922 lines
19 KiB
C
922 lines
19 KiB
C
/*
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* Mes --- Maxwell Equations of Software
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* Copyright © 2016 Jan Nieuwenhuizen <janneke@gnu.org>
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*
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* This file is part of Mes.
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*
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* Mes is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or (at
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* your option) any later version.
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*
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* Mes 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
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with Mes. If not, see <http://www.gnu.org/licenses/>.
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*/
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// (setq comment-start "//")
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// (setq comment-end "")
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/*
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* The Maxwell Equations of Software -- John McCarthy page 13
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* http://www.softwarepreservation.org/projects/LISP/book/LISP%201.5%20Programmers%20Manual.pdf
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*/
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#define _GNU_SOURCE
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#include <assert.h>
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#include <ctype.h>
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#include <stdio.h>
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#include <string.h>
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#include <stdlib.h>
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#include <stdbool.h>
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#define DEBUG 0
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#define MACROS 1
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#define QUASIQUOTE 1
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#ifndef QUOTE_SUGAR
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#define QUOTE_SUGAR 1
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#endif
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enum type {ATOM, NUMBER, PAIR, FUNCTION0, FUNCTION1, FUNCTION2, FUNCTION3};
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struct scm_t;
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typedef struct scm_t* (*function0_t) (void);
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typedef struct scm_t* (*function1_t) (struct scm_t*);
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typedef struct scm_t* (*function2_t) (struct scm_t*, struct scm_t*);
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typedef struct scm_t* (*function3_t) (struct scm_t*, struct scm_t*, struct scm_t*);
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typedef struct scm_t {
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enum type type;
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union {
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char *name;
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struct scm_t* car;
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};
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union {
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int value;
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function0_t function0;
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function1_t function1;
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function2_t function2;
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function3_t function3;
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struct scm_t* cdr;
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};
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} scm;
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#define MES 1
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#include "mes.h"
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scm *display_helper (scm*, bool, char*, bool);
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bool
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symbol_eq (scm *x, char *s)
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{
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return x->type == ATOM && !strcmp (x->name, s);
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}
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scm scm_nil = {ATOM, "()"};
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scm scm_dot = {ATOM, "."};
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scm scm_t = {ATOM, "#t"};
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scm scm_f = {ATOM, "#f"};
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scm scm_lambda = {ATOM, "lambda"};
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scm scm_label = {ATOM, "label"};
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scm scm_unspecified = {ATOM, "*unspecified*"};
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scm scm_symbol_cond = {ATOM, "cond"};
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scm scm_symbol_quote = {ATOM, "quote"};
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#if QUASIQUOTE
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scm scm_symbol_quasiquote = {ATOM, "quasiquote"};
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scm scm_symbol_unquote = {ATOM, "unquote"};
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#endif
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#if MACROS
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scm scm_macro = {ATOM, "*macro*"};
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#endif
