2016-05-28 15:39:44 +01:00
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/*
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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 <stdarg.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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2016-05-15 23:07:44 +01:00
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#define DEBUG 0
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2016-05-28 15:39:44 +01:00
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#ifndef QUOTE_SUGAR
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#define QUOTE_SUGAR 1
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#endif
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2016-05-15 23:07:44 +01:00
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enum type {ATOM, NUMBER, PAIR, FUNCTION0, FUNCTION1, FUNCTION2, FUNCTION3};
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2016-05-28 15:39:44 +01:00
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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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2016-05-15 23:07:44 +01:00
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scm scm_nil = {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_define = {ATOM, "define"};
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scm scm_macro = {ATOM, "*macro*"};
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2016-05-28 15:39:44 +01:00
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// PRIMITIVES
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2016-05-15 23:07:44 +01:00
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scm *
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atom (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 scm_atom = {FUNCTION1, .name="atom", .function1 = &atom};
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2016-05-28 15:39:44 +01:00
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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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2016-05-15 23:07:44 +01:00
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&& x->value == y->value)
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// FIXME: alist lookup symbols
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|| (atom (x) == &scm_t
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&& x->type != NUMBER
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&& y->type != NUMBER
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&& atom (y) == &scm_t
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&& !strcmp (x->name, y->name)))
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2016-05-28 15:39:44 +01:00
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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 *eval (scm*, scm*);
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2016-05-15 23:07:44 +01:00
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scm *display (scm*);
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2016-05-28 15:39:44 +01:00
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scm scm_quote;
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scm *
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quote (scm *x)
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{
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return cons (&scm_quote, x);
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}
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2016-05-15 23:07:44 +01:00
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#if QUASIQUOTE
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scm scm_unquote;
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scm *
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unquote (scm *x)
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{
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return cons (&scm_unquote, x);
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}
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scm scm_quasiquote;
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scm *
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quasiquote (scm *x)
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{
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return cons (&scm_quasiquote, x);
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}
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scm *eval_quasiquote (scm *, scm *);
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#endif
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2016-05-28 15:39:44 +01:00
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2016-05-15 23:07:44 +01:00
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//Primitives
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scm scm_car = {FUNCTION1, "car", .function1 = &car};
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scm scm_cdr = {FUNCTION1, "cdr", .function1 = &cdr};
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scm scm_cons = {FUNCTION2, "cons", .function2 = &cons};
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scm scm_cond = {FUNCTION2, "cond"}; //, .function2 = &cond};
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scm scm_eq_p = {FUNCTION2, "eq", .function2 = &eq_p};
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scm scm_null_p = {FUNCTION1, "null", .function1 = &null_p};
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scm scm_pair_p = {FUNCTION1, "pair", .function1 = &pair_p};
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scm scm_quote = {FUNCTION1, "quote", .function1 = "e};
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#if QUASIQUOTE
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scm scm_unquote = {FUNCTION1, "unquote", .function1 = &unquote};
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scm scm_quasiquote = {FUNCTION1, "quasiquote", .function1 = &quasiquote};
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#endif
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//Library functions
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2016-05-28 15:39:44 +01:00
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scm scm_read;
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2016-05-15 23:07:44 +01:00
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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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2016-05-28 15:39:44 +01:00
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scm *caddr (scm *x) {return car (cdr (cdr (x)));}
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2016-05-15 23:07:44 +01:00
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scm *cdadr (scm *x) {return cdr (car (cdr (x)));}
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2016-05-28 15:39:44 +01:00
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scm *cadar (scm *x) {return car (cdr (car (x)));}
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2016-05-15 23:07:44 +01:00
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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 scm_caar = {FUNCTION1, .name="caar ", .function1 = &caar };
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scm scm_cadr = {FUNCTION1, .name="cadr ", .function1 = &cadr };
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scm scm_cdar = {FUNCTION1, .name="cdar ", .function1 = &cdar };
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scm scm_cddr = {FUNCTION1, .name="cddr ", .function1 = &cddr };
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scm scm_caadr = {FUNCTION1, .name="caadr", .function1 = &caadr};
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scm scm_caddr = {FUNCTION1, .name="caddr", .function1 = &caddr};
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scm scm_cdadr = {FUNCTION1, .name="cdadr", .function1 = &cdadr};
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scm scm_cadar = {FUNCTION1, .name="cadar", .function1 = &cadar};
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scm scm_cddar = {FUNCTION1, .name="cddar", .function1 = &cddar};
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scm scm_cdddr = {FUNCTION1, .name="cdddr", .function1 = &cdddr};
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2016-05-28 15:39:44 +01:00
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scm *
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list (scm *x, ...)
