6 files changed, 845 insertions, 24 deletions

diff --git a/src/scheme/ao_scheme.h b/src/scheme/ao_scheme.h
index 4589f8a5..10518716 100644
--- a/src/scheme/ao_scheme.h
+++ b/src/scheme/ao_scheme.h
@@ -31,7 +31,7 @@
 typedef uint16_t	ao_poly;
 typedef int16_t		ao_signed_poly;
 
-#ifdef AO_SCHEME_SAVE
+#if AO_SCHEME_SAVE
 
 struct ao_scheme_os_save {
 	ao_poly		atoms;
@@ -77,6 +77,9 @@ extern uint8_t ao_scheme_const[AO_SCHEME_POOL_CONST] __attribute__((aligned(4)))
 #ifndef AO_SCHEME_POOL
 #define AO_SCHEME_POOL	3072
 #endif
+#ifndef AO_SCHEME_POOL_EXTRA
+#define AO_SCHEME_POOL_EXTRA 0
+#endif
 extern uint8_t		ao_scheme_pool[AO_SCHEME_POOL + AO_SCHEME_POOL_EXTRA] __attribute__((aligned(4)));
 #endif
 
@@ -745,6 +748,7 @@ char *
 ao_scheme_args_name(uint8_t args);
 
 /* read */
+extern int			ao_scheme_read_list;
 extern struct ao_scheme_cons	*ao_scheme_read_cons;
 extern struct ao_scheme_cons	*ao_scheme_read_cons_tail;
 extern struct ao_scheme_cons	*ao_scheme_read_stack;
diff --git a/src/scheme/ao_scheme_builtin.c b/src/scheme/ao_scheme_builtin.c
index 49f218f6..aa818646 100644
--- a/src/scheme/ao_scheme_builtin.c
+++ b/src/scheme/ao_scheme_builtin.c
@@ -636,7 +636,7 @@ ao_scheme_do_collect(struct ao_scheme_cons *cons)
 	int	free;
 	(void) cons;
 	free = ao_scheme_collect(AO_SCHEME_COLLECT_FULL);
-	return ao_scheme_int_poly(free);
+	return ao_scheme_integer_poly(free);
 }
 
 ao_poly
diff --git a/src/scheme/ao_scheme_const.scheme b/src/scheme/ao_scheme_const.scheme
new file mode 100644
index 00000000..422bdd63
--- /dev/null
+++ b/src/scheme/ao_scheme_const.scheme
@@ -0,0 +1,813 @@
+;
+; Copyright © 2016 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.
+;
+; Lisp code placed in ROM
+
+					; return a list containing all of the arguments
+(def (quote list) (lambda l l))
+
+(def (quote def!)
+     (macro (name value)
+	    (list
+	     def
+	     (list quote name)
+	     value)
+	    )
+     )
+
+(begin
+ (def! append
+   (lambda args
+	  (def! append-list
+	    (lambda (a b)
+	      (cond ((null? a) b)
+		    (else (cons (car a) (append-list (cdr a) b)))
+		    )
+	      )
+	    )
+	    
+	  (def! 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)
+
+(append '(a b c) '(d e f) '(g h i))
+
+					; boolean operators
+
+(begin
+ (def! or
+   (macro l
+	  (def! _or
+	    (lambda (l)
+	      (cond ((null? l) #f)
+		    ((null? (cdr l))
+		     (car l))
+		    (else
+		     (list
+		      cond
+		      (list
+		       (car l))
+		      (list
+		       'else
+		       (_or (cdr l))
+		       )
+		      )
+		     )
+		    )
+	      )
+	    )
+	  (_or l)))
+ 'or)
+
+					; execute to resolve macros
+
+(or #f #t)
+
+(begin
+ (def! and
+   (macro l
+	  (def! _and
+	    (lambda (l)
+	      (cond ((null? l) #t)
+		    ((null? (cdr l))
+		     (car l))
+		    (else
+		     (list
+		      cond
+		      (list
+		       (car l)
+		       (_and (cdr l))
+		       )
+		      )
+		     )
+		    )
+	      )
+	    )
+	  (_and l)
+	  )
+   )
+ 'and)
+
+					; execute to resolve macros
+
+(and #t #f)
+
+(begin
+ (def! quasiquote
+   (macro (x)
+	  (def! constant?
