shithub: mlisp

Download patch

ref: 3e8336c0ea2e6f70eb0b277f3d0927b114d0709c
author: aap <[email protected]>
date: Fri Aug 19 06:30:52 EDT 2022

first commit

--- /dev/null
+++ b/LICENSE
@@ -1,0 +1,21 @@
+MIT License
+
+Copyright (c) 2018 
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
--- /dev/null
+++ b/Makefile
@@ -1,0 +1,6 @@
+CFLAGS=-g -Wall -Wextra -DLISP$(bits)
+LDFLAGS=-lm
+lisp: lisp.o subr.o mem.o
+lisp.o: lisp.h
+subr.o: lisp.h
+mem.o: lisp.h
--- /dev/null
+++ b/README.md
@@ -1,0 +1,34 @@
+# LISP
+
+This is an implementation of LISP inspired by MacLISP.
+It's still rather incomplete and whether I want to reach
+full MacLISP compatibility is also still uncertain.
+
+
+## Build
+
+On a 64 bit system just type `make` on UNIX, `mk` on Plan 9.
+On a 32 bit system: `bits=32 make/mk`.
+
+## How to use
+
+You're talking to a REPL. e.g.
+
+```
+% ./lisp
+*
+(car '(a b))
+
+A
+```
+
+## To-Do
+
+* Figure out what to do about lexical vs dynamic binding
+* Implement most of actual MacLISP functions
+* Arrays
+* Strings
+* maybe Bignums?
+* Better storage management
+* Assembler (and compiler?)
+* some code examples
--- /dev/null
+++ b/lib.l
@@ -1,0 +1,101 @@
+;;; taken from MACLISP
+(defprop defun
+  (lambda (l)
+    (cond ((and (caddr l)
+                (atom (caddr l)))
+           (list 'defprop (cadr l)
+                 (cons 'lambda (cons (cadddr l) (cddddr l)))
+                 (caddr l)))
+          (t (list 'defprop (cadr l)
+                   (cons 'lambda (cons (caddr l) (cdddr l)))
+                   'expr))))
+  macro)
+
+;; LET
+(defun let-vars (l) (maplist #'(lambda (x) (caar x)) (cadr l))) 
+(defun let-vals (l) (maplist #'(lambda (x) (cadar x)) (cadr l))) 
+(defun let macro (l)
+  (cons (cons 'lambda (cons (let-vars l) (cddr l)))
+        (let-vals l)))
+
+
+
+
+;;;
+;;; examples
+;;;
+
+
+;;; compute greatest common divisor
+(defun gcd (a b)
+  (cond ((lessp a b) (gcd b a))
+        ((eq b 0) a)
+        (t (gcd b (difference a b)))))
+
+
+;;; differentiate expression exp w.r.t. x
+(defun diff (exp x)
+  (cond ((eq exp x) 1)
+        ((atom exp) 0)
+        ((eq (car exp) 'plus)
+         (cons 'plus (mapcar #'(lambda (j) (diff j x)) (cdr exp))))
+        ((eq (car exp) 'times)
+         (cons 'plus
+               (maplist
+                 #'(lambda (J)
+                     (cons 'times
+                           (maplist
+                             #'(lambda (K)
+                                 (cond ((equal J K) (diff (car K) x))
+                                       (t (car K))))
+                               (cdr exp))))
+                   (cdr exp))))
+        (t 'invalid)))
+
+
+
+;;; simplify mathematical expression
+(defun simplify (exp)
+  (cond ((atom exp) exp)
+         ((eq (car exp) 'plus) (simpsum (simplis (cdr exp))))
+         ((eq (car exp) 'times) (simpprod (simplis (cdr exp))))
+         (t exp)))
+
+;;; simplify a list of expressions
+(defun simplis (lst)
+  (mapcar #'(lambda (l) (simplify l)) lst))
+
+;;; simplify the terms of a sum
+(defun simpsum (terms)
+  (prog (sep const var)
+    (setq sep (separate terms nil nil))
+    (setq const (car sep))
+    (setq var (cadr sep))
+    (setq const (eval (cons 'plus const) nil))
+    (return (cond ((null var) const)
+                  ((eq const 0)
+                   (cond ((null (cdr var)) (car var))
+                         (t (cons 'plus var))))
+                  (t (cons 'plus (cons const var)))))))
+
+;;; simplify the terms of a product
+(defun simpprod (terms)
+  (prog (sep const var)
+    (setq sep (separate terms nil nil))
+    (setq const (car sep))
+    (setq var (cadr sep))
+    (setq const (eval (cons 'times const) nil))
+    (return (cond ((null var) const)
+                  ((eq const 0) 0)
+                  ((eq const 1)
+                   (cond ((null (cdr var)) (car var))
+                         (t (cons 'times var))))
+                  (t (cons 'times (cons const var)))))))
+
+;;; separate constants from variables in a list
+(defun separate (lst const var)
+  (cond ((null lst)
+         (list const var))
+        ((numberp (car lst))
+         (separate (cdr lst) (cons (car lst) const) var))
+        (t (separate (cdr lst) const (cons (car lst) var)))))
--- /dev/null
+++ b/lisp.c
@@ -1,0 +1,1033 @@
+#include "lisp.h"
+
+#ifdef PLAN9
+void exit(int n)
+{
+	if(n == 0)
+		exits(nil);
+	exits("error");
+}
+#endif
+
+FILE *sysin, *sysout, *syserr;
+
+C *fclist;
+F *fflist;
+C *pdl[PDLSZ];
+int pdp;
+Temlis temlis;
+C **alist;
+int nargs;
+C *oblist;
+Arglist largs;
+
+int gcen;
+int gcdbg = 0;
+
+void *Atom = (void*)CAR_ATOM;
+void *Fixnum = (void*)(CAR_ATOM|CAR_FIX);
+void *Flonum = (void*)(CAR_ATOM|CAR_FLO);
+
+/* absence of a value */
+C *noval = (C*)~0;
+
+/* some important atoms */
+C *pname;
+C *value;
+C *expr;
+C *subr;
+C *lsubr;
+C *fexpr;
+C *fsubr;
+C *macro;
+C *t;
+C *quote;
+C *label;
+C *function;
+C *funarg;
+C *lambda;
+C *cond;
+C *set;
+C *setq;
+C *go;
+C *retrn;
+
+C *star;
+C *digits[10];
+C *plus, *minus;
+
+jmp_buf tljmp;
+
+/* print error and jmp back into toplevel */
+void
+err(char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	vfprintf(syserr, fmt, ap);
+	fprintf(syserr, "\n");
+	va_end(ap);
+	longjmp(tljmp, 1);
+}
+
+void
+panic(char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	vfprintf(syserr, fmt, ap);
+	fprintf(syserr, "\n");
+	va_end(ap);
+#ifdef PLAN9
+	exits("panic");
+#else
+	exit(1);
+#endif
+}
+
+C**
+push(C *c)
+{
+	C **p;
+	assert(pdp >= 0 && pdp < PDLSZ);
+	p = &pdl[pdp++];
+	*p = c;
+	return p;
+}
+
+C*
+pop(void)
+{
+	assert(pdp > 0 && pdp <= PDLSZ);
+	return pdl[--pdp];
+}
+
+C*
+cons(void *a, C *d)
+{
+	C *c;
+	if(((P)a & CAR_ATOM) == 0)
+		temlis.ca = a;
+	temlis.cd = d;
+	if(gcen && (fclist == nil || gcdbg))
+		gc();
+	c = fclist;
+	assert(c != nil);
+	fclist = fclist->d;
+	temlis.ca = nil;
+	temlis.cd = nil;
+	c->a = a;
+	c->d = d;
+	return c;
+}
+
+F*
+consw(word fw)
+{
+	F *f;
+	if(gcen && (fflist == nil || gcdbg))
+		gc();
+	f = fflist;
+	assert(f != nil);
+	fflist = fflist->p;
+	f->fw = fw;
+	return f;
+}
+
+C*
+mkfix(fixnum fix)
+{
+	C *c;
+	if(fix >= 0 && fix < 10)
+		return digits[fix];
+	c = cons(Fixnum, nil);