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{
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va_list args;
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scm *lst = &scm_nil;
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va_start (args, x);
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while (x != &scm_unspecified)
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{
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lst = cons (x, lst);
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x = va_arg (args, scm*);
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}
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va_end (args);
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return lst;
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}
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// Page 12
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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 (x == &scm_nil)
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return 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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2016-05-15 23:07:44 +01:00
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scm scm_pairlis = {FUNCTION3, .name="pairlis", .function3 = &pairlis};
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2016-05-28 15:39:44 +01:00
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scm *
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assoc (scm *x, scm *a)
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{
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2016-05-15 23:07:44 +01:00
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//printf ("assoc: %s\n" , x->name);
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2016-05-28 15:39:44 +01:00
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// not Page 12:
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2016-05-15 23:07:44 +01:00
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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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2016-05-28 15:39:44 +01:00
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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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2016-05-15 23:07:44 +01:00
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scm scm_assoc = {FUNCTION2, .name="assoc", .function2 = &assoc};
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2016-05-28 15:39:44 +01:00
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// Page 13
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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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2016-05-15 23:07:44 +01:00
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scm *builtin_p (scm*);
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2016-05-28 15:39:44 +01:00
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scm *call (scm *, scm*);
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scm *display (scm*);
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2016-05-15 23:07:44 +01:00
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scm *newline ();
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2016-05-28 15:39:44 +01:00
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// .. continued Page 13
