mirror of
https://git.savannah.gnu.org/git/guile.git
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53befeb700
(Not quite finished, the following will be done tomorrow. module/srfi/*.scm module/rnrs/*.scm module/scripts/*.scm testsuite/*.scm guile-readline/* )
2349 lines
65 KiB
C
2349 lines
65 KiB
C
/* Copyright (C) 1999,2000,2001, 2003, 2006, 2008 Free Software Foundation, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public License
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* as published by the Free Software Foundation; either version 3 of
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* the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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* 02110-1301 USA
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*/
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include "libguile/_scm.h"
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#include "libguile/alist.h"
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#include "libguile/eval.h"
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#include "libguile/hash.h"
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#include "libguile/list.h"
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#include "libguile/ports.h"
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#include "libguile/smob.h"
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#include "libguile/symbols.h"
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#include "libguile/vectors.h"
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#include "libguile/weaks.h"
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#include "libguile/environments.h"
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scm_t_bits scm_tc16_environment;
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scm_t_bits scm_tc16_observer;
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#define DEFAULT_OBARRAY_SIZE 31
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SCM scm_system_environment;
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/* error conditions */
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/*
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* Throw an error if symbol is not bound in environment func
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*/
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void
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scm_error_environment_unbound (const char *func, SCM env, SCM symbol)
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{
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/* Dirk:FIXME:: Should throw an environment:unbound type error */
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char error[] = "Symbol `~A' not bound in environment `~A'.";
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SCM arguments = scm_cons2 (symbol, env, SCM_EOL);
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scm_misc_error (func, error, arguments);
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}
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/*
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* Throw an error if func tried to create (define) or remove
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* (undefine) a new binding for symbol in env
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*/
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void
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scm_error_environment_immutable_binding (const char *func, SCM env, SCM symbol)
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{
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/* Dirk:FIXME:: Should throw an environment:immutable-binding type error */
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char error[] = "Immutable binding in environment ~A (symbol: `~A').";
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SCM arguments = scm_cons2 (env, symbol, SCM_EOL);
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scm_misc_error (func, error, arguments);
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}
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/*
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* Throw an error if func tried to change an immutable location.
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*/
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void
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scm_error_environment_immutable_location (const char *func, SCM env, SCM symbol)
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{
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/* Dirk:FIXME:: Should throw an environment:immutable-location type error */
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char error[] = "Immutable location in environment `~A' (symbol: `~A').";
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SCM arguments = scm_cons2 (env, symbol, SCM_EOL);
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scm_misc_error (func, error, arguments);
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}
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/* generic environments */
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/* Create an environment for the given type. Dereferencing type twice must
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* deliver the initialized set of environment functions. Thus, type will
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* also determine the signature of the underlying environment implementation.
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* Dereferencing type once will typically deliver the data fields used by the
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* underlying environment implementation.
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*/
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SCM
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scm_make_environment (void *type)
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{
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return scm_cell (scm_tc16_environment, (scm_t_bits) type);
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}
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SCM_DEFINE (scm_environment_p, "environment?", 1, 0, 0,
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(SCM obj),
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"Return @code{#t} if @var{obj} is an environment, or @code{#f}\n"
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"otherwise.")
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#define FUNC_NAME s_scm_environment_p
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{
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return scm_from_bool (SCM_ENVIRONMENT_P (obj));
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}
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#undef FUNC_NAME
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SCM_DEFINE (scm_environment_bound_p, "environment-bound?", 2, 0, 0,
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(SCM env, SCM sym),
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"Return @code{#t} if @var{sym} is bound in @var{env}, or\n"
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"@code{#f} otherwise.")
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#define FUNC_NAME s_scm_environment_bound_p
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{
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SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
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SCM_ASSERT (scm_is_symbol (sym), sym, SCM_ARG2, FUNC_NAME);
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return scm_from_bool (SCM_ENVIRONMENT_BOUND_P (env, sym));
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}
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#undef FUNC_NAME
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SCM_DEFINE (scm_environment_ref, "environment-ref", 2, 0, 0,
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(SCM env, SCM sym),
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"Return the value of the location bound to @var{sym} in\n"
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"@var{env}. If @var{sym} is unbound in @var{env}, signal an\n"
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"@code{environment:unbound} error.")
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#define FUNC_NAME s_scm_environment_ref
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{
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SCM val;
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SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
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SCM_ASSERT (scm_is_symbol (sym), sym, SCM_ARG2, FUNC_NAME);
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val = SCM_ENVIRONMENT_REF (env, sym);
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if (!SCM_UNBNDP (val))
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return val;
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else
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scm_error_environment_unbound (FUNC_NAME, env, sym);
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}
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#undef FUNC_NAME
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/* This C function is identical to environment-ref, except that if symbol is
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* unbound in env, it returns the value SCM_UNDEFINED, instead of signalling
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* an error.
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*/
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SCM
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scm_c_environment_ref (SCM env, SCM sym)
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{
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SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_ref");
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SCM_ASSERT (scm_is_symbol (sym), sym, SCM_ARG2, "scm_c_environment_ref");
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return SCM_ENVIRONMENT_REF (env, sym);
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}
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static SCM
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environment_default_folder (SCM proc, SCM symbol, SCM value, SCM tail)
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{
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return scm_call_3 (proc, symbol, value, tail);
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}
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SCM_DEFINE (scm_environment_fold, "environment-fold", 3, 0, 0,
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(SCM env, SCM proc, SCM init),
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"Iterate over all the bindings in @var{env}, accumulating some\n"
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"value.\n"
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"For each binding in @var{env}, apply @var{proc} to the symbol\n"
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"bound, its value, and the result from the previous application\n"
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"of @var{proc}.\n"
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"Use @var{init} as @var{proc}'s third argument the first time\n"
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"@var{proc} is applied.\n"
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"If @var{env} contains no bindings, this function simply returns\n"
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"@var{init}.\n"
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"If @var{env} binds the symbol sym1 to the value val1, sym2 to\n"
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"val2, and so on, then this procedure computes:\n"
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"@lisp\n"
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" (proc sym1 val1\n"
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" (proc sym2 val2\n"
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" ...\n"
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" (proc symn valn\n"
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" init)))\n"
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"@end lisp\n"
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"Each binding in @var{env} will be processed exactly once.\n"
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"@code{environment-fold} makes no guarantees about the order in\n"
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"which the bindings are processed.\n"
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"Here is a function which, given an environment, constructs an\n"
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"association list representing that environment's bindings,\n"
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"using environment-fold:\n"
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"@lisp\n"
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" (define (environment->alist env)\n"
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" (environment-fold env\n"
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" (lambda (sym val tail)\n"
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" (cons (cons sym val) tail))\n"
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" '()))\n"
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"@end lisp")
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#define FUNC_NAME s_scm_environment_fold
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{
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SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
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SCM_ASSERT (scm_is_true (scm_procedure_p (proc)),
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proc, SCM_ARG2, FUNC_NAME);
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return SCM_ENVIRONMENT_FOLD (env, environment_default_folder, proc, init);
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}
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#undef FUNC_NAME
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/* This is the C-level analog of environment-fold. For each binding in ENV,
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* make the call:
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* (*proc) (data, symbol, value, previous)
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* where previous is the value returned from the last call to *PROC, or INIT
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* for the first call. If ENV contains no bindings, return INIT.
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*/
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SCM
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scm_c_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init)
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{
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SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_fold");
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return SCM_ENVIRONMENT_FOLD (env, proc, data, init);
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}
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SCM_DEFINE (scm_environment_define, "environment-define", 3, 0, 0,
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(SCM env, SCM sym, SCM val),
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"Bind @var{sym} to a new location containing @var{val} in\n"
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"@var{env}. If @var{sym} is already bound to another location\n"
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"in @var{env} and the binding is mutable, that binding is\n"
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"replaced. The new binding and location are both mutable. The\n"
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"return value is unspecified.\n"
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"If @var{sym} is already bound in @var{env}, and the binding is\n"
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"immutable, signal an @code{environment:immutable-binding} error.")
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#define FUNC_NAME s_scm_environment_define
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{
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SCM status;
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SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
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SCM_ASSERT (scm_is_symbol (sym), sym, SCM_ARG2, FUNC_NAME);
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status = SCM_ENVIRONMENT_DEFINE (env, sym, val);
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if (scm_is_eq (status, SCM_ENVIRONMENT_SUCCESS))
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return SCM_UNSPECIFIED;
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else if (scm_is_eq (status, SCM_ENVIRONMENT_BINDING_IMMUTABLE))
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scm_error_environment_immutable_binding (FUNC_NAME, env, sym);
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else
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abort();
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}
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#undef FUNC_NAME
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SCM_DEFINE (scm_environment_undefine, "environment-undefine", 2, 0, 0,
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(SCM env, SCM sym),
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"Remove any binding for @var{sym} from @var{env}. If @var{sym}\n"
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"is unbound in @var{env}, do nothing. The return value is\n"
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"unspecified.\n"
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"If @var{sym} is already bound in @var{env}, and the binding is\n"
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"immutable, signal an @code{environment:immutable-binding} error.")
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#define FUNC_NAME s_scm_environment_undefine
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{
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SCM status;
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SCM_ASSERT(SCM_ENVIRONMENT_P(env), env, SCM_ARG1, FUNC_NAME);
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SCM_ASSERT(scm_is_symbol(sym), sym, SCM_ARG2, FUNC_NAME);
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status = SCM_ENVIRONMENT_UNDEFINE (env, sym);
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if (scm_is_eq (status, SCM_ENVIRONMENT_SUCCESS))
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return SCM_UNSPECIFIED;
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else if (scm_is_eq (status, SCM_ENVIRONMENT_BINDING_IMMUTABLE))
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scm_error_environment_immutable_binding (FUNC_NAME, env, sym);
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else
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abort();
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}
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#undef FUNC_NAME
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SCM_DEFINE (scm_environment_set_x, "environment-set!", 3, 0, 0,
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(SCM env, SCM sym, SCM val),
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"If @var{env} binds @var{sym} to some location, change that\n"
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"location's value to @var{val}. The return value is\n"
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"unspecified.\n"
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"If @var{sym} is not bound in @var{env}, signal an\n"
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"@code{environment:unbound} error. If @var{env} binds @var{sym}\n"
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"to an immutable location, signal an\n"
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"@code{environment:immutable-location} error.")
