-/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2005,2006,2007,2008,2009
- * 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 3 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
- */
-
-\f
-
-#ifdef HAVE_CONFIG_H
-# include <config.h>
-#endif
-
-#include <alloca.h>
-
-#include "libguile/__scm.h"
-
-#include <assert.h>
-#include "libguile/_scm.h"
-#include "libguile/continuations.h"
-#include "libguile/eq.h"
-#include "libguile/list.h"
-#include "libguile/macros.h"
-#include "libguile/memoize.h"
-#include "libguile/modules.h"
-#include "libguile/srcprop.h"
-#include "libguile/ports.h"
-#include "libguile/print.h"
-#include "libguile/strings.h"
-#include "libguile/throw.h"
-#include "libguile/validate.h"
-
-
-\f
-
-
-#if 0
-#define CAR(x) SCM_CAR(x)
-#define CDR(x) SCM_CDR(x)
-#define CAAR(x) SCM_CAAR(x)
-#define CADR(x) SCM_CADR(x)
-#define CDAR(x) SCM_CDAR(x)
-#define CDDR(x) SCM_CDDR(x)
-#define CADDR(x) SCM_CADDR(x)
-#define CDDDR(x) SCM_CDDDR(x)
-#define CADDDR(x) SCM_CDDDR(x)
-#else
-#define CAR(x) scm_car(x)
-#define CDR(x) scm_cdr(x)
-#define CAAR(x) scm_caar(x)
-#define CADR(x) scm_cadr(x)
-#define CDAR(x) scm_cdar(x)
-#define CDDR(x) scm_cddr(x)
-#define CADDR(x) scm_caddr(x)
-#define CDDDR(x) scm_cdddr(x)
-#define CADDDR(x) scm_cadddr(x)
-#endif
-
-
-static const char s_bad_expression[] = "Bad expression";
-static const char s_expression[] = "Missing or extra expression in";
-static const char s_missing_expression[] = "Missing expression in";
-static const char s_extra_expression[] = "Extra expression in";
-static const char s_empty_combination[] = "Illegal empty combination";
-static const char s_missing_body_expression[] = "Missing body expression in";
-static const char s_mixed_body_forms[] = "Mixed definitions and expressions in";
-static const char s_bad_define[] = "Bad define placement";
-static const char s_missing_clauses[] = "Missing clauses";
-static const char s_misplaced_else_clause[] = "Misplaced else clause";
-static const char s_bad_case_clause[] = "Bad case clause";
-static const char s_bad_case_labels[] = "Bad case labels";
-static const char s_duplicate_case_label[] = "Duplicate case label";
-static const char s_bad_cond_clause[] = "Bad cond clause";
-static const char s_missing_recipient[] = "Missing recipient in";
-static const char s_bad_variable[] = "Bad variable";
-static const char s_bad_bindings[] = "Bad bindings";
-static const char s_bad_binding[] = "Bad binding";
-static const char s_duplicate_binding[] = "Duplicate binding";
-static const char s_bad_exit_clause[] = "Bad exit clause";
-static const char s_bad_formals[] = "Bad formals";
-static const char s_bad_formal[] = "Bad formal";
-static const char s_duplicate_formal[] = "Duplicate formal";
-static const char s_splicing[] = "Non-list result for unquote-splicing";
-static const char s_bad_slot_number[] = "Bad slot number";
-
-
-/* Signal a syntax error. We distinguish between the form that caused the
- * error and the enclosing expression. The error message will print out as
- * shown in the following pattern. The file name and line number are only
- * given when they can be determined from the erroneous form or from the
- * enclosing expression.
- *
- * <filename>: In procedure memoization:
- * <filename>: In file <name>, line <nr>: <error-message> in <expression>. */
-
-SCM_SYMBOL (syntax_error_key, "syntax-error");
-
-/* The prototype is needed to indicate that the function does not return. */
-static void
-syntax_error (const char* const, const SCM, const SCM) SCM_NORETURN;
-
-static void
-syntax_error (const char* const msg, const SCM form, const SCM expr)
-{
- SCM msg_string = scm_from_locale_string (msg);
- SCM filename = SCM_BOOL_F;
- SCM linenr = SCM_BOOL_F;
- const char *format;
- SCM args;
-
- if (scm_is_pair (form))
- {
- filename = scm_source_property (form, scm_sym_filename);
- linenr = scm_source_property (form, scm_sym_line);
- }
-
- if (scm_is_false (filename) && scm_is_false (linenr) && scm_is_pair (expr))
- {
- filename = scm_source_property (expr, scm_sym_filename);
- linenr = scm_source_property (expr, scm_sym_line);
- }
-
- if (!SCM_UNBNDP (expr))
- {
- if (scm_is_true (filename))
- {
- format = "In file ~S, line ~S: ~A ~S in expression ~S.";
- args = scm_list_5 (filename, linenr, msg_string, form, expr);
- }
- else if (scm_is_true (linenr))
- {
- format = "In line ~S: ~A ~S in expression ~S.";
- args = scm_list_4 (linenr, msg_string, form, expr);
- }
- else
- {
- format = "~A ~S in expression ~S.";
- args = scm_list_3 (msg_string, form, expr);
- }
- }
- else
- {
- if (scm_is_true (filename))
- {
- format = "In file ~S, line ~S: ~A ~S.";
- args = scm_list_4 (filename, linenr, msg_string, form);
- }
- else if (scm_is_true (linenr))
- {
- format = "In line ~S: ~A ~S.";
- args = scm_list_3 (linenr, msg_string, form);
- }
- else
- {
- format = "~A ~S.";
- args = scm_list_2 (msg_string, form);
- }
- }
-
- scm_error (syntax_error_key, "memoization", format, args, SCM_BOOL_F);
-}
-
-
-/* Shortcut macros to simplify syntax error handling. */
-#define ASSERT_SYNTAX(cond, message, form) \
- { if (SCM_UNLIKELY (!(cond))) \
- syntax_error (message, form, SCM_UNDEFINED); }
-#define ASSERT_SYNTAX_2(cond, message, form, expr) \
- { if (SCM_UNLIKELY (!(cond))) \
- syntax_error (message, form, expr); }
-
-\f
-
-
-/* {Evaluator memoized expressions}
- */
-
-scm_t_bits scm_tc16_memoized;
-
-#define MAKMEMO(n, args) (scm_cell (scm_tc16_memoized | ((n) << 16), (scm_t_bits)(args)))
-
-#define MAKMEMO_BEGIN(exps) \
- MAKMEMO (SCM_M_BEGIN, exps)
-#define MAKMEMO_IF(test, then, else_) \
- MAKMEMO (SCM_M_IF, scm_cons (test, scm_cons (then, else_)))
-#define MAKMEMO_LAMBDA(nreq, rest, body) \
- MAKMEMO (SCM_M_LAMBDA, scm_cons (SCM_I_MAKINUM (nreq), scm_cons (rest, body)))
-#define MAKMEMO_LET(inits, body) \
- MAKMEMO (SCM_M_LET, scm_cons (inits, body))
-#define MAKMEMO_QUOTE(exp) \
- MAKMEMO (SCM_M_QUOTE, exp)
-#define MAKMEMO_DEFINE(var, val) \
- MAKMEMO (SCM_M_DEFINE, scm_cons (var, val))
-#define MAKMEMO_APPLY(exp) \
- MAKMEMO (SCM_M_APPLY, exp)
-#define MAKMEMO_CONT(proc) \
- MAKMEMO (SCM_M_CONT, proc)
-#define MAKMEMO_CALL_WITH_VALUES(prod, cons) \
- MAKMEMO (SCM_M_CALL_WITH_VALUES, scm_cons (prod, cons))
-#define MAKMEMO_CALL(proc, args) \
- MAKMEMO (SCM_M_CALL, scm_cons (proc, args))
-#define MAKMEMO_LEX_REF(n) \
- MAKMEMO (SCM_M_LEXICAL_REF, SCM_I_MAKINUM (n))
-#define MAKMEMO_LEX_SET(n, val) \
- MAKMEMO (SCM_M_LEXICAL_SET, scm_cons (SCM_I_MAKINUM (n), val))
-#define MAKMEMO_TOP_REF(var) \
- MAKMEMO (SCM_M_TOPLEVEL_REF, var)
-#define MAKMEMO_TOP_SET(var, val) \
- MAKMEMO (SCM_M_TOPLEVEL_SET, scm_cons (var, val))
-#define MAKMEMO_MOD_REF(mod, var, public) \
- MAKMEMO (SCM_M_MODULE_REF, scm_cons (mod, scm_cons (var, public)))
-#define MAKMEMO_MOD_SET(val, mod, var, public) \
- MAKMEMO (SCM_M_MODULE_SET, scm_cons (val, scm_cons (mod, scm_cons (var, public))))
-
-\f
-
-/* This table must agree with the list of M_ constants in memoize.h */
-static const char *const memoized_tags[] =
-{
- "begin",
- "if",
- "lambda",
- "let",
- "quote",
- "define",
- "apply",
- "call-with-current-continuation",
- "call-with-values",
- "call",
- "lexical-ref",
- "lexical-set!",
- "toplevel-ref",
- "toplevel-set!",
- "module-ref",
- "module-set",
-};
-
-static int
-scm_print_memoized (SCM memoized, SCM port, scm_print_state *pstate)
-{
- scm_puts ("#<memoized ", port);
- scm_write (scm_unmemoize_expression (memoized), port);
- scm_puts (">", port);
- return 1;
-}
-
-static SCM scm_m_at (SCM xorig, SCM env);
-static SCM scm_m_atat (SCM xorig, SCM env);
-static SCM scm_m_and (SCM xorig, SCM env);
-static SCM scm_m_apply (SCM xorig, SCM env);
-static SCM scm_m_begin (SCM xorig, SCM env);
-static SCM scm_m_cont (SCM xorig, SCM env);
-static SCM scm_m_at_call_with_values (SCM xorig, SCM env);
-static SCM scm_m_cond (SCM xorig, SCM env);