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scm scm_symbol_EOF = {ATOM, "EOF"};
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scm scm_symbol_EOF2 = {ATOM, "EOF2"};
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scm scm_symbol_current_module = {ATOM, "current-module"};
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scm scm_symbol_define = {ATOM, "define"};
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scm scm_symbol_define_macro = {ATOM, "define-macro"};
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scm scm_symbol_eval = {ATOM, "eval"};
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scm scm_symbol_loop2 = {ATOM, "loop2"};
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scm scm_symbol_set_x = {ATOM, "set!"};
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// PRIMITIVES
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scm *
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atom_p (scm *x)
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{
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return x->type == PAIR ? &scm_f : &scm_t;
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}
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scm *
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car (scm *x)
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{
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assert (x->type == PAIR);
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return x->car;
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}
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scm *
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cdr (scm *x)
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{
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assert (x->type == PAIR);
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return x->cdr;
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}
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scm *
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cons (scm *x, scm *y)
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{
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scm *p = malloc (sizeof (scm));
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p->type = PAIR;
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p->car = x;
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p->cdr = y;
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return p;
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}
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scm *
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eq_p (scm *x, scm *y)
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{
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return (x == y
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|| (x->type == NUMBER && y->type == NUMBER
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&& x->value == y->value)
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// FIXME: alist lookup symbols
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|| (atom_p (x) == &scm_t
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&& x->type != NUMBER
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&& y->type != NUMBER
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&& atom_p (y) == &scm_t
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&& !strcmp (x->name, y->name)))
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? &scm_t : &scm_f;
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}
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scm *
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null_p (scm *x)
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{
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return eq_p (x, &scm_nil);
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}
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scm *
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pair_p (scm *x)
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{
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return x->type == PAIR ? &scm_t : &scm_f;
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}
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scm *
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set_cdr_x (scm *x, scm *e)
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{
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assert (x->type == PAIR);
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x->cdr = e;
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}
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scm *
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set_env_x (scm *x, scm *e, scm *a)
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{
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return set_cdr_x (assoc (x, a), e);
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}
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scm *
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quote (scm *x)
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{
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return cons (&scm_symbol_quote, x);
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}
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#if QUASIQUOTE
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scm *
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unquote (scm *x)
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{
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return cons (&scm_symbol_unquote, x);
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}
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scm *
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quasiquote (scm *x)
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{
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return cons (&scm_symbol_quasiquote, x);
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}