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#define FUNC_NAME s_scm_environment_set_x
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{
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SCM status;
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SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
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SCM_ASSERT (scm_is_symbol (sym), sym, SCM_ARG2, FUNC_NAME);
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status = SCM_ENVIRONMENT_SET (env, sym, val);
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if (scm_is_eq (status, SCM_ENVIRONMENT_SUCCESS))
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return SCM_UNSPECIFIED;
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else if (SCM_UNBNDP (status))
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scm_error_environment_unbound (FUNC_NAME, env, sym);
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else if (scm_is_eq (status, SCM_ENVIRONMENT_LOCATION_IMMUTABLE))
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scm_error_environment_immutable_binding (FUNC_NAME, env, sym);
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else
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abort();
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}
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#undef FUNC_NAME
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SCM_DEFINE (scm_environment_cell, "environment-cell", 3, 0, 0,
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(SCM env, SCM sym, SCM for_write),
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"Return the value cell which @var{env} binds to @var{sym}, or\n"
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"@code{#f} if the binding does not live in a value cell.\n"
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"The argument @var{for-write} indicates whether the caller\n"
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"intends to modify the variable's value by mutating the value\n"
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"cell. If the variable is immutable, then\n"
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"@code{environment-cell} signals an\n"
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"@code{environment:immutable-location} error.\n"
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"If @var{sym} is unbound in @var{env}, signal an\n"
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"@code{environment:unbound} error.\n"
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"If you use this function, you should consider using\n"
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"@code{environment-observe}, to be notified when @var{sym} gets\n"
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"re-bound to a new value cell, or becomes undefined.")
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#define FUNC_NAME s_scm_environment_cell
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{
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SCM location;
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SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
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SCM_ASSERT (scm_is_symbol (sym), sym, SCM_ARG2, FUNC_NAME);
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SCM_ASSERT (scm_is_bool (for_write), for_write, SCM_ARG3, FUNC_NAME);
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location = SCM_ENVIRONMENT_CELL (env, sym, scm_is_true (for_write));
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if (!SCM_IMP (location))
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return location;
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else if (SCM_UNBNDP (location))
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scm_error_environment_unbound (FUNC_NAME, env, sym);
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else if (scm_is_eq (location, SCM_ENVIRONMENT_LOCATION_IMMUTABLE))
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scm_error_environment_immutable_location (FUNC_NAME, env, sym);
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else /* no cell */
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return location;
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}
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#undef FUNC_NAME
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/* This C function is identical to environment-cell, with the following
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* exceptions: If symbol is unbound in env, it returns the value
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* SCM_UNDEFINED, instead of signalling an error. If symbol is bound to an
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* immutable location but the cell is requested for write, the value
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* SCM_ENVIRONMENT_LOCATION_IMMUTABLE is returned.
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*/
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SCM
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scm_c_environment_cell(SCM env, SCM sym, int for_write)
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{
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SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, "scm_c_environment_cell");
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SCM_ASSERT (scm_is_symbol (sym), sym, SCM_ARG2, "scm_c_environment_cell");
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return SCM_ENVIRONMENT_CELL (env, sym, for_write);
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}
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static void
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environment_default_observer (SCM env, SCM proc)
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{
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scm_call_1 (proc, env);
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}
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SCM_DEFINE (scm_environment_observe, "environment-observe", 2, 0, 0,
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(SCM env, SCM proc),
|
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"Whenever @var{env}'s bindings change, apply @var{proc} to\n"
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"@var{env}.\n"
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"This function returns an object, token, which you can pass to\n"
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"@code{environment-unobserve} to remove @var{proc} from the set\n"
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"of procedures observing @var{env}. The type and value of\n"
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"token is unspecified.")
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#define FUNC_NAME s_scm_environment_observe
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{
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SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
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return SCM_ENVIRONMENT_OBSERVE (env, environment_default_observer, proc, 0);
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}
|
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#undef FUNC_NAME
|
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|
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SCM_DEFINE (scm_environment_observe_weak, "environment-observe-weak", 2, 0, 0,
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(SCM env, SCM proc),
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"This function is the same as environment-observe, except that\n"
|
||
"the reference @var{env} retains to @var{proc} is a weak\n"
|
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"reference. This means that, if there are no other live,\n"
|
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"non-weak references to @var{proc}, it will be\n"
|
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"garbage-collected, and dropped from @var{env}'s\n"
|
||
"list of observing procedures.")
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#define FUNC_NAME s_scm_environment_observe_weak
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{
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SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
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return SCM_ENVIRONMENT_OBSERVE (env, environment_default_observer, proc, 1);
|
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}
|
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#undef FUNC_NAME
|
||
|
||
|
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/* This is the C-level analog of the Scheme functions environment-observe and
|
||
* environment-observe-weak. Whenever env's bindings change, call the
|
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* function proc, passing it env and data. If weak_p is non-zero, env will
|
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* retain only a weak reference to data, and if data is garbage collected, the
|
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* entire observation will be dropped. This function returns a token, with
|
||
* the same meaning as those returned by environment-observe and
|
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* environment-observe-weak.
|
||
*/
|
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SCM
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scm_c_environment_observe (SCM env, scm_environment_observer proc, SCM data, int weak_p)
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#define FUNC_NAME "scm_c_environment_observe"
|
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{
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SCM_ASSERT (SCM_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
|
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|
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return SCM_ENVIRONMENT_OBSERVE (env, proc, data, weak_p);
|
||
}
|
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#undef FUNC_NAME
|
||
|
||
|
||
SCM_DEFINE (scm_environment_unobserve, "environment-unobserve", 1, 0, 0,
|
||
(SCM token),
|
||
"Cancel the observation request which returned the value\n"
|
||
"@var{token}. The return value is unspecified.\n"
|
||
"If a call @code{(environment-observe env proc)} returns\n"
|
||
"@var{token}, then the call @code{(environment-unobserve token)}\n"
|
||
"will cause @var{proc} to no longer be called when @var{env}'s\n"
|
||
"bindings change.")
|
||
#define FUNC_NAME s_scm_environment_unobserve
|
||
{
|
||
SCM env;
|
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|
||
SCM_ASSERT (SCM_OBSERVER_P (token), token, SCM_ARG1, FUNC_NAME);
|
||
|
||
env = SCM_OBSERVER_ENVIRONMENT (token);
|
||
SCM_ENVIRONMENT_UNOBSERVE (env, token);
|
||
|
||
return SCM_UNSPECIFIED;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
environment_mark (SCM env)
|
||
{
|
||
return (*(SCM_ENVIRONMENT_FUNCS (env)->mark)) (env);
|
||
}
|
||
|
||
|
||
static size_t
|
||
environment_free (SCM env)
|
||
{
|
||
(*(SCM_ENVIRONMENT_FUNCS (env)->free)) (env);
|
||
return 0;
|
||
}
|
||
|
||
|
||
static int
|
||
environment_print (SCM env, SCM port, scm_print_state *pstate)
|
||
{
|
||
return (*(SCM_ENVIRONMENT_FUNCS (env)->print)) (env, port, pstate);
|
||
}
|
||
|
||
|
||
|
||
/* observers */
|
||
|
||
static SCM
|
||
observer_mark (SCM observer)
|
||
{
|
||
scm_gc_mark (SCM_OBSERVER_ENVIRONMENT (observer));
|
||
scm_gc_mark (SCM_OBSERVER_DATA (observer));
|
||
return SCM_BOOL_F;
|
||
}
|
||
|
||
|
||
static int
|
||
observer_print (SCM type, SCM port, scm_print_state *pstate SCM_UNUSED)
|
||
{
|
||
SCM address = scm_from_size_t (SCM_UNPACK (type));
|
||
SCM base16 = scm_number_to_string (address, scm_from_int (16));
|
||
|
||
scm_puts ("#<observer ", port);
|
||
scm_display (base16, port);
|
||
scm_puts (">", port);
|
||
|
||
return 1;
|
||
}
|
||
|
||
|
||
|
||
/* obarrays
|
||
*
|
||
* Obarrays form the basic lookup tables used to implement most of guile's
|
||
* built-in environment types. An obarray is implemented as a hash table with
|
||
* symbols as keys. The content of the data depends on the environment type.
|
||
*/
|
||
|
||
|
||
/*
|
||
* Enter symbol into obarray. The symbol must not already exist in obarray.
|
||
* The freshly generated (symbol . data) cell is returned.
|
||
*/
|
||
static SCM
|
||
obarray_enter (SCM obarray, SCM symbol, SCM data)
|
||
{
|
||
size_t hash = scm_i_symbol_hash (symbol) % SCM_HASHTABLE_N_BUCKETS (obarray);
|
||
SCM entry = scm_cons (symbol, data);
|
||
SCM slot = scm_cons (entry, SCM_HASHTABLE_BUCKET (obarray, hash));
|
||
SCM_SET_HASHTABLE_BUCKET (obarray, hash, slot);
|
||
SCM_HASHTABLE_INCREMENT (obarray);
|
||
if (SCM_HASHTABLE_N_ITEMS (obarray) > SCM_HASHTABLE_UPPER (obarray))
|
||
scm_i_rehash (obarray, scm_i_hash_symbol, 0, "obarray_enter");
|
||
|
||
return entry;
|
||
}
|
||
|
||
|
||
/*
|
||
* Enter symbol into obarray. An existing entry for symbol is replaced. If
|
||
* an entry existed, the old (symbol . data) cell is returned, #f otherwise.
|
||
*/
|
||
static SCM
|
||
obarray_replace (SCM obarray, SCM symbol, SCM data)
|
||
{
|
||
size_t hash = scm_i_symbol_hash (symbol) % SCM_HASHTABLE_N_BUCKETS (obarray);
|
||
SCM new_entry = scm_cons (symbol, data);
|
||
SCM lsym;
|
||
SCM slot;
|
||
|
||
for (lsym = SCM_HASHTABLE_BUCKET (obarray, hash);
|
||
!scm_is_null (lsym);
|
||
lsym = SCM_CDR (lsym))
|
||
{
|
||
SCM old_entry = SCM_CAR (lsym);
|
||
if (scm_is_eq (SCM_CAR (old_entry), symbol))
|
||
{
|
||
SCM_SETCAR (lsym, new_entry);
|
||
return old_entry;
|
||
}
|
||
}
|
||
|
||
slot = scm_cons (new_entry, SCM_HASHTABLE_BUCKET (obarray, hash));
|
||
SCM_SET_HASHTABLE_BUCKET (obarray, hash, slot);
|
||
SCM_HASHTABLE_INCREMENT (obarray);
|
||
if (SCM_HASHTABLE_N_ITEMS (obarray) > SCM_HASHTABLE_UPPER (obarray))
|
||
scm_i_rehash (obarray, scm_i_hash_symbol, 0, "obarray_replace");
|
||
|
||
return SCM_BOOL_F;
|
||
}
|
||
|
||
|
||
/*
|
||
* Look up symbol in obarray
|
||
*/
|
||
static SCM
|
||
obarray_retrieve (SCM obarray, SCM sym)
|
||
{
|
||
size_t hash = scm_i_symbol_hash (sym) % SCM_HASHTABLE_N_BUCKETS (obarray);
|
||
SCM lsym;
|
||
|
||
for (lsym = SCM_HASHTABLE_BUCKET (obarray, hash);
|
||
!scm_is_null (lsym);
|
||
lsym = SCM_CDR (lsym))
|
||
{
|
||
SCM entry = SCM_CAR (lsym);
|
||
if (scm_is_eq (SCM_CAR (entry), sym))
|
||
return entry;
|
||
}
|
||
|
||
return SCM_UNDEFINED;
|
||
}
|
||
|
||
|
||
/*
|
||
* Remove entry from obarray. If the symbol was found and removed, the old
|
||
* (symbol . data) cell is returned, #f otherwise.