-static SCM scm_m_define (SCM x, SCM env);
-static SCM scm_m_eval_when (SCM xorig, SCM env);
-static SCM scm_m_if (SCM xorig, SCM env);
-static SCM scm_m_lambda (SCM xorig, SCM env);
-static SCM scm_m_let (SCM xorig, SCM env);
-static SCM scm_m_letrec (SCM xorig, SCM env);
-static SCM scm_m_letstar (SCM xorig, SCM env);
-static SCM scm_m_or (SCM xorig, SCM env);
-static SCM scm_m_quote (SCM xorig, SCM env);
-static SCM scm_m_set_x (SCM xorig, SCM env);
-
-
-\f
-
-
-typedef SCM (*t_syntax_transformer) (SCM, SCM);
-
-static t_syntax_transformer
-memoize_env_ref_transformer (SCM env, SCM x)
-{
- SCM var;
- for (; scm_is_pair (env); env = CDR (env))
- if (scm_is_eq (x, CAR (env)))
- return NULL; /* lexical */
-
- var = scm_module_variable (env, x);
- if (scm_is_true (var) && scm_is_true (scm_variable_bound_p (var))
- && SCM_MACROP (scm_variable_ref (var)))
- {
- SCM mac = scm_variable_ref (var);
- if (SCM_IMP (SCM_MACRO_CODE (mac))
- || SCM_TYP7 (SCM_MACRO_CODE (mac)) != scm_tc7_subr_2)
- syntax_error ("bad macro", x, SCM_UNDEFINED);
- else
- return (t_syntax_transformer)SCM_SUBRF (SCM_MACRO_CODE (mac)); /* global macro */
- }
- else
- return NULL; /* anything else */
-}
-
-static int
-memoize_env_var_is_free (SCM env, SCM x)
-{
- for (; scm_is_pair (env); env = CDR (env))
- if (scm_is_eq (x, CAR (env)))
- return 0; /* bound */
- return 1; /* free */
-}
-
-static int
-memoize_env_lexical_index (SCM env, SCM x)
-{
- int i = 0;
- for (; scm_is_pair (env); env = CDR (env), i++)
- if (scm_is_eq (x, CAR (env)))
- return i; /* bound */
- return -1; /* free */
-}
-
-static SCM
-memoize_env_extend (SCM env, SCM vars)
-{
- return scm_append (scm_list_2 (vars, env));
-}
-
-static SCM
-memoize (SCM exp, SCM env)
-{
- if (scm_is_pair (exp))
- {
- SCM CAR;
- t_syntax_transformer trans;
-
- CAR = CAR (exp);
- if (scm_is_symbol (CAR))
- trans = memoize_env_ref_transformer (env, CAR);
- else
- trans = NULL;
-
- if (trans)
- return trans (exp, env);
- else
- {
- SCM args = SCM_EOL;
- for (; scm_is_pair (exp); exp = CDR (exp))
- args = scm_cons (memoize (CAR (exp), env), args);
- if (scm_is_null (exp))
- return MAKMEMO (SCM_M_CALL, scm_reverse_x (args, SCM_UNDEFINED));
- else
- syntax_error ("expected a proper list", exp, SCM_UNDEFINED);
- }
- }
- else if (scm_is_symbol (exp))
- {
- int i = memoize_env_lexical_index (env, exp);
- if (i < 0)
- return MAKMEMO_TOP_REF (exp);
- else
- return MAKMEMO_LEX_REF (i);
- }
- else
- return MAKMEMO_QUOTE (exp);
-}
-
-static SCM
-memoize_exprs (SCM forms, const SCM env)
-{
- SCM ret = SCM_EOL;
-
- for (; !scm_is_null (forms); forms = CDR (forms))
- ret = scm_cons (memoize (CAR (forms), env), ret);
- return scm_reverse_x (ret, SCM_UNDEFINED);
-}
-
-static SCM
-memoize_sequence (const SCM forms, const SCM env)
-{
- ASSERT_SYNTAX (scm_ilength (forms) >= 1, s_bad_expression,
- scm_cons (scm_sym_begin, forms));
- return MAKMEMO_BEGIN (memoize_exprs (forms, env));
-}
-
-
-\f
-/* Memoization. */
-
-/* bimacros (built-in macros) have isym codes.
- mmacros don't exist at runtime, they just expand out to more primitive
- forms. */
-SCM_SYNTAX (s_at, "@", scm_i_makbimacro, scm_m_at);
-SCM_SYNTAX (s_atat, "@@", scm_i_makbimacro, scm_m_atat);
-SCM_SYNTAX (s_and, "and", scm_makmmacro, scm_m_and);
-SCM_SYNTAX (s_begin, "begin", scm_i_makbimacro, scm_m_begin);
-SCM_SYNTAX (s_atcall_cc, "@call-with-current-continuation", scm_i_makbimacro, scm_m_cont);
-SCM_SYNTAX (s_at_call_with_values, "@call-with-values", scm_i_makbimacro, scm_m_at_call_with_values);
-SCM_SYNTAX (s_cond, "cond", scm_makmmacro, scm_m_cond);
-SCM_SYNTAX (s_define, "define", scm_i_makbimacro, scm_m_define);
-SCM_SYNTAX (s_eval_when, "eval-when", scm_makmmacro, scm_m_eval_when);
-SCM_SYNTAX (s_if, "if", scm_i_makbimacro, scm_m_if);
-SCM_SYNTAX (s_lambda, "lambda", scm_i_makbimacro, scm_m_lambda);
-SCM_SYNTAX (s_let, "let", scm_i_makbimacro, scm_m_let);
-SCM_SYNTAX (s_letrec, "letrec", scm_makmmacro, scm_m_letrec);
-SCM_SYNTAX (s_letstar, "let*", scm_makmmacro, scm_m_letstar);
-SCM_SYNTAX (s_or, "or", scm_makmmacro, scm_m_or);
-SCM_SYNTAX (s_quote, "quote", scm_i_makbimacro, scm_m_quote);
-SCM_SYNTAX (s_set_x, "set!", scm_i_makbimacro, scm_m_set_x);
-SCM_SYNTAX (s_atapply, "@apply", scm_i_makbimacro, scm_m_apply);
-
-
-SCM_GLOBAL_SYMBOL (scm_sym_apply, "apply");
-SCM_GLOBAL_SYMBOL (scm_sym_arrow, "=>");
-SCM_GLOBAL_SYMBOL (scm_sym_at, "@");
-SCM_GLOBAL_SYMBOL (scm_sym_atat, "@@");
-SCM_GLOBAL_SYMBOL (scm_sym_at_call_with_values, "@call-with-values");
-SCM_GLOBAL_SYMBOL (scm_sym_atapply, "@apply");
-SCM_GLOBAL_SYMBOL (scm_sym_atcall_cc, "@call-with-current-continuation");
-SCM_GLOBAL_SYMBOL (scm_sym_begin, "begin");
-SCM_GLOBAL_SYMBOL (scm_sym_case, "case");
-SCM_GLOBAL_SYMBOL (scm_sym_cond, "cond");
-SCM_GLOBAL_SYMBOL (scm_sym_define, "define");
-SCM_GLOBAL_SYMBOL (scm_sym_else, "else");
-SCM_GLOBAL_SYMBOL (scm_sym_eval_when, "eval-when");
-SCM_GLOBAL_SYMBOL (scm_sym_if, "if");
-SCM_GLOBAL_SYMBOL (scm_sym_lambda, "lambda");
-SCM_GLOBAL_SYMBOL (scm_sym_let, "let");
-SCM_GLOBAL_SYMBOL (scm_sym_letrec, "letrec");
-SCM_GLOBAL_SYMBOL (scm_sym_letstar, "let*");
-SCM_GLOBAL_SYMBOL (scm_sym_or, "or");
-SCM_GLOBAL_SYMBOL (scm_sym_quote, "quote");
-SCM_GLOBAL_SYMBOL (scm_sym_set_x, "set!");
-SCM_SYMBOL (sym_eval, "eval");
-SCM_SYMBOL (sym_load, "load");
-
-SCM_GLOBAL_SYMBOL (scm_sym_unquote, "unquote");
-SCM_GLOBAL_SYMBOL (scm_sym_quasiquote, "quasiquote");
-SCM_GLOBAL_SYMBOL (scm_sym_uq_splicing, "unquote-splicing");
-
-
-static SCM
-scm_m_at (SCM expr, SCM env SCM_UNUSED)
-{
- ASSERT_SYNTAX (scm_ilength (expr) == 3, s_bad_expression, expr);
- ASSERT_SYNTAX (scm_ilength (CADR (expr)) > 0, s_bad_expression, expr);
- ASSERT_SYNTAX (scm_is_symbol (CADDR (expr)), s_bad_expression, expr);
-
- return MAKMEMO_MOD_REF (CADR (expr), CADDR (expr), SCM_BOOL_T);
-}
-
-static SCM
-scm_m_atat (SCM expr, SCM env SCM_UNUSED)
-{
- ASSERT_SYNTAX (scm_ilength (expr) == 3, s_bad_expression, expr);
- ASSERT_SYNTAX (scm_ilength (CADR (expr)) > 0, s_bad_expression, expr);
- ASSERT_SYNTAX (scm_is_symbol (CADDR (expr)), s_bad_expression, expr);
-
- return MAKMEMO_MOD_REF (CADR (expr), CADDR (expr), SCM_BOOL_F);
-}
-
-static SCM
-scm_m_and (SCM expr, SCM env)
-{
- const SCM cdr_expr = CDR (expr);
-
- if (scm_is_null (cdr_expr))
- return MAKMEMO_QUOTE (SCM_BOOL_T);
- ASSERT_SYNTAX (scm_is_pair (cdr_expr), s_bad_expression, expr);
-
- if (scm_is_null (CDR (cdr_expr)))
- return memoize (CAR (cdr_expr), env);
- else
- return MAKMEMO_IF (memoize (CAR (cdr_expr), env),
- scm_m_and (cdr_expr, env),
- MAKMEMO_QUOTE (SCM_BOOL_F));
-}
-
-static SCM
-scm_m_apply (SCM expr, SCM env)
-{
- const SCM cdr_expr = CDR (expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 0, s_bad_expression, expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) == 2, s_missing_expression, expr);
-
- return MAKMEMO_APPLY (memoize_exprs (cdr_expr, env));
-}
-
-static SCM
-scm_m_begin (SCM expr, SCM env)
-{
- const SCM cdr_expr = CDR (expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 1, s_bad_expression, expr);
- return MAKMEMO_BEGIN (memoize_exprs (cdr_expr, env));
-}
-
-static SCM
-scm_m_cont (SCM expr, SCM env)
-{
- const SCM cdr_expr = CDR (expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 0, s_bad_expression, expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) == 1, s_expression, expr);
-
- return MAKMEMO_CONT (memoize (CADR (expr), env));
-}
-
-static SCM
-scm_m_at_call_with_values (SCM expr, SCM env)
-{
- const SCM cdr_expr = CDR (expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 0, s_bad_expression, expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) == 2, s_expression, expr);
-
- return MAKMEMO_CALL_WITH_VALUES (memoize (CADR (expr), env),
- memoize (CADDR (expr), env));
-}
-
-static SCM
-scm_m_cond (SCM expr, SCM env)
-{
- /* Check, whether 'else or '=> is a literal, i. e. not bound to a value. */
