| 1 | /* Copyright (C) 1995,1996,1997,1998, 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/root.h" |
| 49 | #include "libguile/smob.h" |
| 50 | |
| 51 | #include "libguile/validate.h" |
| 52 | #include "libguile/macros.h" |
| 53 | |
| 54 | scm_bits_t scm_tc16_macro; |
| 55 | |
| 56 | SCM_DEFINE (scm_makacro, "procedure->syntax", 1, 0, 0, |
| 57 | (SCM code), |
| 58 | "Return a @dfn{macro} which, when a symbol defined to this value\n" |
| 59 | "appears as the first symbol in an expression, returns the\n" |
| 60 | "result of applying @var{code} to the expression and the\n" |
| 61 | "environment.") |
| 62 | #define FUNC_NAME s_scm_makacro |
| 63 | { |
| 64 | SCM_VALIDATE_PROC (1,code); |
| 65 | SCM_RETURN_NEWSMOB (scm_tc16_macro, SCM_UNPACK (code)); |
| 66 | } |
| 67 | #undef FUNC_NAME |
| 68 | |
| 69 | |
| 70 | SCM_DEFINE (scm_makmacro, "procedure->macro", 1, 0, 0, |
| 71 | (SCM code), |
| 72 | "Return a @dfn{macro} which, when a symbol defined to this value\n" |
| 73 | "appears as the first symbol in an expression, evaluates the\n" |
| 74 | "result of applying @var{code} to the expression and the\n" |
| 75 | "environment. The value returned from @var{code} which has been\n" |
| 76 | "passed to @code{procedure->memoizing-macro} replaces the form\n" |
| 77 | "passed to @var{code}. For example:\n" |
| 78 | "\n" |
| 79 | "@lisp\n" |
| 80 | "(define trace\n" |
| 81 | " (procedure->macro\n" |
| 82 | " (lambda (x env) `(set! ,(cadr x) (tracef ,(cadr x) ',(cadr x))))))\n\n" |
| 83 | "(trace @i{foo}) @equiv{} (set! @i{foo} (tracef @i{foo} '@i{foo})).\n" |
| 84 | "@end lisp") |
| 85 | #define FUNC_NAME s_scm_makmacro |
| 86 | { |
| 87 | SCM_VALIDATE_PROC (1,code); |
| 88 | SCM_RETURN_NEWSMOB (scm_tc16_macro | (1L << 16), SCM_UNPACK (code)); |
| 89 | } |
| 90 | #undef FUNC_NAME |
| 91 | |
| 92 | |
| 93 | SCM_DEFINE (scm_makmmacro, "procedure->memoizing-macro", 1, 0, 0, |
| 94 | (SCM code), |
| 95 | "Return a @dfn{macro} which, when a symbol defined to this value\n" |
| 96 | "appears as the first symbol in an expression, evaluates the\n" |
| 97 | "result of applying @var{proc} to the expression and the\n" |
| 98 | "environment. The value returned from @var{proc} which has been\n" |
| 99 | "passed to @code{procedure->memoizing-macro} replaces the form\n" |
| 100 | "passed to @var{proc}. For example:\n" |
| 101 | "\n" |
| 102 | "@lisp\n" |
| 103 | "(define trace\n" |
| 104 | " (procedure->macro\n" |
| 105 | " (lambda (x env) `(set! ,(cadr x) (tracef ,(cadr x) ',(cadr x))))))\n\n" |
| 106 | "(trace @i{foo}) @equiv{} (set! @i{foo} (tracef @i{foo} '@i{foo})).\n" |
| 107 | "@end lisp") |
| 108 | #define FUNC_NAME s_scm_makmmacro |
| 109 | { |
| 110 | SCM_VALIDATE_PROC (1,code); |
| 111 | SCM_RETURN_NEWSMOB (scm_tc16_macro | (2L << 16), SCM_UNPACK (code)); |
| 112 | } |
| 113 | #undef FUNC_NAME |
| 114 | |
| 115 | |