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scm *eval_quasiquote (scm *, scm *);
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#endif
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//Library functions
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// Derived, non-primitives
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scm *caar (scm *x) {return car (car (x));}
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scm *cadr (scm *x) {return car (cdr (x));}
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scm *cdar (scm *x) {return cdr (car (x));}
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scm *cddr (scm *x) {return cdr (cdr (x));}
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scm *caadr (scm *x) {return car (car (cdr (x)));}
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scm *caddr (scm *x) {return car (cdr (cdr (x)));}
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scm *cdadr (scm *x) {return cdr (car (cdr (x)));}
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scm *cadar (scm *x) {return car (cdr (car (x)));}
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scm *cddar (scm *x) {return cdr (cdr (car (x)));}
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scm *cdddr (scm *x) {return cdr (cdr (cdr (x)));}
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scm* make_atom (char const *);
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scm *
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pairlis (scm *x, scm *y, scm *a)
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{
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#if DEBUG
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printf ("pairlis x=");
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display (x);
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printf (" y=");
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display (y);
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puts ("");
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#endif
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if (x == &scm_nil)
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return a;
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if (atom_p (x) == &scm_t)
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return cons (cons (x, y), a);
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return cons (cons (car (x), car (y)),
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pairlis (cdr (x), cdr (y), a));
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}
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scm *
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assoc (scm *x, scm *a)
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{
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if (a == &scm_nil) {
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#if DEBUG
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printf ("alist miss: %s\n", x->name);
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#endif
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return &scm_f;
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}
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if (eq_p (caar (a), x) == &scm_t)
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return car (a);
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return assoc (x, cdr (a));
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}
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scm *apply (scm*, scm*, scm*);
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scm *eval_ (scm*, scm*);
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scm *apply_ (scm*, scm*, scm*);
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scm *
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eval_quote (scm *fn, scm *x)
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{
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return apply (fn, x, &scm_nil);
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}
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scm *builtin_p (scm*);
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scm *call (scm *, scm*);
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scm *display (scm*);
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scm *newline ();
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scm *
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apply_ (scm *fn, scm *x, scm *a)
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{
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#if DEBUG
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printf ("apply fn=");
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display (fn);
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printf (" x=");
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display (x);
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puts ("");
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#endif
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if (atom_p (fn) != &scm_f)
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{
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if (fn == &scm_symbol_current_module) // FIXME
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return a;
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if (builtin_p (fn) == &scm_t)
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return call (fn, x);
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return apply (eval (fn, a), x, a);
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}
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else if (car (fn) == &scm_lambda) {
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scm *body = cddr (fn);
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scm *ca = cadr (fn);
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scm *ax = pairlis (cadr (fn), x, a);
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scm *result = eval (car (body), ax);