- const int else_literal_p = memoize_env_var_is_free (env, scm_sym_else);
- const int arrow_literal_p = memoize_env_var_is_free (env, scm_sym_arrow);
-
- const SCM clauses = CDR (expr);
- SCM clause_idx;
- SCM ret, loc;
-
- ASSERT_SYNTAX (scm_ilength (clauses) >= 0, s_bad_expression, expr);
- ASSERT_SYNTAX (scm_ilength (clauses) >= 1, s_missing_clauses, expr);
-
- ret = scm_cons (SCM_UNDEFINED, MAKMEMO_QUOTE (SCM_UNSPECIFIED));
- loc = ret;
-
- for (clause_idx = clauses;
- !scm_is_null (clause_idx);
- clause_idx = CDR (clause_idx))
- {
- SCM test;
-
- const SCM clause = CAR (clause_idx);
- const long length = scm_ilength (clause);
- ASSERT_SYNTAX_2 (length >= 1, s_bad_cond_clause, clause, expr);
-
- test = CAR (clause);
- if (scm_is_eq (test, scm_sym_else) && else_literal_p)
- {
- const int last_clause_p = scm_is_null (CDR (clause_idx));
- ASSERT_SYNTAX_2 (length >= 2,
- s_bad_cond_clause, clause, expr);
- ASSERT_SYNTAX_2 (last_clause_p,
- s_misplaced_else_clause, clause, expr);
- SCM_SETCDR (loc,
- memoize (scm_cons (scm_sym_begin, CDR (clause)), env));
- }
- else if (length >= 2
- && scm_is_eq (CADR (clause), scm_sym_arrow)
- && arrow_literal_p)
- {
- SCM tmp = scm_gensym (scm_from_locale_string ("cond "));
- SCM i;
- SCM new_env = scm_cons (tmp, env);
- ASSERT_SYNTAX_2 (length > 2, s_missing_recipient, clause, expr);
- ASSERT_SYNTAX_2 (length == 3, s_extra_expression, clause, expr);
- i = MAKMEMO_IF (MAKMEMO_LEX_REF (0),
- MAKMEMO_CALL (memoize (CADDR (clause),
- scm_cons (tmp, new_env)),
- scm_list_1 (MAKMEMO_LEX_REF (0))),
- MAKMEMO_QUOTE (SCM_UNSPECIFIED));
- SCM_SETCDR (loc,
- MAKMEMO_LET (scm_list_1 (memoize (CAR (clause), env)),
- i));
- env = new_env;
- loc = scm_last_pair (SCM_MEMOIZED_ARGS (i));
- }
- /* FIXME length == 1 case */
- else
- {
- SCM i = MAKMEMO_IF (memoize (CAR (clause), env),
- memoize (scm_cons (scm_sym_begin, CDR (clause)), env),
- MAKMEMO_QUOTE (SCM_UNSPECIFIED));
- SCM_SETCDR (loc, i);
- loc = scm_last_pair (SCM_MEMOIZED_ARGS (i));
- }
- }
-
- return CDR (ret);
-}
-
-/* According to Section 5.2.1 of R5RS we first have to make sure that the
- variable is bound, and then perform the `(set! variable expression)'
- operation. However, EXPRESSION _can_ be evaluated before VARIABLE is
- bound. This means that EXPRESSION won't necessarily be able to assign
- values to VARIABLE as in `(define foo (begin (set! foo 1) (+ foo 1)))'. */
-static SCM
-scm_m_define (SCM expr, SCM env)
-{
- const SCM cdr_expr = CDR (expr);
- SCM body;
- SCM variable;
-
- ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 0, s_bad_expression, expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 2, s_missing_expression, expr);
- ASSERT_SYNTAX (!scm_is_pair (env), s_bad_define, expr);
-
- body = CDR (cdr_expr);
- variable = CAR (cdr_expr);
-
- if (scm_is_pair (variable))
- {
- ASSERT_SYNTAX_2 (scm_is_symbol (CAR (variable)), s_bad_variable, variable, expr);
- return MAKMEMO_DEFINE (CAR (variable),
- memoize (scm_cons (scm_sym_lambda,
- scm_cons (CDR (variable), body)),
- env));
- }
- ASSERT_SYNTAX_2 (scm_is_symbol (variable), s_bad_variable, variable, expr);
- ASSERT_SYNTAX (scm_ilength (body) == 1, s_expression, expr);
- return MAKMEMO_DEFINE (variable, memoize (CAR (body), env));
-}
-
-static SCM
-scm_m_eval_when (SCM expr, SCM env)
-{
- ASSERT_SYNTAX (scm_ilength (expr) >= 3, s_bad_expression, expr);
- ASSERT_SYNTAX (scm_ilength (CADR (expr)) > 0, s_bad_expression, expr);
-
- if (scm_is_true (scm_memq (sym_eval, CADR (expr)))
- || scm_is_true (scm_memq (sym_load, CADR (expr))))
- return MAKMEMO_BEGIN (memoize_exprs (CDDR (expr), env));
- else
- return MAKMEMO_QUOTE (SCM_UNSPECIFIED);
-}
-
-static SCM
-scm_m_if (SCM expr, SCM env SCM_UNUSED)
-{
- const SCM cdr_expr = CDR (expr);
- const long length = scm_ilength (cdr_expr);
- ASSERT_SYNTAX (length == 2 || length == 3, s_expression, expr);
- return MAKMEMO_IF (memoize (CADR (expr), env),
- memoize (CADDR (expr), env),
- ((length == 3)
- ? memoize (CADDDR (expr), env)
- : MAKMEMO_QUOTE (SCM_UNSPECIFIED)));
-}
-
-/* A helper function for memoize_lambda to support checking for duplicate
- * formal arguments: Return true if OBJ is `eq?' to one of the elements of
- * LIST or to the CDR of the last cons. Therefore, LIST may have any of the
- * forms that a formal argument can have:
- * <rest>, (<arg1> ...), (<arg1> ... . <rest>) */
-static int
-c_improper_memq (SCM obj, SCM list)
-{
- for (; scm_is_pair (list); list = CDR (list))
- {
- if (scm_is_eq (CAR (list), obj))
- return 1;
- }
- return scm_is_eq (list, obj);
-}
-
-static SCM
-scm_m_lambda (SCM expr, SCM env SCM_UNUSED)
-{
- SCM formals;
- SCM formals_idx;
- SCM formal_vars = SCM_EOL;
- int nreq = 0;
-
- const SCM cdr_expr = CDR (expr);
- const long length = scm_ilength (cdr_expr);
- ASSERT_SYNTAX (length >= 0, s_bad_expression, expr);
- ASSERT_SYNTAX (length >= 2, s_missing_expression, expr);
-
- /* Before iterating the list of formal arguments, make sure the formals
- * actually are given as either a symbol or a non-cyclic list. */
- formals = CAR (cdr_expr);
- if (scm_is_pair (formals))
- {
- /* Dirk:FIXME:: We should check for a cyclic list of formals, and if
- * detected, report a 'Bad formals' error. */
- }
- else
- {
- ASSERT_SYNTAX_2 (scm_is_symbol (formals) || scm_is_null (formals),
- s_bad_formals, formals, expr);
- }
-
- /* Now iterate the list of formal arguments to check if all formals are
- * symbols, and that there are no duplicates. */
- formals_idx = formals;
- while (scm_is_pair (formals_idx))
- {
- const SCM formal = CAR (formals_idx);
- const SCM next_idx = CDR (formals_idx);
- ASSERT_SYNTAX_2 (scm_is_symbol (formal), s_bad_formal, formal, expr);
- ASSERT_SYNTAX_2 (!c_improper_memq (formal, next_idx),
- s_duplicate_formal, formal, expr);
- nreq++;
- formal_vars = scm_cons (formal, formal_vars);
- formals_idx = next_idx;
- }
- ASSERT_SYNTAX_2 (scm_is_null (formals_idx) || scm_is_symbol (formals_idx),
- s_bad_formal, formals_idx, expr);
- if (scm_is_symbol (formals_idx))
- formal_vars = scm_cons (formals_idx, formal_vars);
- return MAKMEMO_LAMBDA (nreq, scm_symbol_p (formals_idx),
- memoize_sequence (CDDR (expr),
- memoize_env_extend (env, formal_vars)));
-}
-
-/* Check if the format of the bindings is ((<symbol> <init-form>) ...). */
-static void
-check_bindings (const SCM bindings, const SCM expr)
-{
- SCM binding_idx;
-
- ASSERT_SYNTAX_2 (scm_ilength (bindings) >= 0,
- s_bad_bindings, bindings, expr);
-
- binding_idx = bindings;
- for (; !scm_is_null (binding_idx); binding_idx = CDR (binding_idx))
- {
- SCM name; /* const */
-
- const SCM binding = CAR (binding_idx);
- ASSERT_SYNTAX_2 (scm_ilength (binding) == 2,
- s_bad_binding, binding, expr);
-
- name = CAR (binding);
- ASSERT_SYNTAX_2 (scm_is_symbol (name), s_bad_variable, name, expr);
- }
-}
-
-/* The bindings, which must have the format ((v1 i1) (v2 i2) ... (vn in)), are
- * transformed to the lists (vn .. v2 v1) and (i1 i2 ... in). If a duplicate
- * variable name is detected, an error is signalled. */
-static int
-transform_bindings (const SCM bindings, const SCM expr,
- SCM *const rvarptr, SCM *const initptr)
-{
- SCM rvariables = SCM_EOL;
- SCM rinits = SCM_EOL;
- SCM binding_idx = bindings;
- int n = 0;
- for (; !scm_is_null (binding_idx); binding_idx = CDR (binding_idx))
- {
- const SCM binding = CAR (binding_idx);
- const SCM CDR_binding = CDR (binding);
- const SCM name = CAR (binding);
- ASSERT_SYNTAX_2 (scm_is_false (scm_c_memq (name, rvariables)),
- s_duplicate_binding, name, expr);
- rvariables = scm_cons (name, rvariables);
- rinits = scm_cons (CAR (CDR_binding), rinits);
- n++;
- }
- *rvarptr = rvariables;
- *initptr = scm_reverse_x (rinits, SCM_UNDEFINED);
- return n;
-}
-
-/* This function is a helper function for memoize_let. It transforms
- * (let name ((var init) ...) body ...) into
- * ((letrec ((name (lambda (var ...) body ...))) name) init ...)