|
||
*/
|
||
static SCM
|
||
obarray_remove (SCM obarray, SCM sym)
|
||
{
|
||
size_t hash = scm_i_symbol_hash (sym) % SCM_HASHTABLE_N_BUCKETS (obarray);
|
||
SCM table_entry = SCM_HASHTABLE_BUCKET (obarray, hash);
|
||
SCM handle = scm_sloppy_assq (sym, table_entry);
|
||
|
||
if (scm_is_pair (handle))
|
||
{
|
||
SCM new_table_entry = scm_delq1_x (handle, table_entry);
|
||
SCM_SET_HASHTABLE_BUCKET (obarray, hash, new_table_entry);
|
||
SCM_HASHTABLE_DECREMENT (obarray);
|
||
}
|
||
|
||
return handle;
|
||
}
|
||
|
||
|
||
static void
|
||
obarray_remove_all (SCM obarray)
|
||
{
|
||
size_t size = SCM_HASHTABLE_N_BUCKETS (obarray);
|
||
size_t i;
|
||
|
||
for (i = 0; i < size; i++)
|
||
{
|
||
SCM_SET_HASHTABLE_BUCKET (obarray, i, SCM_EOL);
|
||
}
|
||
SCM_SET_HASHTABLE_N_ITEMS (obarray, 0);
|
||
}
|
||
|
||
|
||
|
||
/* core environments base
|
||
*
|
||
* This struct and the corresponding functions form a base class for guile's
|
||
* built-in environment types.
|
||
*/
|
||
|
||
|
||
struct core_environments_base {
|
||
struct scm_environment_funcs *funcs;
|
||
|
||
SCM observers;
|
||
SCM weak_observers;
|
||
};
|
||
|
||
|
||
#define CORE_ENVIRONMENTS_BASE(env) \
|
||
((struct core_environments_base *) SCM_CELL_WORD_1 (env))
|
||
#define CORE_ENVIRONMENT_OBSERVERS(env) \
|
||
(CORE_ENVIRONMENTS_BASE (env)->observers)
|
||
#define SCM_SET_CORE_ENVIRONMENT_OBSERVERS(env, v) \
|
||
(CORE_ENVIRONMENT_OBSERVERS (env) = (v))
|
||
#define CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR(env) \
|
||
(CORE_ENVIRONMENTS_BASE (env)->weak_observers)
|
||
#define CORE_ENVIRONMENT_WEAK_OBSERVERS(env) \
|
||
(scm_c_vector_ref (CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env), 0))
|
||
#define SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS(env, v) \
|
||
(scm_c_vector_set_x (CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env), 0, (v)))
|
||
|
||
|
||
|
||
static SCM
|
||
core_environments_observe (SCM env, scm_environment_observer proc, SCM data, int weak_p)
|
||
{
|
||
SCM observer = scm_double_cell (scm_tc16_observer,
|
||
SCM_UNPACK (env),
|
||
SCM_UNPACK (data),
|
||
(scm_t_bits) proc);
|
||
|
||
if (!weak_p)
|
||
{
|
||
SCM observers = CORE_ENVIRONMENT_OBSERVERS (env);
|
||
SCM new_observers = scm_cons (observer, observers);
|
||
SCM_SET_CORE_ENVIRONMENT_OBSERVERS (env, new_observers);
|
||
}
|
||
else
|
||
{
|
||
SCM observers = CORE_ENVIRONMENT_WEAK_OBSERVERS (env);
|
||
SCM new_observers = scm_acons (SCM_BOOL_F, observer, observers);
|
||
SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS (env, new_observers);
|
||
}
|
||
|
||
return observer;
|
||
}
|
||
|
||
|
||
static void
|
||
core_environments_unobserve (SCM env, SCM observer)
|
||
{
|
||
unsigned int handling_weaks;
|
||
for (handling_weaks = 0; handling_weaks <= 1; ++handling_weaks)
|
||
{
|
||
SCM l = handling_weaks
|
||
? CORE_ENVIRONMENT_WEAK_OBSERVERS (env)
|
||
: CORE_ENVIRONMENT_OBSERVERS (env);
|
||
|
||
if (!scm_is_null (l))
|
||
{
|
||
SCM rest = SCM_CDR (l);
|
||
SCM first = handling_weaks
|
||
? SCM_CDAR (l)
|
||
: SCM_CAR (l);
|
||
|
||
if (scm_is_eq (first, observer))
|
||
{
|
||
/* Remove the first observer */
|
||
if (handling_weaks)
|
||
SCM_SET_CORE_ENVIRONMENT_WEAK_OBSERVERS (env, rest);
|
||
else
|
||
SCM_SET_CORE_ENVIRONMENT_OBSERVERS (env, rest);
|
||
return;
|
||
}
|
||
|
||
do {
|
||
SCM rest = SCM_CDR (l);
|
||
|
||
if (!scm_is_null (rest))
|
||
{
|
||
SCM next = handling_weaks
|
||
? SCM_CDAR (l)
|
||
: SCM_CAR (l);
|
||
|
||
if (scm_is_eq (next, observer))
|
||
{
|
||
SCM_SETCDR (l, SCM_CDR (rest));
|
||
return;
|
||
}
|
||
}
|
||
|
||
l = rest;
|
||
} while (!scm_is_null (l));
|
||
}
|
||
}
|
||
|
||
/* Dirk:FIXME:: What to do now, since the observer is not found? */
|
||
}
|
||
|
||
|
||
static SCM
|
||
core_environments_mark (SCM env)
|
||
{
|
||
scm_gc_mark (CORE_ENVIRONMENT_OBSERVERS (env));
|
||
return CORE_ENVIRONMENT_WEAK_OBSERVER_VECTOR (env);
|
||
}
|
||
|
||
|
||
static void
|
||
core_environments_finalize (SCM env SCM_UNUSED)
|
||
{
|
||
}
|
||
|
||
|
||
static void
|
||
core_environments_preinit (struct core_environments_base *body)
|
||
{
|
||
body->funcs = NULL;
|
||
body->observers = SCM_BOOL_F;
|
||
body->weak_observers = SCM_BOOL_F;
|
||
}
|
||
|
||
|
||
static void
|
||
core_environments_init (struct core_environments_base *body,
|
||
struct scm_environment_funcs *funcs)
|
||
{
|
||
body->funcs = funcs;
|
||
body->observers = SCM_EOL;
|
||
body->weak_observers = scm_make_weak_value_alist_vector (scm_from_int (1));
|
||
}
|
||
|
||
|
||
/* Tell all observers to clear their caches.
|
||
*
|
||
* Environments have to be informed about changes in the following cases:
|
||
* - The observed env has a new binding. This must be always reported.
|
||
* - The observed env has dropped a binding. This must be always reported.
|
||
* - A binding in the observed environment has changed. This must only be
|
||
* reported, if there is a chance that the binding is being cached outside.
|
||
* However, this potential optimization is not performed currently.
|
||
*
|
||
* Errors that occur while the observers are called are accumulated and
|
||
* signalled as one single error message to the caller.
|
||
*/
|
||
|
||
struct update_data
|
||
{
|
||
SCM observer;
|
||
SCM environment;
|
||
};
|
||
|
||
|
||
static SCM
|
||
update_catch_body (void *ptr)
|
||
{
|
||
struct update_data *data = (struct update_data *) ptr;
|
||
SCM observer = data->observer;
|
||
|
||
(*SCM_OBSERVER_PROC (observer))
|
||
(data->environment, SCM_OBSERVER_DATA (observer));
|
||
|
||
return SCM_UNDEFINED;
|
||
}
|
||
|
||
|
||
static SCM
|
||
update_catch_handler (void *ptr, SCM tag, SCM args)
|
||
{
|
||
struct update_data *data = (struct update_data *) ptr;
|
||
SCM observer = data->observer;
|
||
SCM message =
|
||
scm_from_locale_string ("Observer `~A' signals `~A' error: ~S");
|
||
|
||
return scm_cons (message, scm_list_3 (observer, tag, args));
|
||
}
|
||
|
||
|
||
static void
|
||
core_environments_broadcast (SCM env)
|
||
#define FUNC_NAME "core_environments_broadcast"
|
||
{
|
||
unsigned int handling_weaks;
|
||
SCM errors = SCM_EOL;
|
||
|
||
for (handling_weaks = 0; handling_weaks <= 1; ++handling_weaks)
|
||
{
|
||
SCM observers = handling_weaks
|
||
? CORE_ENVIRONMENT_WEAK_OBSERVERS (env)
|
||
: CORE_ENVIRONMENT_OBSERVERS (env);
|
||
|
||
for (; !scm_is_null (observers); observers = SCM_CDR (observers))
|
||
{
|
||
struct update_data data;
|
||
SCM observer = handling_weaks
|
||
? SCM_CDAR (observers)
|
||
: SCM_CAR (observers);
|
||
SCM error;
|
||
|
||
data.observer = observer;
|
||
data.environment = env;
|
||
|
||
error = scm_internal_catch (SCM_BOOL_T,
|
||
update_catch_body, &data,
|
||
update_catch_handler, &data);
|
||
|
||
if (!SCM_UNBNDP (error))
|
||
errors = scm_cons (error, errors);
|
||
}
|
||
}
|
||
|
||
if (!scm_is_null (errors))
|
||
{
|
||
/* Dirk:FIXME:: As soon as scm_misc_error is fixed to handle the name
|
||
* parameter correctly it should not be necessary any more to also pass
|
||
* namestr in order to get the desired information from the error
|
||
* message.
|
||
*/
|
||
SCM ordered_errors = scm_reverse (errors);
|
||
scm_misc_error
|
||
(FUNC_NAME,
|
||
"Observers of `~A' have signalled the following errors: ~S",
|
||
scm_cons2 (env, ordered_errors, SCM_EOL));
|
||
}
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
|
||
/* leaf environments
|
||
*
|
||
* A leaf environment is simply a mutable set of definitions. A leaf
|
||
* environment supports no operations beyond the common set.
|
||
*
|
||
* Implementation: The obarray of the leaf environment holds (symbol . value)
|
||
* pairs. No further information is necessary, since all bindings and
|
||
* locations in a leaf environment are mutable.
