libguile/alist.c

   1 /* Copyright (C) 1995, 96, 97, 98, 99, 2000, 2001 Free Software Foundation, Inc.
   2  *
   3  * This library is free software; you can redistribute it and/or
   4  * modify it under the terms of the GNU Lesser General Public
   5  * License as published by the Free Software Foundation; either
   6  * version 2.1 of the License, or (at your option) any later version.
   7  *
   8  * This library 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 GNU
  11  * Lesser General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU Lesser General Public
  14  * License along with this library; if not, write to the Free Software
  15  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  16  */
  17
  18
  19 \f
  20 #include "libguile/_scm.h"
  21 #include "libguile/eq.h"
  22 #include "libguile/list.h"
  23 #include "libguile/lang.h"
  24
  25 #include "libguile/validate.h"
  26 #include "libguile/alist.h"
  27
  28 \f
  29
  30 SCM_DEFINE (scm_acons, "acons", 3, 0, 0,
  31            (SCM key, SCM value, SCM alist),
  32             "Add a new key-value pair to @var{alist}.  A new pair is\n"
  33             "created whose car is @var{key} and whose cdr is @var{value}, and the\n"
  34             "pair is consed onto @var{alist}, and the new list is returned.  This\n"
  35             "function is @emph{not} destructive; @var{alist} is not modified.")
  36 #define FUNC_NAME s_scm_acons
  37 {
  38   return scm_cell (SCM_UNPACK (scm_cell (SCM_UNPACK (key),
  39                                          SCM_UNPACK (value))),
  40                    SCM_UNPACK (alist));
  41 }
  42 #undef FUNC_NAME
  43
  44 \f
  45
  46 SCM_DEFINE (scm_sloppy_assq, "sloppy-assq", 2, 0, 0,
  47             (SCM key, SCM alist),
  48             "Behaves like @code{assq} but does not do any error checking.\n"
  49             "Recommended only for use in Guile internals.")
  50 #define FUNC_NAME s_scm_sloppy_assq
  51 {
  52   for (; SCM_CONSP (alist); alist = SCM_CDR (alist))
  53     {
  54       SCM tmp = SCM_CAR (alist);
  55       if (SCM_CONSP (tmp) && scm_is_eq (SCM_CAR (tmp), key))
  56         return tmp;
  57     }
  58   return SCM_BOOL_F;
  59 }
  60 #undef FUNC_NAME
  61
  62
  63
  64 SCM_DEFINE (scm_sloppy_assv, "sloppy-assv", 2, 0, 0,
  65             (SCM key, SCM alist),
  66             "Behaves like @code{assv} but does not do any error checking.\n"
  67             "Recommended only for use in Guile internals.")
  68 #define FUNC_NAME s_scm_sloppy_assv
  69 {
  70   for (; SCM_CONSP (alist); alist = SCM_CDR (alist))
  71     {
  72       SCM tmp = SCM_CAR (alist);
  73       if (SCM_CONSP (tmp)
  74           && scm_is_true (scm_eqv_p (SCM_CAR (tmp), key)))
  75         return tmp;
  76     }
  77   return SCM_BOOL_F;
  78 }
  79 #undef FUNC_NAME
  80
  81
  82 SCM_DEFINE (scm_sloppy_assoc, "sloppy-assoc", 2, 0, 0,
  83             (SCM key, SCM alist),
  84             "Behaves like @code{assoc} but does not do any error checking.\n"
  85             "Recommended only for use in Guile internals.")
  86 #define FUNC_NAME s_scm_sloppy_assoc
  87 {
  88   for (; SCM_CONSP (alist); alist = SCM_CDR (alist))
  89     {
  90       SCM tmp = SCM_CAR (alist);
  91       if (SCM_CONSP (tmp)
  92           && scm_is_true (scm_equal_p (SCM_CAR (tmp), key)))
  93         return tmp;
  94     }
  95   return SCM_BOOL_F;
  96 }
  97 #undef FUNC_NAME
  98
  99
 100 \f
 101
 102 SCM_DEFINE (scm_assq, "assq", 2, 0, 0,
 103            (SCM key, SCM alist),
 104             "@deffnx {Scheme Procedure} assv key alist\n"
 105             "@deffnx {Scheme Procedure} assoc key alist\n"
 106             "Fetch the entry in @var{alist} that is associated with @var{key}.  To\n"
 107             "decide whether the argument @var{key} matches a particular entry in\n"
 108             "@var{alist}, @code{assq} compares keys with @code{eq?}, @code{assv}\n"
 109             "uses @code{eqv?} and @code{assoc} uses @code{equal?}.  If @var{key}\n"
 110             "cannot be found in @var{alist} (according to whichever equality\n"
 111             "predicate is in use), then return @code{#f}.  These functions\n"
 112             "return the entire alist entry found (i.e. both the key and the value).")