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scm *
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apply (scm *fn, scm *x, scm *a)
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{
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2016-05-15 23:07:44 +01:00
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#if DEBUG
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2016-05-28 15:39:44 +01:00
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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 (fn) != &scm_f)
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{
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2016-05-15 23:07:44 +01:00
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if (builtin_p (fn) == &scm_t)
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2016-05-28 15:39:44 +01:00
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return call (fn, x);
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2016-05-15 23:07:44 +01:00
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return apply (eval (fn, a), x, a);
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2016-05-28 15:39:44 +01:00
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}
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2016-05-15 23:07:44 +01:00
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// Page 12: single statement lambda
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// else if (car (fn) == &scm_lambda)
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// return eval (caddr (fn), pairlis (cadr (fn), x, a));
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// Multi-statement lambda
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else if (car (fn) == &scm_lambda) {
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scm *body = cddr (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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2016-05-28 15:39:44 +01:00
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else if (car (fn) == &scm_label)
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2016-05-15 23:07:44 +01:00
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return apply (caddr (fn), x, cons (cons (cadr (fn), caddr (fn)), a));
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2016-05-28 15:39:44 +01:00
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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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2016-05-15 23:07:44 +01:00
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#if DEBUG
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printf ("eval e=");
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display (e);
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// printf (" a=");
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// display (a);
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puts ("");
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#endif
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2016-05-28 15:39:44 +01:00
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// not Page 12
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2016-05-15 23:07:44 +01:00
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if (e->type == NUMBER)
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return e;
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//
