libguile/alist.c

   1 /* Copyright (C) 1995, 96, 97, 98, 99, 2000, 2001 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
  43 \f
  44 #include "libguile/_scm.h"
  45 #include "libguile/eq.h"
  46 #include "libguile/list.h"
  47
  48 #include "libguile/validate.h"
  49 #include "libguile/alist.h"
  50
  51 \f
  52
  53 SCM_DEFINE (scm_acons, "acons", 3, 0, 0,
  54            (SCM key, SCM value, SCM alist),
  55             "Add a new key-value pair to @var{alist}.  A new pair is\n"
  56             "created whose car is @var{key} and whose cdr is @var{value}, and the\n"
  57             "pair is consed onto @var{alist}, and the new list is returned.  This\n"
  58             "function is @emph{not} destructive; @var{alist} is not modified.")
  59 #define FUNC_NAME s_scm_acons
  60 {
  61   SCM pair;
  62   SCM head;
  63
  64   SCM_NEWCELL (pair);
  65   SCM_SET_CELL_OBJECT_0 (pair, key);
  66   SCM_SET_CELL_OBJECT_1 (pair, value);
  67
  68   SCM_NEWCELL (head);
  69   SCM_SET_CELL_OBJECT_0 (head, pair);
  70   SCM_SET_CELL_OBJECT_1 (head, alist);
  71
  72   return head;
  73 }
  74 #undef FUNC_NAME
  75
  76 \f
  77
  78 SCM_DEFINE (scm_sloppy_assq, "sloppy-assq", 2, 0, 0,
  79             (SCM key, SCM alist),
  80             "Behaves like @code{assq} but does not do any error checking.\n"
  81             "Recommended only for use in Guile internals.")
  82 #define FUNC_NAME s_scm_sloppy_assq
  83 {
  84   for (; SCM_CONSP (alist); alist = SCM_CDR (alist))
  85     {
  86       SCM tmp = SCM_CAR (alist);
  87       if (SCM_CONSP (tmp) && SCM_EQ_P (SCM_CAR (tmp), key))
  88         return tmp;
  89     }
  90   return SCM_BOOL_F;
  91 }
  92 #undef FUNC_NAME
  93
  94
  95
  96 SCM_DEFINE (scm_sloppy_assv, "sloppy-assv", 2, 0, 0,
  97             (SCM key, SCM alist),
  98             "Behaves like @code{assv} but does not do any error checking.\n"
  99             "Recommended only for use in Guile internals.")
 100 #define FUNC_NAME s_scm_sloppy_assv
 101 {
 102   for (; SCM_CONSP (alist); alist = SCM_CDR (alist))
 103     {
 104       SCM tmp = SCM_CAR (alist);
 105       if (SCM_CONSP (tmp)
 106           && SCM_NFALSEP (scm_eqv_p (SCM_CAR (tmp), key)))
 107         return tmp;
 108     }
 109   return SCM_BOOL_F;
 110 }
 111 #undef FUNC_NAME
 112
 113
 114 SCM_DEFINE (scm_sloppy_assoc, "sloppy-assoc", 2, 0, 0,
 115             (SCM key, SCM alist),
 116             "Behaves like @code{assoc} but does not do any error checking.\n"
 117             "Recommended only for use in Guile internals.")