+					; A constant value is either a pair starting with quote,
+					; or anything which is neither a pair nor a symbol
+
+	    (lambda (exp)
+	      (cond ((pair? exp)
+		     (eq? (car exp) 'quote)
+		     )
+		    (else
+		     (not (symbol? exp))
+		     )
+		    )
+	      )
+	    )
+	  (def! combine-skeletons
+	    (lambda (left right exp)
+	      (cond
+	       ((and (constant? left) (constant? right)) 
+		(cond ((and (eqv? (eval left) (car exp))
+			    (eqv? (eval right) (cdr exp)))
+		       (list 'quote exp)
+		       )
+		      (else
+		       (list 'quote (cons (eval left) (eval right)))
+		       )
+		      )
+		)
+	       ((null? right)
+		(list 'list left)
+		)
+	       ((and (pair? right) (eq? (car right) 'list))
+		(cons 'list (cons left (cdr right)))
+		)
+	       (else
+		(list 'cons left right)
+		)
+	       )
+	      )
+	    )
+
+	  (def! expand-quasiquote
+	    (lambda (exp nesting)
+	      (cond
+
+					; non cons -- constants
+					; themselves, others are
+					; quoted
+
+	       ((not (pair? exp)) 
+		(cond ((constant? exp)
+		       exp
+		       )
+		      (else
+		       (list 'quote exp)
+		       )
+		      )
+		)
+
+					; check for an unquote exp and
+					; add the param unquoted
+
+	       ((and (eq? (car exp) 'unquote) (= (length exp) 2))
+		(cond ((= nesting 0)
+		       (car (cdr exp))
+		       )
+		      (else
+		       (combine-skeletons ''unquote 
+					  (expand-quasiquote (cdr exp) (- nesting 1))
+					  exp))
+		      )
+		)
+
+					; nested quasi-quote --
+					; construct the right
+					; expression
+
+	       ((and (eq? (car exp) 'quasiquote) (= (length exp) 2))
+		(combine-skeletons ''quasiquote 
+				   (expand-quasiquote (cdr exp) (+ nesting 1))
+				   exp))
+
+					; check for an
+					; unquote-splicing member,
+					; compute the expansion of the
+					; value and append the rest of
+					; the quasiquote result to it
+
+	       ((and (pair? (car exp))
+		     (eq? (car (car exp)) 'unquote-splicing)
+		     (= (length (car exp)) 2))
+		(cond ((= nesting 0)
+		       (list 'append (car (cdr (car exp)))
+			     (expand-quasiquote (cdr exp) nesting))
+		       )
+		      (else
+		       (combine-skeletons (expand-quasiquote (car exp) (- nesting 1))
+					  (expand-quasiquote (cdr exp) nesting)
+					  exp))
+		      )
+		)
+
+					; for other lists, just glue
+					; the expansion of the first
+					; element to the expansion of
+					; the rest of the list
+
+	       (else (combine-skeletons (expand-quasiquote (car exp) nesting)
+					(expand-quasiquote (cdr exp) nesting)
+					exp)
+		     )
+	       )
+	      )
+	    )
+	  (def! result (expand-quasiquote x 0))
+	  result
+	  )
+   )
+ 'quasiquote)
+
+					;
+					; Define a variable without returning the value
+					; Useful when defining functions to avoid
+					; having lots of output generated.
+					;
+					; Also accepts the alternate
+					; form for defining lambdas of
+					; (define (name x y z) sexprs ...) 
