libguile/alist.c

   1 /* Copyright (C) 1995, 96, 97, 98, 99, 2000 Free Software Foundation, Inc.
   2  *
   3  * This program is free software; you can redistribute it and/or modify
   4  * it under the terms of the GNU General Public License as published by
   5  * the Free Software Foundation; either version 2, or (at your option)
   6  * any later version.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this software; see the file COPYING.  If not, write to
  15  * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  16  * Boston, MA 02111-1307 USA
  17  *
  18  * As a special exception, the Free Software Foundation gives permission
  19  * for additional uses of the text contained in its release of GUILE.
  20  *
  21  * The exception is that, if you link the GUILE library with other files
  22  * to produce an executable, this does not by itself cause the
  23  * resulting executable to be covered by the GNU General Public License.
  24  * Your use of that executable is in no way restricted on account of
  25  * linking the GUILE library code into it.
  26  *
  27  * This exception does not however invalidate any other reasons why
  28  * the executable file might be covered by the GNU General Public License.
  29  *
  30  * This exception applies only to the code released by the
  31  * Free Software Foundation under the name GUILE.  If you copy
  32  * code from other Free Software Foundation releases into a copy of
  33  * GUILE, as the General Public License permits, the exception does
  34  * not apply to the code that you add in this way.  To avoid misleading
  35  * anyone as to the status of such modified files, you must delete
  36  * this exception notice from them.
  37  *
  38  * If you write modifications of your own for GUILE, it is your choice
  39  * whether to permit this exception to apply to your modifications.
  40  * If you do not wish that, delete this exception notice.  */
  41
  42 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
  43    gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
  44
  45 \f
  46 #include <stdio.h>
  47 #include "libguile/_scm.h"
  48 #include "libguile/eq.h"
  49 #include "libguile/list.h"
  50
  51 #include "libguile/validate.h"
  52 #include "libguile/alist.h"
  53
  54 \f
  55
  56 SCM_DEFINE (scm_acons, "acons", 3, 0, 0,
  57            (SCM key, SCM value, SCM alist),
  58             "Adds a new key-value pair to @var{alist}.  A new pair is\n"
  59             "created whose car is @var{key} and whose cdr is @var{value}, and the\n"
  60             "pair is consed onto @var{alist}, and the new list is returned.  This\n"
  61             "function is @emph{not} destructive; @var{alist} is not modified.")
  62 #define FUNC_NAME s_scm_acons
  63 {
  64   SCM pair;
  65   SCM head;
  66
  67   SCM_NEWCELL (pair);
  68   SCM_SET_CELL_OBJECT_0 (pair, key);
  69   SCM_SET_CELL_OBJECT_1 (pair, value);
  70
  71   SCM_NEWCELL (head);
  72   SCM_SET_CELL_OBJECT_0 (head, pair);
  73   SCM_SET_CELL_OBJECT_1 (head, alist);
  74
  75   return head;
  76 }
  77 #undef FUNC_NAME
  78
  79 \f
  80
  81 SCM_DEFINE (scm_sloppy_assq, "sloppy-assq", 2, 0, 0,
  82             (SCM key, SCM alist),
  83             "Behaves like @code{assq} but does not do any error checking.\n"
  84             "Recommended only for use in Guile internals.")
  85 #define FUNC_NAME s_scm_sloppy_assq
  86 {
  87   for (; SCM_CONSP (alist); alist = SCM_CDR (alist))
  88     {
  89       SCM tmp = SCM_CAR (alist);
  90       if (SCM_CONSP (tmp) && SCM_EQ_P (SCM_CAR (tmp), key))
  91         return tmp;
  92     }
  93   return SCM_BOOL_F;
  94 }
  95 #undef FUNC_NAME
  96
  97
  98
  99 SCM_DEFINE (scm_sloppy_assv, "sloppy-assv", 2, 0, 0,
 100             (SCM key, SCM alist),
 101             "Behaves like @code{assv} but does not do any error checking.\n"
 102             "Recommended only for use in Guile internals.")
