-/* Copyright (C) 1995, 1996, 1998, 1999, 2000 Free Software Foundation, Inc.
+/* Copyright (C) 1995,1996,1998,1999,2000,2001, 2003, 2004 Free Software Foundation, Inc.
*
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2, or (at your option)
- * any later version.
- *
- * This program 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 General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this software; see the file COPYING. If not, write to
- * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
- * Boston, MA 02111-1307 USA
- *
- * As a special exception, the Free Software Foundation gives permission
- * for additional uses of the text contained in its release of GUILE.
- *
- * The exception is that, if you link the GUILE library with other files
- * to produce an executable, this does not by itself cause the
- * resulting executable to be covered by the GNU General Public License.
- * Your use of that executable is in no way restricted on account of
- * linking the GUILE library code into it.
- *
- * This exception does not however invalidate any other reasons why
- * the executable file might be covered by the GNU General Public License.
+ * 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 exception applies only to the code released by the
- * Free Software Foundation under the name GUILE. If you copy
- * code from other Free Software Foundation releases into a copy of
- * GUILE, as the General Public License permits, the exception does
- * not apply to the code that you add in this way. To avoid misleading
- * anyone as to the status of such modified files, you must delete
- * this exception notice from them.
+ * 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.
*
- * If you write modifications of your own for GUILE, it is your choice
- * whether to permit this exception to apply to your modifications.
- * If you do not wish that, delete this exception notice. */
+ * 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
+ */
-/* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
- gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
\f
+#include <assert.h>
+
#include "libguile/_scm.h"
#include "libguile/eval.h"
#include "libguile/alist.h"
Things that can be on the wind list:
+ #<frame>
+ #<winder>
(enter-proc . leave-proc) dynamic-wind
(tag . jmpbuf) catch
(tag . lazy-catch) lazy-catch
tag is either a symbol or a boolean
- ((fluid ...) . (value ...)) with-fluids
-
*/
"@lisp\n"
"(define x 'normal-binding)\n"
"@result{} x\n"
- "(define a-cont (call-with-current-continuation \n"
+ "(define a-cont (call-with-current-continuation\n"
" (lambda (escape)\n"
" (let ((old-x x))\n"
" (dynamic-wind\n"
" ;;\n"
" (lambda () (set! x old-x)))))))\n"
"\n"
- ";; Prints: \n"
+ ";; Prints:\n"
"special-binding\n"
";; Evaluates to:\n"
"@result{} a-cont\n"
SCM_ASSERT (SCM_NFALSEP (scm_thunk_p (out_guard)),
out_guard,
SCM_ARG3, FUNC_NAME);
- scm_apply (in_guard, SCM_EOL, SCM_EOL);
+ scm_call_0 (in_guard);
scm_dynwinds = scm_acons (in_guard, out_guard, scm_dynwinds);
- ans = scm_apply (thunk, SCM_EOL, SCM_EOL);
+ ans = scm_call_0 (thunk);
scm_dynwinds = SCM_CDR (scm_dynwinds);
- scm_apply (out_guard, SCM_EOL, SCM_EOL);
+ scm_call_0 (out_guard);
return ans;
}
#undef FUNC_NAME
-/* The implementation of a C-callable dynamic-wind,
- * scm_internal_dynamic_wind, requires packaging of C pointers in a
- * smob. Objects of this type are pushed onto the dynwind chain.