|
||
*/
|
||
|
||
|
||
struct leaf_environment {
|
||
struct core_environments_base base;
|
||
|
||
SCM obarray;
|
||
};
|
||
|
||
|
||
#define LEAF_ENVIRONMENT(env) \
|
||
((struct leaf_environment *) SCM_CELL_WORD_1 (env))
|
||
|
||
|
||
|
||
static SCM
|
||
leaf_environment_ref (SCM env, SCM sym)
|
||
{
|
||
SCM obarray = LEAF_ENVIRONMENT (env)->obarray;
|
||
SCM binding = obarray_retrieve (obarray, sym);
|
||
return SCM_UNBNDP (binding) ? binding : SCM_CDR (binding);
|
||
}
|
||
|
||
|
||
static SCM
|
||
leaf_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init)
|
||
{
|
||
size_t i;
|
||
SCM result = init;
|
||
SCM obarray = LEAF_ENVIRONMENT (env)->obarray;
|
||
|
||
for (i = 0; i < SCM_HASHTABLE_N_BUCKETS (obarray); i++)
|
||
{
|
||
SCM l;
|
||
for (l = SCM_HASHTABLE_BUCKET (obarray, i);
|
||
!scm_is_null (l);
|
||
l = SCM_CDR (l))
|
||
{
|
||
SCM binding = SCM_CAR (l);
|
||
SCM symbol = SCM_CAR (binding);
|
||
SCM value = SCM_CDR (binding);
|
||
result = (*proc) (data, symbol, value, result);
|
||
}
|
||
}
|
||
return result;
|
||
}
|
||
|
||
|
||
static SCM
|
||
leaf_environment_define (SCM env, SCM sym, SCM val)
|
||
#define FUNC_NAME "leaf_environment_define"
|
||
{
|
||
SCM obarray = LEAF_ENVIRONMENT (env)->obarray;
|
||
|
||
obarray_replace (obarray, sym, val);
|
||
core_environments_broadcast (env);
|
||
|
||
return SCM_ENVIRONMENT_SUCCESS;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
leaf_environment_undefine (SCM env, SCM sym)
|
||
#define FUNC_NAME "leaf_environment_undefine"
|
||
{
|
||
SCM obarray = LEAF_ENVIRONMENT (env)->obarray;
|
||
SCM removed = obarray_remove (obarray, sym);
|
||
|
||
if (scm_is_true (removed))
|
||
core_environments_broadcast (env);
|
||
|
||
return SCM_ENVIRONMENT_SUCCESS;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
leaf_environment_set_x (SCM env, SCM sym, SCM val)
|
||
#define FUNC_NAME "leaf_environment_set_x"
|
||
{
|
||
SCM obarray = LEAF_ENVIRONMENT (env)->obarray;
|
||
SCM binding = obarray_retrieve (obarray, sym);
|
||
|
||
if (!SCM_UNBNDP (binding))
|
||
{
|
||
SCM_SETCDR (binding, val);
|
||
return SCM_ENVIRONMENT_SUCCESS;
|
||
}
|
||
else
|
||
{
|
||
return SCM_UNDEFINED;
|
||
}
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
leaf_environment_cell (SCM env, SCM sym, int for_write SCM_UNUSED)
|
||
{
|
||
SCM obarray = LEAF_ENVIRONMENT (env)->obarray;
|
||
SCM binding = obarray_retrieve (obarray, sym);
|
||
return binding;
|
||
}
|
||
|
||
|
||
static SCM
|
||
leaf_environment_mark (SCM env)
|
||
{
|
||
scm_gc_mark (LEAF_ENVIRONMENT (env)->obarray);
|
||
return core_environments_mark (env);
|
||
}
|
||
|
||
|
||
static void
|
||
leaf_environment_free (SCM env)
|
||
{
|
||
core_environments_finalize (env);
|
||
scm_gc_free (LEAF_ENVIRONMENT (env), sizeof (struct leaf_environment),
|
||
"leaf environment");
|
||
}
|
||
|
||
|
||
static int
|
||
leaf_environment_print (SCM type, SCM port, scm_print_state *pstate SCM_UNUSED)
|
||
{
|
||
SCM address = scm_from_size_t (SCM_UNPACK (type));
|
||
SCM base16 = scm_number_to_string (address, scm_from_int (16));
|
||
|
||
scm_puts ("#<leaf environment ", port);
|
||
scm_display (base16, port);
|
||
scm_puts (">", port);
|
||
|
||
return 1;
|
||
}
|
||
|
||
|
||
static struct scm_environment_funcs leaf_environment_funcs = {
|
||
leaf_environment_ref,
|
||
leaf_environment_fold,
|
||
leaf_environment_define,
|
||
leaf_environment_undefine,
|
||
leaf_environment_set_x,
|
||
leaf_environment_cell,
|
||
core_environments_observe,
|
||
core_environments_unobserve,
|
||
leaf_environment_mark,
|
||
leaf_environment_free,
|
||
leaf_environment_print
|
||
};
|
||
|
||
|
||
void *scm_type_leaf_environment = &leaf_environment_funcs;
|
||
|
||
|
||
SCM_DEFINE (scm_make_leaf_environment, "make-leaf-environment", 0, 0, 0,
|
||
(),
|
||
"Create a new leaf environment, containing no bindings.\n"
|
||
"All bindings and locations created in the new environment\n"
|
||
"will be mutable.")
|
||
#define FUNC_NAME s_scm_make_leaf_environment
|
||
{
|
||
size_t size = sizeof (struct leaf_environment);
|
||
struct leaf_environment *body = scm_gc_malloc (size, "leaf environment");
|
||
SCM env;
|
||
|
||
core_environments_preinit (&body->base);
|
||
body->obarray = SCM_BOOL_F;
|
||
|
||
env = scm_make_environment (body);
|
||
|
||
core_environments_init (&body->base, &leaf_environment_funcs);
|
||
body->obarray = scm_c_make_hash_table (DEFAULT_OBARRAY_SIZE);
|
||
|
||
return env;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
SCM_DEFINE (scm_leaf_environment_p, "leaf-environment?", 1, 0, 0,
|
||
(SCM object),
|
||
"Return @code{#t} if object is a leaf environment, or @code{#f}\n"
|
||
"otherwise.")
|
||
#define FUNC_NAME s_scm_leaf_environment_p
|
||
{
|
||
return scm_from_bool (SCM_LEAF_ENVIRONMENT_P (object));
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
|
||
/* eval environments
|
||
*
|
||
* A module's source code refers to definitions imported from other modules,
|
||
* and definitions made within itself. An eval environment combines two
|
||
* environments -- a local environment and an imported environment -- to
|
||
* produce a new environment in which both sorts of references can be
|
||
* resolved.
|
||
*
|
||
* Implementation: The obarray of the eval environment is used to cache
|
||
* entries from the local and imported environments such that in most of the
|
||
* cases only a single lookup is necessary. Since for neither the local nor
|
||
* the imported environment it is known, what kind of environment they form,
|
||
* the most general case is assumed. Therefore, entries in the obarray take
|
||
* one of the following forms:
|
||
*
|
||
* 1) (<symbol> location mutability . source-env), where mutability indicates
|
||
* one of the following states: IMMUTABLE if the location is known to be
|
||
* immutable, MUTABLE if the location is known to be mutable, UNKNOWN if
|
||
* the location has only been requested for non modifying accesses.
|
||
*
|
||
* 2) (symbol . source-env) if the symbol has a binding in the source-env, but
|
||
* if the source-env can't provide a cell for the binding. Thus, for every
|
||
* access, the source-env has to be contacted directly.
|
||
*/
|
||
|
||
|
||
struct eval_environment {
|
||
struct core_environments_base base;
|
||
|
||
SCM obarray;
|
||
|
||
SCM imported;
|
||
SCM imported_observer;
|
||
SCM local;
|
||
SCM local_observer;
|
||
};
|
||
|
||
|
||
#define EVAL_ENVIRONMENT(env) \
|
||
((struct eval_environment *) SCM_CELL_WORD_1 (env))
|
||
|
||
#define IMMUTABLE SCM_I_MAKINUM (0)
|
||
#define MUTABLE SCM_I_MAKINUM (1)
|
||
#define UNKNOWN SCM_I_MAKINUM (2)
|
||
|
||
#define CACHED_LOCATION(x) SCM_CAR (x)
|
||
#define CACHED_MUTABILITY(x) SCM_CADR (x)
|
||
#define SET_CACHED_MUTABILITY(x, v) SCM_SETCAR (SCM_CDR (x), (v))
|
||
#define CACHED_SOURCE_ENVIRONMENT(x) SCM_CDDR (x)
|
||
|
||
|
||
|
||
/* eval_environment_lookup will report one of the following distinct results:
|
||
* a) (<object> . value) if a cell could be obtained.
|
||
* b) <environment> if the environment has to be contacted directly.
|
||
* c) IMMUTABLE if an immutable cell was requested for write.
|
||
* d) SCM_UNDEFINED if there is no binding for the symbol.
|
||
*/
|
||
static SCM
|
||
eval_environment_lookup (SCM env, SCM sym, int for_write)
|
||
{
|
||
SCM obarray = EVAL_ENVIRONMENT (env)->obarray;
|
||
SCM binding = obarray_retrieve (obarray, sym);
|
||
|
||
if (!SCM_UNBNDP (binding))
|
||
{
|
||
/* The obarray holds an entry for the symbol. */
|
||
|
||
SCM entry = SCM_CDR (binding);
|
||
|
||
if (scm_is_pair (entry))
|
||
{
|
||
/* The entry in the obarray is a cached location. */
|
||
|
||
SCM location = CACHED_LOCATION (entry);
|
||
SCM mutability;
|
||
|
||
if (!for_write)
|
||
return location;
|
||
|
||
mutability = CACHED_MUTABILITY (entry);
|
||
if (scm_is_eq (mutability, MUTABLE))
|
||
return location;
|
||
|
||
if (scm_is_eq (mutability, UNKNOWN))
|
||
{
|
||
SCM source_env = CACHED_SOURCE_ENVIRONMENT (entry);
|
||
SCM location = SCM_ENVIRONMENT_CELL (source_env, sym, 1);
|
||
|
||
if (scm_is_pair (location))
|
||
{
|
||
SET_CACHED_MUTABILITY (entry, MUTABLE);
|
||
return location;
|
||
}
|
||
else /* IMMUTABLE */
|
||
{
|
||
SET_CACHED_MUTABILITY (entry, IMMUTABLE);
|
||
return IMMUTABLE;
|
||
}
|
||
}
|
||
|
||
return IMMUTABLE;
|
||
}
|
||
else
|
||
{
|
||
/* The obarray entry is an environment */
|
||
|
||
return entry;
|
||
}
|
||
}
|
||
else
|
||
{
|
||
/* There is no entry for the symbol in the obarray. This can either
|
||
* mean that there has not been a request for the symbol yet, or that
|
||
* the symbol is really undefined. We are looking for the symbol in
|
||
* both the local and the imported environment. If we find a binding, a
|
||
* cached entry is created.