 103 #define FUNC_NAME s_scm_sloppy_assv
 104 {
 105   for (; SCM_CONSP (alist); alist = SCM_CDR (alist))
 106     {
 107       SCM tmp = SCM_CAR (alist);
 108       if (SCM_CONSP (tmp)
 109           && SCM_NFALSEP (scm_eqv_p (SCM_CAR (tmp), key)))
 110         return tmp;
 111     }
 112   return SCM_BOOL_F;
 113 }
 114 #undef FUNC_NAME
 115
 116
 117 SCM_DEFINE (scm_sloppy_assoc, "sloppy-assoc", 2, 0, 0,
 118             (SCM key, SCM alist),
 119             "Behaves like @code{assoc} but does not do any error checking.\n"
 120             "Recommended only for use in Guile internals.")
 121 #define FUNC_NAME s_scm_sloppy_assoc
 122 {
 123   for (; SCM_CONSP (alist); alist = SCM_CDR (alist))
 124     {
 125       SCM tmp = SCM_CAR (alist);
 126       if (SCM_CONSP (tmp)
 127           && SCM_NFALSEP (scm_equal_p (SCM_CAR (tmp), key)))
 128         return tmp;
 129     }
 130   return SCM_BOOL_F;
 131 }
 132 #undef FUNC_NAME
 133
 134
 135 \f
 136
 137 SCM_DEFINE (scm_assq, "assq", 2, 0, 0,
 138            (SCM key, SCM alist),
 139             "@deffnx primitive assv key alist\n"
 140             "@deffnx primitive assoc key alist\n"
 141             "Fetches the entry in @var{alist} that is associated with @var{key}.  To\n"
 142             "decide whether the argument @var{key} matches a particular entry in\n"
 143             "@var{alist}, @code{assq} compares keys with @code{eq?}, @code{assv}\n"
 144             "uses @code{eqv?} and @code{assoc} uses @code{equal?}.  If @var{key}\n"
 145             "cannot be found in @var{alist} (according to whichever equality\n"
 146             "predicate is in use), then @code{#f} is returned.  These functions\n"
 147             "return the entire alist entry found (i.e. both the key and the value).")
 148 #define FUNC_NAME s_scm_assq
 149 {
 150   SCM ls = alist;
 151   for (; SCM_CONSP (ls); ls = SCM_CDR (ls))
 152     {
 153       SCM tmp = SCM_CAR (ls);
 154       SCM_ASSERT_TYPE (SCM_CONSP (tmp), alist, SCM_ARG2, FUNC_NAME,
 155                        "association list");
 156       if (SCM_EQ_P (SCM_CAR (tmp), key))
 157         return tmp;
 158     }
 159   SCM_ASSERT_TYPE (SCM_NULLP (ls), alist, SCM_ARG2, FUNC_NAME,
 160                    "association list");
 161   return SCM_BOOL_F;
 162 }
 163 #undef FUNC_NAME
 164
 165
 166 SCM_DEFINE (scm_assv, "assv", 2, 0, 0,
 167            (SCM key, SCM alist),
 168             "Behaves like @code{assq} but uses @code{eqv?} for key comparison.")
 169 #define FUNC_NAME s_scm_assv
 170 {
 171   SCM ls = alist;
 172   for(; SCM_CONSP (ls); ls = SCM_CDR (ls))
 173     {
 174       SCM tmp = SCM_CAR (ls);
 175       SCM_ASSERT_TYPE (SCM_CONSP (tmp), alist, SCM_ARG2, FUNC_NAME,
 176                        "association list");
 177       if (SCM_NFALSEP (scm_eqv_p (SCM_CAR (tmp), key)))
 178         return tmp;
 179     }
 180   SCM_ASSERT_TYPE (SCM_NULLP (ls), alist, SCM_ARG2, FUNC_NAME,
 181                    "association list");
 182   return SCM_BOOL_F;
 183 }
 184 #undef FUNC_NAME
 185
 186
 187 SCM_DEFINE (scm_assoc, "assoc", 2, 0, 0,
 188            (SCM key, SCM alist),
 189             "Behaves like @code{assq} but uses @code{equal?} for key comparison.")
