if (!SCM_NULLP (env) || SCM_UNBNDP (SCM_VARIABLE_REF (real_var)))
{
errout:
- /* scm_everr (vloc, genv,...) */
if (check)
{
if (SCM_NULLP (env))
}
return !SCM_NULLP (args) ? 1 : 0;
}
+
#endif
static int
#undef FUNC_NAME
static SCM
-scm_deval_args (SCM l, SCM env, SCM proc, SCM *lloc)
+deval_args (SCM l, SCM env, SCM proc, SCM *lloc)
{
SCM *results = lloc, res;
while (SCM_CONSP (l))
#endif /* !DEVAL */
-/* SECTION: Some local definitions for the evaluator.
+/* SECTION: This code is compiled twice.
*/
+
/* Update the toplevel environment frame ENV so that it refers to the
- current module.
-*/
+ * current module. */
#define UPDATE_TOPLEVEL_ENV(env) \
do { \
SCM p = scm_current_module_lookup_closure (); \
#define CHECK_EQVISH(A,B) (SCM_EQ_P ((A), (B)) || (!SCM_FALSEP (scm_eqv_p ((A), (B)))))
#endif /* DEVAL */
-#define BUILTIN_RPASUBR /* Handle rpsubrs and asubrs without calling apply */
-
-/* SECTION: This is the evaluator. Like any real monster, it has
- * three heads. This code is compiled twice.
- */
+/* This is the evaluator. Like any real monster, it has three heads:
+ *
+ * scm_ceval is the non-debugging evaluator, scm_deval is the debugging
+ * version. Both are implemented using a common code base, using the
+ * following mechanism: SCM_CEVAL is a macro, which is either defined to
+ * scm_ceval or scm_deval. Thus, there is no function SCM_CEVAL, but the code
+ * for SCM_CEVAL actually compiles to either scm_ceval or scm_deval. When
+ * SCM_CEVAL is defined to scm_ceval, it is known that the macro DEVAL is not
+ * defined. When SCM_CEVAL is defined to scm_deval, then the macro DEVAL is
+ * known to be defined. Thus, in SCM_CEVAL parts for the debugging evaluator
+ * are enclosed within #ifdef DEVAL ... #endif.
+ *
+ * All three (scm_ceval, scm_deval and their common implementation SCM_CEVAL)
+ * take two input parameters, x and env: x is a single expression to be
+ * evalutated. env is the environment in which bindings are searched.
+ *
+ * x is known to be a cell (i. e. a pair or any other non-immediate). Since x
+ * is a single expression, it is necessarily in a tail position. If x is just
+ * a call to another function like in the expression (foo exp1 exp2 ...), the
+ * realization of that call therefore _must_not_ increase stack usage (the
+ * evaluation of exp1, exp2 etc., however, may do so). This is realized by
+ * making extensive use of 'goto' statements within the evaluator: The gotos
+ * replace recursive calls to SCM_CEVAL, thus re-using the same stack frame
+ * that SCM_CEVAL was already using. If, however, x represents some form that
+ * requires to evaluate a sequence of expressions like (begin exp1 exp2 ...),
+ * then recursive calls to SCM_CEVAL are performed for all but the last
+ * expression of that sequence. */
#if 0
-
SCM
scm_ceval (SCM x, SCM env)
{}
#endif
-#if 0
+#if 0
SCM
scm_deval (SCM x, SCM env)
{}
* Even frames are eval frames, odd frames are apply frames.
*/
debug.vect = (scm_t_debug_info *) alloca (scm_debug_eframe_size
- * sizeof (debug.vect[0]));
+ * sizeof (scm_t_debug_info));
debug.info = debug.vect;
debug_info_end = debug.vect + scm_debug_eframe_size;
scm_last_debug_frame = &debug;
switch (SCM_TYP7 (x))
{
case scm_tc7_symbol:
- /* Only happens when called at top level.
- */
+ /* Only happens when called at top level. */
x = scm_cons (x, SCM_UNDEFINED);
RETURN (*scm_lookupcar (x, env, 1));
case SCM_BIT8(SCM_MAKISYM (0)):
proc = SCM_CAR (x);
SCM_ASRTGO (SCM_ISYMP (proc), badfun);
- switch SCM_ISYMNUM (proc)
+ switch (SCM_ISYMNUM (proc))
{
case (SCM_ISYMNUM (SCM_IM_APPLY)):
proc = SCM_CDR (x);
default:
proc = x;
badfun:
- /* scm_everr (x, env,...) */
scm_misc_error (NULL, "Wrong type to apply: ~S", scm_list_1 (proc));
case scm_tc7_vector:
case scm_tc7_wvect:
umwrongnumargs:
unmemocar (x, env);
wrongnumargs:
- /* scm_everr (x, env,...) */
scm_wrong_num_args (proc);
default:
/* handle macros here */
#endif
#ifdef DEVAL
debug.info->a.args = scm_cons2 (t.arg1, arg2,
- scm_deval_args (x, env, proc,
- SCM_CDRLOC (SCM_CDR (debug.info->a.args))));
+ deval_args (x, env, proc, SCM_CDRLOC (SCM_CDR (debug.info->a.args))));
#endif
ENTER_APPLY;
evap3:
*/
#if 0
-
SCM
scm_apply (SCM proc, SCM arg1, SCM args)
{}
#endif
#if 0
-
SCM
scm_dapply (SCM proc, SCM arg1, SCM args)
{ /* empty */ }
#ifndef SCM_GOOPS_H
#define SCM_GOOPS_H
+
/* Copyright (C) 1998,1999,2000,2001 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,
* 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. */
+
\f
/* This software is a derivative work of other copyrighted softwares; the
#endif
-#endif /* SCM_GOOPS_H */
+#endif /* SCM_GOOPS_H */
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/
HCoop / bpt / guile.git / commitdiff