src/envs.c

   1 /* Copyright (C) 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 #include <string.h>
  43 #include "envs.h"
  44
  45 #define ENV_OBARRAY_SIZE 31
  46
  47 \f
  48 scm_bits_t scm_tc16_env;
  49
  50 SCM
  51 scm_c_make_env (void)
  52 {
  53   struct scm_env *p = scm_must_malloc (sizeof (struct scm_env),
  54                                        "scm_c_make_env");
  55   p->identifier = SCM_BOOL_F;
  56   p->obarray    = scm_c_make_hash_table (ENV_OBARRAY_SIZE);
  57   SCM_RETURN_NEWSMOB (scm_tc16_env, p);
  58 }
  59
  60 static SCM
  61 env_mark (SCM obj)
  62 {
  63   struct scm_env *p = SCM_ENV_DATA (obj);
  64   scm_gc_mark (p->identifier);
  65   return p->obarray;
  66 }
  67
  68 static scm_sizet
  69 env_free (SCM obj)
  70 {
  71   scm_must_free (SCM_ENV_DATA (obj));
  72   return sizeof (struct scm_env);
  73 }
  74
  75 \f
  76 /*
  77  * C interface
  78  */
  79
  80 static SCM env_table;
  81 static SCM load_env;
  82
  83 SCM
  84 scm_c_lookup_env (SCM identifier)
  85 {
  86   /* Check if the env is already loaded */
  87   SCM vcell = scm_sym2ovcell_soft (identifier, env_table);
  88
  89   /* If not, load the env */
  90   if (SCM_FALSEP (vcell))
  91     {
  92       SCM env = scm_apply (SCM_CDR (load_env),
  93                            SCM_LIST1 (identifier), SCM_EOL);
  94       if (!SCM_ENV_P (env))
  95         scm_misc_error ("scm_c_lookup_env",
  96                         "Invalid env: ~S", SCM_LIST1 (env));
  97       scm_intern_symbol (env_table, identifier);
  98       vcell = scm_sym2ovcell_soft (identifier, env_table);
  99       SCM_SETCDR (vcell, env);
 100     }
 101
 102   return SCM_CDR (vcell);
 103 }
 104
 105 SCM
 106 scm_c_env_vcell (SCM env, SCM name, int intern)
 107 {
 108   SCM ob = SCM_ENV_OBARRAY (env);
 109   if (intern)
 110     scm_intern_symbol (ob, name);
 111   return scm_sym2ovcell_soft (name, ob);
 112 }
 113
 114 \f
 115 /*
 116  * Scheme interface
 117  */
 118
 119 SCM_DEFINE (scm_make_env, "make-env", 0, 0, 0,
 120             (),
 121             "")
 122 #define FUNC_NAME s_scm_make_env
 123 {
 124   return scm_c_make_env ();
 125 }
 126 #undef FUNC_NAME
 127
 128 SCM_DEFINE (scm_env_p, "env?", 1, 0, 0,
 129             (SCM x),
 130             "")
 131 #define FUNC_NAME s_scm_env_p
 132 {
 133   return SCM_BOOL (SCM_ENV_P (x));
 134 }
 135 #undef FUNC_NAME
 136
 137 SCM_DEFINE (scm_env_identifier, "env-identifier", 1, 0, 0,
 138             (SCM env),
 139             "")
 140 #define FUNC_NAME s_scm_env_identifier
 141 {
 142   SCM_VALIDATE_ENV (1, env);
 143   return SCM_ENV_IDENTIFIER (env);
 144 }
 145 #undef FUNC_NAME
 146
 147 SCM_DEFINE (scm_set_env_identifier_x, "set-env-identifier!", 2, 0, 0,
 148             (SCM env, SCM identifier),
 149             "")
 150 #define FUNC_NAME s_scm_set_env_identifier_x
 151 {
