCM_SETCAR (p, y); |
| 356 | SCM_SETCAR (rest, x); |
| 357 | } |
| 358 | return p; |
| 359 | } |
| 360 | else if (n == 1) |
| 361 | { |
| 362 | SCM p = *seq; |
| 363 | *seq = SCM_CDR (p); |
| 364 | SCM_SETCDR (p, SCM_EOL); |
| 365 | return p; |
| 366 | } |
| 367 | else |
| 368 | return SCM_EOL; |
| 369 | } /* scm_merge_list_step */ |
| 370 | |
| 371 | |
| 372 | SCM_DEFINE (scm_sort_x, "sort!", 2, 0, 0, |
| 373 | (SCM items, SCM less), |
| 374 | "Sort the sequence @var{items}, which may be a list or a\n" |
| 375 | "vector. @var{less} is used for comparing the sequence\n" |
| 376 | "elements. The sorting is destructive, that means that the\n" |
| 377 | "input sequence is modified to produce the sorted result.\n" |
| 378 | "This is not a stable sort.") |
| 379 | #define FUNC_NAME s_scm_sort_x |
| 380 | { |
| 381 | long len; /* list/vector length */ |
| 382 | if (SCM_NULL_OR_NIL_P (items)) |
| 383 | return items; |
| 384 | |
| 385 | if (scm_is_pair (items)) |
| 386 | { |
| 387 | const scm_t_trampoline_2 cmp = compare_function (less, 2, FUNC_NAME); |
| 388 | SCM_VALIDATE_LIST_COPYLEN (1, items, len); |
| 389 | return scm_merge_list_step (&items, cmp, less, len); |
| 390 | } |
| 391 | else if (scm_is_vector (items)) |
| 392 | { |
| 393 | scm_restricted_vector_sort_x (items, |
| 394 | less, |
| 395 | scm_from_int (0), |
| 396 | scm_vector_length (items)); |
| 397 | return items; |
| 398 | } |
| 399 | else |
| 400 | SCM_WRONG_TYPE_ARG (1, items); |
| 401 | } |
| 402 | #undef FUNC_NAME |
| 403 | |
| 404 | |
| 405 | SCM_DEFINE (scm_sort, "sort", 2, 0, 0, |
| 406 | (SCM items, SCM less), |
| 407 | "Sort the sequence @var{items}, which may be a list or a\n" |
| 408 | "vector. @var{less} is used for comparing the sequence\n" |
| 409 | "elements. This is not a stable sort.") |
| 410 | #define FUNC_NAME s_scm_sort |
| 411 | { |
| 412 | if (SCM_NULL_OR_NIL_P (items)) |
| 413 | return items; |
| 414 | |
| 415 | if (scm_is_pair (items)) |
| 416 | return scm_sort_x (scm_list_copy (items), less); |
| 417 | else if (scm_is_vector (items)) |
| 418 | return scm_sort_x (scm_vector_copy (items), less); |
| 419 | else |
| 420 | SCM_WRONG_TYPE_ARG (1, items); |
| 421 | } |
| 422 | #undef FUNC_NAME |
| 423 | |
| 424 | |
| 425 | static void |
| 426 | scm_merge_vector_x (SCM *vec, |
| 427 | SCM *temp, |
| 428 | scm_t_trampoline_2 cmp, |
| 429 | SCM less, |
| 430 | size_t low, |
| 431 | size_t mid, |
| 432 | size_t high, |
| 433 | ssize_t inc) |
| 434 | { |
| 435 | size_t it; /* Index for temp vector */ |
| 436 | size_t i1 = low; /* Index for lower vector segment */ |
| 437 | size_t i2 = mid + 1; /* Index for upper vector segment */ |
| 438 | |
| 439 | #define VEC(i) vec[(i)*inc] |
| 440 | |
| 441 | /* Copy while both segments contain more characters */ |
| 442 | for (it = low; (i1 <= mid) && (i2 <= high); ++it) |
| 443 | { |
| 444 | if (scm_is_true ((*cmp) (less, VEC(i2), VEC(i1)))) |
| 445 | temp[it] = VEC(i2++); |
| 446 | else |
| 447 | temp[it] = VEC(i1++); |
| 448 | } |
| 449 | |
| 450 | { |
| 451 | /* Copy while first segment contains more characters */ |
| 452 | while (i1 <= mid) |
| 453 | temp[it++] = VEC(i1++); |
| 454 | |
| 455 | /* Copy while second segment contains more characters */ |
| 456 | while (i2 <= high) |
| 457 | temp[it++] = VEC(i2++); |
| 458 | |
| 459 | /* Copy back from temp to vp */ |
| 460 | for (it = low; it <= high; it++) |
| 461 | VEC(it) = temp[it]; |
| 462 | } |
| 463 | } /* scm_merge_vector_x */ |
| 464 | |
| 465 | |
| 466 | static void |
| 467 | scm_merge_vector_step (SCM *vec, |
| 468 | SCM *temp, |
| 469 | scm_t_trampoline_2 cmp, |
| 470 | SCM less, |
| 471 | size_t low, |
| 472 | size_t high, |
| 473 | ssize_t inc) |
| 474 | { |
| 475 | if (high > low) |
| 476 | { |
| 477 | size_t mid = (low + high) / 2; |
| 478 | SCM_TICK; |
| 479 | scm_merge_vector_step (vec, temp, cmp, less, low, mid, inc); |
| 480 | scm_merge_vector_step (vec, temp, cmp, less, mid+1, high, inc); |
| 481 | scm_merge_vector_x (vec, temp, cmp, less, low, mid, high, inc); |
| 482 | } |
