altos/lisp: Add floats

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

13 files changed, 384 insertions, 64 deletions

diff --git a/src/lisp/Makefile b/src/lisp/Makefile
index 4563dad3..05f54550 100644
--- a/src/lisp/Makefile
+++ b/src/lisp/Makefile
@@ -19,6 +19,6 @@ OBJS=$(SRCS:.c=.o)
 CFLAGS=-DAO_LISP_MAKE_CONST -O0 -g -I. -Wall -Wextra -no-pie
 
 ao_lisp_make_const:  $(OBJS)
-	$(CC) $(CFLAGS) -o $@ $(OBJS)
+	$(CC) $(CFLAGS) -o $@ $(OBJS) -lm
 
 $(OBJS): $(HDRS)
diff --git a/src/lisp/Makefile-inc b/src/lisp/Makefile-inc
index 6c8702fb..a097f1be 100644
--- a/src/lisp/Makefile-inc
+++ b/src/lisp/Makefile-inc
@@ -6,6 +6,7 @@ LISP_SRCS=\
 	ao_lisp_int.c \
 	ao_lisp_poly.c \
 	ao_lisp_bool.c \
+	ao_lisp_float.c \
 	ao_lisp_builtin.c \
 	ao_lisp_read.c \
 	ao_lisp_frame.c \
diff --git a/src/lisp/ao_lisp.h b/src/lisp/ao_lisp.h
index 08278fe7..cbbbe9a4 100644
--- a/src/lisp/ao_lisp.h
+++ b/src/lisp/ao_lisp.h
@@ -96,7 +96,8 @@ extern uint8_t		ao_lisp_pool[AO_LISP_POOL + AO_LISP_POOL_EXTRA] __attribute__((a
 #define AO_LISP_STACK		8
 #define AO_LISP_BOOL		9
 #define AO_LISP_BIGINT		10
-#define AO_LISP_NUM_TYPE	11
+#define AO_LISP_FLOAT		11
+#define AO_LISP_NUM_TYPE	12
 
 /* Leave two bits for types to use as they please */
 #define AO_LISP_OTHER_TYPE_MASK	0x3f
@@ -170,6 +171,13 @@ struct ao_lisp_bigint {
 	uint32_t		value;
 };
 
+struct ao_lisp_float {
+	uint8_t			type;
+	uint8_t			pad1;
+	uint16_t		pad2;
+	float			value;
+};
+
 #if __BYTE_ORDER == __LITTLE_ENDIAN
 static inline uint32_t
 ao_lisp_int_bigint(int32_t i) {
@@ -442,6 +450,22 @@ ao_lisp_poly_bool(ao_poly poly)
 {
 	return ao_lisp_ref(poly);
 }
+
+static inline ao_poly
+ao_lisp_float_poly(struct ao_lisp_float *f)
+{
+	return ao_lisp_poly(f, AO_LISP_OTHER);
+}
+
+static inline struct ao_lisp_float *
+ao_lisp_poly_float(ao_poly poly)
+{
+	return ao_lisp_ref(poly);
+}
+
+float
+ao_lisp_poly_number(ao_poly p);
+
 /* memory functions */
 
 extern int ao_lisp_collects[2];
@@ -524,6 +548,10 @@ extern const struct ao_lisp_type ao_lisp_cons_type;
 struct ao_lisp_cons *
 ao_lisp_cons_cons(ao_poly car, ao_poly cdr);
 
+/* Return a cons or NULL for a proper list, else error */
+struct ao_lisp_cons *
+ao_lisp_cons_cdr(struct ao_lisp_cons *cons);
+
 ao_poly
 ao_lisp__cons(ao_poly car, ao_poly cdr);
 
@@ -632,6 +660,24 @@ ao_lisp_eval(ao_poly p);
 ao_poly
 ao_lisp_set_cond(struct ao_lisp_cons *cons);
 