+	c->fix = fix;
+	return c;
+}
+
+C*
+mkflo(flonum flo)
+{
+	C *c;
+	c = cons(Flonum, nil);
+	c->flo = flo;
+	return c;
+}
+
+C*
+mksubr(C *(*subr)(void), int n)
+{
+	F nf, sf;
+	nf.n = n;
+	sf.subr = subr;
+	temlis.ca = consw(nf.fw);
+	temlis.cd = consw(sf.fw);
+	return cons(temlis.ca, temlis.cd);
+}
+
+int
+atom(C *c)
+{
+	return c == nil || c->ap & CAR_ATOM;
+}
+
+int
+fixnump(C *c)
+{
+	return c != nil && c->ap & CAR_ATOM && c->ap & CAR_FIX;
+}
+
+int
+flonump(C *c)
+{
+	return c != nil && c->ap & CAR_ATOM && c->ap & CAR_FLO;
+}
+
+int
+numberp(C *c)
+{
+	return c != nil && c->ap & CAR_ATOM && c->ap & CAR_NUM;
+}
+
+int
+listp(C *c)
+{
+	return c == nil || !(c->ap & CAR_ATOM);
+}
+
+fixnum
+length(C *c)
+{
+	fixnum n;
+	if(!listp(c))
+		err("error: not a list");
+	for(n = 0; c != nil; c = c->d){
+		if(atom(c))
+			err("error: not a proper list");
+		n++;
+	}
+	return n;
+}
+
+/* functions for handling pnames */
+int
+matchpname(C *c, char *name)
+{
+	int i;
+	char *s;
+	char c1, c2;
+
+	s = name;
+	i = 0;
+	for(;;){
+		c1 = *s++;
+		c2 = c ? c->af->c[i++] : '\0';
+		if(i == C2W){
+			i = 0;
+			c = c->d;
+		}
+		if(c1 != c2)
+			return 0;
+		if(c1 == '\0')
+			return 1;
+	}
+}
+
+C*
+makepname(char *name)
+{
+	int i;
+	F w;
+	char *s;
+	C *ret, **next;
+
+	/* TODO: maybe do this elsewhere? */
+	ret = cons(nil, nil);
+	temlis.pn = ret;
+	next = &ret->a;
+
+	/* split up name into full words
+	 * and build list structure */
+	s = name;
+	while(*s != '\0'){
+		w.fw = 0;
+		for(i = 0; i < C2W; i++){
+			if(*s == '\0')
+				break;
+			w.c[i] = *s++;
+		}
+		*next = cons(consw(w.fw), nil);
+		next = &(*next)->d;
+	}
+	temlis.pn = nil;
+	return ret;
+}
+
+C*
+get(C *l, C *p)
+{
+	assert(l != nil);
+	for(; l->d != nil; l = l->d->d){
+		assert(listp(l->d));
+		if(l->d->a == p){
+			assert(listp(l->d->d));
+			return l->d->d->a;
+		}
+	}
+	return nil;
+}
+C*
+getx(C *l, C *p)
+{
+	for(l = l->d; l != nil; l = l->d->d)
+		if(l->a == p)
+			return l->d;
+	return nil;
+}
+
+/* returns noval instead of evaluating a function */
+C*
+assq(C *x, C *y)
+{
+	for(; y != nil; y = y->d)
+		if(y->a->a == x)
+			return y->a;
+	return nil;
+}
+
+C*
+putprop(C *a, C *val, C *ind)
+{
+	C *tt;
+	if(a == nil || numberp(a))
+		err("error: no p-list");
+	for(tt = a->d; tt != nil; tt = tt->d->d)
+		if(tt->a == ind){
+			tt->d->a = val;
+			return val;
+		}
+	temlis.a = a;
+	temlis.b = ind;
+	a->d = cons(ind, cons(val, a->d));
+	temlis.a = nil;
+	temlis.b = nil;
+	return val;
+}
+
+C*
+nconc(C *x, C *e)
+{
+	C *m;
+	if(x == nil) return e;
+	m = x;
+	for(; x->d != nil; x = x->d);
+	x->d = e;
+	return m;
+}
+
+C*
+pair(C *x, C *y)
+{
+	C *m, **p;
+// TODO: must save here?
+	temlis.b = x;
+	temlis.c = y;
+	assert(temlis.a == nil);
+	p = (C**)&temlis.a;
+	while(x != nil && y != nil){
+		*p = cons(cons(x->a, y->a), nil);
+		p = &(*p)->d;
+		x = x->d;
+		y = y->d;
+	}
+	if(x != nil || y != nil)
+		err("error: pair not same length");
+	m = temlis.a;
+	temlis.a = nil;
+	temlis.b = nil;
+	temlis.c = nil;
+	return m;
+}
+
+C*
+intern(char *name)
+{
+	C *c;
+	C *pn;
+	for(c = oblist; c; c = c->d){
+		if(numberp(c->a))
+			continue;
+		pn = get(c->a, pname);
+		if(pn == nil)
+			continue;
+		if(matchpname(pn, name))
+			return c->a;
+	}
+	c = cons(Atom,
+		cons(pname,
+		makepname(name)));
+	oblist = cons(c, oblist);
+	return c;
+}
+
+/*
+ * output
+ */
+
+void
+princpname(C *c)
+{
+	char chr;
+	word fw;
+	int i;
+	for(c = c->a; c != nil; c = c->d){
+		fw = ((F*)c->a)->fw;
+		for(i = 0; i < C2W; i++){
+			chr = fw&0xFF;
+			if(chr == 0) return;
+			putc(chr, sysout);
+			fw >>= 8;
+		}
+	}
+}
+
+void
+printpname(C *c)
+{
+	char chr;
+	C *cc;
+	word fw;
+	int i;
+	int spec;
+
+	cc = c;
+	spec = 0;
+	for(c = c->a; c != nil; c = c->d){
+		fw = ((F*)c->a)->fw;
+		for(i = 0; i < C2W; i++){
+			chr = fw&0xFF;
+			if(chr == 0) goto pr;
+			if(!isupper(fw&0x7F)){
+				spec = 1;
+				goto pr;
+			}
+			fw >>= 8;
+		}
+	}
+pr:
+	if(spec) putc('|', sysout);
+	princpname(cc);
+	if(spec) putc('|', sysout);
+}
+
+void
+printatom(C *c, void (*pnm)(C *c))
+{
+	if(c == nil)
+		fprintf(sysout, "NIL");
+	else if(fixnump(c))
+		fprintf(sysout, "%lld", (long long int)c->fix);
+	else if(flonump(c))
+		fprintf(sysout, "%f", c->flo);
+	else{
+		assert(atom(c));
+		for(; c != nil; c = c->d)
+			if(c->a == pname){
+				pnm(c->d);
+				return;
+			}
+		fprintf(sysout, "%%ATOM%%");
+	}
+}
+
+void
+printsxp(C *c, void (*pnm)(C *c))
+{
+	int fst;
+	if(atom(c))
+		printatom(c, pnm);
+	else{
+		putc('(', sysout);
+		fst = 1;
+		for(; c != nil; c = c->d){
+			if(atom(c)){
+				fprintf(sysout, " . ");
+				printatom(c, pnm);
+				break;
+			}
+			if(!fst)
+				putc(' ', sysout);
+			lprint(c->a);
+			fst = 0;
+		}
+		putc(')', sysout);
+	}
+}
+
+void
+lprint(C *c)
+{
+	printsxp(c, printpname);
+}
+
+void
+princ(C *c)
+{
+	printsxp(c, princpname);
+}
+
+/*
+ * input
+ */
+
+int nextc;
+
+static int
+chsp(void)
+{
+	int c;
+	if(nextc){
+		c = nextc;
+		nextc = 0;
+		return c;
+	}
+	c = getc(sysin);
+	// remove comments
+	if(c == ';')
+		while(c != '\n')
+			c = getc(sysin);
+	if(isspace(c))
+		c = ' ';
+	return c;
+}
+
+static int
+ch(void)
+{
+	int c;
+	while(c = chsp(), c == ' ');
+	return c;
+}
+
+C*
+readnum(char *buf)
+{
+	int c;
+	int type;
+	fixnum oct;
+	fixnum dec;
+	flonum flo, fract, div;
+	int sign;
+	int ndigits;
+
+	sign = 1;
+	type = 0;	/* octal */
+	oct = 0;
+	dec = 0;
+	flo = 0.0;
+	fract = 0.0;
+	div = 10.0;
+	ndigits = 0;
+
+
+	c = *buf;
+	if(c == '-' || c == '+'){
+		sign = c == '-' ? -1 : 1;
+		buf++;
+	}
+
+	while(c = *buf++, c != '\0'){
+		if(c >= '0' && c <= '9'){
+			if(type == 0){
+				oct = oct*8 + c-'0';
+				dec = dec*10 + c-'0';
+				flo = flo*10.0 + c-'0';
+			}else{
+				type = 2;	/* float */
+				fract += (c-'0')/div;
+				div *= 10.0;
+			}
+			ndigits++;
+		}else if(c == '.' && type == 0){
+			type = 1;	/* decimal */
+		}else
+			return nil;
+	}
+	if(ndigits == 0)
+		return nil;
+// use decimal default for now
+//	if(type == 0)
+//		return mkfix(sign*oct);
+//	if(type == 1)
+//		return mkfix(sign*dec);
+	if(type == 0 || type == 1)
+		return mkfix(sign*dec);
+	return mkflo(sign*(flo+fract));
+}
+
+C*
+readatom(void)
+{
+	C *num;