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else if (atom (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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// not Page 12
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if (builtin_p (e) == &scm_t)
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2016-05-28 15:39:44 +01:00
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return e;
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//
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else if (atom (car (e)) == &scm_t)
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{
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2016-05-15 23:07:44 +01:00
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scm *macro;
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#if DEBUG
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printf ("e:");
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|
display (e);
|
|
|
|
puts ("");
|
|
|
|
scm *macros = cdr (assoc (&scm_macro, a));
|
|
|
|
if (pair_p (macros) == &scm_t) {
|
|
|
|
printf ("macros:");
|
|
|
|
display (macros);
|
|
|
|
puts ("");
|
|
|
|
}
|
|
|
|
#endif
|
2016-05-28 15:39:44 +01:00
|
|
|
if (car (e) == &scm_quote)
|
|
|
|
return cadr (e);
|
2016-05-15 23:07:44 +01:00
|
|
|
#if QUASIQUOTE
|
|
|
|
else if (car (e) == &scm_unquote)
|
|
|
|
return eval (cadr (e), a);
|
|
|
|
else if (car (e) == &scm_quasiquote) {
|
|
|
|
#if DEBUG
|
|
|
|
printf ("cadr e:");
|
|
|
|
display (cadr (e));
|
|
|
|
puts ("");
|
|
|
|
printf ("qq:");
|
|
|
|
display (eval_quasiquote (cadr (e), a));
|
|
|
|
puts ("");
|
|
|
|
#endif
|
|
|
|
return eval_quasiquote (cadr (e), a);
|
|
|
|
}
|
|
|
|
#endif
|
2016-05-28 15:39:44 +01:00
|
|
|
else if (car (e) == &scm_cond)
|
|
|
|
return evcon (cdr (e), a);
|
2016-05-15 23:07:44 +01:00
|
|
|
//return cond (cdr (e), a);
|
|
|
|
else if ((macro = assoc (car (e), cdr (assoc (&scm_macro, a)))) != &scm_f) {
|
|
|
|
#if DEBUG
|
|
|
|
printf ("eval macro:");
|
|
|
|
display (cdr (macro));
|
|
|
|
puts ("");
|
|
|
|
printf ("macro evlis:");
|
|
|
|
display (evlis (cdr (e), a));
|
|
|
|
puts ("");
|
|
|
|
#endif
|
|
|
|
return eval (apply
|
|
|
|
(cdr (macro),
|
|
|
|
evlis (cdr (e), a),
|
|
|
|
a),
|
|
|
|
a);
|
|
|
|
}
|
2016-05-28 15:39:44 +01:00
|
|
|
else
|
|
|
|
return apply (car (e), evlis (cdr (e), a), a);
|
|
|
|
}
|
|
|
|
return apply (car (e), evlis (cdr (e), a), a);
|
|
|
|
}
|
|
|
|
|
|
|
|
scm *
|
|
|
|
evcon (scm *c, scm *a)
|
|
|
|
{
|
2016-05-15 23:07:44 +01:00
|
|
|
// if (eval (caar (c), a) != &scm_f)
|
|
|
|
// return eval (cadar (c), a);
|
|
|
|
if (eval (caar (c), a) != &scm_f) {
|
|
|
|
if (cddar (c) == &scm_nil)
|
|
|
|
return eval (cadar (c), a);
|
|
|
|
eval (cadar (c), a);
|
|
|
|
return evcon (cons (cons (&scm_t, cddar (c)), &scm_nil), a);
|
|
|
|
}
|
2016-05-28 15:39:44 +01:00
|
|
|
return evcon (cdr (c), a);
|
|
|
|
}
|
2016-05-15 23:07:44 +01:00
|
|
|
scm scm_evcon = {FUNCTION2, .name="evcon", .function2 = &evcon};
|
2016-05-28 15:39:44 +01:00
|
|
|
|
|
|
|
scm *
|
|
|
|
evlis (scm *m, scm *a)
|
|
|
|
{
|
|
|
|
if (m == &scm_nil)
|
|
|
|
return &scm_nil;
|
|
|
|
return cons (eval (car (m), a), evlis (cdr (m), a));
|
|
|
|
}
|
2016-05-15 23:07:44 +01:00
|
|
|
scm scm_evlis = {FUNCTION2, .name="evlis", .function2 = &evlis};
|
2016-05-28 15:39:44 +01:00
|
|
|
|
|
|
|
// EXTRAS
|
|
|
|
|
|
|
|
scm *
|