+/* float */
+extern const struct ao_lisp_type ao_lisp_float_type;
+
+void
+ao_lisp_float_write(ao_poly p);
+
+ao_poly
+ao_lisp_float_get(float value);
+
+static inline uint8_t
+ao_lisp_number_typep(uint8_t t)
+{
+	return ao_lisp_integer_typep(t) || (t == AO_LISP_FLOAT);
+}
+
+float
+ao_lisp_poly_number(ao_poly p);
+
 /* builtin */
 void
 ao_lisp_builtin_write(ao_poly b);
diff --git a/src/lisp/ao_lisp_builtin.c b/src/lisp/ao_lisp_builtin.c
index e5370f90..d4dc8a86 100644
--- a/src/lisp/ao_lisp_builtin.c
+++ b/src/lisp/ao_lisp_builtin.c
@@ -14,6 +14,7 @@
 
 #include "ao_lisp.h"
 #include <limits.h>
+#include <math.h>
 
 static int
 builtin_size(void *addr)
@@ -98,7 +99,7 @@ ao_lisp_check_argc(ao_poly name, struct ao_lisp_cons *cons, int min, int max)
 
 	while (cons && argc <= max) {
 		argc++;
-		cons = ao_lisp_poly_cons(cons->cdr);
+		cons = ao_lisp_cons_cdr(cons);
 	}
 	if (argc < min || argc > max)
 		return ao_lisp_error(AO_LISP_INVALID, "%s: invalid arg count", ao_lisp_poly_atom(name)->name);
@@ -113,7 +114,7 @@ ao_lisp_arg(struct ao_lisp_cons *cons, int argc)
 	while (argc--) {
 		if (!cons)
 			return AO_LISP_NIL;
-		cons = ao_lisp_poly_cons(cons->cdr);
+		cons = ao_lisp_cons_cdr(cons);
 	}
 	return cons->car;
 }
@@ -162,17 +163,17 @@ ao_lisp_do_cons(struct ao_lisp_cons *cons)
 ao_poly
 ao_lisp_do_last(struct ao_lisp_cons *cons)
 {
-	ao_poly	l;
+	struct ao_lisp_cons	*list;
 	if (!ao_lisp_check_argc(_ao_lisp_atom_last, cons, 1, 1))
 		return AO_LISP_NIL;
 	if (!ao_lisp_check_argt(_ao_lisp_atom_last, cons, 0, AO_LISP_CONS, 1))
 		return AO_LISP_NIL;
-	l = ao_lisp_arg(cons, 0);
-	while (l) {
-		struct ao_lisp_cons *list = ao_lisp_poly_cons(l);
+	for (list = ao_lisp_poly_cons(ao_lisp_arg(cons, 0));
+	     list;
+	     list = ao_lisp_cons_cdr(list))
+	{
 		if (!list->cdr)
 			return list->car;
-		l = list->cdr;
 	}
 	return AO_LISP_NIL;
 }
@@ -253,7 +254,7 @@ ao_lisp_do_write(struct ao_lisp_cons *cons)
 	while (cons) {
 		val = cons->car;
 		ao_lisp_poly_write(val);
-		cons = ao_lisp_poly_cons(cons->cdr);
+		cons = ao_lisp_cons_cdr(cons);
 		if (cons)
 			printf(" ");
 	}
@@ -268,39 +269,38 @@ ao_lisp_do_display(struct ao_lisp_cons *cons)
 	while (cons) {
 		val = cons->car;
 		ao_lisp_poly_display(val);
-		cons = ao_lisp_poly_cons(cons->cdr);
+		cons = ao_lisp_cons_cdr(cons);
 	}
 	return _ao_lisp_bool_true;
 }
 
 ao_poly
-ao_lisp_math(struct ao_lisp_cons *cons, enum ao_lisp_builtin_id op)
+ao_lisp_math(struct ao_lisp_cons *orig_cons, enum ao_lisp_builtin_id op)
 {
-	struct ao_lisp_cons *orig_cons = cons;
+	struct ao_lisp_cons *cons = cons;
 	ao_poly	ret = AO_LISP_NIL;
 