 113 #define FUNC_NAME s_scm_assq
 114 {
 115   SCM ls = alist;
 116   for (; SCM_CONSP (ls); ls = SCM_CDR (ls))
 117     {
 118       SCM tmp = SCM_CAR (ls);
 119       SCM_ASSERT_TYPE (SCM_CONSP (tmp), alist, SCM_ARG2, FUNC_NAME,
 120                        "association list");
 121       if (scm_is_eq (SCM_CAR (tmp), key))
 122         return tmp;
 123     }
 124   SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (ls), alist, SCM_ARG2, FUNC_NAME,
 125                    "association list");
 126   return SCM_BOOL_F;
 127 }
 128 #undef FUNC_NAME
 129
 130
 131 SCM_DEFINE (scm_assv, "assv", 2, 0, 0,
 132            (SCM key, SCM alist),
 133             "Behaves like @code{assq} but uses @code{eqv?} for key comparison.")
 134 #define FUNC_NAME s_scm_assv
 135 {
 136   SCM ls = alist;
 137   for(; SCM_CONSP (ls); ls = SCM_CDR (ls))
 138     {
 139       SCM tmp = SCM_CAR (ls);
 140       SCM_ASSERT_TYPE (SCM_CONSP (tmp), alist, SCM_ARG2, FUNC_NAME,
 141                        "association list");
 142       if (scm_is_true (scm_eqv_p (SCM_CAR (tmp), key)))
 143         return tmp;
 144     }
 145   SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (ls), alist, SCM_ARG2, FUNC_NAME,
 146                    "association list");
 147   return SCM_BOOL_F;
 148 }
 149 #undef FUNC_NAME
 150
 151
 152 SCM_DEFINE (scm_assoc, "assoc", 2, 0, 0,
 153            (SCM key, SCM alist),
 154             "Behaves like @code{assq} but uses @code{equal?} for key comparison.")
 155 #define FUNC_NAME s_scm_assoc
 156 {
 157   SCM ls = alist;
 158   for(; SCM_CONSP (ls); ls = SCM_CDR (ls))
 159     {
 160       SCM tmp = SCM_CAR (ls);
 161       SCM_ASSERT_TYPE (SCM_CONSP (tmp), alist, SCM_ARG2, FUNC_NAME,
 162                        "association list");
 163       if (scm_is_true (scm_equal_p (SCM_CAR (tmp), key)))
 164         return tmp;
 165     }
 166   SCM_ASSERT_TYPE (SCM_NULL_OR_NIL_P (ls), alist, SCM_ARG2, FUNC_NAME,
 167                    "association list");
 168   return SCM_BOOL_F;
 169 }
 170 #undef FUNC_NAME
 171
 172
 173 \f
 174
 175 /* Dirk:API2.0:: We should not return #f if the key was not found.  In the
 176  * current solution we can not distinguish between finding a (key . #f) pair
 177  * and not finding the key at all.
 178  *
 179  * Possible alternative solutions:
 180  * 1) Remove assq-ref from the API:  assq is sufficient.
 181  * 2) Signal an error (what error type?) if the key is not found.
 182  * 3) provide an additional 'default' parameter.
 183  * 3.1) The default parameter is mandatory.
 184  * 3.2) The default parameter is optional, but if no default is given and
 185  *      the key is not found, signal an error (what error type?).
 186  */
 187 SCM_DEFINE (scm_assq_ref, "assq-ref", 2, 0, 0,
 188             (SCM alist, SCM key),
 189             "@deffnx {Scheme Procedure} assv-ref alist key\n"
 190             "@deffnx {Scheme Procedure} assoc-ref alist key\n"
 191             "Like @code{assq}, @code{assv} and @code{assoc}, except that only the\n"
 192             "value associated with @var{key} in @var{alist} is returned.  These\n"
 193             "functions are equivalent to\n\n"
 194             "@lisp\n"
 195             "(let ((ent (@var{associator} @var{key} @var{alist})))\n"
 196             "  (and ent (cdr ent)))\n"
 197             "@end lisp\n\n"
 198             "where @var{associator} is one of @code{assq}, @code{assv} or @code{assoc}.")
 199 #define FUNC_NAME s_scm_assq_ref
 200 {
 201   SCM handle;
 202
 203   handle = scm_sloppy_assq (key, alist);
 204   if (SCM_CONSP (handle))
 205     {
 206       return SCM_CDR (handle);
 207     }
 208   return SCM_BOOL_F;
 209 }
 210 #undef FUNC_NAME
 211
 212
 213 SCM_DEFINE (scm_assv_ref, "assv-ref", 2, 0, 0,
 214             (SCM alist, SCM key),
 215             "Behaves like @code{assq-ref} but uses @code{eqv?} for key comparison.")
 216 #define FUNC_NAME s_scm_assv_ref
 217 {
 218   SCM handle;
 219
 220   handle = scm_sloppy_assv (key, alist);
 221   if (SCM_CONSP (handle))
 222     {
 223       return SCM_CDR (handle);
 224     }
 225   return SCM_BOOL_F;
 226 }
 227 #undef FUNC_NAME
 228
 229
 230 SCM_DEFINE (scm_assoc_ref, "assoc-ref", 2, 0, 0,
 231             (SCM alist, SCM key),
 232             "Behaves like @code{assq-ref} but uses @code{equal?} for key comparison.")