|
||
*/
|
||
|
||
struct eval_environment *body = EVAL_ENVIRONMENT (env);
|
||
unsigned int handling_import;
|
||
|
||
for (handling_import = 0; handling_import <= 1; ++handling_import)
|
||
{
|
||
SCM source_env = handling_import ? body->imported : body->local;
|
||
SCM location = SCM_ENVIRONMENT_CELL (source_env, sym, for_write);
|
||
|
||
if (!SCM_UNBNDP (location))
|
||
{
|
||
if (scm_is_pair (location))
|
||
{
|
||
SCM mutability = for_write ? MUTABLE : UNKNOWN;
|
||
SCM entry = scm_cons2 (location, mutability, source_env);
|
||
obarray_enter (obarray, sym, entry);
|
||
return location;
|
||
}
|
||
else if (scm_is_eq (location, SCM_ENVIRONMENT_LOCATION_NO_CELL))
|
||
{
|
||
obarray_enter (obarray, sym, source_env);
|
||
return source_env;
|
||
}
|
||
else
|
||
{
|
||
return IMMUTABLE;
|
||
}
|
||
}
|
||
}
|
||
|
||
return SCM_UNDEFINED;
|
||
}
|
||
}
|
||
|
||
|
||
static SCM
|
||
eval_environment_ref (SCM env, SCM sym)
|
||
#define FUNC_NAME "eval_environment_ref"
|
||
{
|
||
SCM location = eval_environment_lookup (env, sym, 0);
|
||
|
||
if (scm_is_pair (location))
|
||
return SCM_CDR (location);
|
||
else if (!SCM_UNBNDP (location))
|
||
return SCM_ENVIRONMENT_REF (location, sym);
|
||
else
|
||
return SCM_UNDEFINED;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
eval_environment_folder (SCM extended_data, SCM symbol, SCM value, SCM tail)
|
||
{
|
||
SCM local = SCM_CAR (extended_data);
|
||
|
||
if (!SCM_ENVIRONMENT_BOUND_P (local, symbol))
|
||
{
|
||
SCM proc_as_nr = SCM_CADR (extended_data);
|
||
unsigned long int proc_as_ul = scm_to_ulong (proc_as_nr);
|
||
scm_environment_folder proc = (scm_environment_folder) proc_as_ul;
|
||
SCM data = SCM_CDDR (extended_data);
|
||
|
||
return (*proc) (data, symbol, value, tail);
|
||
}
|
||
else
|
||
{
|
||
return tail;
|
||
}
|
||
}
|
||
|
||
|
||
static SCM
|
||
eval_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init)
|
||
{
|
||
SCM local = EVAL_ENVIRONMENT (env)->local;
|
||
SCM imported = EVAL_ENVIRONMENT (env)->imported;
|
||
SCM proc_as_nr = scm_from_ulong ((unsigned long) proc);
|
||
SCM extended_data = scm_cons2 (local, proc_as_nr, data);
|
||
SCM tmp_result = scm_c_environment_fold (imported, eval_environment_folder, extended_data, init);
|
||
|
||
return scm_c_environment_fold (local, proc, data, tmp_result);
|
||
}
|
||
|
||
|
||
static SCM
|
||
eval_environment_define (SCM env, SCM sym, SCM val)
|
||
#define FUNC_NAME "eval_environment_define"
|
||
{
|
||
SCM local = EVAL_ENVIRONMENT (env)->local;
|
||
return SCM_ENVIRONMENT_DEFINE (local, sym, val);
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
eval_environment_undefine (SCM env, SCM sym)
|
||
#define FUNC_NAME "eval_environment_undefine"
|
||
{
|
||
SCM local = EVAL_ENVIRONMENT (env)->local;
|
||
return SCM_ENVIRONMENT_UNDEFINE (local, sym);
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
eval_environment_set_x (SCM env, SCM sym, SCM val)
|
||
#define FUNC_NAME "eval_environment_set_x"
|
||
{
|
||
SCM location = eval_environment_lookup (env, sym, 1);
|
||
|
||
if (scm_is_pair (location))
|
||
{
|
||
SCM_SETCDR (location, val);
|
||
return SCM_ENVIRONMENT_SUCCESS;
|
||
}
|
||
else if (SCM_ENVIRONMENT_P (location))
|
||
{
|
||
return SCM_ENVIRONMENT_SET (location, sym, val);
|
||
}
|
||
else if (scm_is_eq (location, IMMUTABLE))
|
||
{
|
||
return SCM_ENVIRONMENT_LOCATION_IMMUTABLE;
|
||
}
|
||
else
|
||
{
|
||
return SCM_UNDEFINED;
|
||
}
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
eval_environment_cell (SCM env, SCM sym, int for_write)
|
||
#define FUNC_NAME "eval_environment_cell"
|
||
{
|
||
SCM location = eval_environment_lookup (env, sym, for_write);
|
||
|
||
if (scm_is_pair (location))
|
||
return location;
|
||
else if (SCM_ENVIRONMENT_P (location))
|
||
return SCM_ENVIRONMENT_LOCATION_NO_CELL;
|
||
else if (scm_is_eq (location, IMMUTABLE))
|
||
return SCM_ENVIRONMENT_LOCATION_IMMUTABLE;
|
||
else
|
||
return SCM_UNDEFINED;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
eval_environment_mark (SCM env)
|
||
{
|
||
struct eval_environment *body = EVAL_ENVIRONMENT (env);
|
||
|
||
scm_gc_mark (body->obarray);
|
||
scm_gc_mark (body->imported);
|
||
scm_gc_mark (body->imported_observer);
|
||
scm_gc_mark (body->local);
|
||
scm_gc_mark (body->local_observer);
|
||
|
||
return core_environments_mark (env);
|
||
}
|
||
|
||
|
||
static void
|
||
eval_environment_free (SCM env)
|
||
{
|
||
core_environments_finalize (env);
|
||
scm_gc_free (EVAL_ENVIRONMENT (env), sizeof (struct eval_environment),
|
||
"eval environment");
|
||
}
|
||
|
||
|
||
static int
|
||
eval_environment_print (SCM type, SCM port, scm_print_state *pstate SCM_UNUSED)
|
||
{
|
||
SCM address = scm_from_size_t (SCM_UNPACK (type));
|
||
SCM base16 = scm_number_to_string (address, scm_from_int (16));
|
||
|
||
scm_puts ("#<eval environment ", port);
|
||
scm_display (base16, port);
|
||
scm_puts (">", port);
|
||
|
||
return 1;
|
||
}
|
||
|
||
|
||
static struct scm_environment_funcs eval_environment_funcs = {
|
||
eval_environment_ref,
|
||
eval_environment_fold,
|
||
eval_environment_define,
|
||
eval_environment_undefine,
|
||
eval_environment_set_x,
|
||
eval_environment_cell,
|
||
core_environments_observe,
|
||
core_environments_unobserve,
|
||
eval_environment_mark,
|
||
eval_environment_free,
|
||
eval_environment_print
|
||
};
|
||
|
||
|
||
void *scm_type_eval_environment = &eval_environment_funcs;
|
||
|
||
|
||
static void
|
||
eval_environment_observer (SCM caller SCM_UNUSED, SCM eval_env)
|
||
{
|
||
SCM obarray = EVAL_ENVIRONMENT (eval_env)->obarray;
|
||
|
||
obarray_remove_all (obarray);
|
||
core_environments_broadcast (eval_env);
|
||
}
|
||
|
||
|
||
SCM_DEFINE (scm_make_eval_environment, "make-eval-environment", 2, 0, 0,
|
||
(SCM local, SCM imported),
|
||
"Return a new environment object eval whose bindings are the\n"
|
||
"union of the bindings in the environments @var{local} and\n"
|
||
"@var{imported}, with bindings from @var{local} taking\n"
|
||
"precedence. Definitions made in eval are placed in @var{local}.\n"
|
||
"Applying @code{environment-define} or\n"
|
||
"@code{environment-undefine} to eval has the same effect as\n"
|
||
"applying the procedure to @var{local}.\n"
|
||
"Note that eval incorporates @var{local} and @var{imported} by\n"
|
||
"reference:\n"
|
||
"If, after creating eval, the program changes the bindings of\n"
|
||
"@var{local} or @var{imported}, those changes will be visible\n"
|
||
"in eval.\n"
|
||
"Since most Scheme evaluation takes place in eval environments,\n"
|
||
"they transparently cache the bindings received from @var{local}\n"
|
||
"and @var{imported}. Thus, the first time the program looks up\n"
|
||
"a symbol in eval, eval may make calls to @var{local} or\n"
|
||
"@var{imported} to find their bindings, but subsequent\n"
|
||
"references to that symbol will be as fast as references to\n"
|
||
"bindings in finite environments.\n"
|
||
"In typical use, @var{local} will be a finite environment, and\n"
|
||
"@var{imported} will be an import environment")
|
||
#define FUNC_NAME s_scm_make_eval_environment
|
||
{
|
||
SCM env;
|
||
struct eval_environment *body;
|
||
|
||
SCM_ASSERT (SCM_ENVIRONMENT_P (local), local, SCM_ARG1, FUNC_NAME);
|
||
SCM_ASSERT (SCM_ENVIRONMENT_P (imported), imported, SCM_ARG2, FUNC_NAME);
|
||
|
||
body = scm_gc_malloc (sizeof (struct eval_environment), "eval environment");
|
||
|
||
core_environments_preinit (&body->base);
|
||
body->obarray = SCM_BOOL_F;
|
||
body->imported = SCM_BOOL_F;
|
||
body->imported_observer = SCM_BOOL_F;
|
||
body->local = SCM_BOOL_F;
|
||
body->local_observer = SCM_BOOL_F;
|
||
|
||
env = scm_make_environment (body);
|
||
|
||
core_environments_init (&body->base, &eval_environment_funcs);
|
||
body->obarray = scm_c_make_hash_table (DEFAULT_OBARRAY_SIZE);
|
||
body->imported = imported;
|
||
body->imported_observer
|
||
= SCM_ENVIRONMENT_OBSERVE (imported, eval_environment_observer, env, 1);
|
||
body->local = local;
|
||
body->local_observer
|
||
= SCM_ENVIRONMENT_OBSERVE (local, eval_environment_observer, env, 1);
|
||
|
||
return env;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
SCM_DEFINE (scm_eval_environment_p, "eval-environment?", 1, 0, 0,
|
||
(SCM object),
|
||
"Return @code{#t} if object is an eval environment, or @code{#f}\n"
|
||
"otherwise.")
|
||
#define FUNC_NAME s_scm_eval_environment_p
|
||
{
|
||
return scm_from_bool (SCM_EVAL_ENVIRONMENT_P (object));
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
SCM_DEFINE (scm_eval_environment_local, "eval-environment-local", 1, 0, 0,
|
||
(SCM env),
|
||
"Return the local environment of eval environment @var{env}.")
|
||
#define FUNC_NAME s_scm_eval_environment_local
|
||
{
|
||
SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
|
||
|
||
return EVAL_ENVIRONMENT (env)->local;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
SCM_DEFINE (scm_eval_environment_set_local_x, "eval-environment-set-local!", 2, 0, 0,
|
||
(SCM env, SCM local),
|
||
"Change @var{env}'s local environment to @var{local}.")
