altos/lisp: Lots more scheme bits

* Arithmetic functions and tests
* append, reverse and list-tail
* set-car! and set-cdr!

Signed-off-by: Keith Packard <keithp@keithp.com>

4 files changed, 240 insertions, 11 deletions

diff --git a/src/lisp/ao_lisp.h b/src/lisp/ao_lisp.h
index 9a48a445..341996c0 100644
--- a/src/lisp/ao_lisp.h
+++ b/src/lisp/ao_lisp.h
@@ -136,7 +136,7 @@ ao_lisp_is_const(ao_poly poly) {
 
 #define AO_LISP_IS_CONST(a)	(ao_lisp_const <= ((uint8_t *) (a)) && ((uint8_t *) (a)) < ao_lisp_const + AO_LISP_POOL_CONST)
 #define AO_LISP_IS_POOL(a)	(ao_lisp_pool <= ((uint8_t *) (a)) && ((uint8_t *) (a)) < ao_lisp_pool + AO_LISP_POOL)
-#define AO_LISP_IS_INT(p)	(ao_lisp_base_type(p) == AO_LISP_INT);
+#define AO_LISP_IS_INT(p)	(ao_lisp_poly_base_type(p) == AO_LISP_INT)
 
 void *
 ao_lisp_ref(ao_poly poly);
diff --git a/src/lisp/ao_lisp_builtin.c b/src/lisp/ao_lisp_builtin.c
index d89404dc..2c5608e7 100644
--- a/src/lisp/ao_lisp_builtin.c
+++ b/src/lisp/ao_lisp_builtin.c
@@ -277,6 +277,7 @@ ao_lisp_do_patom(struct ao_lisp_cons *cons)
 ao_poly
 ao_lisp_math(struct ao_lisp_cons *cons, enum ao_lisp_builtin_id op)
 {
+	struct ao_lisp_cons *orig_cons = cons;
 	ao_poly	ret = AO_LISP_NIL;
 
 	while (cons) {
@@ -284,12 +285,29 @@ ao_lisp_math(struct ao_lisp_cons *cons, enum ao_lisp_builtin_id op)
 		uint8_t		rt = ao_lisp_poly_type(ret);
 		uint8_t		ct = ao_lisp_poly_type(car);
 
-		cons = ao_lisp_poly_cons(cons->cdr);
-
-		if (rt == AO_LISP_NIL)
+		if (cons == orig_cons) {
 			ret = car;
-
-		else if (rt == AO_LISP_INT && ct == AO_LISP_INT) {
+			if (cons->cdr == AO_LISP_NIL && ct == AO_LISP_INT) {
+				switch (op) {
+				case builtin_minus:
+					ret = ao_lisp_int_poly(-ao_lisp_poly_int(ret));
+					break;
+				case builtin_divide:
+					switch (ao_lisp_poly_int(ret)) {
+					case 0:
+						return ao_lisp_error(AO_LISP_DIVIDE_BY_ZERO, "divide by zero");
+					case 1:
+						break;
+					default:
+						ret = ao_lisp_int_poly(0);
+						break;
+					}
+					break;
+				default:
+					break;
+				}
+			}
+		} else if (rt == AO_LISP_INT && ct == AO_LISP_INT) {
 			int	r = ao_lisp_poly_int(ret);
 			int	c = ao_lisp_poly_int(car);
 
@@ -308,11 +326,26 @@ ao_lisp_math(struct ao_lisp_cons *cons, enum ao_lisp_builtin_id op)
 					return ao_lisp_error(AO_LISP_DIVIDE_BY_ZERO, "divide by zero");
 				r /= c;
 				break;
-			case builtin_mod:
+			case builtin_quotient:
 				if (c == 0)
-					return ao_lisp_error(AO_LISP_DIVIDE_BY_ZERO, "mod by zero");
+					return ao_lisp_error(AO_LISP_DIVIDE_BY_ZERO, "quotient by zero");
+				if (r % c != 0 && (c < 0) != (r < 0))
+					r = r / c - 1;
+				else
+					r = r / c;
+				break;
+			case builtin_remainder:
+				if (c == 0)
+					return ao_lisp_error(AO_LISP_DIVIDE_BY_ZERO, "remainder by zero");
 				r %= c;
 				break;
+			case builtin_modulo:
+				if (c == 0)
+					return ao_lisp_error(AO_LISP_DIVIDE_BY_ZERO, "modulo by zero");
+				r %= c;
+				if ((r < 0) != (c < 0))
+					r += c;
+				break;
 			default:
 				break;
 			}
@@ -324,6 +357,8 @@ ao_lisp_math(struct ao_lisp_cons *cons, enum ao_lisp_builtin_id op)
 								     ao_lisp_poly_string(car)));
 		else
 			return ao_lisp_error(AO_LISP_INVALID, "invalid args");
+
+		cons = ao_lisp_poly_cons(cons->cdr);
 	}
 	return ret;
 }
@@ -353,9 +388,21 @@ ao_lisp_do_divide(struct ao_lisp_cons *cons)
 }
 