+					;
+
+(begin
+ (def! define
+   (macro (first . rest)
+					; check for alternate lambda definition form
+
+	  (cond ((list? first)
+		 (set! rest
+		       (append
+			(list
+			 'lambda
+			 (cdr first))
+			rest))
+		 (set! first (car first))
+		 )
+		(else
+		 (set! rest (car rest))
+		 )
+		)
+	  (def! result `(,begin
+			 (,def (,quote ,first) ,rest)
+			 (,quote ,first))
+	    )
+	  result
+	  )
+   )
+ 'define
+ )
+
+					; basic list accessors
+
+(define (caar l) (car (car l)))
+
+(define (cadr l) (car (cdr l)))
+
+(define (cdar l) (cdr (car l)))
+
+(define (caddr l) (car (cdr (cdr l))))
+
+					; (if <condition> <if-true>)
+					; (if <condition> <if-true> <if-false)
+
+(define if
+  (macro (test . args)
+	 (cond ((null? (cdr args))
+		`(cond (,test ,(car args)))
+		)
+	       (else
+		`(cond (,test ,(car args))
+		       (else ,(cadr args)))
+		)
+	       )
+	 )
+  )
+
+(if (> 3 2) 'yes)
+(if (> 3 2) 'yes 'no)
+(if (> 2 3) 'no 'yes)
+(if (> 2 3) 'no)
+
+					; simple math operators
+
+(define zero? (macro (value) `(eq? ,value 0)))
+
+(zero? 1)
+(zero? 0)
+(zero? "hello")
+
+(define positive? (macro (value) `(> ,value 0)))
+
+(positive? 12)
+(positive? -12)
+
+(define negative? (macro (value) `(< ,value 0)))
+
+(negative? 12)
+(negative? -12)
+
+(define (abs x) (if (>= x 0) x (- x)))
+
+(abs 12)
+(abs -12)
+
+(define max (lambda (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 (lambda (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)
+
+(define (even? x) (zero? (% x 2)))
+
+(even? 2)
+(even? -2)
+(even? 3)
+(even? -1)
+
+(define (odd? x) (not (even? x)))
+
+(odd? 2)
+(odd? -2)
+(odd? 3)
+(odd? -1)
+
+
+(define (list-tail x k)
+  (if (zero? k)
+      x
+    (list-tail (cdr x (- k 1)))
+    )
+  )
+
+(define (list-ref x k)
+  (car (list-tail x k))
+  )
+
+					; define a set of local
+					; variables all at once and
+					; then evaluate a list of
+					; sexprs
+					;
+					; (let (var-defines) sexprs)
+					;
+					; where var-defines are either
+					;
+					; (name value)
+					;
+					; or
+					;
+					; (name)
+					;
+					; e.g.
+					;
+					; (let ((x 1) (y)) (set! y (+ x 1)) y)
+
+(define let
+  (macro (vars . exprs)
+	 (define (make-names vars)
+	   (cond ((not (null? vars))
+		  (cons (car (car vars))
+			(make-names (cdr vars))))
+		 (else ())
+		 )
+	   )
+
+					; the parameters to the lambda is a list
+					; of nils of the right length
+
+	 (define (make-vals vars)
+	   (cond ((not (null? vars))
+		  (cons (cond ((null? (cdr (car vars))) ())
+			      (else
+			       (car (cdr (car vars))))
+			      )
+			(make-vals (cdr vars))))
+		 (else ())
+		 )
+	   )
+					; prepend the set operations
+					; to the expressions
+
+					; build the lambda.
+
+	 `((lambda ,(make-names vars) ,@exprs) ,@(make-vals vars))
+	 )
+     )
+		   
+
+(let ((x 1) (y)) (set! y 2) (+ x y))
+
+					; define a set of local
+					; variables one at a time and
+					; then evaluate a list of
+					; sexprs
+					;
+					; (let* (var-defines) sexprs)
+					;
+					; where var-defines are either
+					;
+					; (name value)
+					;
+					; or
+					;
+					; (name)
+					;
+					; e.g.
+					;
+					; (let* ((x 1) (y)) (set! y (+ x 1)) y)
+
+(define let*
+  (macro (vars . exprs)
+
+					;
+					; make the list of names in the let
+					;
+
+	 (define (make-names vars)
+	   (cond ((not (null? vars))
+		  (cons (car (car vars))
+			(make-names (cdr vars))))
+		 (else ())
+		 )
+	   )
+
+					; the set of expressions is
+					; the list of set expressions
+					; pre-pended to the
+					; expressions to evaluate
+
+	 (define (make-exprs vars exprs)
+	   (cond ((null? vars) exprs)
+		 (else
+		  (cons
+		   (list set
+			 (list quote
+			       (car (car vars))
+			       )
+			 (cond ((null? (cdr (car vars))) ())
+			       (else (cadr (car vars))))
+			 )
+		   (make-exprs (cdr vars) exprs)
+		   )
+		  )
+		 )
+	   )
+
+					; the parameters to the lambda is a list
+					; of nils of the right length
+
+	 (define (make-nils vars)
+	   (cond ((null? vars) ())
+		 (else (cons () (make-nils (cdr vars))))
+		 )
+	   )
+					; build the lambda.