|
||
#define FUNC_NAME s_scm_eval_environment_set_local_x
|
||
{
|
||
struct eval_environment *body;
|
||
|
||
SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
|
||
SCM_ASSERT (SCM_ENVIRONMENT_P (local), local, SCM_ARG2, FUNC_NAME);
|
||
|
||
body = EVAL_ENVIRONMENT (env);
|
||
|
||
obarray_remove_all (body->obarray);
|
||
SCM_ENVIRONMENT_UNOBSERVE (body->local, body->local_observer);
|
||
|
||
body->local = local;
|
||
body->local_observer
|
||
= SCM_ENVIRONMENT_OBSERVE (local, eval_environment_observer, env, 1);
|
||
|
||
core_environments_broadcast (env);
|
||
|
||
return SCM_UNSPECIFIED;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
SCM_DEFINE (scm_eval_environment_imported, "eval-environment-imported", 1, 0, 0,
|
||
(SCM env),
|
||
"Return the imported environment of eval environment @var{env}.")
|
||
#define FUNC_NAME s_scm_eval_environment_imported
|
||
{
|
||
SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
|
||
|
||
return EVAL_ENVIRONMENT (env)->imported;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
SCM_DEFINE (scm_eval_environment_set_imported_x, "eval-environment-set-imported!", 2, 0, 0,
|
||
(SCM env, SCM imported),
|
||
"Change @var{env}'s imported environment to @var{imported}.")
|
||
#define FUNC_NAME s_scm_eval_environment_set_imported_x
|
||
{
|
||
struct eval_environment *body;
|
||
|
||
SCM_ASSERT (SCM_EVAL_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
|
||
SCM_ASSERT (SCM_ENVIRONMENT_P (imported), imported, SCM_ARG2, FUNC_NAME);
|
||
|
||
body = EVAL_ENVIRONMENT (env);
|
||
|
||
obarray_remove_all (body->obarray);
|
||
SCM_ENVIRONMENT_UNOBSERVE (body->imported, body->imported_observer);
|
||
|
||
body->imported = imported;
|
||
body->imported_observer
|
||
= SCM_ENVIRONMENT_OBSERVE (imported, eval_environment_observer, env, 1);
|
||
|
||
core_environments_broadcast (env);
|
||
|
||
return SCM_UNSPECIFIED;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
|
||
/* import environments
|
||
*
|
||
* An import environment combines the bindings of a set of argument
|
||
* environments, and checks for naming clashes.
|
||
*
|
||
* Implementation: The import environment does no caching at all. For every
|
||
* access, the list of imported environments is scanned.
|
||
*/
|
||
|
||
|
||
struct import_environment {
|
||
struct core_environments_base base;
|
||
|
||
SCM imports;
|
||
SCM import_observers;
|
||
|
||
SCM conflict_proc;
|
||
};
|
||
|
||
|
||
#define IMPORT_ENVIRONMENT(env) \
|
||
((struct import_environment *) SCM_CELL_WORD_1 (env))
|
||
|
||
|
||
|
||
/* Lookup will report one of the following distinct results:
|
||
* a) <environment> if only environment binds the symbol.
|
||
* b) (env-1 env-2 ...) for conflicting bindings in env-1, ...
|
||
* c) SCM_UNDEFINED if there is no binding for the symbol.
|
||
*/
|
||
static SCM
|
||
import_environment_lookup (SCM env, SCM sym)
|
||
{
|
||
SCM imports = IMPORT_ENVIRONMENT (env)->imports;
|
||
SCM result = SCM_UNDEFINED;
|
||
SCM l;
|
||
|
||
for (l = imports; !scm_is_null (l); l = SCM_CDR (l))
|
||
{
|
||
SCM imported = SCM_CAR (l);
|
||
|
||
if (SCM_ENVIRONMENT_BOUND_P (imported, sym))
|
||
{
|
||
if (SCM_UNBNDP (result))
|
||
result = imported;
|
||
else if (scm_is_pair (result))
|
||
result = scm_cons (imported, result);
|
||
else
|
||
result = scm_cons2 (imported, result, SCM_EOL);
|
||
}
|
||
}
|
||
|
||
if (scm_is_pair (result))
|
||
return scm_reverse (result);
|
||
else
|
||
return result;
|
||
}
|
||
|
||
|
||
static SCM
|
||
import_environment_conflict (SCM env, SCM sym, SCM imports)
|
||
{
|
||
SCM conflict_proc = IMPORT_ENVIRONMENT (env)->conflict_proc;
|
||
SCM args = scm_cons2 (env, sym, scm_cons (imports, SCM_EOL));
|
||
|
||
return scm_apply_0 (conflict_proc, args);
|
||
}
|
||
|
||
|
||
static SCM
|
||
import_environment_ref (SCM env, SCM sym)
|
||
#define FUNC_NAME "import_environment_ref"
|
||
{
|
||
SCM owner = import_environment_lookup (env, sym);
|
||
|
||
if (SCM_UNBNDP (owner))
|
||
{
|
||
return SCM_UNDEFINED;
|
||
}
|
||
else if (scm_is_pair (owner))
|
||
{
|
||
SCM resolve = import_environment_conflict (env, sym, owner);
|
||
|
||
if (SCM_ENVIRONMENT_P (resolve))
|
||
return SCM_ENVIRONMENT_REF (resolve, sym);
|
||
else
|
||
return SCM_UNSPECIFIED;
|
||
}
|
||
else
|
||
{
|
||
return SCM_ENVIRONMENT_REF (owner, sym);
|
||
}
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
import_environment_folder (SCM extended_data, SCM symbol, SCM value, SCM tail)
|
||
#define FUNC_NAME "import_environment_fold"
|
||
{
|
||
SCM import_env = SCM_CAR (extended_data);
|
||
SCM imported_env = SCM_CADR (extended_data);
|
||
SCM owner = import_environment_lookup (import_env, symbol);
|
||
SCM proc_as_nr = SCM_CADDR (extended_data);
|
||
unsigned long int proc_as_ul = scm_to_ulong (proc_as_nr);
|
||
scm_environment_folder proc = (scm_environment_folder) proc_as_ul;
|
||
SCM data = SCM_CDDDR (extended_data);
|
||
|
||
if (scm_is_pair (owner) && scm_is_eq (SCM_CAR (owner), imported_env))
|
||
owner = import_environment_conflict (import_env, symbol, owner);
|
||
|
||
if (SCM_ENVIRONMENT_P (owner))
|
||
return (*proc) (data, symbol, value, tail);
|
||
else /* unresolved conflict */
|
||
return (*proc) (data, symbol, SCM_UNSPECIFIED, tail);
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
import_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init)
|
||
{
|
||
SCM proc_as_nr = scm_from_ulong ((unsigned long) proc);
|
||
SCM result = init;
|
||
SCM l;
|
||
|
||
for (l = IMPORT_ENVIRONMENT (env)->imports; !scm_is_null (l); l = SCM_CDR (l))
|
||
{
|
||
SCM imported_env = SCM_CAR (l);
|
||
SCM extended_data = scm_cons (env, scm_cons2 (imported_env, proc_as_nr, data));
|
||
|
||
result = scm_c_environment_fold (imported_env, import_environment_folder, extended_data, result);
|
||
}
|
||
|
||
return result;
|
||
}
|
||
|
||
|
||
static SCM
|
||
import_environment_define (SCM env SCM_UNUSED,
|
||
SCM sym SCM_UNUSED,
|
||
SCM val SCM_UNUSED)
|
||
#define FUNC_NAME "import_environment_define"
|
||
{
|
||
return SCM_ENVIRONMENT_BINDING_IMMUTABLE;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
import_environment_undefine (SCM env SCM_UNUSED,
|
||
SCM sym SCM_UNUSED)
|
||
#define FUNC_NAME "import_environment_undefine"
|
||
{
|
||
return SCM_ENVIRONMENT_BINDING_IMMUTABLE;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
import_environment_set_x (SCM env, SCM sym, SCM val)
|
||
#define FUNC_NAME "import_environment_set_x"
|
||
{
|
||
SCM owner = import_environment_lookup (env, sym);
|
||
|
||
if (SCM_UNBNDP (owner))
|
||
{
|
||
return SCM_UNDEFINED;
|
||
}
|
||
else if (scm_is_pair (owner))
|
||
{
|
||
SCM resolve = import_environment_conflict (env, sym, owner);
|
||
|
||
if (SCM_ENVIRONMENT_P (resolve))
|
||
return SCM_ENVIRONMENT_SET (resolve, sym, val);
|
||
else
|
||
return SCM_ENVIRONMENT_LOCATION_IMMUTABLE;
|
||
}
|
||
else
|
||
{
|
||
return SCM_ENVIRONMENT_SET (owner, sym, val);
|
||
}
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
import_environment_cell (SCM env, SCM sym, int for_write)
|
||
#define FUNC_NAME "import_environment_cell"
|
||
{
|
||
SCM owner = import_environment_lookup (env, sym);
|
||
|
||
if (SCM_UNBNDP (owner))
|
||
{
|
||
return SCM_UNDEFINED;
|
||
}
|
||
else if (scm_is_pair (owner))
|
||
{
|
||
SCM resolve = import_environment_conflict (env, sym, owner);
|
||
|
||
if (SCM_ENVIRONMENT_P (resolve))
|
||
return SCM_ENVIRONMENT_CELL (resolve, sym, for_write);
|
||
else
|
||
return SCM_ENVIRONMENT_LOCATION_NO_CELL;
|
||
}
|
||
else
|
||
{
|
||
return SCM_ENVIRONMENT_CELL (owner, sym, for_write);
|
||
}
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
import_environment_mark (SCM env)
|
||
{
|
||
scm_gc_mark (IMPORT_ENVIRONMENT (env)->imports);
|
||
scm_gc_mark (IMPORT_ENVIRONMENT (env)->import_observers);
|
||
scm_gc_mark (IMPORT_ENVIRONMENT (env)->conflict_proc);
|
||
return core_environments_mark (env);
|
||
}
|
||
|
||
|
||
static void
|
||
import_environment_free (SCM env)
|
||
{
|
||
core_environments_finalize (env);
|
||
scm_gc_free (IMPORT_ENVIRONMENT (env), sizeof (struct import_environment),
|
||
"import environment");
|
||
}
|
||
|
||
|
||
static int
|
||
import_environment_print (SCM type, SCM port,
|
||
scm_print_state *pstate SCM_UNUSED)
|
||
{
|
||
SCM address = scm_from_size_t (SCM_UNPACK (type));
|
||
SCM base16 = scm_number_to_string (address, scm_from_int (16));
|
||
|
||
scm_puts ("#<import environment ", port);
|
||
scm_display (base16, port);
|
||
scm_puts (">", port);
|
||
|
||
return 1;
|
||
}
|
||
|
||
|
||
static struct scm_environment_funcs import_environment_funcs = {
|
||
import_environment_ref,
|
||
import_environment_fold,
|
||
import_environment_define,
|
||
import_environment_undefine,
|
||
import_environment_set_x,
|
||
import_environment_cell,
|
||
core_environments_observe,
|
||
core_environments_unobserve,
|
||
import_environment_mark,
|
||
import_environment_free,
|
||
import_environment_print
|
||
};
|
||
|
||
|
||
void *scm_type_import_environment = &import_environment_funcs;
|
||
|
||
|
||
static void
|
||
import_environment_observer (SCM caller SCM_UNUSED, SCM import_env)
|
||
{
|
||
core_environments_broadcast (import_env);
|
||
}
|
||
|
||
|
||
SCM_DEFINE (scm_make_import_environment, "make-import-environment", 2, 0, 0,
|
||
(SCM imports, SCM conflict_proc),
|
||
"Return a new environment @var{imp} whose bindings are the union\n"
|
||
"of the bindings from the environments in @var{imports};\n"
|
||
"@var{imports} must be a list of environments. That is,\n"
|
||
"@var{imp} binds a symbol to a location when some element of\n"
|
||
"@var{imports} does.\n"
|
||
"If two different elements of @var{imports} have a binding for\n"
|
||
"the same symbol, the @var{conflict-proc} is called with the\n"
|
||
"following parameters: the import environment, the symbol and\n"
|
||
"the list of the imported environments that bind the symbol.\n"
|
||
"If the @var{conflict-proc} returns an environment @var{env},\n"
|
||
"the conflict is considered as resolved and the binding from\n"
|
||
"@var{env} is used. If the @var{conflict-proc} returns some\n"
|
||
"non-environment object, the conflict is considered unresolved\n"
|
||
"and the symbol is treated as unspecified in the import\n"
|
||
"environment.\n"
|
||
"The checking for conflicts may be performed lazily, i. e. at\n"
|
||
"the moment when a value or binding for a certain symbol is\n"
|
||
"requested instead of the moment when the environment is\n"
|
||
"created or the bindings of the imports change.\n"
|
||
"All bindings in @var{imp} are immutable. If you apply\n"
|
||
"@code{environment-define} or @code{environment-undefine} to\n"
|
||
"@var{imp}, Guile will signal an\n"
|
||
" @code{environment:immutable-binding} error. However,\n"
|
||
"notice that the set of bindings in @var{imp} may still change,\n"
|
||
"if one of its imported environments changes.")
