libguile/macros.c

   1 /* Copyright (C) 1995,1996,1997,1998,2000,2001,2002,2003, 2006, 2008, 2009 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 License
   5  * as published by the Free Software Foundation; either version 3 of
   6  * the License, or (at your option) any later version.
   7  *
   8  * This library is distributed in the hope that it will be useful, but
   9  * 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., 51 Franklin Street, Fifth Floor, Boston, MA
  16  * 02110-1301 USA
  17  */
  18
  19
  20 \f
  21 #ifdef HAVE_CONFIG_H
  22 # include <config.h>
  23 #endif
  24
  25 #define SCM_BUILDING_DEPRECATED_CODE
  26
  27 #include "libguile/_scm.h"
  28 #include "libguile/alist.h" /* for SCM_EXTEND_ENV (well...) */
  29 #include "libguile/eval.h"
  30 #include "libguile/ports.h"
  31 #include "libguile/print.h"
  32 #include "libguile/root.h"
  33 #include "libguile/smob.h"
  34 #include "libguile/deprecation.h"
  35
  36 #include "libguile/validate.h"
  37 #include "libguile/programs.h"
  38 #include "libguile/macros.h"
  39
  40 #include "libguile/private-options.h"
  41
  42 scm_t_bits scm_tc16_macro;
  43
  44
  45 static int
  46 macro_print (SCM macro, SCM port, scm_print_state *pstate)
  47 {
  48   SCM code = SCM_MACRO_CODE (macro);
  49   if (!SCM_CLOSUREP (code)
  50       || scm_is_false (scm_procedure_p (SCM_PRINT_CLOSURE))
  51       || scm_is_false (scm_printer_apply (SCM_PRINT_CLOSURE,
  52                                         macro, port, pstate)))
  53     {
  54       scm_puts ("#<", port);
  55
  56       if (SCM_MACRO_TYPE (macro) < 4 && SCM_MACRO_IS_EXTENDED (macro))
  57         scm_puts ("extended-", port);
  58
  59       if (!SCM_CLOSUREP (code) && !SCM_PROGRAM_P (code))
  60         scm_puts ("primitive-", port);
  61
  62       if (SCM_MACRO_TYPE (macro) == 0)
  63         scm_puts ("syntax", port);
  64 #if SCM_ENABLE_DEPRECATED == 1
  65       if (SCM_MACRO_TYPE (macro) == 1)
  66         scm_puts ("macro", port);
  67 #endif
  68       if (SCM_MACRO_TYPE (macro) == 2)
  69         scm_puts ("macro!", port);
  70       if (SCM_MACRO_TYPE (macro) == 3)
  71         scm_puts ("builtin-macro!", port);
  72       if (SCM_MACRO_TYPE (macro) == 4)
  73         scm_puts ("syncase-macro", port);
  74
  75       scm_putc (' ', port);
  76       scm_iprin1 (scm_macro_name (macro), port, pstate);
  77
  78       if (SCM_CLOSUREP (code) && SCM_PRINT_SOURCE_P)
  79         {
  80           SCM formals = SCM_CLOSURE_FORMALS (code);
  81           SCM env = SCM_ENV (code);
  82           SCM xenv = SCM_EXTEND_ENV (formals, SCM_EOL, env);
  83           SCM src = scm_i_unmemocopy_body (SCM_CODE (code), xenv);
  84           scm_putc (' ', port);
  85           scm_iprin1 (src, port, pstate);
  86         }
  87
  88       if (SCM_MACRO_IS_EXTENDED (macro))
  89         {
  90           scm_putc (' ', port);
  91           scm_write (SCM_SMOB_OBJECT_2 (macro), port);
  92           scm_putc (' ', port);
  93           scm_write (SCM_SMOB_OBJECT_3 (macro), port);
  94         }
  95
  96       scm_putc ('>', port);
  97     }
  98
  99   return 1;
 100 }
 101
 102 static SCM
 103 makmac (SCM code, scm_t_bits flags)
 104 {
 105   SCM z;
 106   SCM_NEWSMOB (z, scm_tc16_macro, SCM_UNPACK (code));
 107   SCM_SET_SMOB_FLAGS (z, flags);
 108   return z;
 109 }
 110
 111 /* Return a mmacro that is known to be one of guile's built in macros. */
 112 SCM
 113 scm_i_makbimacro (SCM code)
 114 #define FUNC_NAME "scm_i_makbimacro"
 115 {
 116   SCM_VALIDATE_PROC (1, code);
 117   return makmac (code, 3);
 118 }
 119 #undef FUNC_NAME
 120
 121
 122 SCM_DEFINE (scm_makmmacro, "procedure->memoizing-macro", 1, 0, 0,
 123            (SCM code),
 124             "Return a @dfn{macro} which, when a symbol defined to this value\n"
 125             "appears as the first symbol in an expression, evaluates the\n"
 126             "result of applying @var{code} to the expression and the\n"
 127             "environment.\n\n"
 128             "@code{procedure->memoizing-macro} is the same as\n"
 129             "@code{procedure->macro}, except that the expression returned by\n"
 130             "@var{code} replaces the original macro expression in the memoized\n"
 131             "form of the containing code.")