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if (cdr (body) == &scm_nil)
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return result;
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return apply (cons (car (fn), cons (cadr (fn), cdddr (fn))), x, ax);
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}
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else if (car (fn) == &scm_label)
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return apply (caddr (fn), x, cons (cons (cadr (fn), caddr (fn)), a));
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return &scm_unspecified;
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}
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scm *evcon (scm*, scm*);
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scm *evlis (scm*, scm*);
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scm *
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eval_ (scm *e, scm *a)
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{
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#if DEBUG
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printf ("eval e=");
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display (e);
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puts ("");
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#endif
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if (e->type == NUMBER)
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return e;
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else if (atom_p (e) == &scm_t) {
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scm *y = assoc (e, a);
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if (y == &scm_f) {
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printf ("eval: no such symbol: %s\n", e->name);
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exit (1);
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}
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return cdr (y);
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}
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if (builtin_p (e) == &scm_t)
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return e;
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else if (atom_p (car (e)) == &scm_t)
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{
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#if MACROS
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scm *macro;
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#endif // MACROS
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if (car (e) == &scm_symbol_quote)
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return cadr (e);
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if (car (e) == &scm_lambda)
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return e;
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if (car (e) == &scm_symbol_set_x)
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return set_env_x (cadr (e), eval (caddr (e), a), a);
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#if QUASIQUOTE
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else if (car (e) == &scm_symbol_unquote)
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return eval (cadr (e), a);
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else if (car (e) == &scm_symbol_quasiquote) {
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#if DEBUG
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printf ("cadr e:");
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display (cadr (e));
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puts ("");
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printf ("qq:");
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display (eval_quasiquote (cadr (e), a));
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puts ("");
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#endif // DEBUG
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return eval_quasiquote (cadr (e), a);
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}
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#endif // QUASIQUOTE
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else if (car (e) == &scm_symbol_cond)
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return evcon (cdr (e), a);
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#if MACROS
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else if ((macro = assoc (car (e), cdr (assoc (&scm_macro, a)))) != &scm_f)
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return eval (apply_ (cdr (macro), cdr (e), a), a);
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#endif // MACROS
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return apply (car (e), evlis (cdr (e), a), a);
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}
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return apply (car (e), evlis (cdr (e), a), a);
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}
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scm *
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evcon_ (scm *c, scm *a)
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{
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#if DEBUG
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printf ("evcon_ clause=");
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display (car (c));
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puts ("");
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#endif
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if (eval (caar (c), a) != &scm_f) {
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#if DEBUG
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//if (fn != &scm_display && fn != &scm_call)
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//if (fn != &scm_call)
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printf ("#t clause=");
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display (car (c));