- */
+SCM
+scm_internal_dynamic_wind (scm_t_guard before,
+ scm_t_inner inner,
+ scm_t_guard after,
+ void *inner_data,
+ void *guard_data)
+{
+ SCM ans;
+
+ scm_frame_begin (SCM_F_FRAME_REWINDABLE);
+ scm_frame_rewind_handler (before, guard_data, SCM_F_WIND_EXPLICITLY);
+ scm_frame_unwind_handler (after, guard_data, SCM_F_WIND_EXPLICITLY);
+ ans = inner (inner_data);
+ scm_frame_end ();
+ return ans;
+}
-#define SCM_GUARDSP(obj) SCM_TYP16_PREDICATE (tc16_guards, obj)
-#define SCM_BEFORE_GUARD(obj) ((scm_guard_t) SCM_CELL_WORD (obj, 1))
-#define SCM_AFTER_GUARD(obj) ((scm_guard_t) SCM_CELL_WORD (obj, 2))
-#define SCM_GUARD_DATA(obj) ((void *) SCM_CELL_WORD (obj, 3))
+/* Frames and winders. */
-static scm_bits_t tc16_guards;
+static scm_t_bits tc16_frame;
+#define FRAME_P(f) SCM_SMOB_PREDICATE (tc16_frame, (f))
-static int
-guards_print (SCM exp, SCM port, scm_print_state *pstate)
+#define FRAME_F_REWINDABLE (1 << 16)
+#define FRAME_REWINDABLE_P(f) (SCM_CELL_WORD_0(f) & FRAME_F_REWINDABLE)
+
+static scm_t_bits tc16_winder;
+#define WINDER_P(w) SCM_SMOB_PREDICATE (tc16_winder, (w))
+#define WINDER_PROC(w) ((void (*)(void *))SCM_CELL_WORD_1 (w))
+#define WINDER_DATA(w) ((void *)SCM_CELL_WORD_2 (w))
+
+#define WINDER_F_EXPLICIT (1 << 16)
+#define WINDER_F_REWIND (1 << 17)
+#define WINDER_F_MARK (1 << 18)
+#define WINDER_EXPLICIT_P(w) (SCM_CELL_WORD_0(w) & WINDER_F_EXPLICIT)
+#define WINDER_REWIND_P(w) (SCM_CELL_WORD_0(w) & WINDER_F_REWIND)
+#define WINDER_MARK_P(w) (SCM_CELL_WORD_0(w) & WINDER_F_MARK)
+
+void
+scm_frame_begin (scm_t_frame_flags flags)
{
- scm_puts ("#<guards ", port);
- scm_intprint (SCM_UNPACK (SCM_CDR (exp)), 16, port);
- scm_putc ('>', port);
- return 1;
+ SCM f;
+ scm_t_bits fl = ((flags&SCM_F_FRAME_REWINDABLE)? FRAME_F_REWINDABLE : 0);
+ SCM_NEWSMOB (f, tc16_frame | fl, 0);
+ scm_dynwinds = scm_cons (f, scm_dynwinds);
}
-SCM
-scm_internal_dynamic_wind (scm_guard_t before,
- scm_inner_t inner,
- scm_guard_t after,
- void *inner_data,
- void *guard_data)
+void
+scm_frame_end (void)
{
- SCM guards, ans;
- before (guard_data);
- SCM_NEWSMOB3 (guards, tc16_guards, (scm_bits_t) before,
- (scm_bits_t) after, (scm_bits_t) guard_data);
- scm_dynwinds = scm_acons (guards, SCM_BOOL_F, scm_dynwinds);
- ans = inner (inner_data);
- scm_dynwinds = SCM_CDR (scm_dynwinds);
- after (guard_data);
- return ans;
+ /* Unwind upto and including the next frame entry. We can only
+ encounter #<winder> entries on the way.
