[bpt/guile.git] / libguile / hooks.c

/* Copyright (C) 1995,1996,1998,1999,2000,2001, 2003 Free Software Foundation, Inc.
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 */


\f

#include <stdio.h>
#include "libguile/_scm.h"

#include "libguile/eval.h"
#include "libguile/ports.h"
#include "libguile/procprop.h"
#include "libguile/root.h"
#include "libguile/smob.h"
#include "libguile/strings.h"

#include "libguile/validate.h"
#include "libguile/hooks.h"

\f
/* C level hooks
 *
 * Currently, this implementation is separate from the Scheme level
 * hooks.  The possibility exists to implement the Scheme level hooks
 * using C level hooks.
 */

void
scm_c_hook_init (scm_t_c_hook *hook, void *hook_data, scm_t_c_hook_type type)
{
  hook->first = 0;
  hook->type = type;
  hook->data = hook_data;
}

void
scm_c_hook_add (scm_t_c_hook *hook,
		scm_t_c_hook_function func,
		void *func_data, 
		int appendp)
{
  scm_t_c_hook_entry *entry = scm_malloc (sizeof (scm_t_c_hook_entry));
  scm_t_c_hook_entry **loc = &hook->first;
  if (appendp)
    while (*loc)
      loc = &(*loc)->next;
  entry->next = *loc;
  entry->func = func;
  entry->data = func_data;
  *loc = entry;
}

void
scm_c_hook_remove (scm_t_c_hook *hook,
		   scm_t_c_hook_function func,
		   void *func_data)
{
  scm_t_c_hook_entry **loc = &hook->first;
  while (*loc)
    {
      if ((*loc)->func == func && (*loc)->data == func_data)
	{
	  scm_t_c_hook_entry *entry = *loc;
	  *loc = (*loc)->next;
	  free (entry);
	  return;
	}
      loc = &(*loc)->next;
    }
  fprintf (stderr, "Attempt to remove non-existent hook function\n");
  abort ();
}

void *
scm_c_hook_run (scm_t_c_hook *hook, void *data)
{
  scm_t_c_hook_entry *entry = hook->first;
  scm_t_c_hook_type type = hook->type;
  void *res = 0;
  while (entry)
    {
      res = (entry->func) (hook->data, entry->data, data);
      if (res)
	{
	  if (type == SCM_C_HOOK_OR)
	    break;
	}
      else
	{
	  if (type == SCM_C_HOOK_AND)
	    break;
	}
      entry = entry->next;
    }
  return res;
}

\f
/* Scheme level hooks
 *
 * A hook is basically a list of procedures to be called at well defined
 * points in time.
 *
 * Hook arity is not a full member of this type and therefore lacks an
 * accessor.  It exists to aid debugging and is not intended to be used in
 * programs.
 */

scm_t_bits scm_tc16_hook;


static int
hook_print (SCM hook, SCM port, scm_print_state *pstate)
{
  SCM ls, name;
  scm_puts ("#<hook ", port);
  scm_intprint (SCM_HOOK_ARITY (hook), 10, port);
  scm_putc (' ', port);
  scm_intprint (SCM_UNPACK (hook), 16, port);
  ls = SCM_HOOK_PROCEDURES (hook);
  while (SCM_NIMP (ls))
    {
      scm_putc (' ', port);
      name = scm_procedure_name (SCM_CAR (ls));
      if (!SCM_FALSEP (name))
	scm_iprin1 (name, port, pstate);
      else
	scm_putc ('?', port);
      ls = SCM_CDR (ls);
    }
  scm_putc ('>', port);
  return 1;
}


SCM_DEFINE (scm_make_hook, "make-hook", 0, 1, 0, 
            (SCM n_args),
	    "Create a hook for storing procedure of arity @var{n_args}.\n"
	    "@var{n_args} defaults to zero.  The returned value is a hook\n"
	    "object to be used with the other hook procedures.")
#define FUNC_NAME s_scm_make_hook
{
  int n;

  if (SCM_UNBNDP (n_args))
    {
      n = 0;
    }
  else
    {
      SCM_VALIDATE_INUM_COPY (SCM_ARG1, n_args, n);
      if (n < 0 || n > 16)
	SCM_OUT_OF_RANGE (SCM_ARG1, n_args);
    }
  
  SCM_RETURN_NEWSMOB (scm_tc16_hook + (n << 16), SCM_UNPACK (SCM_EOL));
}
#undef FUNC_NAME


