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mes/mes.c
Jan Nieuwenhuizen 6d5811bb98 reader: handle whitespace and comments inside lists.
2016-07-09 18:56:59 +02:00

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/*
* Mes --- Maxwell Equations of Software
* Copyright © 2016 Jan Nieuwenhuizen <janneke@gnu.org>
*
* This file is part of Mes.
*
* Mes is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or (at
* your option) any later version.
*
* Mes 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Mes. If not, see <http://www.gnu.org/licenses/>.
*/
// (setq comment-start "//")
// (setq comment-end "")
/*
* The Maxwell Equations of Software -- John McCarthy page 13
* http://www.softwarepreservation.org/projects/LISP/book/LISP%201.5%20Programmers%20Manual.pdf
*/
#define _GNU_SOURCE
#include <assert.h>
#include <ctype.h>
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
#define DEBUG 0
#define MACROS 1
#define QUASIQUOTE 1
#ifndef QUOTE_SUGAR
#define QUOTE_SUGAR 1
#endif
enum type {ATOM, NUMBER, PAIR, FUNCTION0, FUNCTION1, FUNCTION2, FUNCTION3};
struct scm_t;
typedef struct scm_t* (*function0_t) (void);
typedef struct scm_t* (*function1_t) (struct scm_t*);
typedef struct scm_t* (*function2_t) (struct scm_t*, struct scm_t*);
typedef struct scm_t* (*function3_t) (struct scm_t*, struct scm_t*, struct scm_t*);
typedef struct scm_t {
enum type type;
union {
char *name;
struct scm_t* car;
};
union {
int value;
function0_t function0;
function1_t function1;
function2_t function2;
function3_t function3;
struct scm_t* cdr;
};
} scm;
scm scm_nil = {ATOM, "()"};
scm scm_dot = {ATOM, "."};
scm scm_t = {ATOM, "#t"};
scm scm_f = {ATOM, "#f"};
scm scm_lambda = {ATOM, "lambda"};
scm scm_label = {ATOM, "label"};
scm scm_unspecified = {ATOM, "*unspecified*"};
scm scm_symbol_cond = {ATOM, "cond"};
scm scm_symbol_quote = {ATOM, "quote"};
#if QUASIQUOTE
scm scm_symbol_quasiquote = {ATOM, "quasiquote"};
scm scm_symbol_unquote = {ATOM, "unquote"};
#endif
#if MACROS
scm scm_macro = {ATOM, "*macro*"};
#endif
scm scm_symbol_current_module = {ATOM, "current-module"};
// PRIMITIVES
scm *
atom_p (scm *x)
{
return x->type == PAIR ? &scm_f : &scm_t;
}
scm scm_atom = {FUNCTION1, .name="atom", .function1 = &atom_p};
scm *
car (scm *x)
{
assert (x->type == PAIR);
return x->car;
}
scm *
cdr (scm *x)
{
assert (x->type == PAIR);
return x->cdr;
}
scm *
cons (scm *x, scm *y)
{
scm *p = malloc (sizeof (scm));
p->type = PAIR;
p->car = x;
p->cdr = y;
return p;
}
scm *
eq_p (scm *x, scm *y)
{
return (x == y
|| (x->type == NUMBER && y->type == NUMBER
&& x->value == y->value)
// FIXME: alist lookup symbols
|| (atom_p (x) == &scm_t
&& x->type != NUMBER
&& y->type != NUMBER
&& atom_p (y) == &scm_t
&& !strcmp (x->name, y->name)))
? &scm_t : &scm_f;
}
scm *
null_p (scm *x)
{
return eq_p (x, &scm_nil);
}
scm *
pair_p (scm *x)
{
return x->type == PAIR ? &scm_t : &scm_f;
}
scm *eval (scm*, scm*);
scm *display (scm*);
scm scm_quote;
scm *
quote (scm *x)
{
return cons (&scm_quote, x);
}
#if QUASIQUOTE
scm scm_unquote;
scm *
unquote (scm *x)
{
return cons (&scm_unquote, x);
}
scm scm_quasiquote;
scm *
quasiquote (scm *x)
{
return cons (&scm_quasiquote, x);
}
scm *eval_quasiquote (scm *, scm *);
#endif
//Library functions
scm scm_read;
// Derived, non-primitives
scm *caar (scm *x) {return car (car (x));}
scm *cadr (scm *x) {return car (cdr (x));}
scm *cdar (scm *x) {return cdr (car (x));}
scm *cddr (scm *x) {return cdr (cdr (x));}
scm *caadr (scm *x) {return car (car (cdr (x)));}