-	while (cons) {
+	for (cons = orig_cons; cons; cons = ao_lisp_cons_cdr(cons)) {
 		ao_poly		car = cons->car;
-		ao_poly		cdr;
 		uint8_t		rt = ao_lisp_poly_type(ret);
 		uint8_t		ct = ao_lisp_poly_type(car);
 
 		if (cons == orig_cons) {
 			ret = car;
-			if (cons->cdr == AO_LISP_NIL && ct == AO_LISP_INT) {
+			if (cons->cdr == AO_LISP_NIL) {
 				switch (op) {
 				case builtin_minus:
-					ret = ao_lisp_integer_poly(-ao_lisp_poly_integer(ret));
+					if (ao_lisp_integer_typep(ct))
+						ret = ao_lisp_integer_poly(-ao_lisp_poly_integer(ret));
+					else if (ct == AO_LISP_FLOAT)
+						ret = ao_lisp_float_get(-ao_lisp_poly_number(ret));
 					break;
 				case builtin_divide:
-					switch (ao_lisp_poly_integer(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;
+					if (ao_lisp_integer_typep(ct) && ao_lisp_poly_integer(ret) == 1)
+						;
+					else if (ao_lisp_number_typep(ct)) {
+						float	v = ao_lisp_poly_number(ret);
+						ret = ao_lisp_float_get(1/v);
 					}
 					break;
 				default:
@@ -322,10 +322,54 @@ ao_lisp_math(struct ao_lisp_cons *cons, enum ao_lisp_builtin_id op)
 				r *= c;
 				break;
 			case builtin_divide:
+				if (c != 0 && (r % c) == 0)
+					r /= c;
+				else {
+					ret = ao_lisp_float_get((float) r / (float) c);
+					continue;
+				}
+				break;
+			case builtin_quotient:
+				if (c == 0)
+					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, "divide by zero");
+					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;
+			}
+			ret = ao_lisp_integer_poly(r);
+		} else if (ao_lisp_number_typep(rt) && ao_lisp_number_typep(ct)) {
+			float r = ao_lisp_poly_number(ret);
+			float c = ao_lisp_poly_number(car);
+			switch(op) {
+			case builtin_plus:
+				r += c;
+				break;
+			case builtin_minus:
+				r -= c;
+				break;
+			case builtin_times:
+				r *= c;
+				break;
+			case builtin_divide:
 				r /= c;
 				break;
+#if 0
 			case builtin_quotient:
 				if (c == 0)
 					return ao_lisp_error(AO_LISP_DIVIDE_BY_ZERO, "quotient by zero");
@@ -346,10 +390,11 @@ ao_lisp_math(struct ao_lisp_cons *cons, enum ao_lisp_builtin_id op)
 				if ((r < 0) != (c < 0))
 					r += c;
 				break;
+#endif
 			default:
 				break;
 			}
-			ret = ao_lisp_integer_poly(r);
+			ret = ao_lisp_float_get(r);
 		}
 
 		else if (rt == AO_LISP_STRING && ct == AO_LISP_STRING && op == builtin_plus)
@@ -357,11 +402,6 @@ 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");
-
-		cdr = cons->cdr;
-		if (cdr != AO_LISP_NIL && ao_lisp_poly_type(cdr) != AO_LISP_CONS)
-			return ao_lisp_error(AO_LISP_INVALID, "improper list");
-		cons = ao_lisp_poly_cons(cdr);
 	}
 	return ret;
 }
@@ -417,8 +457,7 @@ ao_lisp_compare(struct ao_lisp_cons *cons, enum ao_lisp_builtin_id op)
 		return _ao_lisp_bool_true;
 