2016-05-15 23:07:44 +01:00
|
|
|
builtin_p (scm *x)
|
2016-05-28 15:39:44 +01:00
|
|
|
{
|
|
|
|
return (x->type == FUNCTION0
|
|
|
|
|| x->type == FUNCTION1
|
|
|
|
|| x->type == FUNCTION2
|
|
|
|
|| x->type == FUNCTION3)
|
|
|
|
? &scm_t : &scm_f;
|
|
|
|
}
|
2016-05-15 23:07:44 +01:00
|
|
|
scm scm_builtin_p = {FUNCTION1, .name="builtin", .function1 = &builtin_p};
|
|
|
|
|
|
|
|
scm *
|
|
|
|
number_p (scm *x)
|
|
|
|
{
|
|
|
|
return x->type == NUMBER ? &scm_t : &scm_f;
|
|
|
|
}
|
|
|
|
scm scm_number_p = {FUNCTION1, .name="number", .function1 = &number_p};
|
|
|
|
|
2016-05-28 15:39:44 +01:00
|
|
|
|
|
|
|
scm *
|
|
|
|
call (scm *fn, scm *x)
|
|
|
|
{
|
|
|
|
if (fn->type == FUNCTION0)
|
|
|
|
return fn->function0 ();
|
|
|
|
else if (fn->type == FUNCTION1)
|
|
|
|
return fn->function1 (car (x));
|
|
|
|
if (fn->type == FUNCTION2)
|
|
|
|
return fn->function2 (car (x), cadr (x));
|
|
|
|
if (fn->type == FUNCTION3)
|
|
|
|
return fn->function3 (car (x), cadr (x), caddr (x));
|
|
|
|
return &scm_unspecified;
|
|
|
|
}
|
2016-05-15 23:07:44 +01:00
|
|
|
scm scm_call = {FUNCTION1, .name="call", .function2 = &call};
|
2016-05-28 15:39:44 +01:00
|
|
|
|
|
|
|
scm *
|
|
|
|
append (scm *x, scm *y)
|
|
|
|
{
|
|
|
|
if (x == &scm_nil) return y;
|
|
|
|
assert (x->type == PAIR);
|
|
|
|
return cons (car (x), append (cdr (x), y));
|
|
|
|
}
|
2016-05-15 23:07:44 +01:00
|
|
|
scm scm_append = {FUNCTION2, .name="append", .function2 = &append};
|
|
|
|
|
2016-05-28 15:39:44 +01:00
|
|
|
|
|
|
|
scm *
|
|
|
|
make_atom (char const *s)
|
|
|
|
{
|
|
|
|
// TODO: alist lookup symbols
|
|
|
|
scm *p = malloc (sizeof (scm));
|
|
|
|
p->type = ATOM;
|
|
|
|
p->name = strdup (s);
|
|
|
|
return p;
|
|
|
|
}
|
|
|
|
|
|
|
|
scm *
|
|
|
|
make_number (int x)
|
|
|
|
{
|
|
|
|
scm *p = malloc (sizeof (scm));
|
|
|
|
p->type = NUMBER;
|
|
|
|
p->value = x;
|
|
|
|
return p;
|
|
|
|
}
|
|
|
|
|
|
|
|
scm *
|
2016-05-15 23:07:44 +01:00
|
|
|
lookup (char *x, scm *a)
|
2016-05-28 15:39:44 +01:00
|
|
|
{
|
|
|
|
if (isdigit (*x) || (*x == '-' && isdigit (*(x+1))))
|
|
|
|
return make_number (atoi (x));
|
|
|
|
if (x) {
|
|
|
|
scm *y = make_atom (x);
|
2016-05-15 23:07:44 +01:00
|
|
|
scm *r = assoc (y, a);
|
|
|
|
#if 0
|
|
|
|
if (!strcmp (x, "eval")) {
|
|
|
|
printf ("lookup %s ==> ", x);
|
|
|
|
display (r);
|
|
|
|
puts ("");
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!strcmp (x, "apply")) {
|
|
|
|
printf ("lookup %s ==> ", x);
|
|
|
|
display (r);
|
|
|
|
puts ("");
|
|
|
|
}
|
|
|
|
#endif
|
2016-05-28 15:39:44 +01:00
|
|
|
if (r != &scm_f) return cdr (r);
|
|
|
|
return y;
|
|
|
|
}
|
|
|
|
|
|
|
|
return &scm_unspecified;
|
|
|
|
}
|
|
|
|
|
|
|
|
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));
|
|
|
|
}
|
|
|
|
|
2016-05-15 23:07:44 +01:00
|
|
|
scm *display_helper (scm*, bool, char*, bool);
|
2016-05-28 15:39:44 +01:00
|
|
|
|
|
|
|
scm *
|
|
|
|
display (scm *x)
|
|
|
|
{
|
2016-05-15 23:07:44 +01:00
|
|
|
return display_helper (x, false, "", false);
|
|
|
|
}
|
|
|
|
scm scm_display = {FUNCTION1, .name="display", .function1 = &display};
|
|
|
|
|
|
|
|
scm *
|
|
|
|
newline ()
|
|
|
|
{
|
|
|
|
puts ("");
|
|
|
|
return &scm_unspecified;
|
2016-05-28 15:39:44 +01:00
|
|
|
}
|
2016-05-15 23:07:44 +01:00
|
|
|
scm scm_newline = {FUNCTION0, .name="newline", .function0 = &newline};
|
2016-05-28 15:39:44 +01:00
|
|
|
|
|
|
|
scm *
|