+ */
+
+ while (SCM_CONSP (scm_dynwinds))
+ {
+ SCM entry = SCM_CAR (scm_dynwinds);
+ scm_dynwinds = SCM_CDR (scm_dynwinds);
+
+ if (FRAME_P (entry))
+ return;
+
+ assert (WINDER_P (entry));
+ if (!WINDER_REWIND_P (entry) && WINDER_EXPLICIT_P (entry))
+ WINDER_PROC(entry) (WINDER_DATA (entry));
+ }
+
+ assert (0);
+}
+
+static SCM
+winder_mark (SCM w)
+{
+ if (WINDER_MARK_P (w))
+ return WINDER_DATA (w);
+ return SCM_BOOL_F;
+}
+
+void
+scm_frame_unwind_handler (void (*proc) (void *), void *data,
+ scm_t_wind_flags flags)
+{
+ SCM w;
+ scm_t_bits fl = ((flags&SCM_F_WIND_EXPLICITLY)? WINDER_F_EXPLICIT : 0);
+ SCM_NEWSMOB2 (w, tc16_winder | fl,
+ (scm_t_bits) proc, (scm_t_bits) data);
+ scm_dynwinds = scm_cons (w, scm_dynwinds);
+}
+
+void
+scm_frame_rewind_handler (void (*proc) (void *), void *data,
+ scm_t_wind_flags flags)
+{
+ SCM w;
+ SCM_NEWSMOB2 (w, tc16_winder | WINDER_F_REWIND,
+ (scm_t_bits) proc, (scm_t_bits) data);
+ scm_dynwinds = scm_cons (w, scm_dynwinds);
+ if (flags & SCM_F_WIND_EXPLICITLY)
+ proc (data);
+}
+
+void
+scm_frame_unwind_handler_with_scm (void (*proc) (SCM), SCM data,
+ scm_t_wind_flags flags)
+{
+ SCM w;
+ scm_t_bits fl = ((flags&SCM_F_WIND_EXPLICITLY)? WINDER_F_EXPLICIT : 0);
+ SCM_NEWSMOB2 (w, tc16_winder | fl | WINDER_F_MARK,
+ (scm_t_bits) proc, SCM_UNPACK (data));
+ scm_dynwinds = scm_cons (w, scm_dynwinds);
+}
+
+void
+scm_frame_rewind_handler_with_scm (void (*proc) (SCM), SCM data,
+ scm_t_wind_flags flags)
+{
+ SCM w;
+ SCM_NEWSMOB2 (w, tc16_winder | WINDER_F_REWIND | WINDER_F_MARK,
+ (scm_t_bits) proc, SCM_UNPACK (data));
+ scm_dynwinds = scm_cons (w, scm_dynwinds);
+ if (flags & SCM_F_WIND_EXPLICITLY)
+ proc (data);
}
#ifdef GUILE_DEBUG
#undef FUNC_NAME
#endif
-static void
-scm_swap_bindings (SCM glocs, SCM vals)
+void
+scm_swap_bindings (SCM vars, SCM vals)
{
SCM tmp;
while (SCM_NIMP (vals))
{
- tmp = SCM_GLOC_VAL (SCM_CAR (glocs));
- SCM_SETCDR (SCM_PACK (SCM_UNPACK (SCM_CAR (glocs)) - 1L),
- SCM_CAR (vals));
+ tmp = SCM_VARIABLE_REF (SCM_CAR (vars));
+ SCM_VARIABLE_SET (SCM_CAR (vars), SCM_CAR (vals));
SCM_SETCAR (vals, tmp);
- glocs = SCM_CDR (glocs);
+ vars = SCM_CDR (vars);
vals = SCM_CDR (vals);
}
}
-void
+void
scm_dowinds (SCM to, long delta)
+{
+ scm_i_dowinds (to, delta, NULL, NULL);
+}
+
+void
+scm_i_dowinds (SCM to, long delta, void (*turn_func) (void *), void *data)
{
tail:
- if (SCM_EQ_P (to, scm_dynwinds));
- else if (0 > delta)
+ if (SCM_EQ_P (to, scm_dynwinds))
+ {
+ if (turn_func)
+ turn_func (data);
+ }
+ else if (delta < 0)
{
SCM wind_elt;
SCM wind_key;
- scm_dowinds (SCM_CDR (to), 1 + delta);
+ scm_i_dowinds (SCM_CDR (to), 1 + delta, turn_func, data);
wind_elt = SCM_CAR (to);
+
#if 0