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printf (" cddar=");
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display (cddar (c));
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printf (" nil=%d", cddar (c) == &scm_nil);
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puts ("");
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#endif
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if (cddar (c) == &scm_nil)
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return eval (cadar (c), a);
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eval (cadar (c), a);
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return evcon_ (cons (cons (&scm_t, cddar (c)), &scm_nil), a);
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}
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return evcon_ (cdr (c), a);
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}
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scm *
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evcon (scm *c, scm *a)
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{
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#if DEBUG
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printf ("\n****evcon=");
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display (c);
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puts ("");
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#endif
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return evcon_ (c, a);
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}
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scm *
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evlis (scm *m, scm *a)
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{
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#if DEBUG
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printf ("evlis m=");
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display (m);
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puts ("");
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#endif
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if (m == &scm_nil)
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return &scm_nil;
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scm *e = eval (car (m), a);
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return cons (e, evlis (cdr (m), a));
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}
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//Helpers
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scm *
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builtin_p (scm *x)
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{
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return (x->type == FUNCTION0
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|| x->type == FUNCTION1
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|| x->type == FUNCTION2
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|| x->type == FUNCTION3)
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? &scm_t : &scm_f;
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}
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scm *
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number_p (scm *x)
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{
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return x->type == NUMBER ? &scm_t : &scm_f;
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}
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scm *
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display (scm *x)
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{
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return display_helper (x, false, "", false);
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}
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scm *
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call (scm *fn, scm *x)
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|
{
|
|
#if DEBUG
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//if (fn != &scm_display && fn != &scm_call)
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//if (fn != &scm_call)
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{
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printf ("\ncall fn=");
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display (fn);
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printf (" x=");
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display (x);
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puts ("");
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}
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#endif
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if (fn->type == FUNCTION0)
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return fn->function0 ();
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if (fn->type == FUNCTION1)
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return fn->function1 (car (x));
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if (fn->type == FUNCTION2)
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return fn->function2 (car (x), cadr (x));
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if (fn->type == FUNCTION3)
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return fn->function3 (car (x), cadr (x), caddr (x));
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return &scm_unspecified;
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}
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scm *
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append (scm *x, scm *y)
|
|
{
|
|
if (x == &scm_nil) return y;
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assert (x->type == PAIR);
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return cons (car (x), append (cdr (x), y));
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}
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|
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scm *