 ao_poly
-ao_lisp_do_mod(struct ao_lisp_cons *cons)
+ao_lisp_do_quotient(struct ao_lisp_cons *cons)
+{
+	return ao_lisp_math(cons, builtin_quotient);
+}
+
+ao_poly
+ao_lisp_do_modulo(struct ao_lisp_cons *cons)
 {
-	return ao_lisp_math(cons, builtin_mod);
+	return ao_lisp_math(cons, builtin_modulo);
+}
+
+ao_poly
+ao_lisp_do_remainder(struct ao_lisp_cons *cons)
+{
+	return ao_lisp_math(cons, builtin_remainder);
 }
 
 ao_poly
@@ -593,5 +640,45 @@ ao_lisp_do_pairp(struct ao_lisp_cons *cons)
 	return _ao_lisp_bool_false;
 }
 
+ao_poly
+ao_lisp_do_numberp(struct ao_lisp_cons *cons)
+{
+	if (!ao_lisp_check_argc(_ao_lisp_atom_led, cons, 1, 1))
+		return AO_LISP_NIL;
+	if (AO_LISP_IS_INT(ao_lisp_arg(cons, 0)))
+		return _ao_lisp_bool_true;
+	return _ao_lisp_bool_false;
+}
+
+ao_poly
+ao_lisp_do_booleanp(struct ao_lisp_cons *cons)
+{
+	if (!ao_lisp_check_argc(_ao_lisp_atom_led, cons, 1, 1))
+		return AO_LISP_NIL;
+	if (ao_lisp_poly_type(ao_lisp_arg(cons, 0)) == AO_LISP_BOOL)
+		return _ao_lisp_bool_true;
+	return _ao_lisp_bool_false;
+}
+
+ao_poly
+ao_lisp_do_set_car(struct ao_lisp_cons *cons)
+{
+	if (!ao_lisp_check_argc(_ao_lisp_atom_led, cons, 2, 2))
+		return AO_LISP_NIL;
+	if (!ao_lisp_check_argt(_ao_lisp_atom_led, cons, 0, AO_LISP_CONS, 0))
+		return AO_LISP_NIL;
+	return ao_lisp_poly_cons(ao_lisp_arg(cons, 0))->car = ao_lisp_arg(cons, 1);
+}
+
+ao_poly
+ao_lisp_do_set_cdr(struct ao_lisp_cons *cons)
+{
+	if (!ao_lisp_check_argc(_ao_lisp_atom_led, cons, 2, 2))
+		return AO_LISP_NIL;
+	if (!ao_lisp_check_argt(_ao_lisp_atom_led, cons, 0, AO_LISP_CONS, 0))
+		return AO_LISP_NIL;
+	return ao_lisp_poly_cons(ao_lisp_arg(cons, 0))->cdr = ao_lisp_arg(cons, 1);
+}
+
 #define AO_LISP_BUILTIN_FUNCS
 #include "ao_lisp_builtin.h"
diff --git a/src/lisp/ao_lisp_builtin.txt b/src/lisp/ao_lisp_builtin.txt
index 2b891dba..b27985ff 100644
--- a/src/lisp/ao_lisp_builtin.txt
+++ b/src/lisp/ao_lisp_builtin.txt
@@ -21,7 +21,9 @@ lexpr	plus		+
 lexpr	minus		-
 lexpr	times		*
 lexpr	divide		/
-lexpr	mod		%
+lexpr	modulo		modulo	%
+lexpr	remainder
+lexpr	quotient
 lexpr	equal		=	eq?	eqv?
 lexpr	less		<
 lexpr	greater		>
@@ -40,3 +42,7 @@ lambda	nullp		null?
 lambda	not
 lambda	listp		list?
 lambda	pairp		pair?
+lambda	numberp		number?	integer?
+lambda	booleanp	boolean?
+lambda	set_car		set-car!
+lambda	set_cdr		set-cdr!
diff --git a/src/lisp/ao_lisp_const.lisp b/src/lisp/ao_lisp_const.lisp
index 37307a68..3ba6aaf5 100644
--- a/src/lisp/ao_lisp_const.lisp
+++ b/src/lisp/ao_lisp_const.lisp
@@ -69,6 +69,93 @@
 (defun 1+ (x) (+ x 1))
 (defun 1- (x) (- x 1))
 