 132 #define FUNC_NAME s_scm_makmmacro
 133 {
 134   SCM_VALIDATE_PROC (1, code);
 135   return makmac (code, 2);
 136 }
 137 #undef FUNC_NAME
 138
 139
 140 SCM_DEFINE (scm_makacro, "procedure->syntax", 1, 0, 0,
 141             (SCM code),
 142             "Return a @dfn{macro} which, when a symbol defined to this value\n"
 143             "appears as the first symbol in an expression, returns the\n"
 144             "result of applying @var{code} to the expression and the\n"
 145             "environment.")
 146 #define FUNC_NAME s_scm_makacro
 147 {
 148   SCM_VALIDATE_PROC (1, code);
 149   return makmac (code, 0);
 150 }
 151 #undef FUNC_NAME
 152
 153
 154 #if SCM_ENABLE_DEPRECATED == 1
 155
 156 SCM_DEFINE (scm_makmacro, "procedure->macro", 1, 0, 0,
 157            (SCM code),
 158             "Return a @dfn{macro} which, when a symbol defined to this value\n"
 159             "appears as the first symbol in an expression, evaluates the\n"
 160             "result of applying @var{code} to the expression and the\n"
 161             "environment.  For example:\n"
 162             "\n"
 163             "@lisp\n"
 164             "(define trace\n"
 165             "  (procedure->macro\n"
 166             "   (lambda (x env) `(set! ,(cadr x) (tracef ,(cadr x) ',(cadr x))))))\n\n"
 167             "(trace @i{foo}) @equiv{} (set! @i{foo} (tracef @i{foo} '@i{foo})).\n"
 168             "@end lisp")
 169 #define FUNC_NAME s_scm_makmacro
 170 {
 171   scm_c_issue_deprecation_warning
 172     ("The function procedure->macro is deprecated, and so are"
 173      " non-memoizing macros in general.  Use memoizing macros"
 174      " or r5rs macros instead.");
 175
 176   SCM_VALIDATE_PROC (1, code);
 177   return makmac (code, 1);
 178 }
 179 #undef FUNC_NAME
 180
 181 #endif
 182
 183 SCM_DEFINE (scm_make_syncase_macro, "make-syncase-macro", 2, 0, 0,
 184             (SCM type, SCM binding),
 185             "Return a @dfn{macro} that requires expansion by syntax-case.\n"
 186             "While users should not call this function, it is useful to know\n"
 187             "that syntax-case macros are represented as Guile primitive macros.")
 188 #define FUNC_NAME s_scm_make_syncase_macro
 189 {
 190   SCM z;
 191   SCM_VALIDATE_SYMBOL (1, type);
 192
 193   SCM_NEWSMOB3 (z, scm_tc16_macro, SCM_UNPACK (binding), SCM_UNPACK (type),
 194                 SCM_UNPACK (binding));
 195   SCM_SET_SMOB_FLAGS (z, 4 | SCM_F_MACRO_EXTENDED);
 196   return z;
 197 }
 198 #undef FUNC_NAME
 199
 200 SCM_DEFINE (scm_make_extended_syncase_macro, "make-extended-syncase-macro", 3, 0, 0,
 201             (SCM m, SCM type, SCM binding),
 202             "Extend a core macro @var{m} with a syntax-case binding.")
 203 #define FUNC_NAME s_scm_make_extended_syncase_macro
 204 {
 205   SCM z;
 206   SCM_VALIDATE_SMOB (1, m, macro);
 207   SCM_VALIDATE_SYMBOL (2, type);
 208
 209   SCM_NEWSMOB3 (z, scm_tc16_macro, SCM_SMOB_DATA (m), SCM_UNPACK (type),
 210                 SCM_UNPACK (binding));
 211   SCM_SET_SMOB_FLAGS (z, SCM_SMOB_FLAGS (m) | SCM_F_MACRO_EXTENDED);
 212   return z;
 213 }
 214 #undef FUNC_NAME
 215
 216
 217
 218 SCM_DEFINE (scm_macro_p, "macro?", 1, 0, 0,
 219             (SCM obj),
 220             "Return @code{#t} if @var{obj} is a regular macro, a memoizing macro, a\n"
 221             "syntax transformer, or a syntax-case macro.")