| 116 | SCM_DEFINE (scm_macro_p, "macro?", 1, 0, 0, |
| 117 | (SCM obj), |
| 118 | "Return @code{#t} if @var{obj} is a regular macro, a memoizing macro or a\n" |
| 119 | "syntax transformer.") |
| 120 | #define FUNC_NAME s_scm_macro_p |
| 121 | { |
| 122 | return SCM_BOOL (SCM_TYP16_PREDICATE (scm_tc16_macro, obj)); |
| 123 | } |
| 124 | #undef FUNC_NAME |
| 125 | |
| 126 | |
| 127 | SCM_SYMBOL (scm_sym_syntax, "syntax"); |
| 128 | SCM_SYMBOL (scm_sym_macro, "macro"); |
| 129 | SCM_SYMBOL (scm_sym_mmacro, "macro!"); |
| 130 | |
| 131 | SCM_DEFINE (scm_macro_type, "macro-type", 1, 0, 0, |
| 132 | (SCM m), |
| 133 | "Return one of the symbols @code{syntax}, @code{macro} or\n" |
| 134 | "@code{macro!}, depending on whether @var{m} is a syntax\n" |
| 135 | "tranformer, a regular macro, or a memoizing macro,\n" |
| 136 | "respectively. If @var{m} is not a macro, @code{#f} is\n" |
| 137 | "returned.") |
| 138 | #define FUNC_NAME s_scm_macro_type |
| 139 | { |
| 140 | if (!SCM_TYP16_PREDICATE (scm_tc16_macro, m)) |
| 141 | return SCM_BOOL_F; |
| 142 | switch (SCM_CELL_WORD_0 (m) >> 16) |
| 143 | { |
| 144 | case 0: return scm_sym_syntax; |
| 145 | case 1: return scm_sym_macro; |
| 146 | case 2: return scm_sym_mmacro; |
| 147 | default: scm_wrong_type_arg (FUNC_NAME, 1, m); |
| 148 | } |
| 149 | } |
| 150 | #undef FUNC_NAME |
| 151 | |
| 152 | |
| 153 | SCM_DEFINE (scm_macro_name, "macro-name", 1, 0, 0, |
| 154 | (SCM m), |
| 155 | "Return the name of the macro @var{m}.") |
| 156 | #define FUNC_NAME s_scm_macro_name |
| 157 | { |
| 158 | SCM_VALIDATE_SMOB (1,m,macro); |
| 159 | return scm_procedure_name (SCM_PACK (SCM_SMOB_DATA (m))); |
| 160 | } |
| 161 | #undef FUNC_NAME |
| 162 | |
| 163 | |
| 164 | SCM_DEFINE (scm_macro_transformer, "macro-transformer", 1, 0, 0, |
| 165 | (SCM m), |
| 166 | "Return the transformer of the macro @var{m}.") |
| 167 | #define FUNC_NAME s_scm_macro_transformer |
| 168 | { |
| 169 | SCM_VALIDATE_SMOB (1,m,macro); |
| 170 | return ((SCM_CLOSUREP (SCM_PACK (SCM_SMOB_DATA (m)))) ? |
| 171 | SCM_PACK(SCM_SMOB_DATA (m)) : SCM_BOOL_F); |
| 172 | } |
| 173 | #undef FUNC_NAME |
| 174 | |
| 175 | SCM |
| 176 | scm_make_synt (const char *name, SCM (*macroizer) (), SCM (*fcn)() ) |
| 177 | { |
| 178 | SCM symcell = scm_sysintern (name, SCM_UNDEFINED); |
| 179 | SCM transformer = scm_make_subr_opt (name, scm_tc7_subr_2, fcn, 0); |
| 180 | SCM_SETCDR (symcell, macroizer (transformer)); |
| 181 | return SCM_CAR (symcell); |
| 182 | } |
| 183 | |
| 184 | void |
| 185 | scm_init_macros () |
| 186 | { |
| 187 | scm_tc16_macro = scm_make_smob_type ("macro", 0); |
| 188 | scm_set_smob_mark (scm_tc16_macro, scm_markcdr); |
| 189 | #ifndef SCM_MAGIC_SNARFER |
| 190 | #include "libguile/macros.x" |
| 191 | #endif |
| 192 | } |
| 193 | |
| 194 | /* |
| 195 | Local Variables: |
| 196 | c-file-style: "gnu" |
| 197 | End: |
| 198 | */ |