|
||
#define FUNC_NAME s_scm_make_import_environment
|
||
{
|
||
size_t size = sizeof (struct import_environment);
|
||
struct import_environment *body = scm_gc_malloc (size, "import environment");
|
||
SCM env;
|
||
|
||
core_environments_preinit (&body->base);
|
||
body->imports = SCM_BOOL_F;
|
||
body->import_observers = SCM_BOOL_F;
|
||
body->conflict_proc = SCM_BOOL_F;
|
||
|
||
env = scm_make_environment (body);
|
||
|
||
core_environments_init (&body->base, &import_environment_funcs);
|
||
body->imports = SCM_EOL;
|
||
body->import_observers = SCM_EOL;
|
||
body->conflict_proc = conflict_proc;
|
||
|
||
scm_import_environment_set_imports_x (env, imports);
|
||
|
||
return env;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
SCM_DEFINE (scm_import_environment_p, "import-environment?", 1, 0, 0,
|
||
(SCM object),
|
||
"Return @code{#t} if object is an import environment, or\n"
|
||
"@code{#f} otherwise.")
|
||
#define FUNC_NAME s_scm_import_environment_p
|
||
{
|
||
return scm_from_bool (SCM_IMPORT_ENVIRONMENT_P (object));
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
SCM_DEFINE (scm_import_environment_imports, "import-environment-imports", 1, 0, 0,
|
||
(SCM env),
|
||
"Return the list of environments imported by the import\n"
|
||
"environment @var{env}.")
|
||
#define FUNC_NAME s_scm_import_environment_imports
|
||
{
|
||
SCM_ASSERT (SCM_IMPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
|
||
|
||
return IMPORT_ENVIRONMENT (env)->imports;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
SCM_DEFINE (scm_import_environment_set_imports_x, "import-environment-set-imports!", 2, 0, 0,
|
||
(SCM env, SCM imports),
|
||
"Change @var{env}'s list of imported environments to\n"
|
||
"@var{imports}, and check for conflicts.")
|
||
#define FUNC_NAME s_scm_import_environment_set_imports_x
|
||
{
|
||
struct import_environment *body = IMPORT_ENVIRONMENT (env);
|
||
SCM import_observers = SCM_EOL;
|
||
SCM l;
|
||
|
||
SCM_ASSERT (SCM_IMPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
|
||
for (l = imports; scm_is_pair (l); l = SCM_CDR (l))
|
||
{
|
||
SCM obj = SCM_CAR (l);
|
||
SCM_ASSERT (SCM_ENVIRONMENT_P (obj), imports, SCM_ARG2, FUNC_NAME);
|
||
}
|
||
SCM_ASSERT (scm_is_null (l), imports, SCM_ARG2, FUNC_NAME);
|
||
|
||
for (l = body->import_observers; !scm_is_null (l); l = SCM_CDR (l))
|
||
{
|
||
SCM obs = SCM_CAR (l);
|
||
SCM_ENVIRONMENT_UNOBSERVE (env, obs);
|
||
}
|
||
|
||
for (l = imports; !scm_is_null (l); l = SCM_CDR (l))
|
||
{
|
||
SCM imp = SCM_CAR (l);
|
||
SCM obs = SCM_ENVIRONMENT_OBSERVE (imp, import_environment_observer, env, 1);
|
||
import_observers = scm_cons (obs, import_observers);
|
||
}
|
||
|
||
body->imports = imports;
|
||
body->import_observers = import_observers;
|
||
|
||
return SCM_UNSPECIFIED;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
|
||
/* export environments
|
||
*
|
||
* An export environment restricts an environment to a specified set of
|
||
* bindings.
|
||
*
|
||
* Implementation: The export environment does no caching at all. For every
|
||
* access, the signature is scanned. The signature that is stored internally
|
||
* is an alist of pairs (symbol . (mutability)).
|
||
*/
|
||
|
||
|
||
struct export_environment {
|
||
struct core_environments_base base;
|
||
|
||
SCM private;
|
||
SCM private_observer;
|
||
|
||
SCM signature;
|
||
};
|
||
|
||
|
||
#define EXPORT_ENVIRONMENT(env) \
|
||
((struct export_environment *) SCM_CELL_WORD_1 (env))
|
||
|
||
|
||
SCM_SYMBOL (symbol_immutable_location, "immutable-location");
|
||
SCM_SYMBOL (symbol_mutable_location, "mutable-location");
|
||
|
||
|
||
|
||
static SCM
|
||
export_environment_ref (SCM env, SCM sym)
|
||
#define FUNC_NAME "export_environment_ref"
|
||
{
|
||
struct export_environment *body = EXPORT_ENVIRONMENT (env);
|
||
SCM entry = scm_assq (sym, body->signature);
|
||
|
||
if (scm_is_false (entry))
|
||
return SCM_UNDEFINED;
|
||
else
|
||
return SCM_ENVIRONMENT_REF (body->private, sym);
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
export_environment_fold (SCM env, scm_environment_folder proc, SCM data, SCM init)
|
||
{
|
||
struct export_environment *body = EXPORT_ENVIRONMENT (env);
|
||
SCM result = init;
|
||
SCM l;
|
||
|
||
for (l = body->signature; !scm_is_null (l); l = SCM_CDR (l))
|
||
{
|
||
SCM symbol = SCM_CAR (l);
|
||
SCM value = SCM_ENVIRONMENT_REF (body->private, symbol);
|
||
if (!SCM_UNBNDP (value))
|
||
result = (*proc) (data, symbol, value, result);
|
||
}
|
||
return result;
|
||
}
|
||
|
||
|
||
static SCM
|
||
export_environment_define (SCM env SCM_UNUSED,
|
||
SCM sym SCM_UNUSED,
|
||
SCM val SCM_UNUSED)
|
||
#define FUNC_NAME "export_environment_define"
|
||
{
|
||
return SCM_ENVIRONMENT_BINDING_IMMUTABLE;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
export_environment_undefine (SCM env SCM_UNUSED, SCM sym SCM_UNUSED)
|
||
#define FUNC_NAME "export_environment_undefine"
|
||
{
|
||
return SCM_ENVIRONMENT_BINDING_IMMUTABLE;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
export_environment_set_x (SCM env, SCM sym, SCM val)
|
||
#define FUNC_NAME "export_environment_set_x"
|
||
{
|
||
struct export_environment *body = EXPORT_ENVIRONMENT (env);
|
||
SCM entry = scm_assq (sym, body->signature);
|
||
|
||
if (scm_is_false (entry))
|
||
{
|
||
return SCM_UNDEFINED;
|
||
}
|
||
else
|
||
{
|
||
if (scm_is_eq (SCM_CADR (entry), symbol_mutable_location))
|
||
return SCM_ENVIRONMENT_SET (body->private, sym, val);
|
||
else
|
||
return SCM_ENVIRONMENT_LOCATION_IMMUTABLE;
|
||
}
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
export_environment_cell (SCM env, SCM sym, int for_write)
|
||
#define FUNC_NAME "export_environment_cell"
|
||
{
|
||
struct export_environment *body = EXPORT_ENVIRONMENT (env);
|
||
SCM entry = scm_assq (sym, body->signature);
|
||
|
||
if (scm_is_false (entry))
|
||
{
|
||
return SCM_UNDEFINED;
|
||
}
|
||
else
|
||
{
|
||
if (!for_write || scm_is_eq (SCM_CADR (entry), symbol_mutable_location))
|
||
return SCM_ENVIRONMENT_CELL (body->private, sym, for_write);
|
||
else
|
||
return SCM_ENVIRONMENT_LOCATION_IMMUTABLE;
|
||
}
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
export_environment_mark (SCM env)
|
||
{
|
||
struct export_environment *body = EXPORT_ENVIRONMENT (env);
|
||
|
||
scm_gc_mark (body->private);
|
||
scm_gc_mark (body->private_observer);
|
||
scm_gc_mark (body->signature);
|
||
|
||
return core_environments_mark (env);
|
||
}
|
||
|
||
|
||
static void
|
||
export_environment_free (SCM env)
|
||
{
|
||
core_environments_finalize (env);
|
||
scm_gc_free (EXPORT_ENVIRONMENT (env), sizeof (struct export_environment),
|
||
"export environment");
|
||
}
|
||
|
||
|
||
static int
|
||
export_environment_print (SCM type, SCM port,
|
||
scm_print_state *pstate SCM_UNUSED)
|
||
{
|
||
SCM address = scm_from_size_t (SCM_UNPACK (type));
|
||
SCM base16 = scm_number_to_string (address, scm_from_int (16));
|
||
|
||
scm_puts ("#<export environment ", port);
|
||
scm_display (base16, port);
|
||
scm_puts (">", port);
|
||
|
||
return 1;
|
||
}
|
||
|
||
|
||
static struct scm_environment_funcs export_environment_funcs = {
|
||
export_environment_ref,
|
||
export_environment_fold,
|
||
export_environment_define,
|
||
export_environment_undefine,
|
||
export_environment_set_x,
|
||
export_environment_cell,
|
||
core_environments_observe,
|
||
core_environments_unobserve,
|
||
export_environment_mark,
|
||
export_environment_free,
|
||
export_environment_print
|
||
};
|
||
|
||
|
||
void *scm_type_export_environment = &export_environment_funcs;
|
||
|
||
|
||
static void
|
||
export_environment_observer (SCM caller SCM_UNUSED, SCM export_env)
|
||
{
|
||
core_environments_broadcast (export_env);
|
||
}
|
||
|
||
|
||
SCM_DEFINE (scm_make_export_environment, "make-export-environment", 2, 0, 0,
|
||
(SCM private, SCM signature),
|
||
"Return a new environment @var{exp} containing only those\n"
|
||
"bindings in private whose symbols are present in\n"
|
||
"@var{signature}. The @var{private} argument must be an\n"
|
||
"environment.\n\n"
|
||
"The environment @var{exp} binds symbol to location when\n"
|