2016-05-15 23:07:44 +01:00
|
|
|
display_helper (scm *x, bool cont, char *sep, bool quote)
|
2016-05-28 15:39:44 +01:00
|
|
|
{
|
|
|
|
scm *r;
|
|
|
|
printf (sep);
|
2016-05-15 23:07:44 +01:00
|
|
|
if (x->type == NUMBER) printf ("%d", x->value);
|
2016-05-28 15:39:44 +01:00
|
|
|
else if (x->type == PAIR) {
|
|
|
|
#if QUOTE_SUGAR
|
|
|
|
if (car (x) == &scm_quote) {
|
|
|
|
printf ("'");
|
2016-05-15 23:07:44 +01:00
|
|
|
return display_helper (car (cdr (x)), cont, "", true);
|
|
|
|
}
|
|
|
|
#if QUASIQUOTE
|
|
|
|
if (car (x) == &scm_quasiquote) {
|
|
|
|
printf ("`");
|
|
|
|
return display_helper (car (cdr (x)), cont, "", true);
|
|
|
|
}
|
|
|
|
if (car (x) == &scm_unquote) {
|
|
|
|
printf (",");
|
|
|
|
return display_helper (car (cdr (x)), cont, "", true);
|
2016-05-28 15:39:44 +01:00
|
|
|
}
|
2016-05-15 23:07:44 +01:00
|
|
|
#endif
|
2016-05-28 15:39:44 +01:00
|
|
|
#endif
|
|
|
|
if (!cont) printf ("(");
|
|
|
|
display (car (x));
|
|
|
|
if (cdr (x)->type == PAIR)
|
2016-05-15 23:07:44 +01:00
|
|
|
display_helper (cdr (x), true, " ", false);
|
2016-05-28 15:39:44 +01:00
|
|
|
else if (cdr (x) != &scm_nil) {
|
|
|
|
printf (" . ");
|
|
|
|
display (cdr (x));
|
|
|
|
}
|
|
|
|
if (!cont) printf (")");
|
|
|
|
}
|
2016-05-15 23:07:44 +01:00
|
|
|
else if (atom (x) == &scm_t) printf (x->name);
|
2016-05-28 15:39:44 +01:00
|
|
|
|
|
|
|
return &scm_unspecified;
|
|
|
|
}
|
|
|
|
|
|
|
|
// READ
|
|
|
|
int
|
|
|
|
ungetchar (int c)
|
|
|
|
{
|
|
|
|
return ungetc (c, stdin);
|
|
|
|
}
|
|
|
|
|
|
|
|
int
|
|
|
|
peekchar ()
|
|
|
|
{
|
|
|
|
int c = getchar ();
|
|
|
|
ungetchar (c);
|
|
|
|
return c;
|
|
|
|
}
|
|
|
|
|
|
|
|
scm*
|
|
|
|
builtin_getchar ()
|
|
|
|
{
|
|
|
|
return make_number (getchar ());
|
|
|
|
}
|
|
|
|
scm scm_getchar = {FUNCTION0, .name="getchar", .function0 = &builtin_getchar};
|
|
|
|
|
|
|
|
scm*
|
|
|
|
builtin_peekchar ()
|
|
|
|
{
|
|
|
|
return make_number (peekchar ());
|
|
|
|
}
|
|
|
|
scm scm_peekchar = {FUNCTION0, .name="peekchar", .function0 = &builtin_peekchar};
|
|
|
|
|
|
|
|
scm*
|
|
|
|
builtin_ungetchar (scm* c)
|
|
|
|
{
|
|
|
|
assert (c->type == NUMBER);
|
|
|
|
ungetchar (c->value);
|
|
|
|
return c;
|
|
|
|
}
|
|
|
|
scm scm_ungetchar = {FUNCTION1, .name="ungetchar", .function1 = &builtin_ungetchar};
|
|
|
|
|
|
|
|
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);
|
2016-05-15 23:07:44 +01:00
|
|
|
if (c == EOF || c == '\n') return lookup (w, a);
|
2016-05-28 15:39:44 +01:00
|
|
|
if (c == ' ') return readword ('\n', w, a);
|
|
|
|
if (c == '(' && !w) return readlis (a);
|
2016-05-15 23:07:44 +01:00
|
|
|
if (c == '(') {ungetchar (c); return lookup (w, a);}
|
2016-05-28 15:39:44 +01:00
|
|
|
if (c == ')' && !w) {ungetchar (c); return &scm_nil;}
|
2016-05-15 23:07:44 +01:00
|
|
|
if (c == ')') {ungetchar (c); return lookup (w, a);}
|
|
|
|
if (c == '\'' && !w) {return cons (lookup ("'", a),
|
2016-05-28 15:39:44 +01:00
|
|
|
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 s[2];
|
|
|
|
s[0] = c;
|
|
|
|
s[1] = 0;
|
|
|
|
char buf[256] = "";
|
|
|
|
return readword (getchar (), strcat (w ? w : buf, s), a);
|
|
|
|
}
|
|
|
|
|
|
|
|
scm *
|
|
|
|
readlis (scm *a)
|
|
|
|
{
|
|
|
|
int c = getchar ();
|
|
|
|
if (c == ')') return &scm_nil;
|
|
|
|
scm *w = readword (c, 0, a);
|
|
|
|
return cons (w, readlis (a));
|
|
|
|
}
|
|
|
|
|
|
|
|
scm *
|
2016-05-15 23:07:44 +01:00
|
|
|