- * and memoizes the expression. It is assumed that the caller has checked
- * that name is a symbol and that there are bindings and a body. */
-static SCM
-memoize_named_let (const SCM expr, SCM env)
-{
- SCM rvariables;
- SCM inits;
- int nreq;
-
- const SCM cdr_expr = CDR (expr);
- const SCM name = CAR (cdr_expr);
- const SCM cddr_expr = CDR (cdr_expr);
- const SCM bindings = CAR (cddr_expr);
- check_bindings (bindings, expr);
-
- nreq = transform_bindings (bindings, expr, &rvariables, &inits);
-
- env = scm_cons (name, env);
- return MAKMEMO_LET
- (scm_list_1 (MAKMEMO_QUOTE (SCM_UNDEFINED)),
- MAKMEMO_BEGIN
- (scm_list_2 (MAKMEMO_LEX_SET
- (0,
- MAKMEMO_LAMBDA
- (nreq, SCM_BOOL_F,
- memoize_sequence (CDDDR (expr),
- memoize_env_extend (env, rvariables)))),
- MAKMEMO_CALL (MAKMEMO_LEX_REF (0),
- memoize_exprs (inits, env)))));
-}
-
-/* (let ((v1 i1) (v2 i2) ...) body) with variables v1 .. vn and initializers
- * i1 .. in is transformed to (#@let (vn ... v2 v1) (i1 i2 ...) body). */
-static SCM
-scm_m_let (SCM expr, SCM env)
-{
- SCM bindings;
-
- const SCM cdr_expr = CDR (expr);
- const long length = scm_ilength (cdr_expr);
- ASSERT_SYNTAX (length >= 0, s_bad_expression, expr);
- ASSERT_SYNTAX (length >= 2, s_missing_expression, expr);
-
- bindings = CAR (cdr_expr);
- if (scm_is_symbol (bindings))
- {
- ASSERT_SYNTAX (length >= 3, s_missing_expression, expr);
- return memoize_named_let (expr, env);
- }
-
- check_bindings (bindings, expr);
- if (scm_is_null (bindings))
- return memoize_sequence (CDDR (expr), env);
- else
- {
- SCM rvariables;
- SCM inits;
- transform_bindings (bindings, expr, &rvariables, &inits);
- return MAKMEMO_LET (memoize_exprs (inits, env),
- memoize_sequence (CDDR (expr),
- memoize_env_extend (env, rvariables)));
- }
-}
-
-static SCM
-scm_m_letrec (SCM expr, SCM env)
-{
- SCM bindings;
-
- const SCM cdr_expr = CDR (expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 0, s_bad_expression, expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 2, s_missing_expression, expr);
-
- bindings = CAR (cdr_expr);
- if (scm_is_null (bindings))
- return memoize_sequence (CDDR (expr), env);
- else
- {
- SCM rvariables;
- SCM inits;
- SCM v, i;
- SCM undefs = SCM_EOL;
- SCM vals = SCM_EOL;
- SCM sets = SCM_EOL;
- SCM new_env;
- int offset;
- int n = transform_bindings (bindings, expr, &rvariables, &inits);
- offset = n;
- new_env = memoize_env_extend (env, rvariables);
- for (v = scm_reverse (rvariables), i = inits; scm_is_pair (v);
- v = CDR (v), i = CDR (i), n--)
- {
- undefs = scm_cons (MAKMEMO_QUOTE (SCM_UNDEFINED), undefs);
- vals = scm_cons (memoize (CAR (i), new_env), vals);
- sets = scm_cons (MAKMEMO_LEX_SET ((n-1) + offset,
- MAKMEMO_LEX_REF (n-1)),
- sets);
- }
- return MAKMEMO_LET
- (undefs,
- MAKMEMO_BEGIN (scm_list_2 (MAKMEMO_LET (scm_reverse (vals),
- MAKMEMO_BEGIN (sets)),
- memoize_sequence (CDDR (expr),
- new_env))));
- }
-}
-
-static SCM
-scm_m_letstar (SCM expr, SCM env SCM_UNUSED)
-{
- SCM bindings;
-
- const SCM cdr_expr = CDR (expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 0, s_bad_expression, expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 2, s_missing_expression, expr);
-
- bindings = CAR (cdr_expr);
- if (scm_is_null (bindings))
- return memoize_sequence (CDDR (expr), env);
- else
- {
- SCM rvariables;
- SCM variables;
- SCM inits;
- SCM ret, loc;
- transform_bindings (bindings, expr, &rvariables, &inits);
- variables = scm_reverse (rvariables);
- ret = scm_cons (SCM_UNDEFINED, SCM_UNSPECIFIED);
- loc = ret;
- for (; scm_is_pair (variables);
- variables = CDR (variables), inits = CDR (inits))
- { SCM x = MAKMEMO_LET (scm_list_1 (memoize (CAR (inits), env)),
- MAKMEMO_QUOTE (SCM_UNSPECIFIED));
- SCM_SETCDR (loc, x);
- loc = scm_last_pair (SCM_MEMOIZED_ARGS (x));
- env = scm_cons (CAR (variables), env);
- }
- SCM_SETCDR (loc, memoize_sequence (CDDR (expr), env));
- return CDR (ret);
- }
-}
-
-static SCM
-scm_m_or (SCM expr, SCM env SCM_UNUSED)
-{
- SCM tail = CDR (expr);
- SCM ret, loc;
- const long length = scm_ilength (tail);
-
- ASSERT_SYNTAX (length >= 0, s_bad_expression, expr);
-
- ret = scm_cons (SCM_UNDEFINED, SCM_UNSPECIFIED);
- loc = ret;
- for (; scm_is_pair (tail); tail = CDR (tail))
- {
- SCM tmp = scm_gensym (scm_from_locale_string ("cond "));
- SCM x = MAKMEMO_IF (MAKMEMO_LEX_REF (0),
- MAKMEMO_LEX_REF (0),
- MAKMEMO_QUOTE (SCM_UNSPECIFIED));
- SCM new_env = scm_cons (tmp, env);
- SCM_SETCDR (loc, MAKMEMO_LET (scm_list_1 (memoize (CAR (tail),
- env)),
- x));
- env = new_env;
- loc = scm_last_pair (SCM_MEMOIZED_ARGS (x));
- }
- SCM_SETCDR (loc, MAKMEMO_QUOTE (SCM_BOOL_F));
- return CDR (ret);
-}
-
-static SCM
-scm_m_quote (SCM expr, SCM env SCM_UNUSED)
-{
- SCM quotee;
-
- const SCM cdr_expr = CDR (expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 0, s_bad_expression, expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) == 1, s_expression, expr);
- quotee = CAR (cdr_expr);
- return MAKMEMO_QUOTE (quotee);
-}
-
-static SCM
-scm_m_set_x (SCM expr, SCM env)
-{
- SCM variable;
- SCM vmem;
-
- const SCM cdr_expr = CDR (expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) >= 0, s_bad_expression, expr);
- ASSERT_SYNTAX (scm_ilength (cdr_expr) == 2, s_expression, expr);
- variable = CAR (cdr_expr);
- vmem = memoize (variable, env);
-
- switch (SCM_MEMOIZED_TAG (vmem))
- {
- case SCM_M_LEXICAL_REF:
- return MAKMEMO_LEX_SET (SCM_I_INUM (SCM_MEMOIZED_ARGS (vmem)),
- memoize (CADDR (expr), env));
- case SCM_M_TOPLEVEL_REF:
- return MAKMEMO_TOP_SET (variable,
- memoize (CADDR (expr), env));
- case SCM_M_MODULE_REF:
- return MAKMEMO_MOD_SET (memoize (CADDR (expr), env),
- CAR (SCM_MEMOIZED_ARGS (vmem)),
- CADR (SCM_MEMOIZED_ARGS (vmem)),
- CDDR (SCM_MEMOIZED_ARGS (vmem)));
- default:
- syntax_error (s_bad_variable, variable, expr);
- }
-}
-
-
-\f
-
-SCM_DEFINE (scm_memoize_expression, "memoize-expression", 1, 0, 0,
- (SCM exp),
- "Memoize the expression @var{exp}.")
