libguile/weaks.c

   1 /*      Copyright (C) 1995,1996,1998 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, Free Software Foundation gives permission
  19  * for additional uses of the text contained in its release of this library.
  20  *
  21  * The exception is that, if you link this 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 this 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
  31  * Free Software Foundation as part of this library.  If you copy
  32  * code from other releases distributed under the terms of the GPL into a copy of
  33  * this library, 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 such code.
  37  *
  38  * If you write modifications of your own for this library, 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 "_scm.h"
  48
  49 #include "scm_validate.h"
  50 #include "weaks.h"
  51 \f
  52
  53
  54 /* {Weak Vectors}
  55  */
  56
  57
  58 SCM_DEFINE (scm_make_weak_vector, "make-weak-vector", 1, 1, 0,
  59            (SCM k, SCM fill),
  60 "Return a weak vector with @var{size} elements. If the optional
  61 argument @var{fill} is given, all entries in the vector will be set to
  62 @var{fill}. The default value for @var{fill} is the empty list.")
  63 #define FUNC_NAME s_scm_make_weak_vector
  64 {
  65   SCM v;
  66   v = scm_make_vector (scm_sum (k, SCM_MAKINUM (2)), fill);
  67   SCM_DEFER_INTS;
  68   SCM_SETLENGTH(v, SCM_INUM (k), scm_tc7_wvect);
  69   SCM_VELTS(v)[0] = SCM_EOL;
  70   SCM_VELTS(v)[1] = (SCM)0;
  71   SCM_SETVELTS(v, SCM_VELTS(v) + 2);
  72   SCM_ALLOW_INTS;
  73   return v;
  74 }
  75 #undef FUNC_NAME
  76
  77
  78 SCM_REGISTER_PROC(s_list_to_weak_vector, "list->weak-vector", 1, 0, 0, scm_weak_vector);
  79
  80 SCM_DEFINE (scm_weak_vector, "weak-vector", 0, 0, 1,
  81            (SCM l),
  82 "@deffnx primitive list->weak-vector l
  83 Construct a weak vector from a list: @code{weak-vector} uses the list of
  84 its arguments while @code{list->weak-vector} uses its only argument
  85 @var{l} (a list) to construct a weak vector the same way
  86 @code{vector->list} would.")
  87 #define FUNC_NAME s_scm_weak_vector
  88 {
  89   SCM res;
  90   register SCM *data;
  91   long i;
  92
  93   i = scm_ilength (l);
  94   SCM_ASSERT (i >= 0, l, SCM_ARG1, FUNC_NAME);
  95   res = scm_make_weak_vector (SCM_MAKINUM (i), SCM_UNSPECIFIED);
  96   data = SCM_VELTS (res);
  97   for (;
  98        i && SCM_CONSP (l);
  99        --i, l = SCM_CDR (l))
 100     *data++ = SCM_CAR (l);
 101   return res;
 102 }
 103 #undef FUNC_NAME
 104
 105
 106 SCM_DEFINE (scm_weak_vector_p, "weak-vector?", 1, 0, 0,
 107            (SCM x),
 108 "Return @var{#t} if @var{obj} is a weak vector. Note that all weak
 109 hashes are also weak vectors.")
 110 #define FUNC_NAME s_scm_weak_vector_p
 111 {
 112   return SCM_BOOL(SCM_WVECTP (x) && !SCM_IS_WHVEC (x));
 113 }
 114 #undef FUNC_NAME
 115
 116
 117
 118 \f
 119
 120
 121
 122 SCM_DEFINE (scm_make_weak_key_hash_table, "make-weak-key-hash-table", 1, 0, 0,
 123            (SCM k),
 124 "@deffnx primitive make-weak-value-hash-table size
 125 @deffnx primitive make-doubly-weak-hash-table size
 126 Return a weak hash table with @var{size} buckets. As with any hash
 127 table, choosing a good size for the table requires some caution.
 128
 129 You can modify weak hash tables in exactly the same way you would modify
 130 regular hash tables. (@pxref{Hash Tables})")
 131 #define FUNC_NAME s_scm_make_weak_key_hash_table
 132 {
 133   SCM v;
 134   SCM_VALIDATE_INUM (1,k);
 135   v = scm_make_weak_vector (k, SCM_EOL);
 136   SCM_ALLOW_INTS;
 137   SCM_VELTS (v)[-1] = 1;
 138   SCM_ALLOW_INTS;
 139   return v;
 140 }
 141 #undef FUNC_NAME
 142
 143
 144 SCM_DEFINE (scm_make_weak_value_hash_table, "make-weak-value-hash-table", 1, 0, 0,
 145             (SCM k),
 146 "")
 147 #define FUNC_NAME s_scm_make_weak_value_hash_table
 148 {
 149   SCM v;
 150   SCM_VALIDATE_INUM (1,k);
 151   v = scm_make_weak_vector (k, SCM_EOL);
 152   SCM_ALLOW_INTS;
 153   SCM_VELTS (v)[-1] = 2;
 154   SCM_ALLOW_INTS;
 155   return v;
 156 }
 157 #undef FUNC_NAME
 158
 159
 160
 161 SCM_DEFINE (scm_make_doubly_weak_hash_table, "make-doubly-weak-hash-table", 1, 0, 0,
 162             (SCM k),
 163 "")
 164 #define FUNC_NAME s_scm_make_doubly_weak_hash_table
 165 {
 166   SCM v;
 167   SCM_VALIDATE_INUM (1,k);
 168   v = scm_make_weak_vector (k, SCM_EOL);
 169   SCM_ALLOW_INTS;
 170   SCM_VELTS (v)[-1] = 3;
 171   SCM_ALLOW_INTS;
 172   return v;
 173 }
 174 #undef FUNC_NAME
 175
 176 SCM_DEFINE (scm_weak_key_hash_table_p, "weak-key-hash-table?", 1, 0, 0,
 177            (SCM x),
 178 "@deffnx primitive weak-value-hash-table? obj
 179 @deffnx primitive doubly-weak-hash-table? obj
 180 Return @var{#t} if @var{obj} is the specified weak hash table. Note
 181 that a doubly weak hash table is neither a weak key nor a weak value
 182 hash table.")
 183 #define FUNC_NAME s_scm_weak_key_hash_table_p
 184 {
 185   return SCM_BOOL(SCM_WVECTP (x) && SCM_IS_WHVEC(x));
 186 }
 187 #undef FUNC_NAME
 188
 189
 190 SCM_DEFINE (scm_weak_value_hash_table_p, "weak-value-hash-table?", 1, 0, 0,
 191             (SCM x),
 192 "")
 193 #define FUNC_NAME s_scm_weak_value_hash_table_p
 194 {
 195   return SCM_BOOL(SCM_WVECTP (x) && SCM_IS_WHVEC_V(x));
 196 }
 197 #undef FUNC_NAME
 198
 199
 200 SCM_DEFINE (scm_doubly_weak_hash_table_p, "doubly-weak-hash-table?", 1, 0, 0,
 201             (SCM x),
 202 "")
 203 #define FUNC_NAME s_scm_doubly_weak_hash_table_p
 204 {
 205   return SCM_BOOL(SCM_WVECTP (x) && SCM_IS_WHVEC_B (x));
 206 }
 207 #undef FUNC_NAME
 208
 209
 210 \f
 211
 212
 213 void
 214 scm_init_weaks ()
 215 {
 216 #include "weaks.x"
 217 }
 218