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/* classes: h_files */
#ifndef SCM_PROCS_H
#define SCM_PROCS_H
/* Copyright (C) 1995,1996,1998,1999,2000,2001, 2006, 2008, 2009 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libguile/__scm.h"
/* Subrs
*/
#define SCM_SUBR_META_INFO(x) ((SCM *) SCM_CELL_WORD_3 (x))
#define SCM_SNAME(x) (SCM_SUBR_META_INFO (x) [0])
#define SCM_SUBRF(x) ((SCM (*)()) SCM_CELL_WORD_1 (x))
#define SCM_DSUBRF(x) ((double (*)()) SCM_CELL_WORD_1 (x))
#define SCM_SUBR_PROPS(x) (SCM_SUBR_META_INFO (x) [1])
#define SCM_SUBR_GENERIC(x) ((SCM *) SCM_CELL_WORD_2 (x))
#define SCM_SET_SUBR_GENERIC(x, g) (*((SCM *) SCM_CELL_WORD_2 (x)) = (g))
#define SCM_SET_SUBR_GENERIC_LOC(x, g) (SCM_SET_CELL_WORD_2 (x, (scm_t_bits) g))
/* Return the most suitable subr type for a subr with REQ required arguments,
OPT optional arguments, and REST (0 or 1) arguments. This has to be in
sync with `create_gsubr ()'. */
#define SCM_SUBR_ARITY_TO_TYPE(req, opt, rest) \
((rest) == 0 \
? ((opt) == 0 \
? ((req) == 0 \
? scm_tc7_subr_0 \
: ((req) == 1 \
? scm_tc7_subr_1 \
: ((req) == 2 \
? scm_tc7_subr_2 \
: ((req) == 3 \
? scm_tc7_subr_3 \
: scm_tc7_gsubr \
| (SCM_GSUBR_MAKTYPE (req, opt, rest) << 8U))))) \
: ((opt) == 1 \
? ((req) == 0 \
? scm_tc7_subr_1o \
: ((req) == 1 \
? scm_tc7_subr_2o \
: scm_tc7_gsubr | \
(SCM_GSUBR_MAKTYPE (req, opt, rest) << 8U))) \
: scm_tc7_gsubr | \
(SCM_GSUBR_MAKTYPE (req, opt, rest) << 8U))) \
: ((rest) == 1 \
? ((opt) == 0 \
? ((req) == 0 \
? scm_tc7_lsubr \
: ((req) == 2 \
? scm_tc7_lsubr_2 \
: scm_tc7_gsubr \
| (SCM_GSUBR_MAKTYPE (req, opt, rest) << 8U))) \
: scm_tc7_gsubr \
| (SCM_GSUBR_MAKTYPE (req, opt, rest) << 8U)) \
: scm_tc7_gsubr \
| (SCM_GSUBR_MAKTYPE (req, opt, rest) << 8U)))
/* Closures
*/
#define SCM_CLOSUREP(x) (!SCM_IMP(x) && (SCM_TYP3 (x) == scm_tc3_closure))
#define SCM_CLOSCAR(x) SCM_PACK (SCM_CELL_WORD_0 (x) - scm_tc3_closure)
#define SCM_CODE(x) SCM_CAR (SCM_CLOSCAR (x))
#define SCM_CLOSURE_FORMALS(x) SCM_CAR (SCM_CODE (x))
#define SCM_CLOSURE_BODY(x) SCM_CDR (SCM_CODE (x))
#define SCM_PROCPROPS(x) SCM_CDR (SCM_CLOSCAR (x))
#define SCM_SETPROCPROPS(x, p) SCM_SETCDR (SCM_CLOSCAR (x), p)
#define SCM_ENV(x) SCM_CELL_OBJECT_1 (x)
#define SCM_TOP_LEVEL(ENV) (scm_is_null (ENV) || (scm_is_true (scm_procedure_p (SCM_CAR (ENV)))))
/* Procedure-with-setter
Four representations for procedure-with-setters were
considered before selecting this one:
1. A closure where the CODE and ENV slots are used to represent
the getter and a new SETTER slot is used for the setter. The
original getter is stored as a `getter' procedure property. For
closure getters, the CODE and ENV slots contains a copy of the
getter's CODE and ENV slots. For subr getters, the CODE contains
a call to the subr.
2. A compiled closure with a call to the getter in the cclo
procedure. The getter and setter are stored in slots 1 and 2.
3. An entity (i.e. a struct with an associated procedure) with a
call to the getter in the entity procedure and the setter stored
in slot 0. The original getter is stored in slot 1.
4. A new primitive procedure type supported in the evaluator. The
getter and setter are stored in a GETTER and SETTER slot. A call
to this procedure type results in a retrieval of the getter and a
jump back to the correct eval dispatcher.
Representation 4 was selected because of efficiency and
simplicity.
Rep 1 has the advantage that there is zero penalty for closure
getters, but primitive getters will get considerable overhead
because the procedure-with-getter will be a closure which calls
the getter.
Rep 3 has the advantage that a GOOPS accessor can be a subclass of
<procedure-with-setter>, but together with rep 2 it suffers from a
three level dispatch for non-GOOPS getters:
cclo/struct --> dispatch proc --> getter
This is because the dispatch procedure must take an extra initial
argument (cclo for rep 2, struct for rep 3).
Rep 4 has the single disadvantage that it uses up one tc7 type
code, but the plan for uniform vectors will very likely free tc7
codes, so this is probably no big problem. Also note that the
GETTER and SETTER slots can live directly on the heap, using the
new four-word cells. */
#define SCM_PROCEDURE_WITH_SETTER_P(obj) (!SCM_IMP(obj) && (SCM_TYP7 (obj) == scm_tc7_pws))
#define SCM_PROCEDURE(obj) SCM_CELL_OBJECT_1 (obj)
#define SCM_SETTER(obj) SCM_CELL_OBJECT_2 (obj)
SCM_API SCM scm_c_make_subr (const char *name, long type, SCM (*fcn)());
SCM_API SCM scm_c_make_subr_with_generic (const char *name, long type,
SCM (*fcn)(), SCM *gf);
SCM_API SCM scm_c_define_subr (const char *name, long type, SCM (*fcn)());
SCM_API SCM scm_c_define_subr_with_generic (const char *name, long type,
SCM (*fcn)(), SCM *gf);
SCM_API SCM scm_procedure_p (SCM obj);
SCM_API SCM scm_closure_p (SCM obj);
SCM_API SCM scm_thunk_p (SCM obj);
SCM_API int scm_subr_p (SCM obj);
SCM_API SCM scm_procedure_documentation (SCM proc);
SCM_API SCM scm_procedure_with_setter_p (SCM obj);
SCM_API SCM scm_make_procedure_with_setter (SCM procedure, SCM setter);
SCM_API SCM scm_procedure (SCM proc);
SCM_API SCM scm_setter (SCM proc);
SCM_INTERNAL void scm_init_procs (void);
#endif /* SCM_PROCS_H */
/*
Local Variables:
c-file-style: "gnu"
End:
*/
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