 233 #define FUNC_NAME s_scm_assoc_ref
 234 {
 235   SCM handle;
 236
 237   handle = scm_sloppy_assoc (key, alist);
 238   if (SCM_CONSP (handle))
 239     {
 240       return SCM_CDR (handle);
 241     }
 242   return SCM_BOOL_F;
 243 }
 244 #undef FUNC_NAME
 245
 246
 247
 248 \f
 249
 250
 251 SCM_DEFINE (scm_assq_set_x, "assq-set!", 3, 0, 0,
 252             (SCM alist, SCM key, SCM val),
 253             "@deffnx {Scheme Procedure} assv-set! alist key value\n"
 254             "@deffnx {Scheme Procedure} assoc-set! alist key value\n"
 255             "Reassociate @var{key} in @var{alist} with @var{value}: find any existing\n"
 256             "@var{alist} entry for @var{key} and associate it with the new\n"
 257             "@var{value}.  If @var{alist} does not contain an entry for @var{key},\n"
 258             "add a new one.  Return the (possibly new) alist.\n\n"
 259             "These functions do not attempt to verify the structure of @var{alist},\n"
 260             "and so may cause unusual results if passed an object that is not an\n"
 261             "association list.")
 262 #define FUNC_NAME s_scm_assq_set_x
 263 {
 264   SCM handle;
 265
 266   handle = scm_sloppy_assq (key, alist);
 267   if (SCM_CONSP (handle))
 268     {
 269       SCM_SETCDR (handle, val);
 270       return alist;
 271     }
 272   else
 273     return scm_acons (key, val, alist);
 274 }
 275 #undef FUNC_NAME
 276
 277 SCM_DEFINE (scm_assv_set_x, "assv-set!", 3, 0, 0,
 278             (SCM alist, SCM key, SCM val),
 279             "Behaves like @code{assq-set!} but uses @code{eqv?} for key comparison.")
 280 #define FUNC_NAME s_scm_assv_set_x
 281 {
 282   SCM handle;
 283
 284   handle = scm_sloppy_assv (key, alist);
 285   if (SCM_CONSP (handle))
 286     {
 287       SCM_SETCDR (handle, val);
 288       return alist;
 289     }
 290   else
 291     return scm_acons (key, val, alist);
 292 }
 293 #undef FUNC_NAME
 294
 295 SCM_DEFINE (scm_assoc_set_x, "assoc-set!", 3, 0, 0,
 296             (SCM alist, SCM key, SCM val),
 297             "Behaves like @code{assq-set!} but uses @code{equal?} for key comparison.")
 298 #define FUNC_NAME s_scm_assoc_set_x
 299 {
 300   SCM handle;
 301
 302   handle = scm_sloppy_assoc (key, alist);
 303   if (SCM_CONSP (handle))
 304     {
 305       SCM_SETCDR (handle, val);
 306       return alist;
 307     }
 308   else
 309     return scm_acons (key, val, alist);
 310 }
 311 #undef FUNC_NAME
 312
 313
 314 \f
 315
 316 SCM_DEFINE (scm_assq_remove_x, "assq-remove!", 2, 0, 0,
 317             (SCM alist, SCM key),
 318             "@deffnx {Scheme Procedure} assv-remove! alist key\n"
 319             "@deffnx {Scheme Procedure} assoc-remove! alist key\n"
 320             "Delete the first entry in @var{alist} associated with @var{key}, and return\n"
 321             "the resulting alist.")
 322 #define FUNC_NAME s_scm_assq_remove_x
 323 {
 324   SCM handle;
 325
 326   handle = scm_sloppy_assq (key, alist);
 327   if (SCM_CONSP (handle))
 328     alist = scm_delq1_x (handle, alist);
 329
 330   return alist;
 331 }
 332 #undef FUNC_NAME
 333
 334
 335 SCM_DEFINE (scm_assv_remove_x, "assv-remove!", 2, 0, 0,
 336             (SCM alist, SCM key),
 337             "Behaves like @code{assq-remove!} but uses @code{eqv?} for key comparison.")
 338 #define FUNC_NAME s_scm_assv_remove_x
 339 {
 340   SCM handle;
 341
 342   handle = scm_sloppy_assv (key, alist);
 343   if (SCM_CONSP (handle))
 344     alist = scm_delq1_x (handle, alist);
 345
 346   return alist;
 347 }
 348 #undef FUNC_NAME
 349
 350
 351 SCM_DEFINE (scm_assoc_remove_x, "assoc-remove!", 2, 0, 0,
 352             (SCM alist, SCM key),
 353             "Behaves like @code{assq-remove!} but uses @code{equal?} for key comparison.")
 354 #define FUNC_NAME s_scm_assoc_remove_x
 355 {
 356   SCM handle;
 357
 358   handle = scm_sloppy_assoc (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 \f
 368
 369
 370
 371 void
 372 scm_init_alist ()
 373 {
 374 #include "libguile/alist.x"
 375 }
 376
 377
 378 /*
 379   Local Variables:
 380   c-file-style: "gnu"
 381   End:
 382 */