libguile/procs.c

   1 /* Copyright (C) 1995,1996,1997,1999,2000,2001, 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
   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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  16  */
  17
  18
  19 \f
  20 #ifdef HAVE_CONFIG_H
  21 # include <config.h>
  22 #endif
  23
  24 #include "libguile/_scm.h"
  25
  26 #include "libguile/objects.h"
  27 #include "libguile/strings.h"
  28 #include "libguile/vectors.h"
  29 #include "libguile/smob.h"
  30 #include "libguile/deprecation.h"
  31
  32 #include "libguile/validate.h"
  33 #include "libguile/procs.h"
  34 #include "libguile/procprop.h"
  35 #include "libguile/objcodes.h"
  36 #include "libguile/programs.h"
  37 \f
  38
  39
  40 /* {Procedures}
  41  */
  42
  43
  44 SCM
  45 scm_c_make_subr (const char *name, long type, SCM (*fcn) ())
  46 {
  47   register SCM z;
  48   SCM *meta_info;
  49
  50   meta_info = scm_gc_malloc (2 * sizeof (*meta_info), "subr meta-info");
  51   meta_info[0] = scm_from_locale_symbol (name);
  52   meta_info[1] = SCM_EOL;  /* properties */
  53
  54   z = scm_double_cell ((scm_t_bits) type, (scm_t_bits) fcn,
  55                        0 /* generic */, (scm_t_bits) meta_info);
  56
  57   return z;
  58 }
  59
  60 SCM
  61 scm_c_define_subr (const char *name, long type, SCM (*fcn) ())
  62 {
  63   SCM subr = scm_c_make_subr (name, type, fcn);
  64   scm_define (SCM_SNAME (subr), subr);
  65   return subr;
  66 }
  67
  68 SCM
  69 scm_c_make_subr_with_generic (const char *name,
  70                               long type, SCM (*fcn) (), SCM *gf)
  71 {
  72   SCM subr = scm_c_make_subr (name, type, fcn);
  73   SCM_SET_SUBR_GENERIC_LOC (subr, gf);
  74   return subr;
  75 }
  76
  77 SCM
  78 scm_c_define_subr_with_generic (const char *name,
  79                                 long type, SCM (*fcn) (), SCM *gf)
  80 {
  81   SCM subr = scm_c_make_subr_with_generic (name, type, fcn, gf);
  82   scm_define (SCM_SNAME (subr), subr);
  83   return subr;
  84 }
  85
  86
  87 SCM_DEFINE (scm_procedure_p, "procedure?", 1, 0, 0,
  88             (SCM obj),
  89             "Return @code{#t} if @var{obj} is a procedure.")
  90 #define FUNC_NAME s_scm_procedure_p
  91 {
  92   if (SCM_NIMP (obj))
  93     switch (SCM_TYP7 (obj))
  94       {
  95       case scm_tcs_struct:
  96         if (!SCM_I_OPERATORP (obj))
  97           break;
  98       case scm_tcs_closures:
  99       case scm_tcs_subrs:
 100       case scm_tc7_pws:
 101         return SCM_BOOL_T;
 102       case scm_tc7_smob:
 103         return scm_from_bool (SCM_SMOB_DESCRIPTOR (obj).apply);
 104       default:
 105         return SCM_BOOL_F;
 106       }
 107   return SCM_BOOL_F;
 108 }
 109 #undef FUNC_NAME
 110
 111 SCM_DEFINE (scm_closure_p, "closure?", 1, 0, 0,
 112            (SCM obj),
 113             "Return @code{#t} if @var{obj} is a closure.")
 114 #define FUNC_NAME s_scm_closure_p
 115 {
 116   return scm_from_bool (SCM_CLOSUREP (obj));
 117 }
 118 #undef FUNC_NAME
 119
 120 SCM_DEFINE (scm_thunk_p, "thunk?", 1, 0, 0,
 121             (SCM obj),
 122             "Return @code{#t} if @var{obj} is a thunk.")
 123 #define FUNC_NAME s_scm_thunk_p
 124 {
 125   if (SCM_NIMP (obj))
 126     {
 127     again:
 128       switch (SCM_TYP7 (obj))
 129         {
 130         case scm_tcs_closures:
 131           return scm_from_bool (!scm_is_pair (SCM_CLOSURE_FORMALS (obj)));
 132         case scm_tc7_subr_0:
 133         case scm_tc7_subr_1o:
 134         case scm_tc7_lsubr:
 135         case scm_tc7_rpsubr:
 136         case scm_tc7_asubr:
 137           return SCM_BOOL_T;
 138         case scm_tc7_gsubr:
 139           return scm_from_bool (SCM_GSUBR_REQ (SCM_GSUBR_TYPE (obj)) == 0);
 140         case scm_tc7_pws:
 141           obj = SCM_PROCEDURE (obj);
 142           goto again;
 143         default:
 144           if (SCM_PROGRAM_P (obj) && SCM_PROGRAM_DATA (obj)->nargs == 0)
 145             return SCM_BOOL_T;
 146           /* otherwise fall through */
 147         }
 148     }
 149   return SCM_BOOL_F;
 150 }
 151 #undef FUNC_NAME
 152
 153 /* Only used internally. */
 154 int
 155 scm_subr_p (SCM obj)
 156 {
 157   if (SCM_NIMP (obj))
 158     switch (SCM_TYP7 (obj))
 159       {
 160       case scm_tcs_subrs:
 161         return 1;
 162       default:
 163         ;
 164       }
 165   return 0;
 166 }
 167
 168 SCM_DEFINE (scm_procedure_documentation, "procedure-documentation", 1, 0, 0,
 169            (SCM proc),
 170             "Return the documentation string associated with @code{proc}.  By\n"
 171             "convention, if a procedure contains more than one expression and the\n"
 172             "first expression is a string constant, that string is assumed to contain\n"
 173             "documentation for that procedure.")