| 483 | } /* scm_merge_vector_step */ |
| 484 | |
| 485 | |
| 486 | SCM_DEFINE (scm_stable_sort_x, "stable-sort!", 2, 0, 0, |
| 487 | (SCM items, SCM less), |
| 488 | "Sort the sequence @var{items}, which may be a list or a\n" |
| 489 | "vector. @var{less} is used for comparing the sequence elements.\n" |
| 490 | "The sorting is destructive, that means that the input sequence\n" |
| 491 | "is modified to produce the sorted result.\n" |
| 492 | "This is a stable sort.") |
| 493 | #define FUNC_NAME s_scm_stable_sort_x |
| 494 | { |
| 495 | const scm_t_trampoline_2 cmp = compare_function (less, 2, FUNC_NAME); |
| 496 | long len; /* list/vector length */ |
| 497 | |
| 498 | if (SCM_NULL_OR_NIL_P (items)) |
| 499 | return items; |
| 500 | |
| 501 | if (scm_is_pair (items)) |
| 502 | { |
| 503 | SCM_VALIDATE_LIST_COPYLEN (1, items, len); |
| 504 | return scm_merge_list_step (&items, cmp, less, len); |
| 505 | } |
| 506 | else if (scm_is_vector (items)) |
| 507 | { |
| 508 | scm_t_array_handle temp_handle, vec_handle; |
| 509 | SCM temp, *temp_elts, *vec_elts; |
| 510 | size_t len; |
| 511 | ssize_t inc; |
| 512 | |
| 513 | vec_elts = scm_vector_writable_elements (items, &vec_handle, |
| 514 | &len, &inc); |
| 515 | temp = scm_c_make_vector (len, SCM_UNDEFINED); |
| 516 | temp_elts = scm_vector_writable_elements (temp, &temp_handle, |
| 517 | NULL, NULL); |
| 518 | |
| 519 | scm_merge_vector_step (vec_elts, temp_elts, cmp, less, 0, len-1, inc); |
| 520 | |
| 521 | scm_array_handle_release (&temp_handle); |
| 522 | scm_array_handle_release (&vec_handle); |
| 523 | |
| 524 | return items; |
| 525 | } |
| 526 | else |
| 527 | SCM_WRONG_TYPE_ARG (1, items); |
| 528 | } |
| 529 | #undef FUNC_NAME |
| 530 | |
| 531 | |
| 532 | SCM_DEFINE (scm_stable_sort, "stable-sort", 2, 0, 0, |
| 533 | (SCM items, SCM less), |
| 534 | "Sort the sequence @var{items}, which may be a list or a\n" |
| 535 | "vector. @var{less} is used for comparing the sequence elements.\n" |
| 536 | "This is a stable sort.") |
| 537 | #define FUNC_NAME s_scm_stable_sort |
| 538 | { |
| 539 | if (SCM_NULL_OR_NIL_P (items)) |
| 540 | return SCM_EOL; |
| 541 | |
| 542 | if (scm_is_pair (items)) |
| 543 | return scm_stable_sort_x (scm_list_copy (items), less); |
| 544 | else if (scm_is_vector (items)) |
| 545 | return scm_stable_sort_x (scm_vector_copy (items), less); |
| 546 | else |
| 547 | SCM_WRONG_TYPE_ARG (1, items); |
| 548 | } |
| 549 | #undef FUNC_NAME |
| 550 | |
| 551 | |
| 552 | SCM_DEFINE (scm_sort_list_x, "sort-list!", 2, 0, 0, |
| 553 | (SCM items, SCM less), |
| 554 | "Sort the list @var{items}, using @var{less} for comparing the\n" |
| 555 | "list elements. The sorting is destructive, that means that the\n" |
| 556 | "input list is modified to produce the sorted result.\n" |
| 557 | "This is a stable sort.") |
| 558 | #define FUNC_NAME s_scm_sort_list_x |
| 559 | { |
| 560 | const scm_t_trampoline_2 cmp = compare_function (less, 2, FUNC_NAME); |
| 561 | long len; |
| 562 | |
| 563 | SCM_VALIDATE_LIST_COPYLEN (1, items, len); |
| 564 | return scm_merge_list_step (&items, cmp, less, len); |
| 565 | } |
| 566 | #undef FUNC_NAME |
| 567 | |
| 568 | |
| 569 | SCM_DEFINE (scm_sort_list, "sort-list", 2, 0, 0, |
| 570 | (SCM items, SCM less), |
| 571 | "Sort the list @var{items}, using @var{less} for comparing the\n" |
| 572 | "list elements. This is a stable sort.") |
| 573 | #define FUNC_NAME s_scm_sort_list |
| 574 | { |
| 575 | const scm_t_trampoline_2 cmp = compare_function (less, 2, FUNC_NAME); |
| 576 | long len; |
| 577 | |
| 578 | SCM_VALIDATE_LIST_COPYLEN (1, items, len); |
| 579 | items = scm_list_copy (items); |
| 580 | return scm_merge_list_step (&items, cmp, less, len); |
| 581 | } |
| 582 | #undef FUNC_NAME |
| 583 | |
| 584 | |
| 585 | void |
| 586 | scm_init_sort () |
| 587 | { |
| 588 | #include "libguile/sort.x" |
| 589 | |
| 590 | scm_add_feature ("sort"); |
| 591 | } |
| 592 | |
| 593 | /* |
| 594 | Local Variables: |
| 595 | c-file-style: "gnu" |
| 596 | End: |
| 597 | */ |