| 1 | /* Copyright (C) 1995,1996,1998,1999,2000,2001, 2003 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 16 | */ |
| 17 | |
| 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 |
| 43 | scm_c_hook_init (scm_t_c_hook *hook, void *hook_data, scm_t_c_hook_type type) |
| 44 | { |
| 45 | hook->first = 0; |
| 46 | hook->type = type; |
| 47 | hook->data = hook_data; |
| 48 | } |
| 49 | |
| 50 | void |
| 51 | scm_c_hook_add (scm_t_c_hook *hook, |
| 52 | scm_t_c_hook_function func, |
| 53 | void *func_data, |
| 54 | int appendp) |
| 55 | { |
| 56 | scm_t_c_hook_entry *entry = scm_malloc (sizeof (scm_t_c_hook_entry)); |
| 57 | scm_t_c_hook_entry **loc = &hook->first; |
| 58 | if (appendp) |
| 59 | while (*loc) |
| 60 | loc = &(*loc)->next; |
| 61 | entry->next = *loc; |
| 62 | entry->func = func; |
| 63 | entry->data = func_data; |
| 64 | *loc = entry; |
| 65 | } |
| 66 | |
| 67 | void |
| 68 | scm_c_hook_remove (scm_t_c_hook *hook, |
| 69 | scm_t_c_hook_function func, |
| 70 | void *func_data) |
| 71 | { |
| 72 | scm_t_c_hook_entry **loc = &hook->first; |
| 73 | while (*loc) |
| 74 | { |
| 75 | if ((*loc)->func == func && (*loc)->data == func_data) |
| 76 | { |
| 77 | scm_t_c_hook_entry *entry = *loc; |
| 78 | *loc = (*loc)->next; |
| 79 | free (entry); |
| 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 * |
| 89 | scm_c_hook_run (scm_t_c_hook *hook, void *data) |
| 90 | { |
| 91 | scm_t_c_hook_entry *entry = hook->first; |
| 92 | scm_t_c_hook_type type = hook->type; |
| 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 | * |
| 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. |
| 121 | */ |
| 122 | |
| 123 | scm_t_bits scm_tc16_hook; |
| 124 | |
| 125 | |
| 126 | static int |
| 127 | hook_print (SCM hook, SCM port, scm_print_state *pstate) |
| 128 | { |
| 129 | SCM ls, name; |
| 130 | scm_puts ("#<hook ", port); |
| 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)); |
| 139 | if (scm_is_true (name)) |
| 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 | |
| 149 | |
| 150 | SCM_DEFINE (scm_make_hook, "make-hook", 0, 1, 0, |
| 151 | (SCM n_args), |
| 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.") |
| 155 | #define FUNC_NAME s_scm_make_hook |
| 156 | { |
| 157 | unsigned int n; |
| 158 | |
| 159 | if (SCM_UNBNDP (n_args)) |
| 160 | n = 0; |
| 161 | else |
| 162 | n = scm_to_unsigned_integer (n_args, 0, 16); |
| 163 | |
| 164 | SCM_RETURN_NEWSMOB (scm_tc16_hook + (n << 16), SCM_UNPACK (SCM_EOL)); |
| 165 | } |
| 166 | #undef FUNC_NAME |
| 167 | |
| 168 | |
| 169 | SCM_DEFINE (scm_hook_p, "hook?", 1, 0, 0, |
| 170 | (SCM x), |
| 171 | "Return @code{#t} if @var{x} is a hook, @code{#f} otherwise.") |
| 172 | #define FUNC_NAME s_scm_hook_p |
| 173 | { |
| 174 | return scm_from_bool (SCM_HOOKP (x)); |
| 175 | } |
| 176 | #undef FUNC_NAME |
| 177 | |
| 178 | |
| 179 | SCM_DEFINE (scm_hook_empty_p, "hook-empty?", 1, 0, 0, |
| 180 | (SCM hook), |
| 181 | "Return @code{#t} if @var{hook} is an empty hook, @code{#f}\n" |
| 182 | "otherwise.") |
| 183 | #define FUNC_NAME s_scm_hook_empty_p |
| 184 | { |
| 185 | SCM_VALIDATE_HOOK (1, hook); |
| 186 | return scm_from_bool (scm_is_null (SCM_HOOK_PROCEDURES (hook))); |
| 187 | } |
| 188 | #undef FUNC_NAME |
| 189 | |
| 190 | |
| 191 | SCM_DEFINE (scm_add_hook_x, "add-hook!", 2, 1, 0, |
| 192 | (SCM hook, SCM proc, SCM append_p), |
| 193 | "Add the procedure @var{proc} to the hook @var{hook}. The\n" |
| 194 | "procedure is added to the end if @var{append_p} is true,\n" |
| 195 | "otherwise it is added to the front. The return value of this\n" |
| 196 | "procedure is not specified.") |
| 197 | #define FUNC_NAME s_scm_add_hook_x |