scm *caddr (scm *x) {return car (cdr (cdr (x)));}
scm *cdadr (scm *x) {return cdr (car (cdr (x)));}
scm *cadar (scm *x) {return car (cdr (car (x)));}
scm *cddar (scm *x) {return cdr (cdr (car (x)));}
scm *cdddr (scm *x) {return cdr (cdr (cdr (x)));}
scm scm_caar = {FUNCTION1, .name="caar ", .function1 = &caar };
scm scm_cadr = {FUNCTION1, .name="cadr ", .function1 = &cadr };
scm scm_cdar = {FUNCTION1, .name="cdar ", .function1 = &cdar };
scm scm_cddr = {FUNCTION1, .name="cddr ", .function1 = &cddr };
scm scm_caadr = {FUNCTION1, .name="caadr", .function1 = &caadr};
scm scm_caddr = {FUNCTION1, .name="caddr", .function1 = &caddr};
scm scm_cdadr = {FUNCTION1, .name="cdadr", .function1 = &cdadr};
scm scm_cadar = {FUNCTION1, .name="cadar", .function1 = &cadar};
scm scm_cddar = {FUNCTION1, .name="cddar", .function1 = &cddar};
scm scm_cdddr = {FUNCTION1, .name="cdddr", .function1 = &cdddr};
scm *
list (scm *x, ...)
{
va_list args;
scm *lst = &scm_nil;
va_start (args, x);
while (x != &scm_unspecified)
{
lst = cons (x, lst);
x = va_arg (args, scm*);
}
va_end (args);
return lst;
}
scm* make_atom (char const *);
scm *
pairlis (scm *x, scm *y, scm *a)
{
#if DEBUG
printf ("pairlis x=");
display (x);
printf (" y=");
display (y);
puts ("");
#endif
if (x == &scm_nil)
return a;
if (atom_p (x) == &scm_t)
return cons (cons (x, y), a);
return cons (cons (car (x), car (y)),
pairlis (cdr (x), cdr (y), a));
}
scm scm_pairlis = {FUNCTION3, .name="pairlis", .function3 = &pairlis};
scm *
assoc (scm *x, scm *a)
{
if (a == &scm_nil) {
#if DEBUG
printf ("alist miss: %s\n", x->name);
#endif
return &scm_f;
}
if (eq_p (caar (a), x) == &scm_t)
return car (a);
return assoc (x, cdr (a));
}
scm scm_assoc = {FUNCTION2, .name="assoc", .function2 = &assoc};
scm *apply (scm*, scm*, scm*);
scm *eval_ (scm*, scm*);
scm *apply_ (scm*, scm*, scm*);
scm *
eval_quote (scm *fn, scm *x)
{
return apply (fn, x, &scm_nil);
}
scm *builtin_p (scm*);
scm *call (scm *, scm*);
scm *display (scm*);
scm *newline ();
scm *
apply_ (scm *fn, scm *x, scm *a)
{
#if DEBUG
printf ("apply fn=");
display (fn);
printf (" x=");
display (x);
puts ("");
#endif
if (atom_p (fn) != &scm_f)
{
if (fn == &scm_symbol_current_module) // FIXME
return a;
if (builtin_p (fn) == &scm_t)
return call (fn, x);
return apply (eval (fn, a), x, a);
}
else if (car (fn) == &scm_lambda) {
scm *body = cddr (fn);
scm *ca = cadr (fn);
scm *ax = pairlis (cadr (fn), x, a);
scm *result = eval (car (body), ax);
if (cdr (body) == &scm_nil)
return result;
return apply (cons (car (fn), cons (cadr (fn), cdddr (fn))), x, ax);
}
else if (car (fn) == &scm_label)
return apply (caddr (fn), x, cons (cons (cadr (fn), caddr (fn)), a));
return &scm_unspecified;
}
scm *evcon (scm*, scm*);
scm *evlis (scm*, scm*);
scm *
eval_ (scm *e, scm *a)
{
#if DEBUG
printf ("eval e=");
display (e);
puts ("");
#endif
if (e->type == NUMBER)
return e;
else if (atom_p (e) == &scm_t) {
scm *y = assoc (e, a);
if (y == &scm_f) {
printf ("eval: no such symbol: %s\n", e->name);
exit (1);
}
return cdr (y);
}
if (builtin_p (e) == &scm_t)
return e;
else if (atom_p (car (e)) == &scm_t)
{
#if MACROS
scm *macro;
#endif // MACROS
if (car (e) == &scm_symbol_quote)
return cadr (e);
#if QUASIQUOTE
else if (car (e) == &scm_symbol_unquote)
return eval (cadr (e), a);
else if (car (e) == &scm_symbol_quasiquote) {
#if DEBUG
printf ("cadr e:");
display (cadr (e));
puts ("");
printf ("qq:");
display (eval_quasiquote (cadr (e), a));
puts ("");
#endif // DEBUG
return eval_quasiquote (cadr (e), a);
}
#endif // QUASIQUOTE