+	int c;
+	char buf[128], *p;
+	int spec, lc;
+
+	p = buf;
+	spec = 0;
+	lc = 1;
+	while(c = chsp(), c != EOF){
+		if(!spec && strchr(" ()", c)){
+			nextc = c;
+			break;
+		}
+		if(c == '|'){
+			lc = 0;
+			spec = !spec;
+			continue;
+		}
+		*p++ = c;
+	}
+	*p = '\0';
+	if(lc)
+		for(p = buf; *p; p++)
+			*p = toupper(*p);
+	if(strcmp(buf, "NIL") == 0)
+		return nil;
+	num = readnum(buf);
+	return num ? num : intern(buf);
+}
+
+C *readsxp(void);
+
+C*
+readlist(void)
+{
+	int first;
+	int c;
+	C **p;
+
+	first = 1;
+	p = push(nil);
+	while(c = ch(), c != ')'){
+		/* TODO: only valid when next letter is space */
+		if(c == '.'){
+			if(first)
+				err("error: unexpected '.'");
+			*p = readsxp();
+			if(c = ch(), c != ')')
+				err("error: expected ')' (got %c)", c);
+			break;
+		}
+		nextc = c;
+		*p = cons(readsxp(), nil);
+		p = &(*p)->d;
+		first = 0;
+	}
+	return pop();
+}
+
+C*
+readsxp(void)
+{
+	int c;
+	c = ch();
+	if(c == EOF)
+		return noval;
+	if(c == '\'')
+		return cons(quote, cons(readsxp(), nil));
+	if(c == '#'){
+		c = ch();
+		if(c == '\'')
+			return cons(function, cons(readsxp(), nil));
+		err("expected '");
+	}
+	if(c == ')')
+		err("error: unexpected ')'");
+	if(c == '(')
+		return readlist();
+	nextc = c;
+	return readatom();
+}
+
+/*
+ * Eval Apply
+ */
+
+Arglist
+spread(C *l)
+{
+	Arglist al;
+	al.nargs = nargs;
+	al.alist = alist;
+	al.pdp = pdp;
+	nargs = 0;
+	alist = &pdl[pdp];
+	for(; l != nil; l = l->d){
+		push(l->a);
+		nargs++;
+	}
+	return al;
+}
+
+void
+restore(Arglist al)
+{
+	pdp = al.pdp;
+	alist = al.alist;
+	nargs = al.nargs;
+}
+
+C*
+evbody(C *c, C *a)
+{
+	C *t;
+	t = nil;
+	for(; c != nil; c = c->d)
+		t = eval(c->a, a);
+	return t;
+}
+
+C*
+evcon(C *c, C *a)
+{
+	C *tt;
+	int spdp;
+	spdp = pdp;
+	push(c);
+	push(a);
+	for(; c != nil; c = c->d){
+		tt = eval(c->a->a, a);
+		if(tt != nil){
+			pdp = spdp;
+			return evbody(c->a->d, a);
+		}
+	}
+	err("error: no cond clause");
+	return nil;	/* make compiler happy */
+}
+
+C*
+applysubr(C *subr, C *args)
+{
+	C *tt;
+	Arglist al;
+
+	al = spread(args);
+	if(subr->af->n != nargs)
+		err("error: arg count (expected %d, got %d)",
+			subr->af->n, nargs);
+	tt = subr->df->subr();
+	restore(al);
+	return tt;
+}
+
+C*
+applylsubr(C *subr, C *args)
+{
+	C *tt;
+	Arglist al, ll;
+
+	al = spread(args);
+	ll = largs;
+	largs.nargs = nargs;
+	largs.alist = alist-1;
+	tt = subr->df->subr();
+	largs = ll;
+	restore(al);
+	return tt;
+}
+
+C*
+eval(C *form, C *a)
+{
+	C *tt, *arg;
+	int spdp;
+	Arglist al;
+
+tail:
+	if(form == nil)
+		return nil;
+	if(numberp(form))
+		return form;
+	if(atom(form)){
+		if(tt = getx(form, value), tt != nil)
+			return tt->a;
+		if(tt = assq(form, a), tt == nil)
+			err("error: no value");
+		return tt->d;
+	}
+	if(form->a == cond)
+		return evcon(form->d, a);
+	spdp = pdp;
+	push(form);
+	push(a);
+	if(atom(form->a)){
+		if(form->a == nil || numberp(form->a))
+lprint(form),
+			err("error: no function");
+		for(tt = form->a->d; tt != nil; tt = tt->d->d){
+			if(tt->a == expr){
+				arg = evlis(form->d, a);
+				pdp = spdp;
+				return apply(tt->d->a, arg, a);
+			}else if(tt->a == fexpr){
+				arg = cons(form->d, cons(a, nil));
+				pdp = spdp;
+				return apply(tt->d->a, arg, a);
+			}else if(tt->a == subr){
+				arg = evlis(form->d, a);
+				pdp = spdp;
+				return applysubr(tt->d->a, arg);
+			}else if(tt->a == lsubr){
+				arg = evlis(form->d, a);
+				pdp = spdp;
+				return applylsubr(tt->d->a, arg);
+			}else if(tt->a == fsubr){
+				pdp = spdp;
+				al = spread(nil);
+				push(form->d);
+				push(a);
+				nargs = 2;
+				tt = tt->d->af->subr();
+				restore(al);
+				return tt;
+			}else if(tt->a == macro){
+				arg = cons(form, nil);
+				pdp = spdp;
+				form = apply(tt->d->a, arg, a);
+				goto tail;
+			}
+		}
+		if(tt = assq(form->a, a), tt == nil)
+lprint(form),
+			err("error: no function");
+		form = cons(tt->d, form->d);
+		pdp = spdp;
+		goto tail;
+	}
+	arg = evlis(form->d, a);
+	pdp = spdp;
+	return apply(form->a, arg, a);
+}
+
+C*
+evlis(C *m, C *a)
+{
+	C **p;
+	int spdp;
+
+	p = push(nil);
+	spdp = pdp;
+	push(m);
+	push(a);
+	for(; m != nil; m = m->d){
+		*p = cons(eval(m->a, a), nil);
+		p = &(*p)->d;
+	}
+	pdp = spdp;
+	return pop();
+}
+
+C*
+apply(C *fn, C *args, C *a)
+{
+	C *tt;
+	int spdp;
+	Arglist al, ll;
+
+	if(atom(fn)){
+		if(fn == nil || numberp(fn))
+lprint(fn),
+			err("error: no function");
+		for(tt = fn->d; tt != nil; tt = tt->d->d){
+			if(tt->a == expr)
+				return apply(tt->d->a, args, a);
+			else if(tt->a == subr)
+				return applysubr(tt->d->a, args);
+			else if(tt->a == lsubr)
+				return applylsubr(tt->d->a, args);
+		}
+		if(tt = assq(fn, a), tt == nil)
+lprint(fn),
+			err("error: no function");
+		return apply(tt->d, args, a);
+	}
+	spdp = pdp;
+	push(fn);
+	push(args);
+	push(a);
+	if(fn->a == label){
+		tt = cons(fn->d->a, fn->d->d->a);
+		a = cons(tt, a);
+		pdp = spdp;
+		return apply(fn->d->d->a, args, a);
+	}
+	if(fn->a == funarg){
+		pdp = spdp;
+		return apply(fn->d->a, args, fn->d->d->a);
+	}
+	if(fn->a == lambda){
+		if(fn->d->a && atom(fn->d->a)){
+			tt = cons(fn->d->a, mkfix(length(args)));
+			pdp = spdp;
+			al = spread(args);
+			ll = largs;
+			largs.nargs = nargs;
+			largs.alist = alist-1;
+			tt = evbody(fn->d->d, cons(tt, a));
+			largs = ll;
+			restore(al);
+			return tt;
+		}else{
+			args = pair(fn->d->a, args);
+			pdp = spdp;
+			return evbody(fn->d->d, nconc(args, a));
+		}
+	}
+	fn = eval(fn, a);
+	pdp = spdp;
+	return apply(fn, args, a);
+}
+
+
+/*
+ * top level
+ */
+
+void
+init(void)
+{
+	int i;
+
+	sysin = stdin;
+	sysout = stdout;
+	syserr = stderr;
+
+	gc();
+
+	/* init oblist so we can use intern */
+	pname = cons(Atom, nil);
+	pname->d = cons(pname, makepname("PNAME"));
+	oblist = cons(pname, nil);
+
+	/* Now enable GC */
+	gcen = 1;
+
+	t = intern("T");
+	value = intern("VALUE");
+	subr = intern("SUBR");
+	lsubr = intern("LSUBR");
+	fsubr = intern("FSUBR");
+	expr = intern("EXPR");
+	fexpr = intern("FEXPR");
+	macro = intern("MACRO");
+	quote = intern("QUOTE");
+	label = intern("LABEL");
+	funarg = intern("FUNARG");
+	function = intern("FUNCTION");
+	lambda = intern("LAMBDA");
