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