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make_atom (char const *s)
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|
{
|
|
// TODO: alist lookup symbols
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|
scm *p = malloc (sizeof (scm));
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|
p->type = ATOM;
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p->name = strdup (s);
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return p;
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}
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|
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scm *
|
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make_number (int x)
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|
{
|
|
scm *p = malloc (sizeof (scm));
|
|
p->type = NUMBER;
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|
p->value = x;
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|
return p;
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|
}
|
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|
|
scm *
|
|
lookup (char *x, scm *a)
|
|
{
|
|
if (isdigit (*x) || (*x == '-' && isdigit (*(x+1))))
|
|
return make_number (atoi (x));
|
|
if (*x == '\'') return &scm_symbol_quote;
|
|
|
|
if (!strcmp (x, scm_symbol_cond.name)) return &scm_symbol_cond;
|
|
if (!strcmp (x, scm_symbol_quote.name)) return &scm_symbol_quote;
|
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if (!strcmp (x, scm_lambda.name)) return &scm_lambda;
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|
if (!strcmp (x, scm_label.name)) return &scm_label;
|
|
if (!strcmp (x, scm_nil.name)) return &scm_nil;
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|
|
#if QUASIQUOTE
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|
if (*x == '`') return &scm_symbol_quasiquote;
|
|
if (*x == ',') return &scm_symbol_unquote;
|
|
if (!strcmp (x, scm_symbol_unquote.name)) return &scm_symbol_unquote;
|
|
if (!strcmp (x, scm_symbol_quasiquote.name)) return &scm_symbol_quasiquote;
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|
#endif
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|
|
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return make_atom (x);
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|
}
|
|
|
|
scm *
|
|
lookup_char (int c, scm *a)
|
|
{
|
|
char buf[2];
|
|
buf[0] = c;
|
|
buf[1] = 0;
|
|
return lookup (buf, a);
|
|
}
|
|
|
|
char *
|
|
list2str (scm *l)
|
|
{
|
|
static char buf[256];
|
|
char *p = buf;
|
|
while (l != &scm_nil) {
|
|
scm *c = car (l);
|
|
assert (c->type == NUMBER);
|
|
*p++ = c->value;
|
|
l = cdr (l);
|
|
}
|
|
*p = 0;
|
|
return buf;
|
|
}
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|
|
|
scm *
|
|
builtin_lookup (scm *l, scm *a)
|
|
{
|
|
return lookup (list2str (l), a);
|
|
}
|
|
|
|
scm *
|
|
cossa (scm *x, scm *a)
|
|
{
|
|
if (a == &scm_nil) return &scm_f;
|
|
if (eq_p (cdar (a), x) == &scm_t)
|
|
return car (a);
|
|
return cossa (x, cdr (a));
|
|
}
|
|
|
|
scm *
|
|
newline ()
|
|
{
|
|
puts ("");
|
|
return &scm_unspecified;
|
|
}
|
|
|
|
scm *
|
|
display_helper (scm *x, bool cont, char *sep, bool quote)
|
|
{
|
|
scm *r;
|
|
printf ("%s", sep);
|
|
if (x->type == NUMBER) printf ("%d", x->value);
|
|
else if (x->type == PAIR) {
|
|
#if QUOTE_SUGAR
|
|
if (car (x) == &scm_quote) {
|
|
printf ("'");
|
|
return display_helper (car (cdr (x)), cont, "", true);
|
|
}
|
|
#if QUASIQUOTE
|
|
if (car (x) == &scm_symbol_quasiquote
|
|
|| car (x) == &scm_quasiquote) {
|
|
printf ("`");
|
|
return display_helper (car (cdr (x)), cont, "", true);
|
|
}
|
|
if (car (x) == &scm_symbol_unquote
|
|
|| car (x) == &scm_unquote) {
|
|
printf (",");
|
|
return display_helper (car (cdr (x)), cont, "", true);
|
|
}
|
|
#endif
|
|
#endif
|
|
if (!cont) printf ("(");
|
|
display (car (x));
|
|
if (cdr (x)->type == PAIR)
|
|
display_helper (cdr (x), true, " ", false);
|
|
else if (cdr (x) != &scm_nil) {
|
|
printf (" . ");
|
|
display (cdr (x));
|
|
}
|
|
if (!cont) printf (")");
|
|
}
|
|
else if (atom_p (x) == &scm_t) printf ("%s", x->name);
|
|
|
|
return &scm_unspecified;
|
|
}
|
|
|
|
// READ
|
|
|
|
int
|
|
ungetchar (int c) //int
|
|
{
|
|
return ungetc (c, stdin);
|
|
}
|
|
|
|
int
|
|
peekchar () //int
|
|
{
|
|
int c = getchar ();
|
|
ungetchar (c);
|
|
return c;
|
|
}
|
|
|
|
scm*
|
|
builtin_getchar ()
|
|
{
|
|
return make_number (getchar ());
|
|
}
|
|
|
|
scm*
|
|
builtin_peekchar ()
|
|
{
|
|
return make_number (peekchar ());
|
|
}
|
|
|
|
scm*
|
|
builtin_ungetchar (scm *c)
|
|
{
|
|
assert (c->type == NUMBER);
|
|
ungetchar (c->value);
|
|
return c;
|
|
}
|
|
|
|
int
|
|
readcomment (int c)
|
|
{
|
|
if (c == '\n') return c;
|
|
return readcomment (getchar ());
|
|
}
|
|
|
|
int
|
|
readblock (int c)
|
|
{
|
|
if (c == '!' && peekchar () == '#') return getchar ();
|
|
return readblock (getchar ());
|
|
}
|
|
|
|
scm *readlis (scm *a);
|
|
|
|
scm *
|
|
readword (int c, char* w, scm *a)
|
|
{
|
|
if (c == EOF && !w) return &scm_nil;
|
|
if (c == '\n' && !w) return readword (getchar (), w, a);
|
|
if (c == '\n' && *w == '.' && w[1] == 0) return &scm_dot;
|
|
if (c == EOF || c == '\n') return lookup (w, a);
|
|
if (c == ' ') return readword ('\n', w, a);
|
|
if (c == '(' && !w) return readlis (a);
|
|
if (c == '(') {ungetchar (c); return lookup (w, a);}
|
|
if (c == ')' && !w) {ungetchar (c); return &scm_nil;}
|
|
if (c == ')') {ungetchar (c); return lookup (w, a);}
|
|
if ((c == '\''
|
|
#if QUASIQUOTE
|
|
|| c == '`'
|
|
|| c == ','
|
|
#endif
|
|
)
|
|
&& !w) {return cons (lookup_char (c, a),
|
|
cons (readword (getchar (), w, a),
|
|
&scm_nil));}
|
|
if (c == ';') {readcomment (c); return readword ('\n', w, a);}
|
|
if (c == '#' && peekchar () == '!') {getchar (); readblock (getchar ()); return readword (getchar (), w, a);}
|
|
char buf[256] = {0};
|
|
char ch = c;
|
|
return readword (getchar (), strncat (w ? w : buf, &ch, 1), a);
|
|
}
|
|
|
|
int
|
|
eat_whitespace (int c)
|
|
{
|
|