+	cond = intern("COND");
+	set = intern("SET");
+	setq = intern("SETQ");
+	go = intern("GO");
+	retrn = intern("RETURN");
+
+	for(i = 0; i < 10; i++){
+		digits[i] = cons(Fixnum, nil);
+		digits[i]->fix = i;
+		oblist = cons(digits[i], oblist);
+	}
+	plus = intern("+");
+	minus = intern("-");
+
+	initsubr();
+
+	star = intern("*");
+}
+
+void
+eval_repl(void)
+{
+	C *e;
+
+	putprop(star, star, value);
+	for(;;){
+		putc('\n', sysout);
+		princ(eval(star, nil));
+		putc('\n', sysout);
+		e = readsxp();
+		if(e == noval)
+			return;
+		e = eval(e, nil);
+		if(e == noval)
+			putprop(star, star, value);
+		else
+			putprop(star, e, value);
+	}
+}
+
+void
+eval_file(void)
+{
+	C *e;
+	for(;;){
+		e = readsxp();
+		if(e == noval)
+			return;
+		eval(e, nil);
+	}
+}
+
+void
+load(char *filename)
+{
+	FILE *oldin, *f;
+	f = fopen(filename, "r");
+	if(f == nil)
+		return;
+	oldin = sysin;
+	sysin = f;
+	if(setjmp(tljmp))
+		exit(1);
+	eval_file();
+	sysin = oldin;
+	fclose(f);
+}
+
+#ifdef PLAN9
+void
+main(int, char**)
+#else
+int
+main()
+#endif
+{
+#ifdef LISP32
+	/* only works on 32 bits */
+	assert(sizeof(void*) == 4);
+#else
+	/* only works on 64 bits */
+	assert(sizeof(void*) == 8);
+#endif
+
+	init();
+
+	load("lib.l");
+
+//	lprint(oblist);
+//	fprintf(sysout, "\n");
+
+	if(setjmp(tljmp))
+		fprintf(sysout, "→\n");
+	pdp = 0;
+	alist = nil;
+	memset(&temlis, 0, sizeof(temlis));
+
+	eval_repl();
+#ifdef PLAN9
+	exits(nil);
+#else
+	return 0;
+#endif
+}
--- /dev/null
+++ b/lisp.h
@@ -1,0 +1,189 @@
+#ifdef PLAN9
+#include <u.h>
+#include <libc.h>
+#include <stdio.h>
+#include <ctype.h>
+typedef uintptr uintptr_t;
+typedef u32int uint32_t;
+typedef s32int int32_t;
+typedef u64int uint64_t;
+typedef s64int int64_t;
+#else
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdarg.h>
+#include <string.h>
+#include <ctype.h>
+#include <math.h>
+#include <setjmp.h>
+#include <assert.h>
+
+#define nil NULL
+#endif
+
+#define FIXMIN (-FIXMAX-1)
+
+/* basic data types */
+typedef uintptr_t P;
+#ifdef LISP32
+/* assume we're running on 32 bits!!! */
+typedef uint32_t word;
+typedef int32_t fixnum;
+typedef float flonum;
+#define FIXMAX ((fixnum)0x7FFFFFFF)
+#define FLOMAX 3.40282347E+38f
+enum
+{
+	B2W = 32,	/* bits per word */
+	C2W = B2W/8,	/* character per word */
+};
+#else
+/* assume we're running on 64 bits!!! */
+typedef uint64_t word;
+typedef int64_t fixnum;
+typedef double flonum;
+#define FIXMAX ((fixnum)0x7FFFFFFFFFFFFFFF)
+#define FLOMAX 1.7976931348623157E+308
+enum
+{
+	B2W = 64,	/* bits per word */
+	C2W = B2W/8,	/* character per word */
+};
+#endif
+
+extern FILE *sysin, *sysout, *syserr;
+
+/* static storage sizes */
+enum
+{
+	NUMCONS = 32*1024,
+	NUMFW = 32*1024,
+	PDLSZ = 1024,
+};
+
+
+typedef struct C C;
+typedef union F F;
+
+/* A cons cell */
+struct C
+{
+	union {
+		C *a;
+		F *af;
+		P ap;
+	};
+	union {
+		C *d;
+		F *df;
+		P dp;
+
+		fixnum fix;
+		flonum flo;
+	};
+};
+
+/* CAR bits */
+enum
+{
+	CAR_MARK = 1,
+	CAR_ATOM = 2,
+	CAR_FIX  = 4,
+	CAR_FLO  = 8,
+	CAR_NUM  = CAR_FIX | CAR_FLO
+};
+
+
+/* A full word */
+union F
+{
+	word fw;
+	char c[C2W];
+	F *p;
+	fixnum n;
+	C *(*subr)(void);
+};
+
+
+/* free storage */
+extern C *fclist;
+extern F *fflist;
+
+/* push down list */
+extern C *pdl[PDLSZ];
+extern int pdp;
+
+/* Temporary variables automatically saved */
+typedef struct Temlis Temlis;
+struct Temlis
+{
+	/* temp */
+	void *a, *b, *c;
+	/* arguments to cons */
+	void *ca;
+	void *cd;
+	/* pname */
+	void *pn;
+};
+extern Temlis temlis;
+extern C **alist;
+extern int nargs;
+extern C *oblist;
+
+typedef struct Arglist Arglist;
+struct Arglist {
+	int nargs;
+	C **alist;
+	int pdp;
+};
+extern Arglist largs;	/* LEXPR/LSUBR args */
+
+extern C *noval;
+extern C *t;
+extern C *value;
+extern C *expr;
+extern C *subr;
+extern C *lsubr;
+extern C *fexpr;
+extern C *fsubr;
+extern C *macro;
+extern C *funarg;
+extern C *cond;
+extern C *set;
+extern C *setq;
+extern C *go;
+extern C *retrn;
+
+void err(char *fmt, ...);
+void panic(char *fmt, ...);
+C **push(C *c);
+C *pop(void);
+
+C *cons(void *a, C *d);
+F *consw(word fw);
+C *mkfix(fixnum fix);
+C *mkflo(flonum flo);
+C *mksubr(C *(*subr)(void), int n);
+int atom(C *c);
+int fixnump(C *c);
+int flonump(C *c);
+int numberp(C *c);
+int listp(C *c);
+fixnum length(C *c);
+C *get(C *l, C *p);
+C *assq(C *x, C *y);
+C *putprop(C *l, C *p, C *ind);
+C *pair(C *x, C *y);
+C *intern(char *name);
+C *readsxp(void);
+void lprint(C *c);
+void princ(C *c);
+void printatom(C *c, void (*pnm)(C *c));
+C *eval(C *form, C *a);
+C *evlis(C *m, C *a);
+C *apply(C *fn, C *args, C *a);
+
+void gc(void);
+
+void initsubr(void);
--- /dev/null
+++ b/mem.c
@@ -1,0 +1,92 @@
+#include "lisp.h"
+
+C cstore[NUMCONS];
+F fstore[NUMFW];
+word fmark[NUMFW/B2W];
+
+void
+mark(C *c)
+{
+	C *a;
+	F *f;
+	int n;
+
+tail:
+	if(c == nil)
+		return;
+
+	/* Mark full word */
+	f = (F*)c;
+	if(f >= &fstore[0] && f < &fstore[NUMFW]){
+		n = f - fstore;
+		fmark[n/B2W] |= (word)1 << n%B2W;
+		return;
+	}
+
+	/* Must be a cons cell */
+	if(c >= &cstore[0] && c < &cstore[NUMCONS]){
+		if(c->ap & CAR_MARK)
+			return;
+		a = c->a;
+		c->ap |= CAR_MARK;
+		if(c->ap & CAR_ATOM){
+			if(c->ap & CAR_NUM)
+				return;
+		}else
+			mark(a);
+		c = c->d;
+		goto tail;
+	}
+
+	panic("invalid ptr: %p\n", c);
+}
+
+void
+gc(void)
+{
+	int i, j;
+	C *c, **cp;
+	F *f;
+	word m;
+	int nc, nf;
+
+	/* Mark */
+	mark(oblist);
+	for(i = 0; i < pdp; i++)
+		mark(pdl[i]);
+	for(cp = (C**)&temlis; cp < (C**)(&temlis+1); cp++)
+		mark(*cp);
+
+	/* Sweep */
+	fclist = nil;
+	nc = 0;
+	for(c = cstore; c < &cstore[NUMCONS]; c++){
+		if(c->ap & CAR_MARK)
+			c->ap &= ~CAR_MARK;
+		else{
+			c->a = nil;
+			c->d = fclist;
+			fclist = c;
+			nc++;
+		}
+	}
+
+	fflist = nil;
+	f = fstore;
+	nf = 0;
+	for(i = 0; i < NUMFW/B2W; i++){
+		m = fmark[i];
+		fmark[i] = 0;
+		for(j = 0; j < B2W; j++){
+			if(!(m&1)){
+				f->p = fflist;
+				fflist = f;
+				nf++;
+			}
+			m >>= 1;
+			f++;
+		}
+	}
+
+//	fprintf(syserr, "reclaimed: %d %d\n", nc, nf);
+}
--- /dev/null
+++ b/mkfile
@@ -1,0 +1,18 @@
+</$objtype/mkfile
+BIN=/$objtype/bin
+CFLAGS=$CFLAGS -DPLAN9 -DLISP$bits
+
+TARG=lisp
+OFILES=\
+	lisp.$O\