 	left = cons->car;
-	cons = ao_lisp_poly_cons(cons->cdr);
-	while (cons) {
+	for (cons = ao_lisp_cons_cdr(cons); cons; cons = ao_lisp_cons_cdr(cons)) {
 		ao_poly	right = cons->car;
 
 		if (op == builtin_equal) {
@@ -477,7 +516,6 @@ ao_lisp_compare(struct ao_lisp_cons *cons, enum ao_lisp_builtin_id op)
 			}
 		}
 		left = right;
-		cons = ao_lisp_poly_cons(cons->cdr);
 	}
 	return _ao_lisp_bool_true;
 }
@@ -641,6 +679,20 @@ ao_lisp_do_pairp(struct ao_lisp_cons *cons)
 }
 
 ao_poly
+ao_lisp_do_integerp(struct ao_lisp_cons *cons)
+{
+	if (!ao_lisp_check_argc(_ao_lisp_atom_led, cons, 1, 1))
+		return AO_LISP_NIL;
+	switch (ao_lisp_poly_type(ao_lisp_arg(cons, 0))) {
+	case AO_LISP_INT:
+	case AO_LISP_BIGINT:
+		return _ao_lisp_bool_true;
+	default:
+		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))
@@ -648,6 +700,7 @@ ao_lisp_do_numberp(struct ao_lisp_cons *cons)
 	switch (ao_lisp_poly_type(ao_lisp_arg(cons, 0))) {
 	case AO_LISP_INT:
 	case AO_LISP_BIGINT:
+	case AO_LISP_FLOAT:
 		return _ao_lisp_bool_true;
 	default:
 		return _ao_lisp_bool_false;
diff --git a/src/lisp/ao_lisp_builtin.txt b/src/lisp/ao_lisp_builtin.txt
index c324ca67..2e11bdad 100644
--- a/src/lisp/ao_lisp_builtin.txt
+++ b/src/lisp/ao_lisp_builtin.txt
@@ -42,7 +42,8 @@ f_lambda	nullp		null?
 f_lambda	not
 f_lambda	listp		list?
 f_lambda	pairp		pair?
-f_lambda	numberp		number?	integer?
+f_lambda	integerp	integer? exact? exact-integer?
+f_lambda	numberp		number? real?
 f_lambda	booleanp	boolean?
 f_lambda	set_car		set-car!
 f_lambda	set_cdr		set-cdr!
@@ -58,3 +59,7 @@ f_lambda	exit
 f_lambda	current_jiffy	current-jiffy
 f_lambda	current_second	current-second
 f_lambda	jiffies_per_second	jiffies-per-second
+f_lambda	finitep		finite?
+f_lambda	infinitep	infinite?
+f_lambda	inexactp	inexact?
+f_lambda	sqrt
diff --git a/src/lisp/ao_lisp_cons.c b/src/lisp/ao_lisp_cons.c
index 9379597c..c70aa1ca 100644
--- a/src/lisp/ao_lisp_cons.c
+++ b/src/lisp/ao_lisp_cons.c
@@ -105,6 +105,19 @@ ao_lisp_cons_cons(ao_poly car, ao_poly cdr)
 	return cons;
 }
 
+struct ao_lisp_cons *
+ao_lisp_cons_cdr(struct ao_lisp_cons *cons)
+{
+	ao_poly	cdr = cons->cdr;
+	if (cdr == AO_LISP_NIL)
+		return NULL;
+	if (ao_lisp_poly_type(cdr) != AO_LISP_CONS) {
+		(void) ao_lisp_error(AO_LISP_INVALID, "improper list");
+		return NULL;
+	}
+	return ao_lisp_poly_cons(cdr);
+}
+
 ao_poly
 ao_lisp__cons(ao_poly car, ao_poly cdr)
 {
diff --git a/src/lisp/ao_lisp_const.lisp b/src/lisp/ao_lisp_const.lisp
index 861a4fc8..9fb7634c 100644
--- a/src/lisp/ao_lisp_const.lisp
+++ b/src/lisp/ao_lisp_const.lisp
@@ -159,9 +159,6 @@
 (odd? 3)
 (odd? -1)
 