readenv (scm *a)
|
2016-05-28 15:39:44 +01:00
|
|
|
{
|
2016-05-15 23:07:44 +01:00
|
|
|
return readword (getchar (), 0, a);
|
2016-05-28 15:39:44 +01:00
|
|
|
}
|
2016-05-15 23:07:44 +01:00
|
|
|
scm scm_readenv = {FUNCTION1, .function1 = &readenv};
|
2016-05-28 15:39:44 +01:00
|
|
|
|
|
|
|
scm *
|
|
|
|
add_environment (scm *a, char *name, scm* x)
|
|
|
|
{
|
|
|
|
return cons (cons (make_atom (name), x), a);
|
|
|
|
}
|
|
|
|
|
|
|
|
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);
|
|
|
|
}
|
|
|
|
|
2016-05-15 23:07:44 +01:00
|
|
|
scm scm_less_p = {FUNCTION2, .name="<", .function2 = &less_p};
|
|
|
|
scm scm_minus = {FUNCTION2, .name="-", .function2 = &minus};
|
|
|
|
|
|
|
|
scm *global_environment;
|
2016-05-28 15:39:44 +01:00
|
|
|
|
|
|
|
scm *
|
2016-05-15 23:07:44 +01:00
|
|
|
apply_environment (scm *fn, scm *x, scm *a)
|
2016-05-28 15:39:44 +01:00
|
|
|
{
|
2016-05-15 23:07:44 +01:00
|
|
|
return apply (fn, x, append (a, global_environment));
|
|
|
|
}
|
|
|
|
|
|
|
|
scm *
|
|
|
|
eval_environment (scm *e, scm *a)
|
|
|
|
{
|
|
|
|
return eval (e, append (a, global_environment));
|
|
|
|
}
|
|
|
|
|
|
|
|
//scm scm_cond = {FUNCTION2, .name="cond", .function2 = &evcon};
|
|
|
|
scm scm_eval = {FUNCTION2, .name="eval", .function2 = &eval_environment};
|
|
|
|
scm scm_apply = {FUNCTION3, .name="apply", .function3 = &apply_environment};
|
|
|
|
|
|
|
|
scm *
|
|
|
|
initial_environment ()
|
|
|
|
{
|
|
|
|
scm_cond.function2 = &evcon;
|
|
|
|
|
2016-05-28 15:39:44 +01:00
|
|
|
scm *a = &scm_nil;
|
2016-05-15 23:07:44 +01:00
|
|
|
|
|
|
|
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, "atom", &scm_atom);
|
|
|
|
a = add_environment (a, "car", &scm_car);
|
|
|
|
a = add_environment (a, "cdr", &scm_cdr);
|
|
|
|
a = add_environment (a, "cons", &scm_cons);
|
|
|
|
a = add_environment (a, "cond", &scm_cond);
|
|
|
|
a = add_environment (a, "eq", &scm_eq_p);
|
|
|
|
|
|
|
|
a = add_environment (a, "null", &scm_null_p);
|
|
|
|
a = add_environment (a, "pair", &scm_pair_p);
|
|
|
|
a = add_environment (a, "quote", &scm_quote);
|
|
|
|
a = add_environment (a, "'", &scm_quote);
|
|
|
|
|
|
|
|
#if QUASIQUOTE
|
|
|
|
a = add_environment (a, "quasiquote", &scm_quasiquote);
|
|
|
|
a = add_environment (a, "unquote", &scm_unquote);
|
|
|
|
a = add_environment (a, ",", &scm_unquote);
|
|
|
|
a = add_environment (a, "`", &scm_quasiquote);
|
|
|
|
#endif
|
|
|
|
|
|
|
|
a = add_environment (a, "evlis", &scm_evlis);
|
|
|
|
a = add_environment (a, "evcon", &scm_evcon);
|
|
|
|
a = add_environment (a, "pairlis", &scm_pairlis);
|
|
|
|
a = add_environment (a, "assoc", &scm_assoc);
|
|
|
|
|
|
|
|
a = add_environment (a, "eval", &scm_eval);
|
|
|
|
a = add_environment (a, "apply", &scm_apply);
|
|
|
|
|
|
|
|
a = add_environment (a, "readenv", &scm_readenv);
|
|
|
|
a = add_environment (a, "display", &scm_display);
|
|
|
|
a = add_environment (a, "newline", &scm_newline);
|
|
|
|
|
|
|
|
a = add_environment (a, "builtin", &scm_builtin_p);
|
|
|
|
a = add_environment (a, "number", &scm_number_p);
|
|
|
|
a = add_environment (a, "call", &scm_call);
|
|
|
|
|
|
|
|
a = add_environment (a, "define", &scm_define);
|
|
|
|
|
2016-05-28 15:39:44 +01:00
|
|
|
a = add_environment (a, "<", &scm_less_p);
|
|
|
|
a = add_environment (a, "-", &scm_minus);
|
2016-05-15 23:07:44 +01:00
|
|
|
|
|
|
|
// DERIVED
|
|
|
|
a = add_environment (a, "caar", &scm_caar);