+	subr.$O\
+	mem.$O
+
+HFILES=lisp.h
+
+UPDATE=\
+	mkfile\
+	$HFILES\
+	${OFILES:%.$O=%.c}\
+
+</sys/src/cmd/mkone
--- /dev/null
+++ b/subr.c
@@ -1,0 +1,1213 @@
+#include "lisp.h"
+/*
+#include <limits.h>
+#include <float.h>
+#include <math.h>
+*/
+
+int
+floeq(flonum x, flonum y)
+{
+	return fabs(x-y) < 0.000003;
+}
+
+int
+equal(C *a, C *b)
+{
+	if(atom(a) != atom(b))
+		return 0;
+	if(atom(a)){
+		if(fixnump(a))
+			return fixnump(b) &&
+				a->fix == b->fix;
+		if(flonump(a))
+			return flonump(b) &&
+				floeq(a->flo, b->flo);
+		return a == b;
+	}
+	return equal(a->a, b->a)
+		&& equal(a->d, b->d);
+}
+
+/* this is a bit ugly... */
+int
+getnumcase(C *lt, C *rt)
+{
+	int type;
+	type = 0;
+	if(fixnump(lt))
+		{}
+	else if(flonump(lt))
+		type |= 1;
+	else
+		type |= ~0;
+	if(fixnump(rt))
+		{}
+	else if(flonump(rt))
+		type |= 2;
+	else
+		type |= ~0;
+	return type;
+}
+
+/* Types */
+
+C *atom_subr(void){
+	return atom(alist[0]) ? t : nil;
+}
+C *fixp_subr(void){
+	return fixnump(alist[0]) ? t : nil;
+}
+C *floatp_subr(void){
+	return flonump(alist[0]) ? t : nil;
+}
+C *numberp_subr(void){
+	return numberp(alist[0]) ? t : nil;
+}
+
+/* Basics */
+
+C *eval_subr(void){
+	nargs = 0;
+	return eval(alist[0], alist[1]);
+}
+C *apply_subr(void){
+	nargs = 0;
+	return apply(alist[0], alist[1], alist[2]);
+}
+C *quote_fsubr(void){
+	if(alist[0] == nil)
+		err("error: arg count");
+	return alist[0]->a;
+}
+C *function_fsubr(void){
+	if(alist[0] == nil)
+		err("error: arg count");
+	return cons(funarg, cons(alist[0]->a, cons(alist[1], nil)));
+}
+C *comment_fsubr(void){
+	return noval;
+}
+C *prog2_lsubr(void){
+	if(largs.nargs < 2)
+		err("error: arg count");
+	return largs.alist[2];
+}
+C *progn_lsubr(void){
+	if(largs.nargs < 1)
+		err("error: arg count");
+	return largs.alist[largs.nargs];
+}
+C *arg_subr(void){
+	fixnum n;
+	if(!fixnump(alist[0]))
+		err("error: not a fixnum");
+	n = alist[0]->fix;
+	if(n < 1 || n > largs.nargs)
+		err("error: arg out of bounds");
+	return largs.alist[n];
+}
+
+/* List functions */
+
+C *car(C *pair){
+	if(pair == nil)
+		return nil;
+	if(numberp(pair))
+		err("error: not a pair");
+	return pair->a;
+}
+C *cdr(C *pair){
+	if(pair == nil)
+		return nil;
+	if(numberp(pair))
+		err("error: not a pair");
+	return pair->d;
+}
+C *car_subr(void){ return car(alist[0]); }
+C *cdr_subr(void){ return cdr(alist[0]); }
+C *caar_subr(void){ return car(car(alist[0])); }
+C *cadr_subr(void){ return car(cdr(alist[0])); }
+C *cdar_subr(void){ return cdr(car(alist[0])); }
+C *cddr_subr(void){ return cdr(cdr(alist[0])); }
+C *caaar_subr(void){ return car(car(car(alist[0]))); }
+C *caadr_subr(void){ return car(car(cdr(alist[0]))); }
+C *cadar_subr(void){ return car(cdr(car(alist[0]))); }
+C *caddr_subr(void){ return car(cdr(cdr(alist[0]))); }
+C *cdaar_subr(void){ return cdr(car(car(alist[0]))); }
+C *cdadr_subr(void){ return cdr(car(cdr(alist[0]))); }
+C *cddar_subr(void){ return cdr(cdr(car(alist[0]))); }
+C *cdddr_subr(void){ return cdr(cdr(cdr(alist[0]))); }
+C *caaaar_subr(void){ return car(car(car(car(alist[0])))); }
+C *caaadr_subr(void){ return car(car(car(cdr(alist[0])))); }
+C *caadar_subr(void){ return car(car(cdr(car(alist[0])))); }
+C *caaddr_subr(void){ return car(car(cdr(cdr(alist[0])))); }
+C *cadaar_subr(void){ return car(cdr(car(car(alist[0])))); }
+C *cadadr_subr(void){ return car(cdr(car(cdr(alist[0])))); }
+C *caddar_subr(void){ return car(cdr(cdr(car(alist[0])))); }
+C *cadddr_subr(void){ return car(cdr(cdr(cdr(alist[0])))); }
+C *cdaaar_subr(void){ return cdr(car(car(car(alist[0])))); }
+C *cdaadr_subr(void){ return cdr(car(car(cdr(alist[0])))); }
+C *cdadar_subr(void){ return cdr(car(cdr(car(alist[0])))); }
+C *cdaddr_subr(void){ return cdr(car(cdr(cdr(alist[0])))); }
+C *cddaar_subr(void){ return cdr(cdr(car(car(alist[0])))); }
+C *cddadr_subr(void){ return cdr(cdr(car(cdr(alist[0])))); }
+C *cdddar_subr(void){ return cdr(cdr(cdr(car(alist[0])))); }
+C *cddddr_subr(void){ return cdr(cdr(cdr(cdr(alist[0])))); }
+C *eq_subr(void){
+	return alist[0] == alist[1] ? t : nil;
+}
+C *equal_subr(void){
+	return equal(alist[0], alist[1]) ? t : nil;
+}
+C *assoc_subr(void){
+	C *l;
+	if(!listp(alist[1]))
+		err("error: no list");
+	for(l = alist[1]; l != nil; l = l->d)
+		if(equal(l->a->a, alist[0]))
+			return l->a;
+	return nil;
+}
+C *assq_subr(void){
+	if(!listp(alist[1]))
+		err("error: no list");
+	return assq(alist[0], alist[1]);
+}
+C *sassoc_subr(void){
+	C *l;
+	l = assoc_subr();
+	return l != nil ? l : apply(alist[2], nil, nil);
+}
+C *sassq_subr(void){
+	C *l;
+	l = assq_subr();
+	return l != nil ? l : apply(alist[2], nil, nil);
+}
+C *last_subr(void){
+	C *l;
+	if(!listp(alist[0]))
+		err("error: no list");
+	for(l = alist[0]; l != nil; l = l->d)
+		if(atom(l->d))
+			return l;
+	return nil;
+}
+C *length_subr(void){
+	return mkfix(length(alist[0]));
+}
+C *member_subr(void){
+	C *l;
+	for(l = alist[1]; l != nil; l = l->d){
+		if(atom(l))
+			err("error: no list");
+		if(equal(l->a, alist[0]))
+			return t;
+	}
+	return nil;
+}
+C *memq_subr(void){
+	C *l;
+	for(l = alist[1]; l != nil; l = l->d){
+		if(atom(l))
+			err("error: no list");
+		if(l->a == alist[0])
+			return t;
+	}
+	return nil;
+}
+C *null_subr(void){
+	return alist[0] == nil ? t : nil;
+}
+
+/* Creating list structure */
+
+C *cons_subr(void){
+	return cons(alist[0], alist[1]);
+}
+C *ncons_subr(void){
+	return cons(alist[0], nil);
+}
+C *xcons_subr(void){
+	return cons(alist[1], alist[0]);
+}
+C *list_fsubr(void){
+	return evlis(alist[0], alist[1]) ;
+}
+C *append_subr(void){
+	C *l, **p;
+	assert(temlis.a == nil);
+	p = (C**)&temlis.a;
+	for(l = alist[0]; l != nil; l = l->d){
+		if(atom(l))
+			err("error: no list");
+		*p = cons(l->a, nil);
+		p = &(*p)->d;
+	}
+	*p = alist[1];
+	l = temlis.a;
+	temlis.a = nil;
+	return l;
+}
+C *reverse_subr(void){
+	C *l;
+	assert(temlis.a == nil);
+	for(l = alist[0]; l != nil; l = l->d){
+		if(atom(l))
+			err("error: no list");
+		temlis.a = cons(l->a, temlis.a);
+	}
+	l = temlis.a;
+	temlis.a = nil;
+	return l;
+}
+
+/* Modifying list structure */
+
+C *rplaca_subr(void){
+	if(atom(alist[0]))
+		err("error: atom");
+	alist[0]->a = alist[1];
