| 1 | /* Copyright (C) 1998, 1999, 2000 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 | /* 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 | |
| 47 | #include "libguile/_scm.h" |
| 48 | #include "libguile/eval.h" |
| 49 | #include "libguile/macros.h" |
| 50 | #include "libguile/modules.h" |
| 51 | #include "libguile/fluids.h" |
| 52 | |
| 53 | #include "libguile/validate.h" |
| 54 | #include "libguile/evalext.h" |
| 55 | |
| 56 | SCM_SYMBOL (scm_sym_setter, "setter"); |
| 57 | |
| 58 | SCM |
| 59 | scm_m_generalized_set_x (SCM xorig, SCM env) |
| 60 | { |
| 61 | SCM x = SCM_CDR (xorig); |
| 62 | SCM_ASSYNT (2 == scm_ilength (x), xorig, scm_s_expression, scm_s_set_x); |
| 63 | if (SCM_SYMBOLP (SCM_CAR (x))) |
| 64 | return scm_cons (SCM_IM_SET_X, x); |
| 65 | else if (SCM_CONSP (SCM_CAR (x))) |
| 66 | return scm_cons (SCM_LIST2 (scm_sym_setter, SCM_CAAR (x)), |
| 67 | scm_append (SCM_LIST2 (SCM_CDAR (x), SCM_CDR (x)))); |
| 68 | else |
| 69 | scm_misc_error (scm_s_set_x, scm_s_variable, SCM_EOL); |
| 70 | } |
| 71 | |
| 72 | SCM_DEFINE (scm_definedp, "defined?", 1, 1, 0, |
| 73 | (SCM sym, SCM env), |
| 74 | "Return @code{#t} if @var{sym} is defined in the top-level environment.") |
| 75 | #define FUNC_NAME s_scm_definedp |
| 76 | { |
| 77 | SCM vcell; |
| 78 | |
| 79 | SCM_VALIDATE_SYMBOL (1,sym); |
| 80 | |
| 81 | if (SCM_UNBNDP (env)) |
| 82 | vcell = scm_sym2vcell(sym, |
| 83 | scm_module_system_booted_p |
| 84 | ? SCM_TOP_LEVEL_LOOKUP_CLOSURE |
| 85 | : SCM_EOL, |
| 86 | SCM_BOOL_F); |
| 87 | else |
| 88 | { |
| 89 | SCM frames = env; |
| 90 | register SCM b; |
| 91 | for (; SCM_NIMP (frames); frames = SCM_CDR (frames)) |
| 92 | { |
| 93 | SCM_ASSERT (SCM_CONSP (frames), env, SCM_ARG2, FUNC_NAME); |
| 94 | b = SCM_CAR (frames); |
| 95 | if (SCM_NFALSEP (scm_procedure_p (b))) |
| 96 | break; |
| 97 | SCM_ASSERT (SCM_CONSP (b), env, SCM_ARG2, FUNC_NAME); |
| 98 | for (b = SCM_CAR (b); SCM_NIMP (b); b = SCM_CDR (b)) |
| 99 | { |
| 100 | if (SCM_NCONSP (b)) |
| 101 | { |
| 102 | if (SCM_EQ_P (b, sym)) |
| 103 | return SCM_BOOL_T; |
| 104 | else |
| 105 | break; |
| 106 | } |
| 107 | if (SCM_EQ_P (SCM_CAR (b), sym)) |
| 108 | return SCM_BOOL_T; |
| 109 | } |
| 110 | } |
| 111 | vcell = scm_sym2vcell (sym, |
| 112 | SCM_NIMP (frames) ? SCM_CAR (frames) : SCM_BOOL_F, |
| 113 | SCM_BOOL_F); |
| 114 | } |
| 115 | |
| 116 | return (SCM_FALSEP (vcell) || SCM_UNBNDP (SCM_CDR (vcell)) |
| 117 | ? SCM_BOOL_F |
| 118 | : SCM_BOOL_T); |
| 119 | } |
| 120 | #undef FUNC_NAME |
| 121 | |
| 122 | |
| 123 | SCM_SYNTAX (s_undefine, "undefine", scm_makacro, scm_m_undefine); |
| 124 | |
| 125 | SCM |
| 126 | scm_m_undefine (SCM x, SCM env) |
| 127 | { |
| 128 | SCM arg1 = x; |
| 129 | x = SCM_CDR (x); |
| 130 | SCM_ASSYNT (SCM_TOP_LEVEL (env), arg1, "bad placement ", s_undefine); |
| 131 | SCM_ASSYNT (SCM_CONSP (x) && SCM_NULLP (SCM_CDR (x)), |
| 132 | arg1, scm_s_expression, s_undefine); |
| 133 | x = SCM_CAR (x); |
| 134 | SCM_ASSYNT (SCM_SYMBOLP (x), arg1, scm_s_variable, s_undefine); |
| 135 | arg1 = scm_sym2vcell (x, scm_env_top_level (env), SCM_BOOL_F); |
| 136 | SCM_ASSYNT (SCM_NFALSEP (arg1) && !SCM_UNBNDP (SCM_CDR (arg1)), |
| 137 | x, "variable already unbound ", s_undefine); |
| 138 | SCM_SETCDR (arg1, SCM_UNDEFINED); |
| 139 | #ifdef SICP |
| 140 | return SCM_CAR (arg1); |
| 141 | #else |
| 142 | return SCM_UNSPECIFIED; |
| 143 | #endif |
| 144 | } |
| 145 | |
| 146 | SCM_REGISTER_PROC (s_map_in_order, "map-in-order", 2, 0, 1, scm_map); |
| 147 | |
| 148 | void |
| 149 | scm_init_evalext () |
| 150 | { |
| 151 | scm_make_synt (scm_s_set_x, scm_makmmacro, scm_m_generalized_set_x); |
| 152 | #ifndef SCM_MAGIC_SNARFER |
| 153 | #include "libguile/evalext.x" |
| 154 | #endif |
| 155 | } |
| 156 | |
| 157 | /* |
| 158 | Local Variables: |
| 159 | c-file-style: "gnu" |
| 160 | End: |
| 161 | */ |