else if (car (e) == &scm_symbol_cond)
return evcon (cdr (e), a);
#if MACROS
else if ((macro = assoc (car (e), cdr (assoc (&scm_macro, a)))) != &scm_f)
return eval (apply_ (cdr (macro), cdr (e), a), a);
#endif // MACROS
return apply (car (e), evlis (cdr (e), a), a);
}
return apply (car (e), evlis (cdr (e), a), a);
}
scm *
evcon_ (scm *c, scm *a)
{
#if DEBUG
printf ("evcon_ clause=");
display (car (c));
puts ("");
#endif
if (eval (caar (c), a) != &scm_f) {
#if DEBUG
//if (fn != &scm_display && fn != &scm_call)
//if (fn != &scm_call)
printf ("#t clause=");
display (car (c));
printf (" cddar=");
display (cddar (c));
printf (" nil=%d", cddar (c) == &scm_nil);
puts ("");
#endif
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);
}
return evcon_ (cdr (c), a);
}
scm *
evcon (scm *c, scm *a)
{
#if DEBUG
printf ("\n****evcon=");
display (c);
puts ("");
#endif
return evcon_ (c, a);
}
scm scm_evcon = {FUNCTION2, .name="evcon", .function2 = &evcon};
scm *
evlis (scm *m, scm *a)
{
#if DEBUG
printf ("evlis m=");
display (m);
puts ("");
#endif
if (m == &scm_nil)
return &scm_nil;
return cons (eval (car (m), a), evlis (cdr (m), a));
}
scm scm_evlis = {FUNCTION2, .name="evlis", .function2 = &evlis};
//Primitives
scm scm_car = {FUNCTION1, "car", .function1 = &car};
scm scm_cdr = {FUNCTION1, "cdr", .function1 = &cdr};
scm scm_cons = {FUNCTION2, "cons", .function2 = &cons};
scm scm_cond = {FUNCTION2, "cond", .function2 = &evcon};
scm scm_eq_p = {FUNCTION2, "eq", .function2 = &eq_p};
scm scm_null_p = {FUNCTION1, "null", .function1 = &null_p};
scm scm_pair_p = {FUNCTION1, "pair", .function1 = &pair_p};
scm scm_quote = {FUNCTION1, "quote", .function1 = &quote};
#if QUASIQUOTE
scm scm_unquote = {FUNCTION1, "unquote", .function1 = &unquote};
scm scm_quasiquote = {FUNCTION1, "quasiquote", .function1 = &quasiquote};
#endif
scm scm_eval = {FUNCTION2, .name="eval", .function2 = &eval};
scm scm_apply = {FUNCTION3, .name="apply", .function3 = &apply};
scm scm_apply_ = {FUNCTION3, .name="c:apply", .function3 = &apply_};
scm scm_eval_ = {FUNCTION2, .name="c:eval", .function2 = &eval_};
//Helpers
scm *
builtin_p (scm *x)
{
return (x->type == FUNCTION0
|| x->type == FUNCTION1
|| x->type == FUNCTION2
|| x->type == FUNCTION3)
? &scm_t : &scm_f;
}
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};
scm *display_helper (scm*, bool, char*, bool);
scm *
display (scm *x)
{
return display_helper (x, false, "", false);
}
scm scm_display = {FUNCTION1, .name="display", .function1 = &display};
scm *call (scm*, scm*);
scm scm_call = {FUNCTION2, .name="call", .function2 = &call};
scm *
call (scm *fn, scm *x)
{
#if DEBUG
//if (fn != &scm_display && fn != &scm_call)
//if (fn != &scm_call)
{
printf ("\ncall fn=");
display (fn);
printf (" x=");
display (x);
puts ("");
}
#endif
if (fn->type == FUNCTION0)
return fn->function0 ();
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;
}
scm *
append (scm *x, scm *y)
{
if (x == &scm_nil) return y;
assert (x->type == PAIR);
return cons (car (x), append (cdr (x), y));
}
scm scm_append = {FUNCTION2, .name="append", .function2 = &append};
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 *
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;
if (!strcmp (x, scm_lambda.name)) return &scm_lambda;
if (!strcmp (x, scm_label.name)) return &scm_label;
if (!strcmp (x, scm_nil.name)) return &scm_nil;
#if QUASIQUOTE
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;
#endif
return make_atom (x);
}
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;
}
scm *