+(define zero? (macro (value rest)
+		     (list
+		      eq?
+		      value
+		      0)
+		     )
+  )
+
+(zero? 1)
+(zero? 0)
+(zero? "hello")
+
+(define positive? (macro (value rest)
+			 (list
+			  >
+			  value
+			  0)
+			 )
+  )
+
+(positive? 12)
+(positive? -12)
+
+(define negative? (macro (value rest)
+			 (list
+			  <
+			  value
+			  0)
+			 )
+  )
+
+(negative? 12)
+(negative? -12)
+
+(defun abs (x) (cond ((>= x 0) x)
+		     (else (- x)))
+       )
+
+(abs 12)
+(abs -12)
+
+(define max (lexpr (first rest)
+		   (while (not (null? rest))
+		     (cond ((< first (car rest))
+			    (set! first (car rest)))
+			   )
+		     (set! rest (cdr rest))
+		     )
+		   first)
+  )
+
+(max 1 2 3)
+(max 3 2 1)
+
+(define min (lexpr (first rest)
+		   (while (not (null? rest))
+		     (cond ((> first (car rest))
+			    (set! first (car rest)))
+			   )
+		     (set! rest (cdr rest))
+		     )
+		   first)
+  )
+
+(min 1 2 3)
+(min 3 2 1)
+
+(defun even? (x) (zero? (% x 2)))
+
+(even? 2)
+(even? -2)
+(even? 3)
+(even? -1)
+
+(defun odd? (x) (not (even? x)))
+
+(odd? 2)
+(odd? -2)
+(odd? 3)
+(odd? -1)
+
+(define exact? number?)
+(defun inexact? (x) #f)
+
+					; (if <condition> <if-true>)
+					; (if <condition> <if-true> <if-false)
+
 (define if (macro (test args)
 	       (cond ((null? (cdr args))
 		      (list
@@ -208,6 +295,49 @@
 
 (and #t #f)
 
+
+(define append (lexpr (args)
+		      (let ((append-list (lambda (a b)
+					   (cond ((null? a) b)
+						 (else (cons (car a) (append-list (cdr a) b)))
+						 )
+					   )
+					 )
+			    (append-lists (lambda (lists)
+					    (cond ((null? lists) lists)
+						  ((null? (cdr lists)) (car lists))
+						  (else (append-list (car lists) (append-lists (cdr lists))))
+						  )
+					    )
+					  )
+			    )
+			(append-lists args)
+			)
+		      )
+  )
+
+(append '(a b c) '(d e f) '(g h i))
+
+(defun reverse (list)
+  (let ((result ()))
+    (while (not (null? list))
+      (set! result (cons (car list) result))
+      (set! list (cdr list))
+      )
+    result)
+  )
+
+(reverse '(1 2 3))
+
+(define list-tail
+  (lambda (x k)
+    (if (zero? k)
+	x
+      (list-tail (cdr x) (- k 1)))))
+
+(list-tail '(1 2 3) 2)
+					; recursive equality
+
 (defun equal? (a b)
   (cond ((eq? a b) #t)
 	((and (pair? a) (pair? b))
@@ -220,3 +350,9 @@
 
 (equal? '(a b c) '(a b c))
 (equal? '(a b c) '(a b b))
+
+;(define number->string (lexpr (arg opt)
+;			      (let ((base (if (null? opt) 10 (car opt)))
+					;
+;
+