-#define FUNC_NAME s_scm_memoize_expression
-{
- return memoize (exp, scm_current_module ());
-}
-#undef FUNC_NAME
-
-\f
-
-
-SCM_SYMBOL (sym_placeholder, "_");
-
-static SCM unmemoize (SCM expr);
-
-static SCM
-unmemoize_exprs (SCM exprs)
-{
- SCM ret, tail;
- if (scm_is_null (exprs))
- return SCM_EOL;
- ret = scm_list_1 (unmemoize (CAR (exprs)));
- tail = ret;
- for (exprs = CDR (exprs); !scm_is_null (exprs); exprs = CDR (exprs))
- {
- SCM_SETCDR (tail, scm_list_1 (unmemoize (CAR (exprs))));
- tail = CDR (tail);
- }
- return ret;
-}
-
-static SCM
-unmemoize_bindings (SCM inits)
-{
- SCM ret, tail;
- if (scm_is_null (inits))
- return SCM_EOL;
- ret = scm_list_1 (scm_list_2 (sym_placeholder, unmemoize (CAR (inits))));
- tail = ret;
- for (inits = CDR (inits); !scm_is_null (inits); inits = CDR (inits))
- {
- SCM_SETCDR (tail, scm_list_1 (scm_list_2 (sym_placeholder,
- unmemoize (CAR (inits)))));
- tail = CDR (tail);
- }
- return ret;
-}
-
-static SCM
-unmemoize_lexical (SCM n)
-{
- char buf[16];
- buf[15] = 0;
- snprintf (buf, 15, "<%u>", scm_to_uint32 (n));
- return scm_from_locale_symbol (buf);
-}
-
-static SCM
-unmemoize (const SCM expr)
-{
- SCM args;
-
- if (!SCM_MEMOIZED_P (expr))
- abort ();
-
- args = SCM_MEMOIZED_ARGS (expr);
- switch (SCM_MEMOIZED_TAG (expr))
- {
- case SCM_M_APPLY:
- return scm_cons (scm_sym_atapply, unmemoize_exprs (args));
- case SCM_M_BEGIN:
- return scm_cons (scm_sym_begin, unmemoize_exprs (args));
- case SCM_M_CALL:
- return unmemoize_exprs (args);
- case SCM_M_CONT:
- return scm_list_2 (scm_sym_atcall_cc, unmemoize (args));
- case SCM_M_CALL_WITH_VALUES:
- return scm_list_3 (scm_sym_at_call_with_values,
- unmemoize (CAR (args)), unmemoize (CDR (args)));
- case SCM_M_DEFINE:
- return scm_list_3 (scm_sym_define, CAR (args), unmemoize (CDR (args)));
- case SCM_M_IF:
- return scm_list_4 (scm_sym_if, unmemoize (scm_car (args)),
- unmemoize (scm_cadr (args)), unmemoize (scm_cddr (args)));
- case SCM_M_LAMBDA:
- return scm_list_3 (scm_sym_lambda,
- scm_make_list (CAR (args), sym_placeholder),
- unmemoize (CDDR (args)));
- case SCM_M_LET:
- return scm_list_3 (scm_sym_let,
- unmemoize_bindings (CAR (args)),
- unmemoize (CDR (args)));
- case SCM_M_QUOTE:
- return scm_list_2 (scm_sym_quote, args);
- case SCM_M_LEXICAL_REF:
- return unmemoize_lexical (args);
- case SCM_M_LEXICAL_SET:
- return scm_list_3 (scm_sym_set_x, unmemoize_lexical (CAR (args)),
- unmemoize (CDR (args)));
- case SCM_M_TOPLEVEL_REF:
- return args;
- case SCM_M_TOPLEVEL_SET:
- return scm_list_3 (scm_sym_set_x, CAR (args), unmemoize (CDR (args)));
- case SCM_M_MODULE_REF:
- return scm_list_3 (scm_is_true (CDDR (args)) ? scm_sym_at : scm_sym_atat,
- scm_i_finite_list_copy (CAR (args)),
- CADR (args));
- case SCM_M_MODULE_SET:
- return scm_list_3 (scm_sym_set_x,
- scm_list_3 (scm_is_true (CDDDR (args))
- ? scm_sym_at : scm_sym_atat,
- scm_i_finite_list_copy (CADR (args)),
- CADDR (args)),
- unmemoize (CAR (args)));
- default:
- abort ();
- }
-}
-
-SCM_DEFINE (scm_memoized_p, "memoized?", 1, 0, 0,
- (SCM obj),
- "Return @code{#t} if @var{obj} is memoized.")
-#define FUNC_NAME s_scm_memoized_p
-{
- return scm_from_bool (SCM_MEMOIZED_P (obj));
-}
-#undef FUNC_NAME
-
-SCM_DEFINE (scm_unmemoize_expression, "unmemoize-expression", 1, 0, 0,
- (SCM m),
- "Unmemoize the memoized expression @var{m}.")
-#define FUNC_NAME s_scm_unmemoize_expression
-{
- SCM_VALIDATE_MEMOIZED (1, m);
- return unmemoize (m);
-}
-#undef FUNC_NAME
-
-
-\f
-
-void
-scm_init_memoize ()
-{
- scm_tc16_memoized = scm_make_smob_type ("%memoized", 0);
- scm_set_smob_mark (scm_tc16_memoized, scm_markcdr);
- scm_set_smob_print (scm_tc16_memoized, scm_print_memoized);
-
-#include "libguile/memoize.x"
-}
-
-/*
- Local Variables:
- c-file-style: "gnu"
- End:
-*/
+/* Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003,
+ * 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013
+ * 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 3 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
+ */
+
+\f
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#include "libguile/__scm.h"
+#include "libguile/_scm.h"
+#include "libguile/continuations.h"
+#include "libguile/eq.h"
+#include "libguile/expand.h"
+#include "libguile/list.h"
+#include "libguile/macros.h"
+#include "libguile/memoize.h"
+#include "libguile/modules.h"
+#include "libguile/srcprop.h"
+#include "libguile/ports.h"
+#include "libguile/print.h"
+#include "libguile/strings.h"
+#include "libguile/throw.h"
+#include "libguile/validate.h"
+
+
+\f
+
+
+#define CAR(x) SCM_CAR(x)
+#define CDR(x) SCM_CDR(x)
+#define CAAR(x) SCM_CAAR(x)
+#define CADR(x) SCM_CADR(x)
+#define CDAR(x) SCM_CDAR(x)
+#define CDDR(x) SCM_CDDR(x)
+#define CADDR(x) SCM_CADDR(x)
+#define CDDDR(x) SCM_CDDDR(x)
+#define CADDDR(x) SCM_CADDDR(x)
+
+
+SCM_SYMBOL (sym_case_lambda_star, "case-lambda*");
+
+\f
+
+
+/* {Evaluator memoized expressions}
+ */
+
+scm_t_bits scm_tc16_memoized;
+
+#define MAKMEMO(n, args) \
+ (scm_cell (scm_tc16_memoized | ((n) << 16), SCM_UNPACK (args)))
+
+#define MAKMEMO_BEGIN(exps) \
+ MAKMEMO (SCM_M_BEGIN, exps)
+#define MAKMEMO_IF(test, then, else_) \
+ MAKMEMO (SCM_M_IF, scm_cons (test, scm_cons (then, else_)))
+#define FIXED_ARITY(nreq) \
+ scm_list_1 (SCM_I_MAKINUM (nreq))
+#define REST_ARITY(nreq, rest) \
+ scm_list_2 (SCM_I_MAKINUM (nreq), rest)
+#define FULL_ARITY(nreq, rest, nopt, kw, inits, alt) \
+ scm_list_n (SCM_I_MAKINUM (nreq), rest, SCM_I_MAKINUM (nopt), kw, inits, \
+ alt, SCM_UNDEFINED)
+#define MAKMEMO_LAMBDA(body, arity, docstring) \
+ MAKMEMO (SCM_M_LAMBDA, \
+ scm_cons (body, scm_cons (docstring, arity)))
+#define MAKMEMO_LET(inits, body) \
+ MAKMEMO (SCM_M_LET, scm_cons (inits, body))
+#define MAKMEMO_QUOTE(exp) \
+ MAKMEMO (SCM_M_QUOTE, exp)
+#define MAKMEMO_DEFINE(var, val) \
+ MAKMEMO (SCM_M_DEFINE, scm_cons (var, val))
+#define MAKMEMO_DYNWIND(in, expr, out) \
+ MAKMEMO (SCM_M_DYNWIND, scm_cons (in, scm_cons (expr, out)))
+#define MAKMEMO_WITH_FLUIDS(fluids, vals, expr) \
+ MAKMEMO (SCM_M_WITH_FLUIDS, scm_cons (fluids, scm_cons (vals, expr)))
+#define MAKMEMO_APPLY(proc, args)\
+ MAKMEMO (SCM_M_APPLY, scm_list_2 (proc, args))
+#define MAKMEMO_CONT(proc) \
+ MAKMEMO (SCM_M_CONT, proc)
+#define MAKMEMO_CALL_WITH_VALUES(prod, cons) \
+ MAKMEMO (SCM_M_CALL_WITH_VALUES, scm_cons (prod, cons))
+#define MAKMEMO_CALL(proc, nargs, args) \
+ MAKMEMO (SCM_M_CALL, scm_cons (proc, scm_cons (SCM_I_MAKINUM (nargs), args)))
+#define MAKMEMO_LEX_REF(n) \
+ MAKMEMO (SCM_M_LEXICAL_REF, SCM_I_MAKINUM (n))
+#define MAKMEMO_LEX_SET(n, val) \
+ MAKMEMO (SCM_M_LEXICAL_SET, scm_cons (SCM_I_MAKINUM (n), val))
+#define MAKMEMO_TOP_REF(var) \
+ MAKMEMO (SCM_M_TOPLEVEL_REF, var)
+#define MAKMEMO_TOP_SET(var, val) \
+ MAKMEMO (SCM_M_TOPLEVEL_SET, scm_cons (var, val))
+#define MAKMEMO_MOD_REF(mod, var, public) \
+ MAKMEMO (SCM_M_MODULE_REF, scm_cons (mod, scm_cons (var, public)))
+#define MAKMEMO_MOD_SET(val, mod, var, public) \