 190 #define FUNC_NAME s_scm_assoc
 191 {
 192   SCM ls = alist;
 193   for(; SCM_CONSP (ls); ls = SCM_CDR (ls))
 194     {
 195       SCM tmp = SCM_CAR (ls);
 196       SCM_ASSERT_TYPE (SCM_CONSP (tmp), alist, SCM_ARG2, FUNC_NAME,
 197                        "association list");
 198       if (SCM_NFALSEP (scm_equal_p (SCM_CAR (tmp), key)))
 199         return tmp;
 200     }
 201   SCM_ASSERT_TYPE (SCM_NULLP (ls), alist, SCM_ARG2, FUNC_NAME,
 202                    "association list");
 203   return SCM_BOOL_F;
 204 }
 205 #undef FUNC_NAME
 206
 207
 208 \f
 209
 210 /* Dirk:API2.0:: We should not return #f if the key was not found.  In the
 211  * current solution we can not distinguish between finding a (key . #f) pair
 212  * and not finding the key at all.
 213  *
 214  * Possible alternative solutions:
 215  * 1) Remove assq-ref from the API:  assq is sufficient.
 216  * 2) Signal an error (what error type?) if the key is not found.
 217  * 3) provide an additional 'default' parameter.
 218  * 3.1) The default parameter is mandatory.
 219  * 3.2) The default parameter is optional, but if no default is given and
 220  *      the key is not found, signal an error (what error type?).
 221  */
 222 SCM_DEFINE (scm_assq_ref, "assq-ref", 2, 0, 0,
 223             (SCM alist, SCM key),
 224             "@deffnx primitive assv-ref alist key\n"
 225             "@deffnx primitive assoc-ref alist key\n"
 226             "Like @code{assq}, @code{assv} and @code{assoc}, except that only the\n"
 227             "value associated with @var{key} in @var{alist} is returned.  These\n"
 228             "functions are equivalent to\n\n"
 229             "@lisp\n"
 230             "(let ((ent (@var{associator} @var{key} @var{alist})))\n"
 231             "  (and ent (cdr ent)))\n"
 232             "@end lisp\n\n"
 233             "where @var{associator} is one of @code{assq}, @code{assv} or @code{assoc}.")
 234 #define FUNC_NAME s_scm_assq_ref
 235 {
 236   SCM handle;
 237
 238   handle = scm_sloppy_assq (key, alist);
 239   if (SCM_CONSP (handle))
 240     {
 241       return SCM_CDR (handle);
 242     }
 243   return SCM_BOOL_F;
 244 }
 245 #undef FUNC_NAME
 246
 247
 248 SCM_DEFINE (scm_assv_ref, "assv-ref", 2, 0, 0,
 249             (SCM alist, SCM key),
 250             "Behaves like @code{assq-ref} but uses @code{eqv?} for key comparison.")
 251 #define FUNC_NAME s_scm_assv_ref
 252 {
 253   SCM handle;
 254
 255   handle = scm_sloppy_assv (key, alist);
 256   if (SCM_CONSP (handle))
 257     {
 258       return SCM_CDR (handle);
 259     }
 260   return SCM_BOOL_F;
 261 }
 262 #undef FUNC_NAME
 263
 264
 265 SCM_DEFINE (scm_assoc_ref, "assoc-ref", 2, 0, 0,
 266             (SCM alist, SCM key),
 267             "Behaves like @code{assq-ref} but uses @code{equal?} for key comparison.")
 268 #define FUNC_NAME s_scm_assoc_ref
 269 {
 270   SCM handle;
 271
 272   handle = scm_sloppy_assoc (key, alist);
 273   if (SCM_CONSP (handle))
 274     {
 275       return SCM_CDR (handle);
 276     }
 277   return SCM_BOOL_F;
 278 }
 279 #undef FUNC_NAME
 280
 281
 282
 283 \f
 284
 285
 286 SCM_DEFINE (scm_assq_set_x, "assq-set!", 3, 0, 0,
 287             (SCM alist, SCM key, SCM val),
 288             "@deffnx primitive assv-set! alist key value\n"
 289             "@deffnx primitive assoc-set! alist key value\n"
 290             "Reassociate @var{key} in @var{alist} with @var{value}: find any existing\n"
 291             "@var{alist} entry for @var{key} and associate it with the new\n"
 292             "@var{value}.  If @var{alist} does not contain an entry for @var{key},\n"
 293             "add a new one.  Return the (possibly new) alist.\n\n"
 294             "These functions do not attempt to verify the structure of @var{alist},\n"
 295             "and so may cause unusual results if passed an object that is not an\n"
 296             "association list.")