 222 #define FUNC_NAME s_scm_macro_p
 223 {
 224   return scm_from_bool (SCM_SMOB_PREDICATE (scm_tc16_macro, obj));
 225 }
 226 #undef FUNC_NAME
 227
 228
 229 SCM_SYMBOL (scm_sym_syntax, "syntax");
 230 #if SCM_ENABLE_DEPRECATED == 1
 231 SCM_SYMBOL (scm_sym_macro, "macro");
 232 #endif
 233 SCM_SYMBOL (scm_sym_mmacro, "macro!");
 234 SCM_SYMBOL (scm_sym_bimacro, "builtin-macro!");
 235 SCM_SYMBOL (scm_sym_syncase_macro, "syncase-macro");
 236
 237 SCM_DEFINE (scm_macro_type, "macro-type", 1, 0, 0,
 238             (SCM m),
 239             "Return one of the symbols @code{syntax}, @code{macro},\n"
 240             "@code{macro!}, or @code{syntax-case}, depending on whether\n"
 241             "@var{m} is a syntax transformer, a regular macro, a memoizing\n"
 242             "macro, or a syntax-case macro, respectively.  If @var{m} is\n"
 243             "not a macro, @code{#f} is returned.")
 244 #define FUNC_NAME s_scm_macro_type
 245 {
 246   if (!SCM_SMOB_PREDICATE (scm_tc16_macro, m))
 247     return SCM_BOOL_F;
 248   switch (SCM_MACRO_TYPE (m))
 249     {
 250     case 0: return scm_sym_syntax;
 251 #if SCM_ENABLE_DEPRECATED == 1
 252     case 1: return scm_sym_macro;
 253 #endif
 254     case 2: return scm_sym_mmacro;
 255     case 3: return scm_sym_bimacro;
 256     case 4: return scm_sym_syncase_macro;
 257     default: scm_wrong_type_arg (FUNC_NAME, 1, m);
 258     }
 259 }
 260 #undef FUNC_NAME
 261
 262
 263 SCM_DEFINE (scm_macro_name, "macro-name", 1, 0, 0,
 264             (SCM m),
 265             "Return the name of the macro @var{m}.")
 266 #define FUNC_NAME s_scm_macro_name
 267 {
 268   SCM_VALIDATE_SMOB (1, m, macro);
 269   if (scm_is_true (scm_procedure_p (SCM_SMOB_OBJECT (m))))
 270     return scm_procedure_name (SCM_SMOB_OBJECT (m));
 271   return SCM_BOOL_F;
 272 }
 273 #undef FUNC_NAME
 274
 275
 276 SCM_DEFINE (scm_macro_transformer, "macro-transformer", 1, 0, 0,
 277             (SCM m),
 278             "Return the transformer of the macro @var{m}.")
 279 #define FUNC_NAME s_scm_macro_transformer
 280 {
 281   SCM data;
 282
 283   SCM_VALIDATE_SMOB (1, m, macro);
 284   data = SCM_PACK (SCM_SMOB_DATA (m));
 285
 286   if (SCM_CLOSUREP (data) || SCM_PROGRAM_P (data))
 287     return data;
 288   else
 289     return SCM_BOOL_F;
 290 }
 291 #undef FUNC_NAME
 292
 293 SCM_DEFINE (scm_syncase_macro_type, "syncase-macro-type", 1, 0, 0,
 294             (SCM m),
 295             "Return the type of the macro @var{m}.")
 296 #define FUNC_NAME s_scm_syncase_macro_type
 297 {
 298   SCM_VALIDATE_SMOB (1, m, macro);
 299
 300   if (SCM_MACRO_IS_EXTENDED (m))
 301     return SCM_SMOB_OBJECT_2 (m);
 302   else
 303     return SCM_BOOL_F;
 304 }
 305 #undef FUNC_NAME
 306
 307 SCM_DEFINE (scm_syncase_macro_binding, "syncase-macro-binding", 1, 0, 0,
 308             (SCM m),
 309             "Return the binding of the macro @var{m}.")
 310 #define FUNC_NAME s_scm_syncase_macro_binding
 311 {
 312   SCM_VALIDATE_SMOB (1, m, macro);
 313
 314   if (SCM_MACRO_IS_EXTENDED (m))
 315     return SCM_SMOB_OBJECT_3 (m);
 316   else
 317     return SCM_BOOL_F;
 318 }
 319 #undef FUNC_NAME
 320
 321 SCM
 322 scm_make_synt (const char *name, SCM (*macroizer) (), SCM (*fcn)() )
 323 {
 324   SCM var = scm_c_define (name, SCM_UNDEFINED);
 325   SCM transformer = scm_c_make_subr (name, scm_tc7_subr_2, fcn);
 326   SCM_VARIABLE_SET (var, macroizer (transformer));
 327   return SCM_UNSPECIFIED;
 328 }
 329
 330 void
 331 scm_init_macros ()
 332 {
 333   scm_tc16_macro = scm_make_smob_type ("macro", 0);
 334   scm_set_smob_print (scm_tc16_macro, macro_print);
 335 #include "libguile/macros.x"
 336 }
 337
 338 /*
 339   Local Variables:
 340   c-file-style: "gnu"
 341   End:
 342 */