-(define exact? number?)
-(defun inexact? (x) #f)
-
 					; (if <condition> <if-true>)
 					; (if <condition> <if-true> <if-false)
 
diff --git a/src/lisp/ao_lisp_eval.c b/src/lisp/ao_lisp_eval.c
index 8fa488e2..cfa71fa7 100644
--- a/src/lisp/ao_lisp_eval.c
+++ b/src/lisp/ao_lisp_eval.c
@@ -111,6 +111,7 @@ ao_lisp_eval_sexpr(void)
 	case AO_LISP_BOOL:
 	case AO_LISP_INT:
 	case AO_LISP_BIGINT:
+	case AO_LISP_FLOAT:
 	case AO_LISP_STRING:
 	case AO_LISP_BUILTIN:
 	case AO_LISP_LAMBDA:
diff --git a/src/lisp/ao_lisp_float.c b/src/lisp/ao_lisp_float.c
new file mode 100644
index 00000000..0aa6f2ea
--- /dev/null
+++ b/src/lisp/ao_lisp_float.c
@@ -0,0 +1,148 @@
+/*
+ * Copyright © 2017 Keith Packard <keithp@keithp.com>
+ *
+ * This program 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 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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.
+ */
+
+#include "ao_lisp.h"
+#include <math.h>
+
+static void float_mark(void *addr)
+{
+	(void) addr;
+}
+
+static int float_size(void *addr)
+{
+	if (!addr)
+		return 0;
+	return sizeof (struct ao_lisp_float);
+}
+
+static void float_move(void *addr)
+{
+	(void) addr;
+}
+
+const struct ao_lisp_type ao_lisp_float_type = {
+	.mark = float_mark,
+	.size = float_size,
+	.move = float_move,
+	.name = "float",
+};
+
+void
+ao_lisp_float_write(ao_poly p)
+{
+	struct ao_lisp_float *f = ao_lisp_poly_float(p);
+	float	v = f->value;
+
+	if (isnanf(v))
+		printf("+nan.0");
+	else if (isinff(v)) {
+		if (v < 0)
+			printf("-");
+		else
+			printf("+");
+		printf("inf.0");
+	} else
+		printf ("%g", f->value);
+}
+
+float
+ao_lisp_poly_number(ao_poly p)
+{
+	switch (ao_lisp_poly_base_type(p)) {
+	case AO_LISP_INT:
+		return ao_lisp_poly_int(p);
+	case AO_LISP_OTHER:
+		switch (ao_lisp_other_type(ao_lisp_poly_other(p))) {
+		case AO_LISP_BIGINT:
+			return ao_lisp_bigint_int(ao_lisp_poly_bigint(p)->value);
+		case AO_LISP_FLOAT:
+			return ao_lisp_poly_float(p)->value;
+		}
+	}
+	return NAN;
+}
+
+ao_poly
+ao_lisp_float_get(float value)