 297 #define FUNC_NAME s_scm_assq_set_x
 298 {
 299   SCM handle;
 300
 301   handle = scm_sloppy_assq (key, alist);
 302   if (SCM_CONSP (handle))
 303     {
 304       SCM_SETCDR (handle, val);
 305       return alist;
 306     }
 307   else
 308     return scm_acons (key, val, alist);
 309 }
 310 #undef FUNC_NAME
 311
 312 SCM_DEFINE (scm_assv_set_x, "assv-set!", 3, 0, 0,
 313             (SCM alist, SCM key, SCM val),
 314             "Behaves like @code{assq-set!} but uses @code{eqv?} for key comparison.")
 315 #define FUNC_NAME s_scm_assv_set_x
 316 {
 317   SCM handle;
 318
 319   handle = scm_sloppy_assv (key, alist);
 320   if (SCM_CONSP (handle))
 321     {
 322       SCM_SETCDR (handle, val);
 323       return alist;
 324     }
 325   else
 326     return scm_acons (key, val, alist);
 327 }
 328 #undef FUNC_NAME
 329
 330 SCM_DEFINE (scm_assoc_set_x, "assoc-set!", 3, 0, 0,
 331             (SCM alist, SCM key, SCM val),
 332             "Behaves like @code{assq-set!} but uses @code{equal?} for key comparison.")
 333 #define FUNC_NAME s_scm_assoc_set_x
 334 {
 335   SCM handle;
 336
 337   handle = scm_sloppy_assoc (key, alist);
 338   if (SCM_CONSP (handle))
 339     {
 340       SCM_SETCDR (handle, val);
 341       return alist;
 342     }
 343   else
 344     return scm_acons (key, val, alist);
 345 }
 346 #undef FUNC_NAME
 347
 348
 349 \f
 350
 351 SCM_DEFINE (scm_assq_remove_x, "assq-remove!", 2, 0, 0,
 352             (SCM alist, SCM key),
 353             "@deffnx primitive assv-remove! alist key\n"
 354             "@deffnx primitive assoc-remove! alist key\n"
 355             "Delete the first entry in @var{alist} associated with @var{key}, and return\n"
 356             "the resulting alist.")
 357 #define FUNC_NAME s_scm_assq_remove_x
 358 {
 359   SCM handle;
 360
 361   handle = scm_sloppy_assq (key, alist);
 362   if (SCM_CONSP (handle))
 363     alist = scm_delq1_x (handle, alist);
 364
 365   return alist;
 366 }
 367 #undef FUNC_NAME
 368
 369
 370 SCM_DEFINE (scm_assv_remove_x, "assv-remove!", 2, 0, 0,
 371             (SCM alist, SCM key),
 372             "Behaves like @code{assq-remove!} but uses @code{eqv?} for key comparison.")
 373 #define FUNC_NAME s_scm_assv_remove_x
 374 {
 375   SCM handle;
 376
 377   handle = scm_sloppy_assv (key, alist);
 378   if (SCM_CONSP (handle))
 379     alist = scm_delq1_x (handle, alist);
 380
 381   return alist;
 382 }
 383 #undef FUNC_NAME
 384
 385
 386 SCM_DEFINE (scm_assoc_remove_x, "assoc-remove!", 2, 0, 0,
 387             (SCM alist, SCM key),
 388             "Behaves like @code{assq-remove!} but uses @code{equal?} for key comparison.")
 389 #define FUNC_NAME s_scm_assoc_remove_x
 390 {
 391   SCM handle;
 392
 393   handle = scm_sloppy_assoc (key, alist);
 394   if (SCM_CONSP (handle))
 395     alist = scm_delq1_x (handle, alist);
 396
 397   return alist;
 398 }
 399 #undef FUNC_NAME
 400
 401
 402 \f
 403
 404
 405
 406 void
 407 scm_init_alist ()
 408 {
 409 #ifndef SCM_MAGIC_SNARFER
 410 #include "libguile/alist.x"
 411 #endif
 412 }
 413
 414
 415 /*
 416   Local Variables:
 417   c-file-style: "gnu"
 418   End:
 419 */