 118 #define FUNC_NAME s_scm_sloppy_assoc
 119 {
 120   for (; SCM_CONSP (alist); alist = SCM_CDR (alist))
 121     {
 122       SCM tmp = SCM_CAR (alist);
 123       if (SCM_CONSP (tmp)
 124           && SCM_NFALSEP (scm_equal_p (SCM_CAR (tmp), key)))
 125         return tmp;
 126     }
 127   return SCM_BOOL_F;
 128 }
 129 #undef FUNC_NAME
 130
 131
 132 \f
 133
 134 SCM_DEFINE (scm_assq, "assq", 2, 0, 0,
 135            (SCM key, SCM alist),
 136             "@deffnx {Scheme Procedure} assv key alist\n"
 137             "@deffnx {Scheme Procedure} assoc key alist\n"
 138             "Fetch the entry in @var{alist} that is associated with @var{key}.  To\n"
 139             "decide whether the argument @var{key} matches a particular entry in\n"
 140             "@var{alist}, @code{assq} compares keys with @code{eq?}, @code{assv}\n"
 141             "uses @code{eqv?} and @code{assoc} uses @code{equal?}.  If @var{key}\n"
 142             "cannot be found in @var{alist} (according to whichever equality\n"
 143             "predicate is in use), then return @code{#f}.  These functions\n"
 144             "return the entire alist entry found (i.e. both the key and the value).")
 145 #define FUNC_NAME s_scm_assq
 146 {
 147   SCM ls = alist;
 148   for (; SCM_CONSP (ls); ls = SCM_CDR (ls))
 149     {
 150       SCM tmp = SCM_CAR (ls);
 151       SCM_ASSERT_TYPE (SCM_CONSP (tmp), alist, SCM_ARG2, FUNC_NAME,
 152                        "association list");
 153       if (SCM_EQ_P (SCM_CAR (tmp), key))
 154         return tmp;
 155     }
 156   SCM_ASSERT_TYPE (SCM_NULLP (ls), alist, SCM_ARG2, FUNC_NAME,
 157                    "association list");
 158   return SCM_BOOL_F;
 159 }
 160 #undef FUNC_NAME
 161
 162
 163 SCM_DEFINE (scm_assv, "assv", 2, 0, 0,
 164            (SCM key, SCM alist),
 165             "Behaves like @code{assq} but uses @code{eqv?} for key comparison.")
 166 #define FUNC_NAME s_scm_assv
 167 {
 168   SCM ls = alist;
 169   for(; SCM_CONSP (ls); ls = SCM_CDR (ls))
 170     {
 171       SCM tmp = SCM_CAR (ls);
 172       SCM_ASSERT_TYPE (SCM_CONSP (tmp), alist, SCM_ARG2, FUNC_NAME,
 173                        "association list");
 174       if (SCM_NFALSEP (scm_eqv_p (SCM_CAR (tmp), key)))
 175         return tmp;
 176     }
 177   SCM_ASSERT_TYPE (SCM_NULLP (ls), alist, SCM_ARG2, FUNC_NAME,
 178                    "association list");
 179   return SCM_BOOL_F;
 180 }
 181 #undef FUNC_NAME
 182
 183
 184 SCM_DEFINE (scm_assoc, "assoc", 2, 0, 0,
 185            (SCM key, SCM alist),
 186             "Behaves like @code{assq} but uses @code{equal?} for key comparison.")
 187 #define FUNC_NAME s_scm_assoc
 188 {
 189   SCM ls = alist;
 190   for(; SCM_CONSP (ls); ls = SCM_CDR (ls))
 191     {
 192       SCM tmp = SCM_CAR (ls);
 193       SCM_ASSERT_TYPE (SCM_CONSP (tmp), alist, SCM_ARG2, FUNC_NAME,
 194                        "association list");
 195       if (SCM_NFALSEP (scm_equal_p (SCM_CAR (tmp), key)))
 196         return tmp;
 197     }
 198   SCM_ASSERT_TYPE (SCM_NULLP (ls), alist, SCM_ARG2, FUNC_NAME,
 199                    "association list");
 200   return SCM_BOOL_F;
 201 }
 202 #undef FUNC_NAME
 203
 204
 205 \f
 206
 207 /* Dirk:API2.0:: We should not return #f if the key was not found.  In the
 208  * current solution we can not distinguish between finding a (key . #f) pair
 209  * and not finding the key at all.
 210  *
 211  * Possible alternative solutions:
 212  * 1) Remove assq-ref from the API:  assq is sufficient.