+{
+	struct ao_lisp_float	*f;
+
+	f = ao_lisp_alloc(sizeof (struct ao_lisp_float));
+	f->type = AO_LISP_FLOAT;
+	f->value = value;
+	return ao_lisp_float_poly(f);
+}
+
+ao_poly
+ao_lisp_do_inexactp(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_FLOAT)
+		return _ao_lisp_bool_true;
+	return _ao_lisp_bool_false;
+}
+
+ao_poly
+ao_lisp_do_finitep(struct ao_lisp_cons *cons)
+{
+	ao_poly	value;
+	float	f;
+
+	if (!ao_lisp_check_argc(_ao_lisp_atom_led, cons, 1, 1))
+		return AO_LISP_NIL;
+	value = ao_lisp_arg(cons, 0);
+	switch (ao_lisp_poly_type(value)) {
+	case AO_LISP_INT:
+	case AO_LISP_BIGINT:
+		return _ao_lisp_bool_true;
+	case AO_LISP_FLOAT:
+		f = ao_lisp_poly_float(value)->value;
+		if (!isnan(f) && !isinf(f))
+			return _ao_lisp_bool_true;
+	}
+	return _ao_lisp_bool_false;
+}
+
+ao_poly
+ao_lisp_do_infinitep(struct ao_lisp_cons *cons)
+{
+	ao_poly	value;
+	float	f;
+
+	if (!ao_lisp_check_argc(_ao_lisp_atom_led, cons, 1, 1))
+		return AO_LISP_NIL;
+	value = ao_lisp_arg(cons, 0);
+	switch (ao_lisp_poly_type(value)) {
+	case AO_LISP_FLOAT:
+		f = ao_lisp_poly_float(value)->value;
+		if (isinf(f))
+			return _ao_lisp_bool_true;
+	}
+	return _ao_lisp_bool_false;
+}
+
+ao_poly
+ao_lisp_do_sqrt(struct ao_lisp_cons *cons)
+{
+	ao_poly	value;
+
+	if (!ao_lisp_check_argc(_ao_lisp_atom_sqrt, cons, 1, 1))
+		return AO_LISP_NIL;
+	value = ao_lisp_arg(cons, 0);
+	if (!ao_lisp_number_typep(ao_lisp_poly_type(value)))
+		return ao_lisp_error(AO_LISP_INVALID, "%s: non-numeric", ao_lisp_poly_atom(_ao_lisp_atom_sqrt)->name);
+	return ao_lisp_float_get(sqrtf(ao_lisp_poly_number(value)));
+}
diff --git a/src/lisp/ao_lisp_mem.c b/src/lisp/ao_lisp_mem.c
index f333073a..dc0008c4 100644
--- a/src/lisp/ao_lisp_mem.c
+++ b/src/lisp/ao_lisp_mem.c
@@ -459,6 +459,7 @@ static const struct ao_lisp_type *ao_lisp_types[AO_LISP_NUM_TYPE] = {
 	[AO_LISP_STACK] = &ao_lisp_stack_type,
 	[AO_LISP_BOOL] = &ao_lisp_bool_type,
 	[AO_LISP_BIGINT] = &ao_lisp_bigint_type,
+	[AO_LISP_FLOAT] = &ao_lisp_float_type,
 };
 