+	return alist[0];
+}
+C *rplacd_subr(void){
+	if(atom(alist[0]))		/* this could work on a symbolic atom */
+		err("error: atom");
+	alist[0]->d = alist[1];
+	return alist[0];
+}
+C *nconc_subr(void){
+	C *l;
+	for(l = alist[0]; l != nil; l = l->d){
+		if(atom(l))
+			err("error: no list");
+		if(l->d == nil){
+			l->d = alist[1];
+			break;
+		}
+	}
+	return alist[0];
+}
+C *nreverse_subr(void){
+
+	C *l, *n, *last;
+	last = nil;
+	for(l = alist[0]; l != nil; l = n){
+		if(atom(l))
+			err("error: no list");
+		n = l->d;
+		l->d = last;
+		last = l;
+	}
+	return last;
+}
+
+/* Boolean logic */
+
+C *and_fsubr(void){
+	C *l;
+	int ret;
+	ret = 1;
+	for(l = alist[0]; l != nil; l = l->d)
+		if(eval(l->a, alist[1]) == nil){
+			ret = 0;
+			break;
+		}
+	return ret ? t : nil;
+}
+C *or_fsubr(void){
+	C *l;
+	int ret;
+	ret = 0;
+	for(l = alist[0]; l != nil; l = l->d)
+		if(eval(l->a, alist[1]) != nil){
+			ret = 1;
+			break;
+		}
+	return ret ? t : nil;
+}
+
+/* Symbols, values */
+
+C *setq_fsubr(void){
+	C *tt, *l, *last;
+	last = nil;
+	for(l = alist[0]; l != nil; l = l->d->d){
+		tt = l->a;
+		if(!atom(tt))
+			err("error: need atom");
+		tt = assq(tt, alist[1]);
+		if(tt == nil)
+			err("error: undefined");
+		tt->d = last = eval(l->d->a, alist[1]);
+	}
+	return last;
+}
+/* Has to be FSUBR here, also extended syntax */
+C *set_fsubr(void){
+	C *tt, *l, *last;
+	last = nil;
+	for(l = alist[0]; l != nil; l = l->d->d){
+		tt = eval(l->a, alist[1]);
+		if(!atom(tt))
+			err("error: need atom");
+		tt = assq(tt, alist[1]);
+		if(tt == nil)
+			err("error: undefined");
+		tt->d = last = eval(l->d->a, alist[1]);
+	}
+	return last;
+}
+
+/* slightly advanced cset functions */
+C *cset_subr(void){
+	return putprop(alist[0], alist[1], value);
+}
+C *csetq_fsubr(void){
+	C *l;
+	for(l = alist[0]; l != nil; l = l->d->d){
+		if(!atom(l->a))
+			err("error: need atom");
+		if(l->d == nil){
+			putprop(l->a, nil, value);
+			break;
+		}
+		putprop(l->a, eval(l->d->a, alist[1]), value);
+	}
+	return noval;
+}
+
+/* Property list */
+
+C *get_subr(void){
+	return get(alist[0], alist[1]);
+/*
+	C *l;
+	for(l = alist[0]; l != nil; l = l->d)
+		if(l->a == alist[1])
+			return l->d->a;
+	return nil;
+*/
+}
+C *putprop_subr(void){
+	return putprop(alist[0], alist[1], alist[2]);
+}
+C *defprop_fsubr(void){
+	if(length(alist[0]) != 3)
+		err("error: arg count");
+	return putprop(alist[0]->a, alist[0]->d->a, alist[0]->d->d->a);
+}
+C *remprop_subr(void){
+	C *l, **p;
+	p = &alist[0]->d;
+	for(l = *p; l != nil; l = l->d){
+		if(l->a == alist[1]){
+			*p = l->d->d;
+			break;
+		}
+		p = &(*p)->d;
+	}
+	return nil;
+}
+
+/* Number predicates */
+
+C *zerop_subr(void){
+	int res;
+	res = 0;
+	if(fixnump(alist[0]))
+		res = alist[0]->fix == 0;
+	else if(flonump(alist[0]))
+		res = floeq(alist[0]->flo, 0.0);
+	else
+		err("error: not a number");
+	return res ? t : nil;
+}
+C *plusp_subr(void){
+	int res;
+	res = 0;
+	if(fixnump(alist[0]))
+		res = alist[0]->fix > 0;
+	else if(flonump(alist[0]))
+		res = alist[0]->flo > 0.0;
+	else
+		err("error: not a number");
+	return res ? t : nil;
+}
+C *minusp_subr(void){
+	int res;
+	res = 0;
+	if(fixnump(alist[0]))
+		res = alist[0]->fix < 0;
+	else if(flonump(alist[0]))
+		res = alist[0]->flo < 0.0;
+	else
+		err("error: not a number");
+	return res ? t : nil;
+}
+C *greaterp_lsubr(void){
+	C *lt, *rt;
+	int i;
+
+	if(largs.nargs < 2)
+		err("error: arg count");
+	for(i = 1; i < largs.nargs; i++){
+		lt = largs.alist[i];
+		rt = largs.alist[i+1];
+		switch(getnumcase(lt, rt)){
+		case 0:
+			if(lt->fix <= rt->fix)
+				return nil;
+			break;
+		case 1:
+			if(lt->flo <= rt->fix)
+				return nil;
+			break;
+		case 2:
+			if(lt->fix <= rt->flo)
+				return nil;
+			break;
+		case 3:
+			if(lt->flo <= rt->flo)
+				return nil;
+			break;
+		default:
+			err("error: not a number");
+			return nil;
+		}
+	}
+	return t;
+}
+C *lessp_lsubr(void){
+	C *lt, *rt;
+	int i;
+
+	if(largs.nargs < 2)
+		err("error: arg count");
+	for(i = 1; i < largs.nargs; i++){
+		lt = largs.alist[i];
+		rt = largs.alist[i+1];
+		switch(getnumcase(lt, rt)){
+		case 0:
+			if(lt->fix >= rt->fix)
+				return nil;
+			break;
+		case 1:
+			if(lt->flo >= rt->fix)
+				return nil;
+			break;
+		case 2:
+			if(lt->fix >= rt->flo)
+				return nil;
+			break;
+		case 3:
+			if(lt->flo >= rt->flo)
+				return nil;
+			break;
+		default:
+			err("error: not a number");
+			return nil;
+		}
+	}
+	return t;
+}
+C *max_lsubr(void){
+	int i;
+	C *tt;
+	fixnum fix;
+	flonum flo;
+	int type;
+
+	fix = FIXMIN;
+	flo = -FLOMAX;
+	type = 0;	// fix;
+	for(i = 1; i <= largs.nargs; i++){
+		tt = largs.alist[i];
+		if(fixnump(tt))
+			fix = tt->fix > fix ? tt->fix : fix;
+		else if(flonump(tt)){
+			flo = tt->flo > flo ? tt->flo : flo;
+			type = 1;
+		}else
+			err("error: not a number");
+	}
+	return type == 0 ? mkfix(fix) : mkflo(fix > flo ? fix : flo);
+}
+C *min_lsubr(void){
+	int i;
+	C *tt;
+	fixnum fix;
+	flonum flo;
+	int type;
+
+	fix = FIXMAX;
+	flo = FLOMAX;
+	type = 0;	// fix;
+	for(i = 1; i <= largs.nargs; i++){
+		tt = largs.alist[i];
+		if(fixnump(tt))
+			fix = tt->fix < fix ? tt->fix : fix;
+		else if(flonump(tt)){
+			flo = tt->flo < flo ? tt->flo : flo;
+			type = 1;
+		}else
+			err("error: not a number");
+	}
+	return type == 0 ? mkfix(fix) : mkflo(fix < flo ? fix : flo);
+}
+
+/* Arithmetic */
+
+C *plus_lsubr(void){
+	int i;
+	C *tt;
+	fixnum fix;
+	flonum flo;
+	int type;
+
+	fix = 0;
+	flo = 0.0;
+	type = 0;	// fix;
+	for(i = 1; i <= largs.nargs; i++){
+		tt = largs.alist[i];
+		if(fixnump(tt))
+			fix += tt->fix;
+		else if(flonump(tt)){
+			flo += tt->flo;
+			type = 1;
+		}else
+			err("error: not a number");
+	}
+	return type == 0 ? mkfix(fix) : mkflo(fix+flo);
+}
+C *difference_lsubr(void){
+	int i;
+	C *tt;
+	fixnum fix;
+	flonum flo;
+	int type;
+	int first;
+
+	first = 1;
+	fix = 0;
+	flo = 0.0;
+	type = 0;	// fix;
+	if(largs.nargs == 0)
+		err("error: not enough args");
+	for(i = 1; i <= largs.nargs; i++){
+		tt = largs.alist[i];
+		if(fixnump(tt))
+			fix += first ? tt->fix : -tt->fix;
+		else if(flonump(tt)){
+			flo += first ? tt->flo : -tt->flo;
+			type = 1;
+		}else
+			err("error: not a number");