builtin_lookup (scm *l, scm *a)
{
return lookup (list2str (l), a);
}
scm scm_lookup = {FUNCTION2, .name="lookup", .function2 = &builtin_lookup};
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 scm_newline = {FUNCTION0, .name="newline", .function0 = &newline};
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)
{
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);
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);
}
scm scm_readenv = {FUNCTION1, .name="readenv", .function1 = &readenv};
// Extras to make interesting program
scm *
hello_world ()
{
puts ("c: hello world");
return &scm_unspecified;
}
scm scm_hello_world = {FUNCTION0, .name="hello-world", .function0 = &hello_world};
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)
{
#if DEBUG
printf ("\nminus a=");
display (a);
printf (" b=");
display (b);
puts ("");
#endif
assert (a->type == NUMBER);
assert (b->type == NUMBER);
//return make_number (a->value - b->value);
scm *r = make_number (a->value - b->value);
#if DEBUG
printf (" ==> ");
display (r);
puts ("");
#endif
return r;
}
scm scm_less_p = {FUNCTION2, .name="<", .function2 = &less_p};
scm scm_minus = {FUNCTION2, .name="-", .function2 = &minus};
#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));
}
scm scm_eval_quasiquote = {FUNCTION2, .name="c:eval-quasiquote", .function2 = &eval_quasiquote};
#endif
scm *
add_environment (scm *a, char *name, scm* x)
{
return cons (cons (make_atom (name), x), a);
}
scm *
initial_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, "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);
a = add_environment (a, "eval-quasiquote", &scm_eval_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, "c:eval", &scm_eval_);
a = add_environment (a, "c:apply", &scm_apply_);
a = add_environment (a, "eval", &scm_eval);
a = add_environment (a, "apply", &scm_apply);
a = add_environment (a, "getchar", &scm_getchar);
a = add_environment (a, "peekchar", &scm_peekchar);
a = add_environment (a, "ungetchar", &scm_ungetchar);
a = add_environment (a, "lookup", &scm_lookup);
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, "hello-world", &scm_hello_world);
a = add_environment (a, "<", &scm_less_p);
a = add_environment (a, "-", &scm_minus);
// 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);
a = add_environment (a, "*dot*", &scm_dot);
a = add_environment (a, "current-module", &scm_symbol_current_module);
return a;
}
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_p (cadr (x)) != &scm_f)
return cons (cadr (x), eval (caddr (x), a));
return define_lambda (x, a);
}
scm *
define_macro (scm *x, scm *a)
{
#if DEBUG
printf ("\nc:define_macro a=");
scm *aa =cons (&scm_macro,
cons (define_lambda (x, a),
cdr (assoc (&scm_macro, a))));
display (aa);
puts ("");
#endif
return cons (&scm_macro,
cons (define_lambda (x, a),
cdr (assoc (&scm_macro, a))));
}
scm *
loop (scm *r, scm *e, scm *a)
{
#if DEBUG
printf ("\nc:loop e=");
display (e);
puts ("");
#endif
if (e == &scm_nil)
return r;
else if (eq_p (e, make_atom ("EOF")) == &scm_t)
return apply (cdr (assoc (make_atom ("loop2"), a)),
cons (&scm_unspecified, cons (&scm_t, cons (a, &scm_nil))), a);
else if (eq_p (e, make_atom ("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), 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);
}
int
main (int argc, char *argv[])
{
scm *a = initial_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 (make_atom ("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;
}
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