 static int
diff --git a/src/lisp/ao_lisp_poly.c b/src/lisp/ao_lisp_poly.c
index 94ecd042..e93e1192 100644
--- a/src/lisp/ao_lisp_poly.c
+++ b/src/lisp/ao_lisp_poly.c
@@ -60,6 +60,10 @@ static const struct ao_lisp_funcs ao_lisp_funcs[AO_LISP_NUM_TYPE] = {
 		.write = ao_lisp_bigint_write,
 		.display = ao_lisp_bigint_write,
 	},
+	[AO_LISP_FLOAT] = {
+		.write = ao_lisp_float_write,
+		.display = ao_lisp_float_write,
+	},
 };
 
 static const struct ao_lisp_funcs *
diff --git a/src/lisp/ao_lisp_read.c b/src/lisp/ao_lisp_read.c
index 5115f46e..c5a238cc 100644
--- a/src/lisp/ao_lisp_read.c
+++ b/src/lisp/ao_lisp_read.c
@@ -14,6 +14,7 @@
 
 #include "ao_lisp.h"
 #include "ao_lisp_read.h"
+#include <math.h>
 
 static const uint16_t	lex_classes[128] = {
 	IGNORE,		/* ^@ */
@@ -62,7 +63,7 @@ static const uint16_t	lex_classes[128] = {
  	PRINTABLE|SIGN,		/* + */
  	PRINTABLE,		/* , */
  	PRINTABLE|SIGN,		/* - */
- 	PRINTABLE|SPECIAL,	/* . */
+ 	PRINTABLE|DOTC|FLOATC,	/* . */
  	PRINTABLE,		/* / */
  	PRINTABLE|DIGIT,	/* 0 */
  	PRINTABLE|DIGIT,	/* 1 */
@@ -85,7 +86,7 @@ static const uint16_t	lex_classes[128] = {
 	PRINTABLE,		/*  B */
 	PRINTABLE,		/*  C */
 	PRINTABLE,		/*  D */
-	PRINTABLE,		/*  E */
+	PRINTABLE|FLOATC,	/*  E */
 	PRINTABLE,		/*  F */
 	PRINTABLE,		/*  G */
 	PRINTABLE,		/*  H */
@@ -117,7 +118,7 @@ static const uint16_t	lex_classes[128] = {
 	PRINTABLE,		/*  b */
 	PRINTABLE,		/*  c */
 	PRINTABLE,		/*  d */
-	PRINTABLE,		/*  e */
+	PRINTABLE|FLOATC,	/*  e */
 	PRINTABLE,		/*  f */
 	PRINTABLE,		/*  g */
 	PRINTABLE,		/*  h */
@@ -140,7 +141,7 @@ static const uint16_t	lex_classes[128] = {
 	PRINTABLE,		/*  y */
 	PRINTABLE,		/*  z */
 	PRINTABLE,		/*  { */
-	PRINTABLE|VBAR,		/*  | */
+	PRINTABLE,		/*  | */
 	PRINTABLE,		/*  } */
 	PRINTABLE,		/*  ~ */
 	IGNORE,			/*  ^? */
@@ -247,16 +248,36 @@ lex_quoted(void)
 static char	token_string[AO_LISP_TOKEN_MAX];
 static int32_t	token_int;
 static int	token_len;
+static float	token_float;
 
 static inline void add_token(int c) {
 	if (c && token_len < AO_LISP_TOKEN_MAX - 1)
 		token_string[token_len++] = c;
 }
 
+static inline void del_token(void) {
+	if (token_len > 0)
+		token_len--;
+}
+
 static inline void end_token(void) {
 	token_string[token_len] = '\0';
 }
 
+struct namedfloat {
+	const char	*name;
+	float		value;
+};
+
+static const struct namedfloat namedfloats[] = {
+	{ .name = "+inf.0", .value = INFINITY },
+	{ .name = "-inf.0", .value = -INFINITY },
+	{ .name = "+nan.0", .value = NAN },
+	{ .name = "-nan.0", .value = NAN },
+};
+
+#define NUM_NAMED_FLOATS	(sizeof namedfloats / sizeof namedfloats[0])
+
 static int
 _lex(void)
 {
@@ -279,7 +300,7 @@ _lex(void)
 			continue;
 		}
 
-		if (lex_class & SPECIAL) {
+		if (lex_class & (SPECIAL|DOTC)) {
 			add_token(c);
 			end_token();
 			switch (c) {
@@ -357,47 +378,72 @@ _lex(void)
 			}
 		}
 		if (lex_class & PRINTABLE) {
-			int	isnum;
+			int	isfloat;
 			int	hasdigit;
 			int	isneg;
+			int	isint;
+			int	epos;
 