 213  * 2) Signal an error (what error type?) if the key is not found.
 214  * 3) provide an additional 'default' parameter.
 215  * 3.1) The default parameter is mandatory.
 216  * 3.2) The default parameter is optional, but if no default is given and
 217  *      the key is not found, signal an error (what error type?).
 218  */
 219 SCM_DEFINE (scm_assq_ref, "assq-ref", 2, 0, 0,
 220             (SCM alist, SCM key),
 221             "@deffnx {Scheme Procedure} assv-ref alist key\n"
 222             "@deffnx {Scheme Procedure} assoc-ref alist key\n"
 223             "Like @code{assq}, @code{assv} and @code{assoc}, except that only the\n"
 224             "value associated with @var{key} in @var{alist} is returned.  These\n"
 225             "functions are equivalent to\n\n"
 226             "@lisp\n"
 227             "(let ((ent (@var{associator} @var{key} @var{alist})))\n"
 228             "  (and ent (cdr ent)))\n"
 229             "@end lisp\n\n"
 230             "where @var{associator} is one of @code{assq}, @code{assv} or @code{assoc}.")
 231 #define FUNC_NAME s_scm_assq_ref
 232 {
 233   SCM handle;
 234
 235   handle = scm_sloppy_assq (key, alist);
 236   if (SCM_CONSP (handle))
 237     {
 238       return SCM_CDR (handle);
 239     }
 240   return SCM_BOOL_F;
 241 }
 242 #undef FUNC_NAME
 243
 244
 245 SCM_DEFINE (scm_assv_ref, "assv-ref", 2, 0, 0,
 246             (SCM alist, SCM key),
 247             "Behaves like @code{assq-ref} but uses @code{eqv?} for key comparison.")
 248 #define FUNC_NAME s_scm_assv_ref
 249 {
 250   SCM handle;
 251
 252   handle = scm_sloppy_assv (key, alist);
 253   if (SCM_CONSP (handle))
 254     {
 255       return SCM_CDR (handle);
 256     }
 257   return SCM_BOOL_F;
 258 }
 259 #undef FUNC_NAME
 260
 261
 262 SCM_DEFINE (scm_assoc_ref, "assoc-ref", 2, 0, 0,
 263             (SCM alist, SCM key),
 264             "Behaves like @code{assq-ref} but uses @code{equal?} for key comparison.")
 265 #define FUNC_NAME s_scm_assoc_ref
 266 {
 267   SCM handle;
 268
 269   handle = scm_sloppy_assoc (key, alist);
 270   if (SCM_CONSP (handle))
 271     {
 272       return SCM_CDR (handle);
 273     }
 274   return SCM_BOOL_F;
 275 }
 276 #undef FUNC_NAME
 277
 278
 279
 280 \f
 281
 282
 283 SCM_DEFINE (scm_assq_set_x, "assq-set!", 3, 0, 0,
 284             (SCM alist, SCM key, SCM val),
 285             "@deffnx {Scheme Procedure} assv-set! alist key value\n"
 286             "@deffnx {Scheme Procedure} assoc-set! alist key value\n"
 287             "Reassociate @var{key} in @var{alist} with @var{value}: find any existing\n"
 288             "@var{alist} entry for @var{key} and associate it with the new\n"
 289             "@var{value}.  If @var{alist} does not contain an entry for @var{key},\n"
 290             "add a new one.  Return the (possibly new) alist.\n\n"
 291             "These functions do not attempt to verify the structure of @var{alist},\n"
 292             "and so may cause unusual results if passed an object that is not an\n"
 293             "association list.")