| 198 | { |
| 199 | SCM arity, rest; |
| 200 | int n_args; |
| 201 | SCM_VALIDATE_HOOK (1, hook); |
| 202 | SCM_ASSERT (scm_is_true (arity = scm_i_procedure_arity (proc)), |
| 203 | proc, SCM_ARG2, FUNC_NAME); |
| 204 | n_args = SCM_HOOK_ARITY (hook); |
| 205 | if (scm_to_int (SCM_CAR (arity)) > n_args |
| 206 | || (scm_is_false (SCM_CADDR (arity)) |
| 207 | && (scm_to_int (SCM_CAR (arity)) + scm_to_int (SCM_CADR (arity)) |
| 208 | < n_args))) |
| 209 | scm_wrong_type_arg (FUNC_NAME, 2, proc); |
| 210 | rest = scm_delq_x (proc, SCM_HOOK_PROCEDURES (hook)); |
| 211 | SCM_SET_HOOK_PROCEDURES (hook, |
| 212 | (!SCM_UNBNDP (append_p) && scm_is_true (append_p) |
| 213 | ? scm_append_x (scm_list_2 (rest, scm_list_1 (proc))) |
| 214 | : scm_cons (proc, rest))); |
| 215 | return SCM_UNSPECIFIED; |
| 216 | } |
| 217 | #undef FUNC_NAME |
| 218 | |
| 219 | |
| 220 | SCM_DEFINE (scm_remove_hook_x, "remove-hook!", 2, 0, 0, |
| 221 | (SCM hook, SCM proc), |
| 222 | "Remove the procedure @var{proc} from the hook @var{hook}. The\n" |
| 223 | "return value of this procedure is not specified.") |
| 224 | #define FUNC_NAME s_scm_remove_hook_x |
| 225 | { |
| 226 | SCM_VALIDATE_HOOK (1, hook); |
| 227 | SCM_SET_HOOK_PROCEDURES (hook, |
| 228 | scm_delq_x (proc, SCM_HOOK_PROCEDURES (hook))); |
| 229 | return SCM_UNSPECIFIED; |
| 230 | } |
| 231 | #undef FUNC_NAME |
| 232 | |
| 233 | |
| 234 | SCM_DEFINE (scm_reset_hook_x, "reset-hook!", 1, 0, 0, |
| 235 | (SCM hook), |
| 236 | "Remove all procedures from the hook @var{hook}. The return\n" |
| 237 | "value of this procedure is not specified.") |
| 238 | #define FUNC_NAME s_scm_reset_hook_x |
| 239 | { |
| 240 | SCM_VALIDATE_HOOK (1, hook); |
| 241 | SCM_SET_HOOK_PROCEDURES (hook, SCM_EOL); |
| 242 | return SCM_UNSPECIFIED; |
| 243 | } |
| 244 | #undef FUNC_NAME |
| 245 | |
| 246 | |
| 247 | SCM_DEFINE (scm_run_hook, "run-hook", 1, 0, 1, |
| 248 | (SCM hook, SCM args), |
| 249 | "Apply all procedures from the hook @var{hook} to the arguments\n" |
| 250 | "@var{args}. The order of the procedure application is first to\n" |
| 251 | "last. The return value of this procedure is not specified.") |
| 252 | #define FUNC_NAME s_scm_run_hook |
| 253 | { |
| 254 | SCM_VALIDATE_HOOK (1, hook); |
| 255 | if (scm_ilength (args) != SCM_HOOK_ARITY (hook)) |
| 256 | SCM_MISC_ERROR ("Hook ~S requires ~A arguments", |
| 257 | scm_list_2 (hook, scm_from_int (SCM_HOOK_ARITY (hook)))); |
| 258 | scm_c_run_hook (hook, args); |
| 259 | return SCM_UNSPECIFIED; |
| 260 | } |
| 261 | #undef FUNC_NAME |
| 262 | |
| 263 | |
| 264 | void |
| 265 | scm_c_run_hook (SCM hook, SCM args) |
| 266 | { |
| 267 | SCM procs = SCM_HOOK_PROCEDURES (hook); |
| 268 | while (SCM_NIMP (procs)) |
| 269 | { |
| 270 | scm_apply_0 (SCM_CAR (procs), args); |
| 271 | procs = SCM_CDR (procs); |
| 272 | } |
| 273 | } |
| 274 | |
| 275 | |
| 276 | SCM_DEFINE (scm_hook_to_list, "hook->list", 1, 0, 0, |
| 277 | (SCM hook), |
| 278 | "Convert the procedure list of @var{hook} to a list.") |
| 279 | #define FUNC_NAME s_scm_hook_to_list |
| 280 | { |
| 281 | SCM_VALIDATE_HOOK (1, hook); |
| 282 | return scm_list_copy (SCM_HOOK_PROCEDURES (hook)); |
| 283 | } |
| 284 | #undef FUNC_NAME |
| 285 | |
| 286 | |
| 287 | \f |
| 288 | |
| 289 | void |
| 290 | scm_init_hooks () |
| 291 | { |
| 292 | scm_tc16_hook = scm_make_smob_type ("hook", 0); |
| 293 | scm_set_smob_mark (scm_tc16_hook, scm_markcdr); |
| 294 | scm_set_smob_print (scm_tc16_hook, hook_print); |
| 295 | #include "libguile/hooks.x" |
| 296 | } |
| 297 | |
| 298 | /* |
| 299 | Local Variables: |
| 300 | c-file-style: "gnu" |
| 301 | End: |
| 302 | */ |