-			isnum = 1;
+			isfloat = 1;
+			isint = 1;
 			hasdigit = 0;
 			token_int = 0;
 			isneg = 0;
+			epos = 0;
 			for (;;) {
 				if (!(lex_class & NUMBER)) {
-					isnum = 0;
+					isint = 0;
+					isfloat = 0;
 				} else {
- 					if (token_len != 0 &&
+					if (!(lex_class & INTEGER))
+						isint = 0;
+ 					if (token_len != epos &&
 					    (lex_class & SIGN))
 					{
-						isnum = 0;
+						isint = 0;
+						isfloat = 0;
 					}
 					if (c == '-')
 						isneg = 1;
+					if (c == '.' && epos != 0)
+						isfloat = 0;
+					if (c == 'e' || c == 'E') {
+						if (token_len == 0)
+							isfloat = 0;
+						else
+							epos = token_len + 1;
+					}
 					if (lex_class & DIGIT) {
 						hasdigit = 1;
-						if (isnum)
+						if (isint)
 							token_int = token_int * 10 + c - '0';
 					}
 				}
 				add_token (c);
 				c = lexc ();
-				if (lex_class & (NOTNAME)) {
+				if ((lex_class & (NOTNAME)) && (c != '.' || !isfloat)) {
+					unsigned int u;
 //					if (lex_class & ENDOFFILE)
 //						clearerr (f);
 					lex_unget(c);
 					end_token ();
-					if (isnum && hasdigit) {
+					if (isint && hasdigit) {
 						if (isneg)
 							token_int = -token_int;
 						return NUM;
 					}
+					if (isfloat && hasdigit) {
+						token_float = atof(token_string);
+						return FLOAT;
+					}
+					for (u = 0; u < NUM_NAMED_FLOATS; u++)
+						if (!strcmp(namedfloats[u].name, token_string)) {
+							token_float = namedfloats[u].value;
+							return FLOAT;
+						}
 					return NAME;
 				}
 			}
-
 		}
 	}
 }
@@ -499,6 +545,9 @@ ao_lisp_read(void)
 		case NUM:
 			v = ao_lisp_integer_poly(token_int);
 			break;
+		case FLOAT:
+			v = ao_lisp_float_get(token_float);
+			break;
 		case BOOL:
 			if (token_string[0] == 't')
 				v = _ao_lisp_bool_true;
diff --git a/src/lisp/ao_lisp_read.h b/src/lisp/ao_lisp_read.h
index fc74a8e4..20c9c18a 100644
--- a/src/lisp/ao_lisp_read.h
+++ b/src/lisp/ao_lisp_read.h
@@ -26,28 +26,30 @@
 # define QUOTE	4
 # define STRING	5
 # define NUM	6
-# define DOT	7
-# define BOOL	8
+# define FLOAT	7
+# define DOT	8
+# define BOOL	9
 
 /*
  * character classes
  */
 
 # define PRINTABLE	0x0001	/* \t \n ' ' - '~' */
-# define QUOTED		0x0002	/* \ anything */
-# define SPECIAL	0x0004	/* ( [ { ) ] } ' . */
+# define SPECIAL	0x0002	/* ( [ { ) ] } ' */
+# define DOTC		0x0004	/* . */
 # define WHITE		0x0008	/* ' ' \t \n */
 # define DIGIT		0x0010	/* [0-9] */
 # define SIGN		0x0020	/* +- */
-# define ENDOFFILE	0x0040	/* end of file */
-# define COMMENT	0x0080	/* ; */
-# define IGNORE		0x0100	/* \0 - ' ' */
-# define BACKSLASH	0x0200	/* \ */
-# define VBAR		0x0400	/* | */
+# define FLOATC		0x0040	/* . e E */
+# define ENDOFFILE	0x0080	/* end of file */
+# define COMMENT	0x0100	/* ; */
+# define IGNORE		0x0200	/* \0 - ' ' */
+# define BACKSLASH	0x0400	/* \ */
 # define STRINGC	0x0800	/* " */
 # define POUND		0x1000	/* # */
 
-# define NOTNAME	(STRINGC|VBAR|COMMENT|ENDOFFILE|WHITE|SPECIAL)
-# define NUMBER		(DIGIT|SIGN)
+# define NOTNAME	(STRINGC|COMMENT|ENDOFFILE|WHITE|SPECIAL)
+# define INTEGER	(DIGIT|SIGN)
+# define NUMBER		(INTEGER|FLOATC)
 
 #endif /* _AO_LISP_READ_H_ */