+ MAKMEMO (SCM_M_MODULE_SET, scm_cons (val, scm_cons (mod, scm_cons (var, public))))
+#define MAKMEMO_PROMPT(tag, exp, handler) \
+ MAKMEMO (SCM_M_PROMPT, scm_cons (tag, scm_cons (exp, handler)))
+
+
+/* Primitives for the evaluator */
+scm_t_bits scm_tc16_memoizer;
+#define SCM_MEMOIZER_P(x) (SCM_SMOB_PREDICATE (scm_tc16_memoizer, (x)))
+#define SCM_MEMOIZER(M) (SCM_SMOB_OBJECT_1 (M))
+
+\f
+
+/* This table must agree with the list of M_ constants in memoize.h */
+static const char *const memoized_tags[] =
+{
+ "begin",
+ "if",
+ "lambda",
+ "let",
+ "quote",
+ "define",
+ "dynwind",
+ "with-fluids",
+ "apply",
+ "call/cc",
+ "call-with-values",
+ "call",
+ "lexical-ref",
+ "lexical-set!",
+ "toplevel-ref",
+ "toplevel-set!",
+ "module-ref",
+ "module-set!",
+ "prompt",
+};
+
+static int
+scm_print_memoized (SCM memoized, SCM port, scm_print_state *pstate)
+{
+ scm_puts ("#<memoized ", port);
+ scm_write (scm_unmemoize_expression (memoized), port);
+ scm_puts (">", port);
+ return 1;
+}
+
+
+\f
+
+
+static int
+lookup (SCM x, SCM env)
+{
+ int i = 0;
+ for (; scm_is_pair (env); env = CDR (env), i++)
+ if (scm_is_eq (x, CAR (env)))
+ return i; /* bound */
+ abort ();
+}
+
+
+/* Abbreviate SCM_EXPANDED_REF. Copied because I'm not sure about symbol pasting */
+#define REF(x,type,field) \
+ (scm_struct_ref (x, SCM_I_MAKINUM (SCM_EXPANDED_##type##_##field)))
+
+static SCM list_of_guile = SCM_BOOL_F;
+
+static SCM memoize (SCM exp, SCM env);
+
+static SCM
+memoize_exps (SCM exps, SCM env)
+{
+ SCM ret;
+ for (ret = SCM_EOL; scm_is_pair (exps); exps = CDR (exps))
+ ret = scm_cons (memoize (CAR (exps), env), ret);
+ return scm_reverse_x (ret, SCM_UNDEFINED);
+}
+
+static SCM
+memoize (SCM exp, SCM env)
+{
+ if (!SCM_EXPANDED_P (exp))
+ abort ();
+
+ switch (SCM_EXPANDED_TYPE (exp))
+ {
+ case SCM_EXPANDED_VOID:
+ return MAKMEMO_QUOTE (SCM_UNSPECIFIED);
+
+ case SCM_EXPANDED_CONST:
+ return MAKMEMO_QUOTE (REF (exp, CONST, EXP));
+
+ case SCM_EXPANDED_PRIMITIVE_REF:
+ if (scm_is_eq (scm_current_module (), scm_the_root_module ()))
+ return MAKMEMO_TOP_REF (REF (exp, PRIMITIVE_REF, NAME));
+ else
+ return MAKMEMO_MOD_REF (list_of_guile, REF (exp, PRIMITIVE_REF, NAME),
+ SCM_BOOL_F);
+
+ case SCM_EXPANDED_LEXICAL_REF:
+ return MAKMEMO_LEX_REF (lookup (REF (exp, LEXICAL_REF, GENSYM), env));
+
+ case SCM_EXPANDED_LEXICAL_SET:
+ return MAKMEMO_LEX_SET (lookup (REF (exp, LEXICAL_SET, GENSYM), env),
+ memoize (REF (exp, LEXICAL_SET, EXP), env));
+
+ case SCM_EXPANDED_MODULE_REF:
+ return MAKMEMO_MOD_REF (REF (exp, MODULE_REF, MOD),
+ REF (exp, MODULE_REF, NAME),
+ REF (exp, MODULE_REF, PUBLIC));
+
+ case SCM_EXPANDED_MODULE_SET:
+ return MAKMEMO_MOD_SET (memoize (REF (exp, MODULE_SET, EXP), env),
+ REF (exp, MODULE_SET, MOD),
+ REF (exp, MODULE_SET, NAME),
+ REF (exp, MODULE_SET, PUBLIC));
+
+ case SCM_EXPANDED_TOPLEVEL_REF:
+ return MAKMEMO_TOP_REF (REF (exp, TOPLEVEL_REF, NAME));
+
+ case SCM_EXPANDED_TOPLEVEL_SET:
+ return MAKMEMO_TOP_SET (REF (exp, TOPLEVEL_SET, NAME),
+ memoize (REF (exp, TOPLEVEL_SET, EXP), env));
+
+ case SCM_EXPANDED_TOPLEVEL_DEFINE:
+ return MAKMEMO_DEFINE (REF (exp, TOPLEVEL_DEFINE, NAME),
+ memoize (REF (exp, TOPLEVEL_DEFINE, EXP), env));
+
+ case SCM_EXPANDED_CONDITIONAL:
+ return MAKMEMO_IF (memoize (REF (exp, CONDITIONAL, TEST), env),
+ memoize (REF (exp, CONDITIONAL, CONSEQUENT), env),
+ memoize (REF (exp, CONDITIONAL, ALTERNATE), env));
+
+ case SCM_EXPANDED_APPLICATION:
+ {
+ SCM proc, args;
+
+ proc = REF (exp, APPLICATION, PROC);
+ args = memoize_exps (REF (exp, APPLICATION, ARGS), env);
+
+ if (SCM_EXPANDED_TYPE (proc) == SCM_EXPANDED_TOPLEVEL_REF)
+ {
+ SCM var = scm_module_variable (scm_current_module (),
+ REF (proc, TOPLEVEL_REF, NAME));
+ if (SCM_VARIABLEP (var))
+ {
+ SCM val = SCM_VARIABLE_REF (var);
+ if (SCM_MEMOIZER_P (val))
+ return scm_apply (SCM_SMOB_OBJECT_1 (val), args, SCM_EOL);
+ }
+ }
+ /* otherwise we all fall down here */
+ return MAKMEMO_CALL (memoize (proc, env), scm_ilength (args), args);
+ }
+
+ case SCM_EXPANDED_SEQUENCE:
+ return MAKMEMO_BEGIN (memoize_exps (REF (exp, SEQUENCE, EXPS), env));
+
+ case SCM_EXPANDED_LAMBDA:
+ /* The body will be a lambda-case or #f. */
+ {
+ SCM meta, docstring, body, proc;
+
+ meta = REF (exp, LAMBDA, META);
+ docstring = scm_assoc_ref (meta, scm_sym_documentation);
+
+ body = REF (exp, LAMBDA, BODY);
+ if (scm_is_false (body))
+ /* Give a body to case-lambda with no clauses. */
+ proc = MAKMEMO_LAMBDA
+ (MAKMEMO_CALL
+ (MAKMEMO_MOD_REF (list_of_guile,
+ scm_from_latin1_symbol ("throw"),
+ SCM_BOOL_F),
+ 5,
+ scm_list_5 (MAKMEMO_QUOTE (scm_args_number_key),
+ MAKMEMO_QUOTE (SCM_BOOL_F),
+ MAKMEMO_QUOTE (scm_from_latin1_string
+ ("Wrong number of arguments")),
+ MAKMEMO_QUOTE (SCM_EOL),
+ MAKMEMO_QUOTE (SCM_BOOL_F))),
+ FIXED_ARITY (0),
+ SCM_BOOL_F /* docstring */);
+ else
+ proc = memoize (body, env);
+
+ if (scm_is_string (docstring))
+ {
+ SCM args = SCM_MEMOIZED_ARGS (proc);
+ SCM_SETCAR (SCM_CDR (args), docstring);
+ }
+
+ return proc;
+ }
+
+ case SCM_EXPANDED_LAMBDA_CASE:
+ {
+ SCM req, rest, opt, kw, inits, vars, body, alt;
+ SCM walk, minits, arity, new_env;
+ int nreq, nopt, ntotal;
+
+ req = REF (exp, LAMBDA_CASE, REQ);
+ rest = scm_not (scm_not (REF (exp, LAMBDA_CASE, REST)));
+ opt = REF (exp, LAMBDA_CASE, OPT);
+ kw = REF (exp, LAMBDA_CASE, KW);
+ inits = REF (exp, LAMBDA_CASE, INITS);
+ vars = REF (exp, LAMBDA_CASE, GENSYMS);
+ body = REF (exp, LAMBDA_CASE, BODY);
+ alt = REF (exp, LAMBDA_CASE, ALTERNATE);
+
+ nreq = scm_ilength (req);
+ nopt = scm_is_pair (opt) ? scm_ilength (opt) : 0;
+ ntotal = scm_ilength (vars);
+
+ /* The vars are the gensyms, according to the divine plan. But we need
+ to memoize the inits within their appropriate environment,
+ complicating things. */
+ new_env = env;
+ for (walk = req; scm_is_pair (walk);
+ walk = CDR (walk), vars = CDR (vars))
+ new_env = scm_cons (CAR (vars), new_env);
+
+ minits = SCM_EOL;
+ for (walk = opt; scm_is_pair (walk);
+ walk = CDR (walk), vars = CDR (vars), inits = CDR (inits))
+ {
+ minits = scm_cons (memoize (CAR (inits), new_env), minits);
+ new_env = scm_cons (CAR (vars), new_env);
+ }
+
+ if (scm_is_true (rest))
+ {
+ new_env = scm_cons (CAR (vars), new_env);
+ vars = CDR (vars);
+ }
+
+ for (; scm_is_pair (inits); vars = CDR (vars), inits = CDR (inits))
+ {
+ minits = scm_cons (memoize (CAR (inits), new_env), minits);
+ new_env = scm_cons (CAR (vars), new_env);
+ }
+ if (!scm_is_null (vars))
+ abort ();
+
+ minits = scm_reverse_x (minits, SCM_UNDEFINED);
+
+ if (scm_is_true (kw))
+ {
+ /* (aok? (kw name sym) ...) -> (aok? (kw . index) ...) */
+ SCM aok = CAR (kw), indices = SCM_EOL;
+ for (kw = CDR (kw); scm_is_pair (kw); kw = CDR (kw))
+ {
+ SCM k;
+ int idx;
+
+ k = CAR (CAR (kw));
+ idx = ntotal - 1 - lookup (CADDR (CAR (kw)), new_env);
+ indices = scm_acons (k, SCM_I_MAKINUM (idx), indices);
+ }
+ kw = scm_cons (aok, scm_reverse_x (indices, SCM_UNDEFINED));
+ }
+