||
"@var{env} does, and symbol is exported by @var{signature}.\n\n"
|
||
"@var{signature} is a list specifying which of the bindings in\n"
|
||
"@var{private} should be visible in @var{exp}. Each element of\n"
|
||
"@var{signature} should be a list of the form:\n"
|
||
" (symbol attribute ...)\n"
|
||
"where each attribute is one of the following:\n"
|
||
"@table @asis\n"
|
||
"@item the symbol @code{mutable-location}\n"
|
||
" @var{exp} should treat the\n"
|
||
" location bound to symbol as mutable. That is, @var{exp}\n"
|
||
" will pass calls to @code{environment-set!} or\n"
|
||
" @code{environment-cell} directly through to private.\n"
|
||
"@item the symbol @code{immutable-location}\n"
|
||
" @var{exp} should treat\n"
|
||
" the location bound to symbol as immutable. If the program\n"
|
||
" applies @code{environment-set!} to @var{exp} and symbol, or\n"
|
||
" calls @code{environment-cell} to obtain a writable value\n"
|
||
" cell, @code{environment-set!} will signal an\n"
|
||
" @code{environment:immutable-location} error. Note that, even\n"
|
||
" if an export environment treats a location as immutable, the\n"
|
||
" underlying environment may treat it as mutable, so its\n"
|
||
" value may change.\n"
|
||
"@end table\n"
|
||
"It is an error for an element of signature to specify both\n"
|
||
"@code{mutable-location} and @code{immutable-location}. If\n"
|
||
"neither is specified, @code{immutable-location} is assumed.\n\n"
|
||
"As a special case, if an element of signature is a lone\n"
|
||
"symbol @var{sym}, it is equivalent to an element of the form\n"
|
||
"@code{(sym)}.\n\n"
|
||
"All bindings in @var{exp} are immutable. If you apply\n"
|
||
"@code{environment-define} or @code{environment-undefine} to\n"
|
||
"@var{exp}, Guile will signal an\n"
|
||
"@code{environment:immutable-binding} error. However,\n"
|
||
"notice that the set of bindings in @var{exp} may still change,\n"
|
||
"if the bindings in private change.")
|
||
#define FUNC_NAME s_scm_make_export_environment
|
||
{
|
||
size_t size;
|
||
struct export_environment *body;
|
||
SCM env;
|
||
|
||
SCM_ASSERT (SCM_ENVIRONMENT_P (private), private, SCM_ARG1, FUNC_NAME);
|
||
|
||
size = sizeof (struct export_environment);
|
||
body = scm_gc_malloc (size, "export environment");
|
||
|
||
core_environments_preinit (&body->base);
|
||
body->private = SCM_BOOL_F;
|
||
body->private_observer = SCM_BOOL_F;
|
||
body->signature = SCM_BOOL_F;
|
||
|
||
env = scm_make_environment (body);
|
||
|
||
core_environments_init (&body->base, &export_environment_funcs);
|
||
body->private = private;
|
||
body->private_observer
|
||
= SCM_ENVIRONMENT_OBSERVE (private, export_environment_observer, env, 1);
|
||
body->signature = SCM_EOL;
|
||
|
||
scm_export_environment_set_signature_x (env, signature);
|
||
|
||
return env;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
SCM_DEFINE (scm_export_environment_p, "export-environment?", 1, 0, 0,
|
||
(SCM object),
|
||
"Return @code{#t} if object is an export environment, or\n"
|
||
"@code{#f} otherwise.")
|
||
#define FUNC_NAME s_scm_export_environment_p
|
||
{
|
||
return scm_from_bool (SCM_EXPORT_ENVIRONMENT_P (object));
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
SCM_DEFINE (scm_export_environment_private, "export-environment-private", 1, 0, 0,
|
||
(SCM env),
|
||
"Return the private environment of export environment @var{env}.")
|
||
#define FUNC_NAME s_scm_export_environment_private
|
||
{
|
||
SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
|
||
|
||
return EXPORT_ENVIRONMENT (env)->private;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
SCM_DEFINE (scm_export_environment_set_private_x, "export-environment-set-private!", 2, 0, 0,
|
||
(SCM env, SCM private),
|
||
"Change the private environment of export environment @var{env}.")
|
||
#define FUNC_NAME s_scm_export_environment_set_private_x
|
||
{
|
||
struct export_environment *body;
|
||
|
||
SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
|
||
SCM_ASSERT (SCM_ENVIRONMENT_P (private), private, SCM_ARG2, FUNC_NAME);
|
||
|
||
body = EXPORT_ENVIRONMENT (env);
|
||
SCM_ENVIRONMENT_UNOBSERVE (private, body->private_observer);
|
||
|
||
body->private = private;
|
||
body->private_observer
|
||
= SCM_ENVIRONMENT_OBSERVE (private, export_environment_observer, env, 1);
|
||
|
||
return SCM_UNSPECIFIED;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
SCM_DEFINE (scm_export_environment_signature, "export-environment-signature", 1, 0, 0,
|
||
(SCM env),
|
||
"Return the signature of export environment @var{env}.")
|
||
#define FUNC_NAME s_scm_export_environment_signature
|
||
{
|
||
SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
|
||
|
||
return EXPORT_ENVIRONMENT (env)->signature;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
static SCM
|
||
export_environment_parse_signature (SCM signature, const char* caller)
|
||
{
|
||
SCM result = SCM_EOL;
|
||
SCM l;
|
||
|
||
for (l = signature; scm_is_pair (l); l = SCM_CDR (l))
|
||
{
|
||
SCM entry = SCM_CAR (l);
|
||
|
||
if (scm_is_symbol (entry))
|
||
{
|
||
SCM new_entry = scm_cons2 (entry, symbol_immutable_location, SCM_EOL);
|
||
result = scm_cons (new_entry, result);
|
||
}
|
||
else
|
||
{
|
||
SCM sym;
|
||
SCM new_entry;
|
||
int immutable = 0;
|
||
int mutable = 0;
|
||
SCM mutability;
|
||
SCM l2;
|
||
|
||
SCM_ASSERT (scm_is_pair (entry), entry, SCM_ARGn, caller);
|
||
SCM_ASSERT (scm_is_symbol (SCM_CAR (entry)), entry, SCM_ARGn, caller);
|
||
|
||
sym = SCM_CAR (entry);
|
||
|
||
for (l2 = SCM_CDR (entry); scm_is_pair (l2); l2 = SCM_CDR (l2))
|
||
{
|
||
SCM attribute = SCM_CAR (l2);
|
||
if (scm_is_eq (attribute, symbol_immutable_location))
|
||
immutable = 1;
|
||
else if (scm_is_eq (attribute, symbol_mutable_location))
|
||
mutable = 1;
|
||
else
|
||
SCM_ASSERT (0, entry, SCM_ARGn, caller);
|
||
}
|
||
SCM_ASSERT (scm_is_null (l2), entry, SCM_ARGn, caller);
|
||
SCM_ASSERT (!mutable || !immutable, entry, SCM_ARGn, caller);
|
||
|
||
if (!mutable && !immutable)
|
||
immutable = 1;
|
||
|
||
mutability = mutable ? symbol_mutable_location : symbol_immutable_location;
|
||
new_entry = scm_cons2 (sym, mutability, SCM_EOL);
|
||
result = scm_cons (new_entry, result);
|
||
}
|
||
}
|
||
SCM_ASSERT (scm_is_null (l), signature, SCM_ARGn, caller);
|
||
|
||
/* Dirk:FIXME:: Now we know that signature is syntactically correct. There
|
||
* are, however, no checks for symbols entered twice with contradicting
|
||
* mutabilities. It would be nice, to implement this test, to be able to
|
||
* call the sort functions conveniently from C.
|
||
*/
|
||
|
||
return scm_reverse (result);
|
||
}
|
||
|
||
|
||
SCM_DEFINE (scm_export_environment_set_signature_x, "export-environment-set-signature!", 2, 0, 0,
|
||
(SCM env, SCM signature),
|
||
"Change the signature of export environment @var{env}.")
|
||
#define FUNC_NAME s_scm_export_environment_set_signature_x
|
||
{
|
||
SCM parsed_sig;
|
||
|
||
SCM_ASSERT (SCM_EXPORT_ENVIRONMENT_P (env), env, SCM_ARG1, FUNC_NAME);
|
||
parsed_sig = export_environment_parse_signature (signature, FUNC_NAME);
|
||
|
||
EXPORT_ENVIRONMENT (env)->signature = parsed_sig;
|
||
|
||
return SCM_UNSPECIFIED;
|
||
}
|
||
#undef FUNC_NAME
|
||
|
||
|
||
|
||
void
|
||
scm_environments_prehistory ()
|
||
{
|
||
/* create environment smob */
|
||
scm_tc16_environment = scm_make_smob_type ("environment", 0);
|
||
scm_set_smob_mark (scm_tc16_environment, environment_mark);
|
||
scm_set_smob_free (scm_tc16_environment, environment_free);
|
||
scm_set_smob_print (scm_tc16_environment, environment_print);
|
||
|
||
/* create observer smob */
|
||
scm_tc16_observer = scm_make_smob_type ("observer", 0);
|
||
scm_set_smob_mark (scm_tc16_observer, observer_mark);
|
||
scm_set_smob_print (scm_tc16_observer, observer_print);
|
||
|
||
/* create system environment */
|
||
scm_system_environment = scm_make_leaf_environment ();
|
||
scm_permanent_object (scm_system_environment);
|
||
}
|
||
|
||
|
||
void
|
||
scm_init_environments ()
|
||
{
|
||
#include "libguile/environments.x"
|
||
}
|
||
|
||
|
||
/*
|
||
Local Variables:
|
||
c-file-style: "gnu"
|
||
End:
|
||
*/
|