SCM_DEFINE (scm_hook_p, "hook?", 1, 0, 0, 
            (SCM x),
	    "Return @code{#t} if @var{x} is a hook, @code{#f} otherwise.")
#define FUNC_NAME s_scm_hook_p
{
  return SCM_BOOL (SCM_HOOKP (x));
}
#undef FUNC_NAME


SCM_DEFINE (scm_hook_empty_p, "hook-empty?", 1, 0, 0, 
            (SCM hook),
	    "Return @code{#t} if @var{hook} is an empty hook, @code{#f}\n"
	    "otherwise.")
#define FUNC_NAME s_scm_hook_empty_p
{
  SCM_VALIDATE_HOOK (1, hook);
  return SCM_BOOL (SCM_NULLP (SCM_HOOK_PROCEDURES (hook)));
}
#undef FUNC_NAME


SCM_DEFINE (scm_add_hook_x, "add-hook!", 2, 1, 0, 
            (SCM hook, SCM proc, SCM append_p),
	    "Add the procedure @var{proc} to the hook @var{hook}. The\n"
	    "procedure is added to the end if @var{append_p} is true,\n"
	    "otherwise it is added to the front.  The return value of this\n"
	    "procedure is not specified.")
#define FUNC_NAME s_scm_add_hook_x
{
  SCM arity, rest;
  int n_args;
  SCM_VALIDATE_HOOK (1, hook);
  SCM_ASSERT (!SCM_FALSEP (arity = scm_i_procedure_arity (proc)),
	      proc, SCM_ARG2, FUNC_NAME);
  n_args = SCM_HOOK_ARITY (hook);
  if (SCM_INUM (SCM_CAR (arity)) > n_args
      || (SCM_FALSEP (SCM_CADDR (arity))
	  && (SCM_INUM (SCM_CAR (arity)) + SCM_INUM (SCM_CADR (arity))
	      < n_args)))
    scm_wrong_type_arg (FUNC_NAME, 2, proc);
  rest = scm_delq_x (proc, SCM_HOOK_PROCEDURES (hook));
  SCM_SET_HOOK_PROCEDURES (hook,
			   (!SCM_UNBNDP (append_p) && !SCM_FALSEP (append_p)
			    ? scm_append_x (scm_list_2 (rest, scm_list_1 (proc)))
			    : scm_cons (proc, rest)));
  return SCM_UNSPECIFIED;
}
#undef FUNC_NAME


SCM_DEFINE (scm_remove_hook_x, "remove-hook!", 2, 0, 0, 
            (SCM hook, SCM proc),
	    "Remove the procedure @var{proc} from the hook @var{hook}.  The\n"
	    "return value of this procedure is not specified.")
#define FUNC_NAME s_scm_remove_hook_x
{
  SCM_VALIDATE_HOOK (1, hook);
  SCM_SET_HOOK_PROCEDURES (hook,
			   scm_delq_x (proc, SCM_HOOK_PROCEDURES (hook)));
  return SCM_UNSPECIFIED;
}
#undef FUNC_NAME


SCM_DEFINE (scm_reset_hook_x, "reset-hook!", 1, 0, 0, 
            (SCM hook),
	    "Remove all procedures from the hook @var{hook}.  The return\n"
	    "value of this procedure is not specified.")
#define FUNC_NAME s_scm_reset_hook_x
{
  SCM_VALIDATE_HOOK (1, hook);
  SCM_SET_HOOK_PROCEDURES (hook, SCM_EOL);
  return SCM_UNSPECIFIED;
}
#undef FUNC_NAME


SCM_DEFINE (scm_run_hook, "run-hook", 1, 0, 1, 
            (SCM hook, SCM args),
	    "Apply all procedures from the hook @var{hook} to the arguments\n"
	    "@var{args}.  The order of the procedure application is first to\n"
	    "last.  The return value of this procedure is not specified.")
#define FUNC_NAME s_scm_run_hook
{
  SCM_VALIDATE_HOOK (1, hook);
  if (scm_ilength (args) != SCM_HOOK_ARITY (hook))
    SCM_MISC_ERROR ("Hook ~S requires ~A arguments",
		    scm_list_2 (hook, SCM_MAKINUM (SCM_HOOK_ARITY (hook))));
  scm_c_run_hook (hook, args);
  return SCM_UNSPECIFIED;
}
#undef FUNC_NAME


void
scm_c_run_hook (SCM hook, SCM args)
{
  SCM procs = SCM_HOOK_PROCEDURES (hook);
  while (SCM_NIMP (procs))
    {
      scm_apply_0 (SCM_CAR (procs), args);
      procs = SCM_CDR (procs);
    }
}