 294 #define FUNC_NAME s_scm_assq_set_x
 295 {
 296   SCM handle;
 297
 298   handle = scm_sloppy_assq (key, alist);
 299   if (SCM_CONSP (handle))
 300     {
 301       SCM_SETCDR (handle, val);
 302       return alist;
 303     }
 304   else
 305     return scm_acons (key, val, alist);
 306 }
 307 #undef FUNC_NAME
 308
 309 SCM_DEFINE (scm_assv_set_x, "assv-set!", 3, 0, 0,
 310             (SCM alist, SCM key, SCM val),
 311             "Behaves like @code{assq-set!} but uses @code{eqv?} for key comparison.")
 312 #define FUNC_NAME s_scm_assv_set_x
 313 {
 314   SCM handle;
 315
 316   handle = scm_sloppy_assv (key, alist);
 317   if (SCM_CONSP (handle))
 318     {
 319       SCM_SETCDR (handle, val);
 320       return alist;
 321     }
 322   else
 323     return scm_acons (key, val, alist);
 324 }
 325 #undef FUNC_NAME
 326
 327 SCM_DEFINE (scm_assoc_set_x, "assoc-set!", 3, 0, 0,
 328             (SCM alist, SCM key, SCM val),
 329             "Behaves like @code{assq-set!} but uses @code{equal?} for key comparison.")
 330 #define FUNC_NAME s_scm_assoc_set_x
 331 {
 332   SCM handle;
 333
 334   handle = scm_sloppy_assoc (key, alist);
 335   if (SCM_CONSP (handle))
 336     {
 337       SCM_SETCDR (handle, val);
 338       return alist;
 339     }
 340   else
 341     return scm_acons (key, val, alist);
 342 }
 343 #undef FUNC_NAME
 344
 345
 346 \f
 347
 348 SCM_DEFINE (scm_assq_remove_x, "assq-remove!", 2, 0, 0,
 349             (SCM alist, SCM key),
 350             "@deffnx {Scheme Procedure} assv-remove! alist key\n"
 351             "@deffnx {Scheme Procedure} assoc-remove! alist key\n"
 352             "Delete the first entry in @var{alist} associated with @var{key}, and return\n"
 353             "the resulting alist.")
 354 #define FUNC_NAME s_scm_assq_remove_x
 355 {
 356   SCM handle;
 357
 358   handle = scm_sloppy_assq (key, alist);
 359   if (SCM_CONSP (handle))
 360     alist = scm_delq1_x (handle, alist);
 361
 362   return alist;
 363 }
 364 #undef FUNC_NAME
 365
 366
 367 SCM_DEFINE (scm_assv_remove_x, "assv-remove!", 2, 0, 0,
 368             (SCM alist, SCM key),
 369             "Behaves like @code{assq-remove!} but uses @code{eqv?} for key comparison.")
 370 #define FUNC_NAME s_scm_assv_remove_x
 371 {
 372   SCM handle;
 373
 374   handle = scm_sloppy_assv (key, alist);
 375   if (SCM_CONSP (handle))
 376     alist = scm_delq1_x (handle, alist);
 377
 378   return alist;
 379 }
 380 #undef FUNC_NAME
 381
 382
 383 SCM_DEFINE (scm_assoc_remove_x, "assoc-remove!", 2, 0, 0,
 384             (SCM alist, SCM key),
 385             "Behaves like @code{assq-remove!} but uses @code{equal?} for key comparison.")
 386 #define FUNC_NAME s_scm_assoc_remove_x
 387 {
 388   SCM handle;
 389
 390   handle = scm_sloppy_assoc (key, alist);
 391   if (SCM_CONSP (handle))
 392     alist = scm_delq1_x (handle, alist);
 393
 394   return alist;
 395 }
 396 #undef FUNC_NAME
 397
 398
 399 \f
 400
 401
 402
 403 void
 404 scm_init_alist ()
 405 {
 406 #ifndef SCM_MAGIC_SNARFER
 407 #include "libguile/alist.x"
 408 #endif
 409 }
 410
 411
 412 /*
 413   Local Variables:
 414   c-file-style: "gnu"
 415   End:
 416 */