+		first = 0;
+	}
+	if(largs.nargs == 1)
+		return type == 0 ? mkfix(-fix) : mkflo(-fix-flo);
+	return type == 0 ? mkfix(fix) : mkflo(fix+flo);
+}
+C *times_lsubr(void){
+	int i;
+	C *tt;
+	fixnum fix;
+	flonum flo;
+	int type;
+
+	fix = 1;
+	flo = 1.0;
+	type = 0;	// fix;
+	for(i = 1; i <= largs.nargs; i++){
+		tt = largs.alist[i];
+		if(fixnump(tt))
+			fix *= tt->fix;
+		else if(flonump(tt)){
+			flo *= tt->flo;
+			type = 1;
+		}else
+			err("error: not a number");
+	}
+	return type == 0 ? mkfix(fix) : mkflo(fix*flo);
+}
+C *quotient_lsubr(void){
+	int i;
+	C *tt;
+	fixnum fix;
+	flonum flo;
+	int type;
+
+	fix = 1;
+	flo = 1.0;
+	type = 0;	// fix;
+	if(largs.nargs == 0)
+		return mkfix(1);
+	for(i = 2; i <= largs.nargs; i++){
+		tt = largs.alist[i];
+		if(fixnump(tt))
+			fix *= tt->fix;
+		else if(flonump(tt)){
+			flo *= tt->flo;
+			type = 1;
+		}else
+			err("error: not a number");
+	}
+
+	tt = largs.alist[1];
+	if(largs.nargs == 1){
+		if(fixnump(tt))
+			return mkfix(1/tt->fix);
+		else if(flonump(tt))
+			return mkflo(1.0/tt->flo);
+		else
+			err("error: not a number");
+	}
+
+	if(fixnump(tt))
+		return type == 0 ? mkfix(tt->fix/fix) : mkflo(tt->fix/(fix*flo));
+	else if(flonump(tt))
+		return type == 0 ? mkflo(tt->flo/fix) : mkflo(tt->flo/(fix*flo));
+	else
+		err("error: not a number");
+	/* can't happen */
+	return nil;
+}
+C *add1_subr(void){
+	if(fixnump(alist[0]))
+		return mkfix(alist[0]->fix+1);
+	if(flonump(alist[0]))
+		return mkflo(alist[0]->flo+1.0);
+	err("error: not a number");
+	return nil;
+}
+C *sub1_subr(void){
+	if(fixnump(alist[0]))
+		return mkfix(alist[0]->fix-1);
+	if(flonump(alist[0]))
+		return mkflo(alist[0]->flo-1.0);
+	err("error: not a number");
+	return nil;
+}
+C *remainder_subr(void){
+	switch(getnumcase(alist[0], alist[1])){
+	case 0:
+		if(alist[1]->fix == 0)
+			err("error: division by zero");
+		return mkfix(alist[0]->fix % alist[1]->fix);
+		break;
+	case 1:
+		return mkflo(fmod(alist[0]->flo, alist[1]->fix));
+		break;
+	case 2:
+		return mkflo(fmod(alist[0]->fix, alist[1]->flo));
+		break;
+	case 3:
+		return mkflo(fmod(alist[0]->flo, alist[1]->flo));
+		break;
+	default:
+		err("error: not a number");
+		return nil;
+	}
+}
+C *expt_subr(void){
+	switch(getnumcase(alist[0], alist[1])){
+	case 0:
+		if(alist[1]->fix == 0)
+			err("error: division by zero");
+		return mkfix(pow(alist[0]->fix, alist[1]->fix));
+		break;
+	case 1:
+		return mkflo(exp(log(alist[0]->flo) * alist[1]->fix));
+		break;
+	case 2:
+		return mkflo(exp(log(alist[0]->fix) * alist[1]->flo));
+		break;
+	case 3:
+		return mkflo(exp(log(alist[0]->flo) * alist[1]->flo));
+		break;
+	default:
+		err("error: not a number");
+		return nil;
+	}
+}
+
+/* Bitwise operations */
+
+C *logior_lsubr(void){
+	int i;
+	C *tt;
+	fixnum fix;
+
+	fix = 0;
+	for(i = 1; i <= largs.nargs; i++){
+		tt = largs.alist[i];
+		if(fixnump(tt))
+			fix |= tt->fix;
+		else
+			err("error: not a fixnum");
+	}
+	return mkfix(fix);
+}
+C *logand_lsubr(void){
+	int i;
+	C *tt;
+	fixnum fix;
+
+	fix = ~0;
+	for(i = 1; i <= largs.nargs; i++){
+		tt = largs.alist[i];
+		if(fixnump(tt))
+			fix &= tt->fix;
+		else
+			err("error: not a fixnum");
+	}
+	return mkfix(fix);
+}
+C *logxor_lsubr(void){
+	int i;
+	C *tt;
+	fixnum fix;
+
+	fix = 0;
+	for(i = 1; i <= largs.nargs; i++){
+		tt = largs.alist[i];
+		if(fixnump(tt))
+			fix ^= tt->fix;
+		else
+			err("error: not a fixnum");
+	}
+	return mkfix(fix);
+}
+C *lsh_subr(void){
+	if(!fixnump(alist[0]) || !fixnump(alist[1]))
+		err("error: not a fixnum");
+	if(alist[1]->fix < 0)
+		return mkfix((word)alist[0]->fix >> -alist[1]->fix);
+	else
+		return mkfix((word)alist[0]->fix << alist[1]->fix);
+}
+
+/* Mapping */
+
+C *maplist_subr(void){
+	C *l, *c, **p;
+	p = push(nil);
+	for(l = alist[1]; l != nil; l = l->d){
+		push(c = cons(l, nil));
+		c->a = apply(alist[0], c, nil);
+		c->d = nil;
+		*p = pop();
+		p = &(*p)->d;
+	}
+	return pop();
+}
+C *mapcar_subr(void){
+	C *l, *c, **p;
+	p = push(nil);
+	for(l = alist[1]; l != nil; l = l->d){
+		push(c = cons(l->a, nil));
+		c->a = apply(alist[0], c, nil);
+		c->d = nil;
+		*p = pop();
+		p = &(*p)->d;
+	}
+	return pop();
+}
+C *map_subr(void){
+	C *l, *a;
+	push(a = cons(nil, nil));
+	for(l = alist[1]; l != nil; l = l->d){
+		a->a = l;
+		a->d = nil;
+		apply(alist[0], a, nil);
+	}
+	pop();
+	return nil;
+}
+C *mapc_subr(void){
+	C *l, *a;
+	push(a = cons(nil, nil));
+	for(l = alist[1]; l != nil; l = l->d){
+		a->a = l->a;
+		a->d = nil;
+		apply(alist[0], a, nil);
+	}
+	pop();
+	return nil;
+}
+C *mapcon_subr(void){
+	C *l, *a, **p;
+	p = push(nil);
+	push(a = cons(nil, nil));
+	for(l = alist[1]; l != nil; l = l->d){
+		a->a = l;
+		a->d = nil;
+		*p = apply(alist[0], a, nil);
+		if(*p == nil)
+			err("error: nil in mapcon");
+		for(; *p != nil; p = &(*p)->d)
+			if(atom(*p))
+				err("error: no list");
+	}
+	pop();
+	return pop();
+}
+C *mapcan_subr(void){
+	C *l, *a, **p;
+	p = push(nil);
+	push(a = cons(nil, nil));
+	for(l = alist[1]; l != nil; l = l->d){
+		a->a = l->a;
+		a->d = nil;
+		*p = apply(alist[0], a, nil);
+		if(*p == nil)
+			err("error: nil in mapcon");
+		for(; *p != nil; p = &(*p)->d)
+			if(atom(*p))
+				err("error: no list");
+	}
+	pop();
+	return pop();
+}
+
+/* IO */
+
+C *read_subr(void){
+	return readsxp();
+}
+C *prin1_subr(void){
+	lprint(alist[0]);
+	return t;
+}
+C *print_subr(void){
+	fprintf(sysout, "\n");
+	lprint(alist[0]);
+	return t;
+}
+C *princ_subr(void){
+	princ(alist[0]);
+	return t;
+}
+C *terpri_subr(void){
+	fprintf(sysout, "\n");
+	return nil;
+}
+
+
+/*
+ * LISP 1.5 leftover
+ */
+
+C *attrib_subr(void){
+	C *l;
+	for(l = alist[0]; l != nil; l = l->d){
+//		if(atom(l))	// have to allow this for p-lists
+		if(numberp(l))
+			err("error: no list");
+		if(l->d == nil){
+			l->d = alist[1];
+			break;
+		}
+	}
+	return alist[1];
+}
+C *prop_subr(void){
+	C *l;
+	for(l = alist[0]; l != nil; l = l->d)
+		if(l->a == alist[1])
+			return l->d;
+	return apply(alist[2], nil, nil);
+}
+C *pair_subr(void){
+	return pair(alist[0], alist[1]);
+}
+C *copy_subr(void){
+	C *l, **p;
+	assert(temlis.a == nil);
+	p = (C**)&temlis.a;
+	for(l = alist[0]; l != nil; l = l->d){
+		if(atom(l))