|
|
|
|
a = add_environment (a, "cadr", &scm_cadr);
|
|
|
|
a = add_environment (a, "cdar", &scm_cdar);
|
|
|
|
a = add_environment (a, "cddr", &scm_cddr);
|
|
|
|
a = add_environment (a, "caadr", &scm_caadr);
|
|
|
|
a = add_environment (a, "caddr", &scm_caddr);
|
|
|
|
a = add_environment (a, "cdadr", &scm_cdadr);
|
|
|
|
a = add_environment (a, "cadar", &scm_cadar);
|
|
|
|
a = add_environment (a, "cddar", &scm_cddar);
|
|
|
|
a = add_environment (a, "cdddr", &scm_cdddr);
|
|
|
|
|
|
|
|
a = add_environment (a, "append", &scm_append);
|
|
|
|
|
|
|
|
a = add_environment (a, "*macro*", &scm_nil);
|
|
|
|
|
|
|
|
// Hmm
|
|
|
|
//a = add_environment (a, "*a*", &scm_nil);
|
|
|
|
global_environment = add_environment (a, "*a*", a);
|
2016-05-28 15:39:44 +01:00
|
|
|
return a;
|
|
|
|
}
|
|
|
|
|
2016-05-15 23:07:44 +01:00
|
|
|
#if QUASIQUOTE
|
|
|
|
scm *
|
|
|
|
eval_quasiquote (scm *e, scm *a)
|
|
|
|
{
|
|
|
|
if (e == &scm_nil) return e;
|
|
|
|
else if (atom (e) == &scm_t) return e;
|
|
|
|
else if (car (e) == &scm_unquote)
|
|
|
|
return eval (cadr (e), a);
|
|
|
|
else if (car (e) == &scm_quote)
|
|
|
|
return cadr (e);
|
|
|
|
else if (car (e) == &scm_quasiquote)
|
|
|
|
return cadr (e);
|
|
|
|
return cons (car (e), eval_quasiquote (cdr (e), a));
|
|
|
|
}
|
|
|
|
#endif
|
|
|
|
|
|
|
|
scm *
|
|
|
|
define_lambda (scm *x, scm *a)
|
|
|
|
{
|
|
|
|
return cons (caadr (x), cons (&scm_lambda, cons (cdadr (x), cddr (x))));
|
|
|
|
}
|
|
|
|
|
|
|
|
scm *
|
|
|
|
define (scm *x, scm *a)
|
|
|
|
{
|
|
|
|
if (atom (cadr (x)) != &scm_f)
|
|
|
|
return cons (cadr (x), eval (caddr (x), a));
|
|
|
|
return define_lambda (x, a);
|
|
|
|
}
|
|
|
|
|
|
|
|
scm *
|
|
|
|
define_macro (scm *x, scm *a)
|
|
|
|
{
|
|
|
|
return cons (&scm_macro,
|
|
|
|
cons (define_lambda (x, a),
|
|
|
|
cdr (assoc (&scm_macro, a))));
|
|
|
|
}
|
|
|
|
|
|
|
|
scm *
|
|
|
|
loop (scm *r, scm *e, scm *a)
|
|
|
|
{
|
|
|
|
//global_environment = add_environment (a, "*a*", a);
|
|
|
|
if (e == &scm_nil) return r; //a;
|
|
|
|
else if (eq_p (e, make_atom ("exit")) == &scm_t)
|
|
|
|
return apply (cdr (assoc (make_atom ("loop"), a)),
|
|
|
|
cons (&scm_unspecified, cons (&scm_t, cons (a, &scm_nil))), a);
|
|
|
|
else if (atom (e) == &scm_t)
|
|
|
|
return loop (eval (e, a), readenv (a), a);
|
|
|
|
else if (eq_p (car (e), make_atom ("define")) == &scm_t)
|
|
|
|
return loop (&scm_unspecified,
|
|
|
|
readenv (a),
|
|
|
|
cons (define (e, a), a));
|
|
|
|
else if (eq_p (car (e), make_atom ("define-macro")) == &scm_t)
|
|
|
|
return loop (&scm_unspecified,
|
|
|
|
readenv (a),
|
|
|
|
cons (define_macro (e, a), a));
|
|
|
|
return loop (eval (e, a), readenv (a), a);
|
|
|
|
}
|
|
|
|
|
2016-05-28 15:39:44 +01:00
|
|
|
int
|
|
|
|
main (int argc, char *argv[])
|
|
|
|
{
|
2016-05-15 23:07:44 +01:00
|
|
|
scm *a = initial_environment ();
|
|
|
|
//global_environment = a;
|
|
|
|
scm *x = readenv (a);
|
2016-05-28 15:39:44 +01:00
|
|
|
#if DEBUG
|
2016-05-15 23:07:44 +01:00
|
|
|
printf ("program=");
|
|
|
|
display (x);
|
2016-05-28 15:39:44 +01:00
|
|
|
puts ("");
|
|
|
|
#endif
|
2016-05-15 23:07:44 +01:00
|
|
|
//display (eval (x, a));
|
|
|
|
display (loop (&scm_unspecified, x, a));
|
|
|
|
// loop (&scm_unspecified, x, a);
|
|
|
|
//loop (&scm_unspecified, read (), initial_environment ());
|
|
|
|
newline ();
|
|
|
|
return 0;
|
2016-05-28 15:39:44 +01:00
|
|
|
}
|