 152   SCM_VALIDATE_ENV (1, env);
 153   SCM_VALIDATE_SYMBOL (2, identifier);
 154   SCM_ENV_IDENTIFIER (env) = identifier;
 155   return SCM_UNSPECIFIED;
 156 }
 157 #undef FUNC_NAME
 158
 159 SCM_DEFINE (scm_env_bound_p, "env-bound?", 2, 0, 0,
 160             (SCM env, SCM name),
 161             "")
 162 #define FUNC_NAME s_scm_env_bound_p
 163 {
 164   SCM vcell;
 165   SCM_VALIDATE_ENV (1, env);
 166   SCM_VALIDATE_SYMBOL (2, name);
 167   vcell = scm_sym2ovcell_soft (name, SCM_ENV_OBARRAY (env));
 168   return SCM_BOOL (!SCM_FALSEP (vcell) && !SCM_UNBNDP (SCM_CDR (vcell)));
 169 }
 170 #undef FUNC_NAME
 171
 172 SCM_DEFINE (scm_env_ref, "env-ref", 2, 0, 0,
 173             (SCM env, SCM name),
 174             "")
 175 #define FUNC_NAME s_scm_env_ref
 176 {
 177   SCM vcell;
 178   SCM_VALIDATE_ENV (1, env);
 179   SCM_VALIDATE_SYMBOL (2, name);
 180   vcell = scm_sym2ovcell_soft (name, SCM_ENV_OBARRAY (env));
 181   if (SCM_FALSEP (vcell) || SCM_UNBNDP (SCM_CDR (vcell)))
 182     SCM_MISC_ERROR ("Unbound variable in env: ~A, ~A",
 183                     SCM_LIST2 (env, name));
 184   return SCM_CDR (vcell);
 185 }
 186 #undef FUNC_NAME
 187
 188 SCM_DEFINE (scm_env_set_x, "env-set!", 3, 0, 0,
 189             (SCM env, SCM name, SCM val),
 190             "")
 191 #define FUNC_NAME s_scm_env_set_x
 192 {
 193   SCM vcell;
 194   SCM_VALIDATE_ENV (1, env);
 195   SCM_VALIDATE_SYMBOL (2, name);
 196   vcell = scm_sym2ovcell_soft (name, SCM_ENV_OBARRAY (env));
 197   if (SCM_FALSEP (vcell))
 198     SCM_MISC_ERROR ("Unbound variable in env: ~A, ~A",
 199                     SCM_LIST2 (env, name));
 200   SCM_SETCDR (vcell, val);
 201   return SCM_UNSPECIFIED;
 202 }
 203 #undef FUNC_NAME
 204
 205 SCM_DEFINE (scm_env_define, "env-define", 3, 0, 0,
 206             (SCM env, SCM name, SCM val),
 207             "")
 208 #define FUNC_NAME s_scm_env_define
 209 {
 210   SCM vcell;
 211   SCM_VALIDATE_ENV (1, env);
 212   SCM_VALIDATE_SYMBOL (2, name);
 213   vcell = scm_c_env_vcell (env, name, 1);
 214   SCM_SETCDR (vcell, val);
 215   return SCM_UNSPECIFIED;
 216 }
 217 #undef FUNC_NAME
 218
 219 \f
 220 void
 221 scm_init_envs (void)
 222 {
 223   SCM mod;
 224
 225   scm_tc16_env = scm_make_smob_type ("env", 0);
 226   scm_set_smob_mark (scm_tc16_env, env_mark);
 227   scm_set_smob_free (scm_tc16_env, env_free);
 228
 229   env_table = scm_permanent_object (scm_c_make_hash_table (51));
 230
 231 #ifndef SCM_MAGIC_SNARFER
 232 #include "envs.x"
 233 #endif
 234
 235   mod = scm_current_module ();
 236   load_env = scm_eval_closure_lookup (scm_standard_eval_closure (mod),
 237                                       scm_str2symbol ("load-env"),
 238                                       SCM_BOOL_T);
 239   load_env = SCM_VARVCELL (load_env);
 240 }
 241
 242 /*
 243   Local Variables:
 244   c-file-style: "gnu"
 245   End:
 246 */