 174 #define FUNC_NAME s_scm_procedure_documentation
 175 {
 176   SCM code;
 177   SCM_ASSERT (scm_is_true (scm_procedure_p (proc)),
 178               proc, SCM_ARG1, FUNC_NAME);
 179   switch (SCM_TYP7 (proc))
 180     {
 181     case scm_tcs_closures:
 182       code = SCM_CLOSURE_BODY (proc);
 183       if (scm_is_null (SCM_CDR (code)))
 184         return SCM_BOOL_F;
 185       code = SCM_CAR (code);
 186       if (scm_is_string (code))
 187         return code;
 188       else
 189         return SCM_BOOL_F;
 190     default:
 191       return SCM_BOOL_F;
 192     }
 193 }
 194 #undef FUNC_NAME
 195
 196
 197 /* Procedure-with-setter
 198  */
 199
 200 SCM_DEFINE (scm_procedure_with_setter_p, "procedure-with-setter?", 1, 0, 0,
 201             (SCM obj),
 202             "Return @code{#t} if @var{obj} is a procedure with an\n"
 203             "associated setter procedure.")
 204 #define FUNC_NAME s_scm_procedure_with_setter_p
 205 {
 206   return scm_from_bool(SCM_PROCEDURE_WITH_SETTER_P (obj));
 207 }
 208 #undef FUNC_NAME
 209
 210 SCM_DEFINE (scm_make_procedure_with_setter, "make-procedure-with-setter", 2, 0, 0,
 211             (SCM procedure, SCM setter),
 212             "Create a new procedure which behaves like @var{procedure}, but\n"
 213             "with the associated setter @var{setter}.")
 214 #define FUNC_NAME s_scm_make_procedure_with_setter
 215 {
 216   SCM name, ret;
 217   SCM_VALIDATE_PROC (1, procedure);
 218   SCM_VALIDATE_PROC (2, setter);
 219   ret = scm_double_cell (scm_tc7_pws,
 220                          SCM_UNPACK (procedure),
 221                          SCM_UNPACK (setter), 0);
 222   /* don't use procedure_name, because don't care enough to do a reverse
 223      lookup */
 224   switch (SCM_TYP7 (procedure)) {
 225   case scm_tcs_subrs:
 226     name = SCM_SNAME (procedure);
 227     break;
 228   default:
 229     name = scm_procedure_property (procedure, scm_sym_name);
 230     break;
 231   }
 232   if (scm_is_true (name))
 233     scm_set_procedure_property_x (ret, scm_sym_name, name);
 234   return ret;
 235 }
 236 #undef FUNC_NAME
 237
 238 SCM_DEFINE (scm_procedure, "procedure", 1, 0, 0,
 239             (SCM proc),
 240             "Return the procedure of @var{proc}, which must be either a\n"
 241             "procedure with setter, or an operator struct.")
 242 #define FUNC_NAME s_scm_procedure
 243 {
 244   SCM_VALIDATE_NIM (1, proc);
 245   if (SCM_PROCEDURE_WITH_SETTER_P (proc))
 246     return SCM_PROCEDURE (proc);
 247   else if (SCM_STRUCTP (proc))
 248     {
 249       SCM_ASSERT (SCM_I_OPERATORP (proc), proc, SCM_ARG1, FUNC_NAME);
 250       return proc;
 251     }
 252   SCM_WRONG_TYPE_ARG (1, proc);
 253   return SCM_BOOL_F; /* not reached */
 254 }
 255 #undef FUNC_NAME
 256
 257 SCM_GPROC (s_setter, "setter", 1, 0, 0, scm_setter, g_setter);
 258
 259 SCM
 260 scm_setter (SCM proc)
 261 {
 262   SCM_GASSERT1 (SCM_NIMP (proc), g_setter, proc, SCM_ARG1, s_setter);
 263   if (SCM_PROCEDURE_WITH_SETTER_P (proc))
 264     return SCM_SETTER (proc);
 265   else if (SCM_STRUCTP (proc))
 266     {
 267       SCM setter;
 268       SCM_GASSERT1 (SCM_I_OPERATORP (proc),
 269                     g_setter, proc, SCM_ARG1, s_setter);
 270       setter = (SCM_I_ENTITYP (proc)
 271                 ? SCM_ENTITY_SETTER (proc)
 272                 : SCM_OPERATOR_SETTER (proc));
 273       if (SCM_NIMP (setter))
 274         return setter;
 275       /* fall through */
 276     }
 277   SCM_WTA_DISPATCH_1 (g_setter, proc, SCM_ARG1, s_setter);
 278   return SCM_BOOL_F; /* not reached */
 279 }
 280
 281 \f
 282 void
 283 scm_init_procs ()
 284 {
 285 #include "libguile/procs.x"
 286 }
 287
 288 /*
 289   Local Variables:
 290   c-file-style: "gnu"
 291   End:
 292 */