if (SCM_INUMP (wind_elt))
{
else
#endif
{
- wind_key = SCM_CAR (wind_elt);
- /* key = #t | symbol | thunk | list of glocs | list of fluids */
- if (SCM_NIMP (wind_key))
+ if (FRAME_P (wind_elt))
+ {
+ if (!FRAME_REWINDABLE_P (wind_elt))
+ scm_misc_error ("dowinds",
+ "cannot invoke continuation from this context",
+ SCM_EOL);
+ }
+ else if (WINDER_P (wind_elt))
+ {
+ if (WINDER_REWIND_P (wind_elt))
+ WINDER_PROC (wind_elt) (WINDER_DATA (wind_elt));
+ }
+ else
{
- if (SCM_TYP3 (wind_key) == scm_tc3_cons_gloc)
- scm_swap_bindings (wind_key, SCM_CDR (wind_elt));
- else if (SCM_TYP3 (wind_key) == scm_tc3_cons)
- scm_swap_fluids (wind_key, SCM_CDR (wind_elt));
- else if (SCM_GUARDSP (wind_key))
- SCM_BEFORE_GUARD (wind_key) (SCM_GUARD_DATA (wind_key));
- else if (SCM_TYP3 (wind_key) == scm_tc3_closure)
- scm_apply (wind_key, SCM_EOL, SCM_EOL);
+ wind_key = SCM_CAR (wind_elt);
+ /* key = #t | symbol | thunk | list of variables */
+ if (SCM_NIMP (wind_key))
+ {
+ if (SCM_CONSP (wind_key))
+ {
+ if (SCM_VARIABLEP (SCM_CAR (wind_key)))
+ scm_swap_bindings (wind_key, SCM_CDR (wind_elt));
+ }
+ else if (SCM_TYP3 (wind_key) == scm_tc3_closure)
+ scm_call_0 (wind_key);
+ }
}
}
scm_dynwinds = to;
}
else
{
- SCM from;
SCM wind_elt;
SCM wind_key;
- from = SCM_CDR (SCM_CAR (scm_dynwinds));
wind_elt = SCM_CAR (scm_dynwinds);
scm_dynwinds = SCM_CDR (scm_dynwinds);
+
#if 0
if (SCM_INUMP (wind_elt))
{
else
#endif
{
- wind_key = SCM_CAR (wind_elt);
- if (SCM_NIMP (wind_key))
+ if (FRAME_P (wind_elt))
+ {
+ /* Nothing to do. */
+ }
+ else if (WINDER_P (wind_elt))
+ {
+ if (!WINDER_REWIND_P (wind_elt))
+ WINDER_PROC (wind_elt) (WINDER_DATA (wind_elt));
+ }
+ else
{
- if (SCM_TYP3 (wind_key) == scm_tc3_cons_gloc)
- scm_swap_bindings (wind_key, from);
- else if (SCM_TYP3 (wind_key) == scm_tc3_cons)
- scm_swap_fluids_reverse (wind_key, from);
- else if (SCM_GUARDSP (wind_key))
- SCM_AFTER_GUARD (wind_key) (SCM_GUARD_DATA (wind_key));
- else if (SCM_TYP3 (wind_key) == scm_tc3_closure)
- scm_apply (from, SCM_EOL, SCM_EOL);
+ wind_key = SCM_CAR (wind_elt);
+ if (SCM_NIMP (wind_key))
+ {
+ if (SCM_CONSP (wind_key))
+ {
+ if (SCM_VARIABLEP (SCM_CAR (wind_key)))
+ scm_swap_bindings (wind_key, SCM_CDR (wind_elt));
+ }
+ else if (SCM_TYP3 (wind_key) == scm_tc3_closure)
+ scm_call_0 (SCM_CDR (wind_elt));
+ }
}
}
delta--;
}
}
-
-
void
scm_init_dynwind ()
{
- tc16_guards = scm_make_smob_type ("guards", 0);
- scm_set_smob_print (tc16_guards, guards_print);
-#ifndef SCM_MAGIC_SNARFER
+ tc16_frame = scm_make_smob_type ("frame", 0);
+
+ tc16_winder = scm_make_smob_type ("winder", 0);
+ scm_set_smob_mark (tc16_winder, winder_mark);
+
#include "libguile/dynwind.x"
-#endif
}
/*
HCoop / bpt / guile.git / blobdiff