Talk about kluge at top of srfi13.scm.
[bpt/guile.git] / libguile / hooks.c
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56e55ac7 1/* Copyright (C) 1995,1996,1998,1999,2000,2001 Free Software Foundation, Inc.
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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 <stdio.h>
48#include "libguile/_scm.h"
49
50#include "libguile/eval.h"
51#include "libguile/ports.h"
52#include "libguile/procprop.h"
53#include "libguile/root.h"
54#include "libguile/smob.h"
55#include "libguile/strings.h"
56
57#include "libguile/validate.h"
58#include "libguile/hooks.h"
59
60\f
61/* C level hooks
62 *
63 * Currently, this implementation is separate from the Scheme level
64 * hooks. The possibility exists to implement the Scheme level hooks
65 * using C level hooks.
66 */
67
68void
69scm_c_hook_init (scm_c_hook_t *hook, void *hook_data, scm_c_hook_type_t type)
70{
71 hook->first = 0;
72 hook->type = type;
73 hook->data = hook_data;
74}
75
76void
77scm_c_hook_add (scm_c_hook_t *hook,
78 scm_c_hook_function_t func,
79 void *func_data,
80 int appendp)
81{
82 scm_c_hook_entry_t *entry = scm_must_malloc (sizeof (scm_c_hook_entry_t),
83 "C level hook entry");
84 scm_c_hook_entry_t **loc = &hook->first;
85 if (appendp)
86 while (*loc)
87 *loc = (*loc)->next;
88 entry->next = *loc;
89 entry->func = func;
90 entry->data = func_data;
91 *loc = entry;
92}
93
94void
95scm_c_hook_remove (scm_c_hook_t *hook,
96 scm_c_hook_function_t func,
97 void *func_data)
98{
99 scm_c_hook_entry_t **loc = &hook->first;
100 while (*loc)
101 {
102 if ((*loc)->func == func && (*loc)->data == func_data)
103 {
104 scm_c_hook_entry_t *entry = *loc;
105 *loc = (*loc)->next;
106 scm_must_free (entry);
107 return;
108 }
109 loc = &(*loc)->next;
110 }
111 fprintf (stderr, "Attempt to remove non-existent hook function\n");
112 abort ();
113}
114
115void *
116scm_c_hook_run (scm_c_hook_t *hook, void *data)
117{
118 scm_c_hook_entry_t *entry = hook->first;
119 scm_c_hook_type_t type = hook->type;
120 void *res = 0;
121 while (entry)
122 {
123 res = (entry->func) (hook->data, entry->data, data);
124 if (res)
125 {
126 if (type == SCM_C_HOOK_OR)
127 break;
128 }
129 else
130 {
131 if (type == SCM_C_HOOK_AND)
132 break;
133 }
134 entry = entry->next;
135 }
136 return res;
137}
138
139\f
140/* Scheme level hooks
141 *
142 * A hook is basically a list of procedures to be called at well defined
143 * points in time.
144 *
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145 * Hook arity is not a full member of this type and therefore lacks an
146 * accessor. It exists to aid debugging and is not intended to be used in
147 * programs.
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148 */
149
e841c3e0 150scm_bits_t scm_tc16_hook;
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151
152
abd95148 153static int
e841c3e0 154hook_print (SCM hook, SCM port, scm_print_state *pstate)
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155{
156 SCM ls, name;
157 scm_puts ("#<hook ", port);
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158 scm_intprint (SCM_HOOK_ARITY (hook), 10, port);
159 scm_putc (' ', port);
160 scm_intprint (SCM_UNPACK (hook), 16, port);
161 ls = SCM_HOOK_PROCEDURES (hook);
162 while (SCM_NIMP (ls))
163 {
164 scm_putc (' ', port);
165 name = scm_procedure_name (SCM_CAR (ls));
56e55ac7 166 if (!SCM_FALSEP (name))
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167 scm_iprin1 (name, port, pstate);
168 else
169 scm_putc ('?', port);
170 ls = SCM_CDR (ls);
171 }
172 scm_putc ('>', port);
173 return 1;
174}
175
fde50407 176#if (SCM_DEBUG_DEPRECATED == 0)
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177
178SCM
1be6b49c 179scm_create_hook (const char *name, int n_args)
abd95148 180{
fde50407 181 SCM hook = scm_make_hook (SCM_MAKINUM (n_args));
86d31dfe 182 scm_c_define (name, hook);
fde50407 183 return scm_permanent_object (hook);
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184}
185
fde50407 186#endif
abd95148 187
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188SCM_DEFINE (scm_make_hook, "make-hook", 0, 1, 0,
189 (SCM n_args),
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190 "Create a hook for storing procedure of arity\n"
191 "@var{n_args}. @var{n_args} defaults to zero.")
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192#define FUNC_NAME s_scm_make_hook
193{
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194 int n;
195
196 if (SCM_UNBNDP (n_args))
197 {
198 n = 0;
199 }
200 else
201 {
202 SCM_VALIDATE_INUM_COPY (SCM_ARG1, n_args, n);
203 if (n < 0 || n > 16)
204 SCM_OUT_OF_RANGE (SCM_ARG1, n_args);
205 }
206
207 SCM_RETURN_NEWSMOB (scm_tc16_hook + (n << 16), SCM_UNPACK (SCM_EOL));
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208}
209#undef FUNC_NAME
210
211
212SCM_DEFINE (scm_hook_p, "hook?", 1, 0, 0,
213 (SCM x),
4d66be54 214 "Return @code{#t} if @var{x} is a hook, @code{#f} otherwise.")