+			err("error: no list");
+		*p = cons(l->a, nil);
+		p = &(*p)->d;
+	}
+	l = temlis.a;
+	temlis.a = nil;
+	return l;
+}
+C *efface_subr(void){
+	C *l, **p;
+	p = &alist[1];
+	for(l = alist[1]; l != nil; l = l->d){
+		if(atom(l))
+			err("error: no list");
+		if(equal(l->a, alist[0])){
+			*p = l->d;
+			break;
+		}
+		p = &(*p)->d;
+	}
+	return alist[1];
+}
+
+
+
+/* Prog feature */
+
+typedef struct Prog Prog;
+struct Prog
+{
+	C *a;
+	C *go;
+	C *pc;
+	C *ret;
+};
+
+void
+setq_prog(Prog *prog, C *form)
+{
+	C *tt;
+	if(form == nil)
+		err("error: arg count");
+	if(!atom(form->a))
+		err("error: no atom");
+	tt = assq(form->a, prog->a);
+	if(tt == nil)
+		err("error: undefined");
+	tt->d = eval(form->d->a, prog->a);
+}
+
+void
+set_prog(Prog *prog, C *form)
+{
+	C *tt;
+	if(form == nil)
+		err("error: arg count");
+	tt = eval(form->a, prog->a);
+	if(!atom(tt))
+		err("error: no atom");
+	tt = assq(tt, prog->a);
+	if(tt == nil)
+		err("error: undefined");
+	tt->d = eval(form->d->a, prog->a);
+}
+
+void
+progstmt(Prog *prog, C *form)
+{
+	C *tt;
+	C *pc;
+
+	if(atom(form))
+		{}
+	else if(form->a == setq)
+		setq_prog(prog, form->d);
+	else if(form->a == set)
+		set_prog(prog, form->d);
+	else if(form->a == cond){
+		for(form = form->d; form != nil; form = form->d)
+			if(eval(form->a->a, prog->a) != nil){
+				for(pc = form->a->d; pc != nil; pc = pc->d)
+					progstmt(prog, pc->a);
+				return;
+			}
+	}else if(form->a == go){
+		if(form->d == nil)
+			err("error: arg count");
+		if(tt = assq(form->d->a, prog->go), tt == nil)
+			err("error: undefined label");
+		prog->pc = tt->d;
+	}else if(form->a == retrn){
+		if(form->d == nil)
+			prog->ret = nil;
+		else
+			prog->ret = eval(form->d->a, prog->a);
+		prog->pc = nil;
+	}else
+		eval(form, prog->a);
+}
+
+C *prog_fsubr(void){
+	Prog prog;
+
+	C *p;
+	C **ap;
+
+	prog.pc = alist[0]->d;
+
+	/* build a-list */
+	assert(temlis.a == nil);
+	ap = (C**)&temlis.a;
+	for(p = alist[0]->a; p != nil; p = p->d){
+		*ap = cons(cons(p->a, nil), nil);
+		ap = &(*ap)->d;
+	}
+	*ap = alist[1];
+	alist[1] = temlis.a;
+	prog.a = alist[1];
+	temlis.a = nil;
+
+	/* build go-list */
+	for(p = prog.pc; p != nil; p = p->d)
+		if(atom(p->a))
+			temlis.a = cons(p, temlis.a);
+	prog.go = temlis.a;
+	temlis.a = nil;
+	alist[nargs++] = prog.go;
+
+	/* execute */
+	prog.ret = nil;
+	while(prog.pc != nil){
+		p = prog.pc->a;
+		prog.pc = prog.pc->d;
+		progstmt(&prog, p);
+	}
+
+	return prog.ret;
+}
+
+void
+initsubr(void)
+{
+	C *a;
+
+	putprop(t, t, value);
+
+#define SUBR(str, func, narg) \
+	a = intern(str); \
+	putprop(a, mksubr(func, narg), subr);
+#define LSUBR(str, func) \
+	a = intern(str); \
+	putprop(a, mksubr(func, -1), lsubr);
+#define FSUBR(str, func) \
+	a = intern(str); \
+	putprop(a, (C*)consw((word)func), fsubr);
+
+	SUBR("ATOM", atom_subr, 1)
+	SUBR("FIXP", fixp_subr, 1)
+	SUBR("FLOATP", floatp_subr, 1)
+	SUBR("NUMBERP", numberp_subr, 1)
+
+	SUBR("APPLY", apply_subr, 3)
+	SUBR("EVAL", eval_subr, 2)
+	FSUBR("QUOTE", quote_fsubr)
+	FSUBR("FUNCTION", function_fsubr)
+	FSUBR("COMMENT", comment_fsubr)
+	LSUBR("PROG2", prog2_lsubr)
+	LSUBR("PROGN", progn_lsubr)
+	SUBR("ARG", arg_subr, 1)
+
+	SUBR("CAR", car_subr, 1)
+	SUBR("CDR", cdr_subr, 1)
+	SUBR("CAAR", caar_subr, 1)
+	SUBR("CADR", cadr_subr, 1)
+	SUBR("CDAR", cdar_subr, 1)
+	SUBR("CDDR", cddr_subr, 1)
+	SUBR("CAAAR", caaar_subr, 1)
+	SUBR("CAADR", caadr_subr, 1)
+	SUBR("CADAR", cadar_subr, 1)
+	SUBR("CADDR", caddr_subr, 1)
+	SUBR("CDAAR", cdaar_subr, 1)
+	SUBR("CDADR", cdadr_subr, 1)
+	SUBR("CDDAR", cddar_subr, 1)
+	SUBR("CDDDR", cdddr_subr, 1)
+	SUBR("CAAAAR", caaaar_subr, 1)
+	SUBR("CAAADR", caaadr_subr, 1)
+	SUBR("CAADAR", caadar_subr, 1)
+	SUBR("CAADDR", caaddr_subr, 1)
+	SUBR("CADAAR", cadaar_subr, 1)
+	SUBR("CADADR", cadadr_subr, 1)
+	SUBR("CADDAR", caddar_subr, 1)
+	SUBR("CADDDR", cadddr_subr, 1)
+	SUBR("CDAAAR", cdaaar_subr, 1)
+	SUBR("CDAADR", cdaadr_subr, 1)
+	SUBR("CDADAR", cdadar_subr, 1)
+	SUBR("CDADDR", cdaddr_subr, 1)
+	SUBR("CDDAAR", cddaar_subr, 1)
+	SUBR("CDDADR", cddadr_subr, 1)
+	SUBR("CDDDAR", cdddar_subr, 1)
+	SUBR("CDDDDR", cddddr_subr, 1)
+	SUBR("EQ", eq_subr, 2)
+	SUBR("EQUAL", equal_subr, 2)
+	SUBR("ASSOC", assoc_subr, 2)
+	SUBR("ASSQ", assq_subr, 2)
+	SUBR("SASSOC", sassoc_subr, 3)
+	SUBR("SASSQ", sassq_subr, 3)
+	SUBR("LAST", last_subr, 1)
+	SUBR("LENGTH", length_subr, 1)
+	SUBR("MEMBER", member_subr, 2)
+	SUBR("MEMQ", memq_subr, 2)
+	SUBR("NOT", null_subr, 1)
+	SUBR("NULL", null_subr, 1)
+
+	SUBR("CONS", cons_subr, 2)
+	SUBR("NCONS", ncons_subr, 1)
+	SUBR("XCONS", xcons_subr, 2)
+	FSUBR("LIST", list_fsubr)
+	SUBR("APPEND", append_subr, 2)
+	SUBR("REVERSE", reverse_subr, 1)
+
+	SUBR("RPLACA", rplaca_subr, 2)
+	SUBR("RPLACD", rplacd_subr, 2)
+	SUBR("NCONC", nconc_subr, 2)
+	SUBR("NREVERSE", nreverse_subr, 1)
+
+	FSUBR("AND", and_fsubr)
+	FSUBR("OR", or_fsubr)
+	FSUBR("PROG", prog_fsubr)
+
+	FSUBR("SETQ", setq_fsubr)
+	FSUBR("SET", set_fsubr)
+	SUBR("CSET", cset_subr, 2)
+	FSUBR("CSETQ", csetq_fsubr)
+
+	SUBR("GET", get_subr, 2)
+	SUBR("PUTPROP", putprop_subr, 3)
+	FSUBR("DEFPROP", defprop_fsubr)
+	SUBR("REMPROP", remprop_subr, 2)
+
+	SUBR("ZEROP", zerop_subr, 1)
+	SUBR("PLUSP", plusp_subr, 1)
+	SUBR("MINUSP", minusp_subr, 1)
+	LSUBR("<", lessp_lsubr)
+	LSUBR(">", greaterp_lsubr)
+	LSUBR("MAX", max_lsubr)
+	LSUBR("MIN", min_lsubr)
+
+	LSUBR("+", plus_lsubr)
+	LSUBR("-", difference_lsubr)
+	LSUBR("*", times_lsubr)
+	LSUBR("/", quotient_lsubr)
+	SUBR("1+", add1_subr, 1)
+	SUBR("1-", sub1_subr, 1)
+	SUBR("\\", remainder_subr, 2)
+	SUBR("EXPT", expt_subr, 2)
+
+	LSUBR("LOGIOR", logior_lsubr)
+	LSUBR("LOGAND", logand_lsubr)
+	LSUBR("LOGXOR", logxor_lsubr)
+	SUBR("LSH", lsh_subr, 2)
+
+	SUBR("MAPLIST", maplist_subr, 2)
+	SUBR("MAPCAR", mapcar_subr, 2)
+	SUBR("MAP", map_subr, 2)
+	SUBR("MAPC", mapc_subr, 2)
+	SUBR("MAPCON", mapcon_subr, 2)
+	SUBR("MAPCAN", mapcan_subr, 2)
+
+	SUBR("READ", read_subr, 0)
+	SUBR("PRIN1", prin1_subr, 1)
+	SUBR("PRINT", print_subr, 1)
+	SUBR("PRINC", princ_subr, 1)
+	SUBR("TERPRI", terpri_subr, 0)
+
+
+
+
+	SUBR("ATTRIB", attrib_subr, 2)
+	SUBR("PROP", prop_subr, 3)
+	SUBR("PAIR", pair_subr, 2)
+	SUBR("COPY", copy_subr, 1)
+	SUBR("EFFACE", efface_subr, 2)
+}