+ if (scm_is_false (alt) && scm_is_false (kw) && scm_is_false (opt))
+ {
+ if (scm_is_false (rest))
+ arity = FIXED_ARITY (nreq);
+ else
+ arity = REST_ARITY (nreq, SCM_BOOL_T);
+ }
+ else if (scm_is_true (alt))
+ arity = FULL_ARITY (nreq, rest, nopt, kw, minits,
+ SCM_MEMOIZED_ARGS (memoize (alt, env)));
+ else
+ arity = FULL_ARITY (nreq, rest, nopt, kw, minits, SCM_BOOL_F);
+
+ return MAKMEMO_LAMBDA (memoize (body, new_env), arity,
+ SCM_BOOL_F /* docstring */);
+ }
+
+ case SCM_EXPANDED_LET:
+ {
+ SCM vars, exps, body, inits, new_env;
+
+ vars = REF (exp, LET, GENSYMS);
+ exps = REF (exp, LET, VALS);
+ body = REF (exp, LET, BODY);
+
+ inits = SCM_EOL;
+ new_env = env;
+ for (; scm_is_pair (vars); vars = CDR (vars), exps = CDR (exps))
+ {
+ new_env = scm_cons (CAR (vars), new_env);
+ inits = scm_cons (memoize (CAR (exps), env), inits);
+ }
+
+ return MAKMEMO_LET (scm_reverse_x (inits, SCM_UNDEFINED),
+ memoize (body, new_env));
+ }
+
+ case SCM_EXPANDED_LETREC:
+ {
+ SCM vars, exps, body, undefs, new_env;
+ int i, nvars, in_order_p;
+
+ vars = REF (exp, LETREC, GENSYMS);
+ exps = REF (exp, LETREC, VALS);
+ body = REF (exp, LETREC, BODY);
+ in_order_p = scm_is_true (REF (exp, LETREC, IN_ORDER_P));
+ nvars = i = scm_ilength (vars);
+ undefs = SCM_EOL;
+ new_env = env;
+
+ for (; scm_is_pair (vars); vars = CDR (vars))
+ {
+ new_env = scm_cons (CAR (vars), new_env);
+ undefs = scm_cons (MAKMEMO_QUOTE (SCM_UNDEFINED), undefs);
+ }
+
+ if (in_order_p)
+ {
+ SCM body_exps = SCM_EOL;
+ for (; scm_is_pair (exps); exps = CDR (exps), i--)
+ body_exps = scm_cons (MAKMEMO_LEX_SET (i-1,
+ memoize (CAR (exps), new_env)),
+ body_exps);
+ body_exps = scm_cons (memoize (body, new_env), body_exps);
+ body_exps = scm_reverse_x (body_exps, SCM_UNDEFINED);
+ return MAKMEMO_LET (undefs, MAKMEMO_BEGIN (body_exps));
+ }
+ else
+ {
+ SCM sets = SCM_EOL, inits = SCM_EOL;
+ for (; scm_is_pair (exps); exps = CDR (exps), i--)
+ {
+ sets = scm_cons (MAKMEMO_LEX_SET ((i-1) + nvars,
+ MAKMEMO_LEX_REF (i-1)),
+ sets);
+ inits = scm_cons (memoize (CAR (exps), new_env), inits);
+ }
+ inits = scm_reverse_x (inits, SCM_UNDEFINED);
+ return MAKMEMO_LET
+ (undefs,
+ MAKMEMO_BEGIN (scm_list_2 (MAKMEMO_LET (inits, MAKMEMO_BEGIN (sets)),
+ memoize (body, new_env))));
+ }
+ }
+
+ case SCM_EXPANDED_DYNLET:
+ return MAKMEMO_WITH_FLUIDS (memoize_exps (REF (exp, DYNLET, FLUIDS), env),
+ memoize_exps (REF (exp, DYNLET, VALS), env),
+ memoize (REF (exp, DYNLET, BODY), env));
+
+ default:
+ abort ();
+ }
+}
+
+
+\f
+
+SCM_DEFINE (scm_memoize_expression, "memoize-expression", 1, 0, 0,
+ (SCM exp),
+ "Memoize the expression @var{exp}.")
+#define FUNC_NAME s_scm_memoize_expression
+{
+ SCM_ASSERT_TYPE (SCM_EXPANDED_P (exp), exp, 1, FUNC_NAME, "expanded");
+ return memoize (exp, scm_current_module ());
+}
+#undef FUNC_NAME
+
+
+\f
+
+#define SCM_MAKE_MEMOIZER(STR, MEMOIZER, N) \
+ (scm_cell (scm_tc16_memoizer, \
+ SCM_UNPACK (scm_c_make_gsubr (STR, N, 0, 0, MEMOIZER))))
+#define SCM_DEFINE_MEMOIZER(STR, MEMOIZER, N) \
+SCM_SNARF_INIT(scm_c_define (STR, SCM_MAKE_MEMOIZER (STR, MEMOIZER, N)))
+
+#define SCM_MAKE_REST_MEMOIZER(STR, MEMOIZER, N) \
+ (scm_cell (scm_tc16_memoizer, \
+ SCM_UNPACK ((scm_c_make_gsubr (STR, N, 0, 1, MEMOIZER)))))
+#define SCM_DEFINE_REST_MEMOIZER(STR, MEMOIZER, N) \
+SCM_SNARF_INIT(scm_c_define (STR, SCM_MAKE_REST_MEMOIZER (STR, MEMOIZER, N)))
+
+static SCM m_apply (SCM proc, SCM arg, SCM rest);
+static SCM m_call_cc (SCM proc);
+static SCM m_call_values (SCM prod, SCM cons);
+static SCM m_dynamic_wind (SCM pre, SCM exp, SCM post);
+static SCM m_prompt (SCM tag, SCM exp, SCM handler);
+
+SCM_DEFINE_REST_MEMOIZER ("@apply", m_apply, 2);
+SCM_DEFINE_MEMOIZER ("@call-with-current-continuation", m_call_cc, 1);
+SCM_DEFINE_MEMOIZER ("@call-with-values", m_call_values, 2);
+SCM_DEFINE_MEMOIZER ("@dynamic-wind", m_dynamic_wind, 3);
+SCM_DEFINE_MEMOIZER ("@prompt", m_prompt, 3);
+
+
+\f
+
+static SCM m_apply (SCM proc, SCM arg, SCM rest)
+#define FUNC_NAME "@apply"
+{
+ long len;
+
+ SCM_VALIDATE_MEMOIZED (1, proc);
+ SCM_VALIDATE_MEMOIZED (2, arg);
+ len = scm_ilength (rest);
+ if (len < 0)
+ abort ();
+ else if (len == 0)
+ return MAKMEMO_APPLY (proc, arg);
+ else
+ {
+ SCM tail;
+
+ rest = scm_reverse (rest);
+ tail = scm_car (rest);
+ rest = scm_cdr (rest);
+ len--;
+
+ while (scm_is_pair (rest))
+ {
+ tail = MAKMEMO_CALL (MAKMEMO_MOD_REF (scm_list_1 (scm_from_latin1_symbol ("guile")),
+ scm_from_latin1_symbol ("cons"),
+ SCM_BOOL_F),
+ 2,
+ scm_list_2 (scm_car (rest), tail));
+ rest = scm_cdr (rest);
+ }
+ return MAKMEMO_APPLY (proc, tail);
+ }
+}
+#undef FUNC_NAME
+
+static SCM m_call_cc (SCM proc)
+#define FUNC_NAME "@call-with-current-continuation"
+{
+ SCM_VALIDATE_MEMOIZED (1, proc);
+ return MAKMEMO_CONT (proc);
+}
+#undef FUNC_NAME
+
+static SCM m_call_values (SCM prod, SCM cons)
+#define FUNC_NAME "@call-with-values"
+{
+ SCM_VALIDATE_MEMOIZED (1, prod);
+ SCM_VALIDATE_MEMOIZED (2, cons);
+ return MAKMEMO_CALL_WITH_VALUES (prod, cons);
+}
+#undef FUNC_NAME
+
+static SCM m_dynamic_wind (SCM in, SCM expr, SCM out)
+#define FUNC_NAME "memoize-dynwind"
+{
+ SCM_VALIDATE_MEMOIZED (1, in);
+ SCM_VALIDATE_MEMOIZED (2, expr);
+ SCM_VALIDATE_MEMOIZED (3, out);
+ return MAKMEMO_DYNWIND (in, expr, out);
+}
+#undef FUNC_NAME
+
+static SCM m_prompt (SCM tag, SCM exp, SCM handler)
+#define FUNC_NAME "@prompt"
+{
+ SCM_VALIDATE_MEMOIZED (1, tag);
+ SCM_VALIDATE_MEMOIZED (2, exp);
+ SCM_VALIDATE_MEMOIZED (3, handler);
+ return MAKMEMO_PROMPT (tag, exp, handler);
+}
+#undef FUNC_NAME
+
+
+\f
+
+SCM_SYMBOL (sym_placeholder, "_");
+
+static SCM unmemoize (SCM expr);
+
+static SCM
+unmemoize_exprs (SCM exprs)
+{
+ SCM ret, tail;
+ if (scm_is_null (exprs))
+ return SCM_EOL;
+ ret = scm_list_1 (unmemoize (CAR (exprs)));
+ tail = ret;
+ for (exprs = CDR (exprs); !scm_is_null (exprs); exprs = CDR (exprs))
+ {
+ SCM_SETCDR (tail, scm_list_1 (unmemoize (CAR (exprs))));
+ tail = CDR (tail);
+ }
+ return ret;
+}
+
+static SCM
+unmemoize_bindings (SCM inits)
+{
+ SCM ret, tail;
+ if (scm_is_null (inits))
+ return SCM_EOL;
+ ret = scm_list_1 (scm_list_2 (sym_placeholder, unmemoize (CAR (inits))));
+ tail = ret;
+ for (inits = CDR (inits); !scm_is_null (inits); inits = CDR (inits))
+ {
+ SCM_SETCDR (tail, scm_list_1 (scm_list_2 (sym_placeholder,
+ unmemoize (CAR (inits)))));
+ tail = CDR (tail);
+ }
+ return ret;
+}
+
+static SCM
+unmemoize_lexical (SCM n)
+{
+ char buf[16];
+ buf[15] = 0;
+ snprintf (buf, 15, "<%u>", scm_to_uint32 (n));
+ return scm_from_locale_symbol (buf);
+}
+
+static SCM
+unmemoize (const SCM expr)
+{
+ SCM args;
+
+ if (!SCM_MEMOIZED_P (expr))
+ abort ();
+
+ args = SCM_MEMOIZED_ARGS (expr);
+ switch (SCM_MEMOIZED_TAG (expr))
+ {
+ case SCM_M_APPLY:
+ return scm_cons (scm_sym_atapply, unmemoize_exprs (args));
+ case SCM_M_BEGIN:
+ return scm_cons (scm_sym_begin, unmemoize_exprs (args));
+ case SCM_M_CALL:
+ return scm_cons (unmemoize (CAR (args)), unmemoize_exprs (CDDR (args)));
