libguile/hooks.h

   1 /* classes: h_files */
   2
   3 #ifndef SCM_HOOKS_H
   4 #define SCM_HOOKS_H
   5
   6 /* Copyright (C) 1995,1996,1999,2000,2001 Free Software Foundation, Inc.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2, or (at your option)
  11  * any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this software; see the file COPYING.  If not, write to
  20  * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  21  * Boston, MA 02111-1307 USA
  22  *
  23  * As a special exception, the Free Software Foundation gives permission
  24  * for additional uses of the text contained in its release of GUILE.
  25  *
  26  * The exception is that, if you link the GUILE library with other files
  27  * to produce an executable, this does not by itself cause the
  28  * resulting executable to be covered by the GNU General Public License.
  29  * Your use of that executable is in no way restricted on account of
  30  * linking the GUILE library code into it.
  31  *
  32  * This exception does not however invalidate any other reasons why
  33  * the executable file might be covered by the GNU General Public License.
  34  *
  35  * This exception applies only to the code released by the
  36  * Free Software Foundation under the name GUILE.  If you copy
  37  * code from other Free Software Foundation releases into a copy of
  38  * GUILE, as the General Public License permits, the exception does
  39  * not apply to the code that you add in this way.  To avoid misleading
  40  * anyone as to the status of such modified files, you must delete
  41  * this exception notice from them.
  42  *
  43  * If you write modifications of your own for GUILE, it is your choice
  44  * whether to permit this exception to apply to your modifications.
  45  * If you do not wish that, delete this exception notice.  */
  46
  47 \f
  48
  49 #include "libguile/__scm.h"
  50
  51 /*
  52  * C level hooks
  53  */
  54
  55 /*
  56  * The interface is designed for and- and or-type hooks which
  57  * both may want to indicate success/failure and return a result.
  58  */
  59
  60 typedef enum scm_t_c_hookype_t {
  61   SCM_C_HOOK_NORMAL,
  62   SCM_C_HOOK_OR,
  63   SCM_C_HOOK_AND
  64 } scm_t_c_hookype_t;
  65
  66 typedef void  *(*scm_t_c_hook_function) (void *hook_data,
  67                                          void *func_data,
  68                                          void *data);
  69
  70 typedef struct scm_t_c_hook_entry {
  71   struct scm_t_c_hook_entry *next;
  72   scm_t_c_hook_function func;
  73   void *data;
  74 } scm_t_c_hook_entry;
  75
  76 typedef struct scm_t_c_hook {
  77   scm_t_c_hook_entry *first;
  78   scm_t_c_hookype_t type;
  79   void *data;
  80 } scm_t_c_hook;
  81
  82 extern void scm_c_hook_init (scm_t_c_hook *hook,
  83                              void *hook_data,
  84                              scm_t_c_hookype_t type);
  85 extern void scm_c_hook_add (scm_t_c_hook *hook,
  86                             scm_t_c_hook_function func,
  87                             void *func_data,
  88                             int appendp);
  89 extern void scm_c_hook_remove (scm_t_c_hook *hook,
  90                                scm_t_c_hook_function func,
  91                                void *func_data);
  92 extern void *scm_c_hook_run (scm_t_c_hook *hook, void *data);
  93
  94 /*
  95  * Scheme level hooks
  96  */
  97
  98 extern scm_t_bits scm_tc16_hook;
  99
 100 #define SCM_HOOKP(x)                    SCM_TYP16_PREDICATE (scm_tc16_hook, x)
 101 #define SCM_HOOK_ARITY(hook)            (SCM_CELL_WORD_0 (hook) >> 16)
 102 #define SCM_HOOK_PROCEDURES(hook)       SCM_CELL_OBJECT_1 (hook)
 103 #define SCM_SET_HOOK_PROCEDURES(hook, procs) SCM_SET_CELL_OBJECT_1 ((hook), (procs))
 104
 105 extern SCM scm_make_hook (SCM n_args);
 106 extern SCM scm_hook_p (SCM x);
 107 extern SCM scm_hook_empty_p (SCM hook);
 108 extern SCM scm_add_hook_x (SCM hook, SCM thunk, SCM appendp);
 109 extern SCM scm_remove_hook_x (SCM hook, SCM thunk);
 110 extern SCM scm_reset_hook_x (SCM hook);
 111 extern SCM scm_run_hook (SCM hook, SCM args);
 112 extern void scm_c_run_hook (SCM hook, SCM args);
 113 extern SCM scm_hook_to_list (SCM hook);
 114 extern void scm_init_hooks (void);
 115
 116 #endif  /* SCM_HOOKS_H */
 117
 118 /*
 119   Local Variables:
 120   c-file-style: "gnu"
 121   End:
 122 */