SCM_DEFINE (scm_hook_to_list, "hook->list", 1, 0, 0, 
            (SCM hook),
	    "Convert the procedure list of @var{hook} to a list.")
#define FUNC_NAME s_scm_hook_to_list
{
  SCM_VALIDATE_HOOK (1, hook);
  return scm_list_copy (SCM_HOOK_PROCEDURES (hook));
}
#undef FUNC_NAME


\f

void
scm_init_hooks ()
{
  scm_tc16_hook = scm_make_smob_type ("hook", 0);
  scm_set_smob_mark (scm_tc16_hook, scm_markcdr);
  scm_set_smob_print (scm_tc16_hook, hook_print);
#include "libguile/hooks.x"
}

/*
  Local Variables:
  c-file-style: "gnu"
  End:
*/
Commit	Line	Data
c35738c1	1	/* Copyright (C) 1995,1996,1998,1999,2000,2001, 2003 Free Software Foundation, Inc.
abd95148	2	*
73be1d9e MV	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.
abd95148	7	*
73be1d9e MV	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.
abd95148	12	*
73be1d9e MV	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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	16	*/
abd95148	17
abd95148 MD	18
	19	\f
	20
	21	#include <stdio.h>
	22	#include "libguile/_scm.h"
	23
	24	#include "libguile/eval.h"
	25	#include "libguile/ports.h"
	26	#include "libguile/procprop.h"
	27	#include "libguile/root.h"
	28	#include "libguile/smob.h"
	29	#include "libguile/strings.h"
	30
	31	#include "libguile/validate.h"
	32	#include "libguile/hooks.h"
	33
	34	\f
	35	/* C level hooks
	36	*
	37	* Currently, this implementation is separate from the Scheme level
	38	* hooks. The possibility exists to implement the Scheme level hooks
	39	* using C level hooks.
	40	*/
	41
	42	void
387d418c	43	scm_c_hook_init (scm_t_c_hook hook, void hook_data, scm_t_c_hook_type type)
abd95148 MD	44	{
	45	hook->first = 0;
	46	hook->type = type;
	47	hook->data = hook_data;
	48	}
	49
	50	void
92c2555f MV	51	scm_c_hook_add (scm_t_c_hook *hook,
92c2555f MV	52	scm_t_c_hook_function func,
abd95148 MD	53	void *func_data,
	54	int appendp)
	55	{
4c9419ac	56	scm_t_c_hook_entry *entry = scm_malloc (sizeof (scm_t_c_hook_entry));
92c2555f	57	scm_t_c_hook_entry **loc = &hook->first;
abd95148 MD	58	if (appendp)
abd95148 MD	59	while (*loc)
c35738c1	60	loc = &(*loc)->next;
abd95148 MD	61	entry->next = *loc;
	62	entry->func = func;
	63	entry->data = func_data;
	64	*loc = entry;
	65	}
	66
	67	void
92c2555f MV	68	scm_c_hook_remove (scm_t_c_hook *hook,
92c2555f MV	69	scm_t_c_hook_function func,
abd95148 MD	70	void *func_data)
abd95148 MD	71	{
92c2555f	72	scm_t_c_hook_entry **loc = &hook->first;
abd95148 MD	73	while (*loc)
	74	{
	75	if ((loc)->func == func && (loc)->data == func_data)
	76	{
92c2555f	77	scm_t_c_hook_entry entry = loc;
abd95148	78	loc = (loc)->next;
4c9419ac	79	free (entry);
abd95148 MD	80	return;
	81	}
	82	loc = &(*loc)->next;
	83	}
	84	fprintf (stderr, "Attempt to remove non-existent hook function\n");
	85	abort ();
	86	}
	87
	88	void *
92c2555f	89	scm_c_hook_run (scm_t_c_hook hook, void data)
abd95148	90	{
92c2555f	91	scm_t_c_hook_entry *entry = hook->first;
387d418c	92	scm_t_c_hook_type type = hook->type;
abd95148 MD	93	void *res = 0;
	94	while (entry)
	95	{
	96	res = (entry->func) (hook->data, entry->data, data);
	97	if (res)
	98	{
	99	if (type == SCM_C_HOOK_OR)
	100	break;
	101	}
	102	else
	103	{
	104	if (type == SCM_C_HOOK_AND)