+ case SCM_M_CONT:
+ return scm_list_2 (scm_sym_atcall_cc, unmemoize (args));
+ case SCM_M_CALL_WITH_VALUES:
+ return scm_list_3 (scm_sym_at_call_with_values,
+ unmemoize (CAR (args)), unmemoize (CDR (args)));
+ case SCM_M_DEFINE:
+ return scm_list_3 (scm_sym_define, CAR (args), unmemoize (CDR (args)));
+ case SCM_M_DYNWIND:
+ return scm_list_4 (scm_sym_at_dynamic_wind,
+ unmemoize (CAR (args)),
+ unmemoize (CADR (args)),
+ unmemoize (CDDR (args)));
+ case SCM_M_WITH_FLUIDS:
+ {
+ SCM binds = SCM_EOL, fluids, vals;
+ for (fluids = CAR (args), vals = CADR (args); scm_is_pair (fluids);
+ fluids = CDR (fluids), vals = CDR (vals))
+ binds = scm_cons (scm_list_2 (unmemoize (CAR (fluids)),
+ unmemoize (CAR (vals))),
+ binds);
+ return scm_list_3 (scm_sym_with_fluids,
+ scm_reverse_x (binds, SCM_UNDEFINED),
+ unmemoize (CDDR (args)));
+ }
+ case SCM_M_IF:
+ return scm_list_4 (scm_sym_if, unmemoize (scm_car (args)),
+ unmemoize (scm_cadr (args)), unmemoize (scm_cddr (args)));
+ case SCM_M_LAMBDA:
+ {
+ SCM body = CAR (args), spec = CDDR (args);
+
+ if (scm_is_null (CDR (spec)))
+ return scm_list_3 (scm_sym_lambda,
+ scm_make_list (CAR (spec), sym_placeholder),
+ unmemoize (CAR (args)));
+ else if (scm_is_null (SCM_CDDR (spec)))
+ {
+ SCM formals = scm_make_list (CAR (spec), sym_placeholder);
+ return scm_list_3 (scm_sym_lambda,
+ scm_is_true (CADR (spec))
+ ? scm_cons_star (sym_placeholder, formals)
+ : formals,
+ unmemoize (CAR (args)));
+ }
+ else
+ {
+ SCM alt, tail;
+
+ alt = CADDR (CDDDR (spec));
+ if (scm_is_true (alt))
+ tail = CDR (unmemoize (alt));
+ else
+ tail = SCM_EOL;
+
+ return scm_cons
+ (sym_case_lambda_star,
+ scm_cons (scm_list_2 (scm_list_5 (CAR (spec),
+ CADR (spec),
+ CADDR (spec),
+ CADDDR (spec),
+ unmemoize_exprs (CADR (CDDDR (spec)))),
+ unmemoize (body)),
+ tail));
+ }
+ }
+ case SCM_M_LET:
+ return scm_list_3 (scm_sym_let,
+ unmemoize_bindings (CAR (args)),
+ unmemoize (CDR (args)));
+ case SCM_M_QUOTE:
+ return scm_list_2 (scm_sym_quote, args);
+ case SCM_M_LEXICAL_REF:
+ return unmemoize_lexical (args);
+ case SCM_M_LEXICAL_SET:
+ return scm_list_3 (scm_sym_set_x, unmemoize_lexical (CAR (args)),
+ unmemoize (CDR (args)));
+ case SCM_M_TOPLEVEL_REF:
+ return args;
+ case SCM_M_TOPLEVEL_SET:
+ return scm_list_3 (scm_sym_set_x, CAR (args), unmemoize (CDR (args)));
+ case SCM_M_MODULE_REF:
+ return SCM_VARIABLEP (args) ? args
+ : scm_list_3 (scm_is_true (CDDR (args)) ? scm_sym_at : scm_sym_atat,
+ scm_i_finite_list_copy (CAR (args)),
+ CADR (args));
+ case SCM_M_MODULE_SET:
+ return scm_list_3 (scm_sym_set_x,
+ SCM_VARIABLEP (CDR (args)) ? CDR (args)
+ : scm_list_3 (scm_is_true (CDDDR (args))
+ ? scm_sym_at : scm_sym_atat,
+ scm_i_finite_list_copy (CADR (args)),
+ CADDR (args)),
+ unmemoize (CAR (args)));
+ case SCM_M_PROMPT:
+ return scm_list_4 (scm_sym_at_prompt,
+ unmemoize (CAR (args)),
+ unmemoize (CADR (args)),
+ unmemoize (CDDR (args)));
+ default:
+ abort ();
+ }
+}
+
+
+\f
+
+SCM_DEFINE (scm_memoized_p, "memoized?", 1, 0, 0,
+ (SCM obj),
+ "Return @code{#t} if @var{obj} is memoized.")
+#define FUNC_NAME s_scm_memoized_p
+{
+ return scm_from_bool (SCM_MEMOIZED_P (obj));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_unmemoize_expression, "unmemoize-expression", 1, 0, 0,
+ (SCM m),
+ "Unmemoize the memoized expression @var{m}.")
+#define FUNC_NAME s_scm_unmemoize_expression
+{
+ SCM_VALIDATE_MEMOIZED (1, m);
+ return unmemoize (m);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_memoized_expression_typecode, "memoized-expression-typecode", 1, 0, 0,
+ (SCM m),
+ "Return the typecode from the memoized expression @var{m}.")
+#define FUNC_NAME s_scm_memoized_expression_typecode
+{
+ SCM_VALIDATE_MEMOIZED (1, m);
+
+ /* The tag is a 16-bit integer so it fits in an inum. */
+ return SCM_I_MAKINUM (SCM_MEMOIZED_TAG (m));
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_memoized_expression_data, "memoized-expression-data", 1, 0, 0,
+ (SCM m),
+ "Return the data from the memoized expression @var{m}.")
+#define FUNC_NAME s_scm_memoized_expression_data
+{
+ SCM_VALIDATE_MEMOIZED (1, m);
+ return SCM_MEMOIZED_ARGS (m);
+}
+#undef FUNC_NAME
+
+SCM_DEFINE (scm_memoized_typecode, "memoized-typecode", 1, 0, 0,
+ (SCM sym),
+ "Return the memoized typecode corresponding to the symbol @var{sym}.")
+#define FUNC_NAME s_scm_memoized_typecode
+{
+ int i;
+
+ SCM_VALIDATE_SYMBOL (1, sym);
+
+ for (i = 0; i < sizeof(memoized_tags)/sizeof(const char*); i++)
+ if (strcmp (scm_i_symbol_chars (sym), memoized_tags[i]) == 0)
+ return scm_from_int32 (i);
+
+ return SCM_BOOL_F;
+}
+#undef FUNC_NAME
+
+SCM_SYMBOL (scm_unbound_variable_key, "unbound-variable");
+static void error_unbound_variable (SCM symbol) SCM_NORETURN;
+static void error_unbound_variable (SCM symbol)
+{
+ scm_error (scm_unbound_variable_key, NULL, "Unbound variable: ~S",
+ scm_list_1 (symbol), SCM_BOOL_F);
+}
+
+SCM_DEFINE (scm_memoize_variable_access_x, "memoize-variable-access!", 2, 0, 0,
+ (SCM m, SCM mod),
+ "Look up and cache the variable that @var{m} will access, returning the variable.")
+#define FUNC_NAME s_scm_memoize_variable_access_x
+{
+ SCM mx;
+ SCM_VALIDATE_MEMOIZED (1, m);
+ mx = SCM_MEMOIZED_ARGS (m);
+ switch (SCM_MEMOIZED_TAG (m))
+ {
+ case SCM_M_TOPLEVEL_REF:
+ if (SCM_VARIABLEP (mx))
+ return mx;
+ else
+ {
+ SCM var = scm_module_variable (mod, mx);
+ if (scm_is_false (var) || scm_is_false (scm_variable_bound_p (var)))
+ error_unbound_variable (mx);
+ SCM_SET_SMOB_OBJECT (m, var);
+ return var;
+ }
+
+ case SCM_M_TOPLEVEL_SET:
+ {
+ SCM var = CAR (mx);
+ if (SCM_VARIABLEP (var))
+ return var;
+ else
+ {
+ var = scm_module_variable (mod, var);
+ if (scm_is_false (var))
+ error_unbound_variable (CAR (mx));
+ SCM_SETCAR (mx, var);
+ return var;
+ }
+ }
+
+ case SCM_M_MODULE_REF:
+ if (SCM_VARIABLEP (mx))
+ return mx;
+ else
+ {
+ SCM var;
+ mod = scm_resolve_module (CAR (mx));
+ if (scm_is_true (CDDR (mx)))
+ mod = scm_module_public_interface (mod);
+ var = scm_module_lookup (mod, CADR (mx));
+ if (scm_is_false (scm_variable_bound_p (var)))
+ error_unbound_variable (CADR (mx));
+ SCM_SET_SMOB_OBJECT (m, var);
+ return var;
+ }
+
+ case SCM_M_MODULE_SET:
+ /* FIXME: not quite threadsafe */
+ if (SCM_VARIABLEP (CDR (mx)))
+ return CDR (mx);
+ else
+ {
+ SCM var;
+ mod = scm_resolve_module (CADR (mx));
+ if (scm_is_true (CDDDR (mx)))
+ mod = scm_module_public_interface (mod);
+ var = scm_module_lookup (mod, CADDR (mx));
+ SCM_SETCDR (mx, var);
+ return var;
+ }
+
+ default:
+ scm_wrong_type_arg (FUNC_NAME, 1, m);
+ return SCM_BOOL_F;
+ }
+}
+#undef FUNC_NAME
+
+
+\f
+
+void
+scm_init_memoize ()
+{
+ scm_tc16_memoized = scm_make_smob_type ("%memoized", 0);
+ scm_set_smob_print (scm_tc16_memoized, scm_print_memoized);
+
+ scm_tc16_memoizer = scm_make_smob_type ("memoizer", 0);
+
+#include "libguile/memoize.x"
+
+ list_of_guile = scm_list_1 (scm_from_latin1_symbol ("guile"));
+}
+
+/*
+ Local Variables:
+ c-file-style: "gnu"
+ End:
+*/