while (c == ' ' || c == '\n') c = getchar ();
|
|
if (c == ';') return eat_whitespace (readcomment (c));
|
|
if (c == '#' && peekchar () == '!') {getchar (); readblock (getchar ()); return eat_whitespace (getchar ());}
|
|
return c;
|
|
}
|
|
|
|
scm *
|
|
readlis (scm *a)
|
|
{
|
|
int c = getchar ();
|
|
c = eat_whitespace (c);
|
|
if (c == ')') return &scm_nil;
|
|
scm *w = readword (c, 0, a);
|
|
if (w == &scm_dot)
|
|
return car (readlis (a));
|
|
return cons (w, readlis (a));
|
|
}
|
|
|
|
scm *
|
|
readenv (scm *a)
|
|
{
|
|
return readword (getchar (), 0, a);
|
|
}
|
|
|
|
// Extras to make interesting program
|
|
|
|
scm *
|
|
hello_world ()
|
|
{
|
|
puts ("c: hello world");
|
|
return &scm_unspecified;
|
|
}
|
|
|
|
scm *
|
|
less_p (scm *a, scm *b)
|
|
{
|
|
assert (a->type == NUMBER);
|
|
assert (b->type == NUMBER);
|
|
return a->value < b->value ? &scm_t : &scm_f;
|
|
}
|
|
|
|
scm *
|
|
minus (scm *a, scm *b)
|
|
{
|
|
assert (a->type == NUMBER);
|
|
assert (b->type == NUMBER);
|
|
return make_number (a->value - b->value);
|
|
}
|
|
|
|
scm *
|
|
plus (scm *a, scm *b)
|
|
{
|
|
assert (a->type == NUMBER);
|
|
assert (b->type == NUMBER);
|
|
return make_number (a->value + b->value);
|
|
}
|
|
|
|
scm *
|
|
divide (scm *a, scm *b)
|
|
{
|
|
assert (a->type == NUMBER);
|
|
assert (b->type == NUMBER);
|
|
return make_number (a->value / b->value);
|
|
}
|
|
|
|
scm *
|
|
multiply (scm *a, scm *b)
|
|
{
|
|
assert (a->type == NUMBER);
|
|
assert (b->type == NUMBER);
|
|
return make_number (a->value * b->value);
|
|
}
|
|
|
|
scm *
|
|
is_p (scm *a, scm *b)
|
|
{
|
|
assert (a->type == NUMBER);
|
|
assert (b->type == NUMBER);
|
|
return a->value == b->value ? &scm_t : &scm_f;
|
|
}
|
|
|
|
#if QUASIQUOTE
|
|
scm *
|
|
eval_quasiquote (scm *e, scm *a)
|
|
{
|
|
#if DEBUG
|
|
printf ("\nc:eval_quasiquote e=");
|
|
display (e);
|
|
if (pair_p (e) == &scm_t) {
|
|
printf ("\ncar (e)=");
|
|
display (car (e));
|
|
printf (" atom=");
|
|
display (atom_p (car (e)));
|
|
}
|
|
puts ("");
|
|
#endif
|
|
if (e == &scm_nil) return e;
|
|
else if (atom_p (e) == &scm_t) return e;
|
|
else if (atom_p (car (e)) == &scm_t)
|
|
return cons (car (e), eval_quasiquote (cdr (e), a));
|
|
else if (eq_p (caar (e), &scm_symbol_unquote) == &scm_t)
|
|
return cons (eval (cadar (e), a), &scm_nil);
|
|
else if (eq_p (caar (e), &scm_symbol_quote) == &scm_t)
|
|
return cons (cadar (e), &scm_nil);
|
|
else if (eq_p (caar (e), &scm_symbol_quasiquote) == &scm_t)
|
|
return cdar (e);
|
|
return cons (car (e), eval_quasiquote (cdr (e), a));
|
|
}
|
|
#endif
|
|
|
|
scm *
|
|
add_environment (scm *a, char *name, scm *x)
|
|
{
|
|
return cons (cons (make_atom (name), x), a);
|
|
}
|
|
|
|
scm *
|
|
mes_environment ()
|
|
{
|
|
scm *a = &scm_nil;
|
|
|
|
a = add_environment (a, "()", &scm_nil);
|
|
a = add_environment (a, "#t", &scm_t);
|
|
a = add_environment (a, "#f", &scm_f);
|
|
a = add_environment (a, "*unspecified*", &scm_unspecified);
|
|
a = add_environment (a, "label", &scm_label);
|
|
a = add_environment (a, "lambda", &scm_lambda);
|
|
a = add_environment (a, "*macro*", &scm_nil);
|
|
a = add_environment (a, "*dot*", &scm_dot);
|
|
a = add_environment (a, "current-module", &scm_symbol_current_module);
|
|
|
|
a = add_environment (a, "'", &scm_quote);
|
|
#if QUASIQUOTE
|
|
a = add_environment (a, ",", &scm_unquote);
|
|
a = add_environment (a, "`", &scm_quasiquote);
|
|
#endif
|
|
|
|
#include "environment.i"
|
|
|
|
return a;
|
|
}
|
|
|
|
scm *
|
|
define_lambda (scm *x)
|
|
{
|
|
return cons (caadr (x), cons (&scm_lambda, cons (cdadr (x), cddr (x))));
|
|
}
|
|
|
|
scm *
|
|
define (scm *x, scm *a)
|
|
{
|
|
if (atom_p (cadr (x)) != &scm_f)
|
|
return cons (cadr (x), eval (caddr (x), a));
|
|
return define_lambda (x);
|
|
}
|
|
|
|
scm *
|
|
define_macro (scm *x, scm *a)
|
|
{
|
|
#if DEBUG
|
|
printf ("\nc:define_macro a=");
|
|
scm *aa =cons (&scm_macro,
|
|
cons (define_lambda (x),
|
|
cdr (assoc (&scm_macro, a))));
|
|
display (aa);
|
|
puts ("");
|
|
#endif
|
|
return cons (&scm_macro,
|
|
cons (define_lambda (x),
|
|
cdr (assoc (&scm_macro, a))));
|
|
}
|
|
|
|
scm *
|
|
loop (scm *r, scm *e, scm *a)
|
|
{
|
|
#if 0//DEBUG
|
|
printf ("\nc:loop e=");
|
|
display (e);
|
|
puts ("");
|
|
#endif
|
|
if (e == &scm_nil)
|
|
return r;
|
|
else if (eq_p (e, &scm_symbol_EOF) == &scm_t)
|
|
return apply (cdr (assoc (&scm_symbol_loop2, a)),
|
|
cons (&scm_unspecified, cons (&scm_t, cons (a, &scm_nil))), a);
|
|
else if (eq_p (e, &scm_symbol_EOF2) == &scm_t)
|
|
return r;
|
|
else if (atom_p (e) == &scm_t)
|
|
return loop (eval (e, a), readenv (a), a);
|
|
else if (eq_p (car (e), &scm_symbol_define) == &scm_t)
|
|
return loop (&scm_unspecified,
|
|
readenv (a),
|
|
cons (define (e, a), a));
|
|
else if (eq_p (car (e), &scm_symbol_define_macro) == &scm_t)
|
|
return loop (&scm_unspecified,
|
|
readenv (a),
|
|
cons (define_macro (e, a), a));
|
|
else if (eq_p (car (e), &scm_symbol_set_x) == &scm_t)
|
|
return loop (set_env_x (cadr (e), eval (caddr (e), a), a), readenv (a), a);
|
|
return loop (eval (e, a), readenv (a), a);
|
|
}
|
|
|
|
int
|
|
main (int argc, char *argv[])
|
|
{
|
|
scm *a = mes_environment ();
|
|
display (loop (&scm_unspecified, readenv (a), a));
|
|
newline ();
|
|
return 0;
|
|
}
|
|
|
|
scm *
|
|
apply (scm *fn, scm *x, scm *a)
|
|
{
|
|
#if DEBUG
|
|
printf ("\nc:apply fn=");
|
|
display (fn);
|
|
printf (" x=");
|
|
display (x);
|
|
puts ("");
|
|
#endif
|
|
if (fn == &scm_apply_)
|
|
return eval_ (x, a);
|
|
return apply_ (fn, x, a);
|
|
}
|
|
|
|
bool evalling_p = false;
|
|
|
|
scm *
|
|
eval (scm *e, scm *a)
|
|
{
|
|
#if DEBUG
|
|
printf ("\nc:eval e=");
|
|
display (e);
|
|
puts ("");
|
|
#endif
|
|
|
|
scm *eval__ = assoc (&scm_symbol_eval, a);
|
|
assert (eval__ != &scm_f);
|
|
eval__ = cdr (eval__);
|
|
if (builtin_p (eval__) == &scm_t
|
|
|| evalling_p)
|
|
return eval_ (e, a);
|
|
evalling_p = true;
|
|
scm *r = apply (eval__, cons (e, cons (a, &scm_nil)), a);
|
|
evalling_p = false;
|
|
return r;
|
|
}
|