libguile/evalext.c

   1 /* Copyright (C) 1998,1999,2000,2001,2002, 2003 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
  21 #include "libguile/_scm.h"
  22 #include "libguile/eval.h"
  23 #include "libguile/macros.h"
  24 #include "libguile/modules.h"
  25 #include "libguile/fluids.h"
  26
  27 #include "libguile/validate.h"
  28 #include "libguile/evalext.h"
  29
  30 SCM_SYMBOL (scm_sym_setter, "setter");
  31
  32 SCM
  33 scm_m_generalized_set_x (SCM xorig, SCM env SCM_UNUSED)
  34 {
  35   SCM x = SCM_CDR (xorig);
  36   SCM_ASSYNT (2 == scm_ilength (x), scm_s_expression, scm_s_set_x);
  37   if (SCM_SYMBOLP (SCM_CAR (x)))
  38     return scm_cons (SCM_IM_SET_X, x);
  39   else if (SCM_CONSP (SCM_CAR (x)))
  40     return scm_cons (scm_list_2 (scm_sym_setter, SCM_CAAR (x)),
  41                      scm_append (scm_list_2 (SCM_CDAR (x), SCM_CDR (x))));
  42   else
  43     scm_misc_error (scm_s_set_x, scm_s_variable, SCM_EOL);
  44 }
  45
  46 SCM_DEFINE (scm_defined_p, "defined?", 1, 1, 0,
  47             (SCM sym, SCM env),
  48             "Return @code{#t} if @var{sym} is defined in the lexical "
  49             "environment @var{env}.  When @var{env} is not specified, "
  50             "look in the top-level environment as defined by the "
  51             "current module.")
  52 #define FUNC_NAME s_scm_defined_p
  53 {
  54   SCM var;
  55
  56   SCM_VALIDATE_SYMBOL (1, sym);
  57
  58   if (SCM_UNBNDP (env))
  59     var = scm_sym2var (sym, scm_current_module_lookup_closure (),
  60                          SCM_BOOL_F);
  61   else
  62     {
  63       SCM frames = env;
  64       register SCM b;
  65       for (; SCM_NIMP (frames); frames = SCM_CDR (frames))
  66         {
  67           SCM_ASSERT (SCM_CONSP (frames), env, SCM_ARG2, FUNC_NAME);
  68           b = SCM_CAR (frames);
  69           if (SCM_NFALSEP (scm_procedure_p (b)))
  70             break;
  71           SCM_ASSERT (SCM_CONSP (b), env, SCM_ARG2, FUNC_NAME);
  72           for (b = SCM_CAR (b); SCM_NIMP (b); b = SCM_CDR (b))
  73             {
  74               if (SCM_NCONSP (b))
  75                 {
  76                   if (SCM_EQ_P (b, sym))
  77                     return SCM_BOOL_T;
  78                   else
  79                     break;
  80                 }
  81               if (SCM_EQ_P (SCM_CAR (b), sym))
  82                 return SCM_BOOL_T;
  83             }
  84         }
  85       var = scm_sym2var (sym,
  86                          SCM_NIMP (frames) ? SCM_CAR (frames) : SCM_BOOL_F,
  87                          SCM_BOOL_F);
  88     }
  89
  90   return (SCM_FALSEP (var) || SCM_UNBNDP (SCM_VARIABLE_REF (var))
  91           ? SCM_BOOL_F
  92           : SCM_BOOL_T);
  93 }
  94 #undef FUNC_NAME
  95
  96 #if (SCM_ENABLE_DEPRECATED == 1)
  97
  98 SCM_SYNTAX (s_undefine, "undefine", scm_makacro, scm_m_undefine);
  99
 100 SCM
 101 scm_m_undefine (SCM x, SCM env)
 102 {
 103   SCM arg1 = x;
 104   x = SCM_CDR (x);
 105   SCM_ASSYNT (SCM_TOP_LEVEL (env), "bad placement ", s_undefine);
 106   SCM_ASSYNT (SCM_CONSP (x) && SCM_NULLP (SCM_CDR (x)),
 107               scm_s_expression, s_undefine);
 108   x = SCM_CAR (x);
 109   SCM_ASSYNT (SCM_SYMBOLP (x), scm_s_variable, s_undefine);
 110   arg1 = scm_sym2var (x, scm_env_top_level (env), SCM_BOOL_F);
 111   SCM_ASSYNT (SCM_NFALSEP (arg1) && !SCM_UNBNDP (SCM_VARIABLE_REF (arg1)),
 112               "variable already unbound ", s_undefine);
 113   SCM_VARIABLE_SET (arg1, SCM_UNDEFINED);
 114 #ifdef SICP
 115   return x;
 116 #else
 117   return SCM_UNSPECIFIED;
 118 #endif
 119 }
 120
 121 #endif
 122
 123 SCM_REGISTER_PROC (s_map_in_order, "map-in-order", 2, 0, 1, scm_map);
 124
 125 SCM_DEFINE (scm_self_evaluating_p, "self-evaluating?", 1, 0, 0,
 126             (SCM obj),
 127             "Return #t for objects which Guile considers self-evaluating")
 128 #define FUNC_NAME s_scm_self_evaluating_p
 129 {
 130   switch (SCM_ITAG3 (obj))
 131     {
 132     case scm_tc3_int_1:
 133     case scm_tc3_int_2:
 134       /* inum */
 135       return SCM_BOOL_T;
 136     case scm_tc3_imm24:
 137         /* characters, booleans, other immediates */
 138       return SCM_BOOL (!SCM_NULLP (obj));
 139     case scm_tc3_cons:
 140       switch (SCM_TYP7 (obj))
 141         {
 142         case scm_tcs_closures:
 143         case scm_tc7_vector:
 144         case scm_tc7_wvect:
 145 #if SCM_HAVE_ARRAYS
 146         case scm_tc7_bvect:
 147         case scm_tc7_byvect:
 148         case scm_tc7_svect:
 149         case scm_tc7_ivect:
 150         case scm_tc7_uvect:
 151         case scm_tc7_fvect:
 152         case scm_tc7_dvect:
 153         case scm_tc7_cvect:
 154 #if SCM_SIZEOF_LONG_LONG != 0
 155         case scm_tc7_llvect:
 156 #endif
 157 #endif
 158         case scm_tc7_string:
 159         case scm_tc7_smob:
 160         case scm_tc7_cclo:
 161         case scm_tc7_pws:
 162         case scm_tcs_subrs:
 163         case scm_tcs_struct:
 164           return SCM_BOOL_T;
 165         default:
 166           return SCM_BOOL_F;
 167         }
 168     }
 169   SCM_MISC_ERROR ("Internal error: Object ~S has unknown type",
 170                   scm_list_1 (obj));
 171   return SCM_UNSPECIFIED; /* never reached */
 172 }
 173 #undef FUNC_NAME
 174
 175 void
 176 scm_init_evalext ()
 177 {
 178   scm_make_synt (scm_s_set_x, scm_makmmacro, scm_m_generalized_set_x);
 179 #include "libguile/evalext.x"
 180 }
 181
 182 /*
 183   Local Variables:
 184   c-file-style: "gnu"
 185   End:
 186 */