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215#define FUNC_NAME s_scm_hook_p
216{
217 return SCM_BOOL (SCM_HOOKP (x));
218}
219#undef FUNC_NAME
220
221
222SCM_DEFINE (scm_hook_empty_p, "hook-empty?", 1, 0, 0,
223 (SCM hook),
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224 "Return @code{#t} if @var{hook} is an empty hook, @code{#f}\n"
225 "otherwise.")
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226#define FUNC_NAME s_scm_hook_empty_p
227{
228 SCM_VALIDATE_HOOK (1, hook);
229 return SCM_BOOL (SCM_NULLP (SCM_HOOK_PROCEDURES (hook)));
230}
231#undef FUNC_NAME
232
233
234SCM_DEFINE (scm_add_hook_x, "add-hook!", 2, 1, 0,
235 (SCM hook, SCM proc, SCM append_p),
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236 "Add the procedure @var{proc} to the hook @var{hook}. The\n"
237 "procedure is added to the end if @var{append_p} is true,\n"
238 "otherwise it is added to the front.")
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239#define FUNC_NAME s_scm_add_hook_x
240{
241 SCM arity, rest;
242 int n_args;
243 SCM_VALIDATE_HOOK (1,hook);
8ff45739 244 SCM_ASSERT (!SCM_FALSEP (arity = scm_i_procedure_arity (proc)),
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245 proc, SCM_ARG2, FUNC_NAME);
246 n_args = SCM_HOOK_ARITY (hook);
247 if (SCM_INUM (SCM_CAR (arity)) > n_args
248 || (SCM_FALSEP (SCM_CADDR (arity))
249 && (SCM_INUM (SCM_CAR (arity)) + SCM_INUM (SCM_CADR (arity))
250 < n_args)))
251 scm_wrong_type_arg (FUNC_NAME, 2, proc);
252 rest = scm_delq_x (proc, SCM_HOOK_PROCEDURES (hook));
253 SCM_SET_HOOK_PROCEDURES (hook,
e11f8b42 254 (!SCM_UNBNDP (append_p) && !SCM_FALSEP (append_p)
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255 ? scm_append_x (SCM_LIST2 (rest, SCM_LIST1 (proc)))
256 : scm_cons (proc, rest)));
257 return SCM_UNSPECIFIED;
258}
259#undef FUNC_NAME
260
261
262SCM_DEFINE (scm_remove_hook_x, "remove-hook!", 2, 0, 0,
263 (SCM hook, SCM proc),
8d1b3ae9 264 "Remove the procedure @var{proc} from the hook @var{hook}.")
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265#define FUNC_NAME s_scm_remove_hook_x
266{
267 SCM_VALIDATE_HOOK (1, hook);
268 SCM_SET_HOOK_PROCEDURES (hook,
269 scm_delq_x (proc, SCM_HOOK_PROCEDURES (hook)));
270 return SCM_UNSPECIFIED;
271}
272#undef FUNC_NAME
273
274
275SCM_DEFINE (scm_reset_hook_x, "reset-hook!", 1, 0, 0,
276 (SCM hook),
8d1b3ae9 277 "Remove all procedures from the hook @var{hook}.")
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278#define FUNC_NAME s_scm_reset_hook_x
279{
280 SCM_VALIDATE_HOOK (1,hook);
281 SCM_SET_HOOK_PROCEDURES (hook, SCM_EOL);
282 return SCM_UNSPECIFIED;
283}
284#undef FUNC_NAME
285
286
287SCM_DEFINE (scm_run_hook, "run-hook", 1, 0, 1,
288 (SCM hook, SCM args),
8d1b3ae9 289 "Apply all procedures from the hook @var{hook} to the arguments\n"
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290 "@var{args}. The order of the procedure application is first to\n"
291 "last.")
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292#define FUNC_NAME s_scm_run_hook
293{
294 SCM_VALIDATE_HOOK (1,hook);
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295 if (scm_ilength (args) != SCM_HOOK_ARITY (hook))
296 SCM_MISC_ERROR ("Hook ~S requires ~A arguments",
297 SCM_LIST2 (hook,SCM_MAKINUM (SCM_HOOK_ARITY (hook))));
298 scm_c_run_hook (hook, args);
299 return SCM_UNSPECIFIED;
300}
301#undef FUNC_NAME
302
303
304void
305scm_c_run_hook (SCM hook, SCM args)
306{
307 SCM procs = SCM_HOOK_PROCEDURES (hook);
308 while (SCM_NIMP (procs))
309 {
310 scm_apply (SCM_CAR (procs), args, SCM_EOL);
311 procs = SCM_CDR (procs);
312 }
313}
314
315
316SCM_DEFINE (scm_hook_to_list, "hook->list", 1, 0, 0,
317 (SCM hook),
8d1b3ae9 318 "Convert the procedure list of @var{hook} to a list.")
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319#define FUNC_NAME s_scm_hook_to_list
320{
321 SCM_VALIDATE_HOOK (1, hook);
322 return scm_list_copy (SCM_HOOK_PROCEDURES (hook));
323}
324#undef FUNC_NAME
325
326
327\f
328
329void
330scm_init_hooks ()
331{
332 scm_tc16_hook = scm_make_smob_type ("hook", 0);
333 scm_set_smob_mark (scm_tc16_hook, scm_markcdr);
e841c3e0 334 scm_set_smob_print (scm_tc16_hook, hook_print);
8dc9439f 335#ifndef SCM_MAGIC_SNARFER
abd95148 336#include "libguile/hooks.x"
8dc9439f 337#endif
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338}
339
340/*
341 Local Variables:
342 c-file-style: "gnu"
343 End:
344*/