	105	break;
	106	}
	107	entry = entry->next;
	108	}
	109	return res;
	110	}
	111
	112	\f
	113	/* Scheme level hooks
	114	*
	115	* A hook is basically a list of procedures to be called at well defined
	116	* points in time.
	117	*
e11f8b42 DH	118	* Hook arity is not a full member of this type and therefore lacks an
	119	* accessor. It exists to aid debugging and is not intended to be used in
	120	* programs.
abd95148 MD	121	*/
abd95148 MD	122
92c2555f	123	scm_t_bits scm_tc16_hook;
abd95148 MD	124
abd95148 MD	125
abd95148	126	static int
e841c3e0	127	hook_print (SCM hook, SCM port, scm_print_state *pstate)
abd95148 MD	128	{
	129	SCM ls, name;
	130	scm_puts ("#<hook ", port);
abd95148 MD	131	scm_intprint (SCM_HOOK_ARITY (hook), 10, port);
	132	scm_putc (' ', port);
	133	scm_intprint (SCM_UNPACK (hook), 16, port);
	134	ls = SCM_HOOK_PROCEDURES (hook);
	135	while (SCM_NIMP (ls))
	136	{
	137	scm_putc (' ', port);
	138	name = scm_procedure_name (SCM_CAR (ls));
56e55ac7	139	if (!SCM_FALSEP (name))
abd95148 MD	140	scm_iprin1 (name, port, pstate);
	141	else
	142	scm_putc ('?', port);
	143	ls = SCM_CDR (ls);
	144	}
	145	scm_putc ('>', port);
	146	return 1;
	147	}
	148
abd95148	149
abd95148 MD	150	SCM_DEFINE (scm_make_hook, "make-hook", 0, 1, 0,
abd95148 MD	151	(SCM n_args),
f91e4547 MG	152	"Create a hook for storing procedure of arity @var{n_args}.\n"
	153	"@var{n_args} defaults to zero. The returned value is a hook\n"
	154	"object to be used with the other hook procedures.")
abd95148 MD	155	#define FUNC_NAME s_scm_make_hook
abd95148 MD	156	{
fde50407 ML	157	int n;
	158
	159	if (SCM_UNBNDP (n_args))
	160	{
	161	n = 0;
	162	}
	163	else
	164	{
	165	SCM_VALIDATE_INUM_COPY (SCM_ARG1, n_args, n);
	166	if (n < 0 \|\| n > 16)
	167	SCM_OUT_OF_RANGE (SCM_ARG1, n_args);
	168	}
	169
	170	SCM_RETURN_NEWSMOB (scm_tc16_hook + (n << 16), SCM_UNPACK (SCM_EOL));
abd95148 MD	171	}
	172	#undef FUNC_NAME
	173
	174
	175	SCM_DEFINE (scm_hook_p, "hook?", 1, 0, 0,
	176	(SCM x),
4d66be54	177	"Return @code{#t} if @var{x} is a hook, @code{#f} otherwise.")
abd95148 MD	178	#define FUNC_NAME s_scm_hook_p
	179	{
	180	return SCM_BOOL (SCM_HOOKP (x));
	181	}
	182	#undef FUNC_NAME
	183
	184
	185	SCM_DEFINE (scm_hook_empty_p, "hook-empty?", 1, 0, 0,
	186	(SCM hook),
4d66be54 MG	187	"Return @code{#t} if @var{hook} is an empty hook, @code{#f}\n"
4d66be54 MG	188	"otherwise.")
abd95148 MD	189	#define FUNC_NAME s_scm_hook_empty_p
	190	{
	191	SCM_VALIDATE_HOOK (1, hook);
	192	return SCM_BOOL (SCM_NULLP (SCM_HOOK_PROCEDURES (hook)));
	193	}
	194	#undef FUNC_NAME
	195
	196
	197	SCM_DEFINE (scm_add_hook_x, "add-hook!", 2, 1, 0,
	198	(SCM hook, SCM proc, SCM append_p),
8d1b3ae9 MG	199	"Add the procedure @var{proc} to the hook @var{hook}. The\n"
8d1b3ae9 MG	200	"procedure is added to the end if @var{append_p} is true,\n"
f91e4547 MG	201	"otherwise it is added to the front. The return value of this\n"
f91e4547 MG	202	"procedure is not specified.")
abd95148 MD	203	#define FUNC_NAME s_scm_add_hook_x
	204	{
	205	SCM arity, rest;
	206	int n_args;
34d19ef6	207	SCM_VALIDATE_HOOK (1, hook);
8ff45739	208	SCM_ASSERT (!SCM_FALSEP (arity = scm_i_procedure_arity (proc)),
abd95148 MD	209	proc, SCM_ARG2, FUNC_NAME);
	210	n_args = SCM_HOOK_ARITY (hook);
	211	if (SCM_INUM (SCM_CAR (arity)) > n_args
	212	\|\| (SCM_FALSEP (SCM_CADDR (arity))
	213	&& (SCM_INUM (SCM_CAR (arity)) + SCM_INUM (SCM_CADR (arity))
	214	< n_args)))
	215	scm_wrong_type_arg (FUNC_NAME, 2, proc);
	216	rest = scm_delq_x (proc, SCM_HOOK_PROCEDURES (hook));
	217	SCM_SET_HOOK_PROCEDURES (hook,
e11f8b42	218	(!SCM_UNBNDP (append_p) && !SCM_FALSEP (append_p)
1afff620	219	? scm_append_x (scm_list_2 (rest, scm_list_1 (proc)))
abd95148 MD	220	: scm_cons (proc, rest)));
	221	return SCM_UNSPECIFIED;
	222	}
	223	#undef FUNC_NAME
	224
	225
	226	SCM_DEFINE (scm_remove_hook_x, "remove-hook!", 2, 0, 0,
	227	(SCM hook, SCM proc),
f91e4547 MG	228	"Remove the procedure @var{proc} from the hook @var{hook}. The\n"
f91e4547 MG	229	"return value of this procedure is not specified.")
abd95148 MD	230	#define FUNC_NAME s_scm_remove_hook_x
	231	{
	232	SCM_VALIDATE_HOOK (1, hook);
	233	SCM_SET_HOOK_PROCEDURES (hook,
	234	scm_delq_x (proc, SCM_HOOK_PROCEDURES (hook)));
	235	return SCM_UNSPECIFIED;
	236	}
	237	#undef FUNC_NAME
	238
	239
	240	SCM_DEFINE (scm_reset_hook_x, "reset-hook!", 1, 0, 0,
	241	(SCM hook),
f91e4547 MG	242	"Remove all procedures from the hook @var{hook}. The return\n"
f91e4547 MG	243	"value of this procedure is not specified.")
abd95148 MD	244	#define FUNC_NAME s_scm_reset_hook_x
abd95148 MD	245	{
34d19ef6	246	SCM_VALIDATE_HOOK (1, hook);
abd95148 MD	247	SCM_SET_HOOK_PROCEDURES (hook, SCM_EOL);
	248	return SCM_UNSPECIFIED;
	249	}
	250	#undef FUNC_NAME
	251
	252
	253	SCM_DEFINE (scm_run_hook, "run-hook", 1, 0, 1,
	254	(SCM hook, SCM args),
8d1b3ae9	255	"Apply all procedures from the hook @var{hook} to the arguments\n"
4d66be54	256	"@var{args}. The order of the procedure application is first to\n"
f91e4547	257	"last. The return value of this procedure is not specified.")
abd95148 MD	258	#define FUNC_NAME s_scm_run_hook
abd95148 MD	259	{
34d19ef6	260	SCM_VALIDATE_HOOK (1, hook);
abd95148 MD	261	if (scm_ilength (args) != SCM_HOOK_ARITY (hook))
abd95148 MD	262	SCM_MISC_ERROR ("Hook ~S requires ~A arguments",
1afff620	263	scm_list_2 (hook, SCM_MAKINUM (SCM_HOOK_ARITY (hook))));
abd95148 MD	264	scm_c_run_hook (hook, args);
	265	return SCM_UNSPECIFIED;
	266	}
	267	#undef FUNC_NAME
	268
	269
	270	void
	271	scm_c_run_hook (SCM hook, SCM args)
	272	{
	273	SCM procs = SCM_HOOK_PROCEDURES (hook);
	274	while (SCM_NIMP (procs))
	275	{
fdc28395	276	scm_apply_0 (SCM_CAR (procs), args);
abd95148 MD	277	procs = SCM_CDR (procs);
	278	}
	279	}
	280
	281
	282	SCM_DEFINE (scm_hook_to_list, "hook->list", 1, 0, 0,
	283	(SCM hook),
8d1b3ae9	284	"Convert the procedure list of @var{hook} to a list.")
abd95148 MD	285	#define FUNC_NAME s_scm_hook_to_list
	286	{
	287	SCM_VALIDATE_HOOK (1, hook);
	288	return scm_list_copy (SCM_HOOK_PROCEDURES (hook));
	289	}
	290	#undef FUNC_NAME
	291
	292
	293	\f
	294
	295	void
	296	scm_init_hooks ()
	297	{
	298	scm_tc16_hook = scm_make_smob_type ("hook", 0);
	299	scm_set_smob_mark (scm_tc16_hook, scm_markcdr);
e841c3e0	300	scm_set_smob_print (scm_tc16_hook, hook_print);
abd95148 MD	301	#include "libguile/hooks.x"
	302	}
	303
	304	/*
	305	Local Variables:
	306	c-file-style: "gnu"
	307	End:
	308	*/