+
+	 `((lambda ,(make-names vars) ,@(make-exprs vars exprs)) ,@(make-nils vars))
+	 )
+     )
+
+(let* ((x 1) (y x)) (+ x y))
+
+(define when (macro (test . l) `(cond (,test ,@l))))
+
+(when #t (write 'when))
+
+(define unless (macro (test . l) `(cond ((not ,test) ,@l))))
+
+(unless #f (write 'unless))
+
+(define (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 x k)
+  (if (zero? k)
+      x
+    (list-tail (cdr x) (- k 1))))
+
+(list-tail '(1 2 3) 2)
+
+(define (list-ref x k) (car (list-tail x k)))
+
+(list-ref '(1 2 3) 2)
+    
+					; recursive equality
+
+(define (equal? a b)
+  (cond ((eq? a b) #t)
+	((and (pair? a) (pair? b))
+	 (and (equal? (car a) (car b))
+	      (equal? (cdr a) (cdr b)))
+	 )
+	(else #f)
+	)
+  )
+
+(equal? '(a b c) '(a b c))
+(equal? '(a b c) '(a b b))
+
+(define member (lambda (obj list . test?)
+		      (cond ((null? list)
+			     #f
+			     )
+			    (else
+			     (if (null? test?) (set! test? equal?) (set! test? (car test?)))
+			     (if (test? obj (car list))
+				 list
+			       (member obj (cdr list) test?))
+			     )
+			    )
+		      )
+  )
+
+(member '(2) '((1) (2) (3)))
+
+(member '(4) '((1) (2) (3)))
+
+(define (memq obj list) (member obj list eq?))
+
+(memq 2 '(1 2 3))
+
+(memq 4 '(1 2 3))
+
+(memq '(2) '((1) (2) (3)))
+
+(define (memv obj list) (member obj list eqv?))
+
+(memv 2 '(1 2 3))
+
+(memv 4 '(1 2 3))
+
+(memv '(2) '((1) (2) (3)))
+
+(define (_assoc obj list test?)
+  (if (null? list)
+      #f
+    (if (test? obj (caar list))
+	(car list)
+      (_assoc obj (cdr list) test?)
+      )
+    )
+  )
+
+(define (assq obj list) (_assoc obj list eq?))
+(define (assv obj list) (_assoc obj list eqv?))
+(define (assoc obj list) (_assoc obj list equal?))
+
+(assq 'a '((a 1) (b 2) (c 3)))
+(assv 'b '((a 1) (b 2) (c 3)))
+(assoc '(c) '((a 1) (b 2) ((c) 3)))
+
+(define char? integer?)
+
+(char? #\q)
+(char? "h")
+
+(define (char-upper-case? c) (<= #\A c #\Z))
+
+(char-upper-case? #\a)
+(char-upper-case? #\B)
+(char-upper-case? #\0)
+(char-upper-case? #\space)
+
+(define (char-lower-case? c) (<= #\a c #\a))
+
+(char-lower-case? #\a)
+(char-lower-case? #\B)
+(char-lower-case? #\0)
+(char-lower-case? #\space)
+
+(define (char-alphabetic? c) (or (char-upper-case? c) (char-lower-case? c)))
+
+(char-alphabetic? #\a)
+(char-alphabetic? #\B)
+(char-alphabetic? #\0)
+(char-alphabetic? #\space)
+
+(define (char-numeric? c) (<= #\0 c #\9))
+
+(char-numeric? #\a)
+(char-numeric? #\B)
+(char-numeric? #\0)
+(char-numeric? #\space)
+
+(define (char-whitespace? c) (or (<= #\tab c #\return) (= #\space c)))
+
+(char-whitespace? #\a)
+(char-whitespace? #\B)
+(char-whitespace? #\0)
+(char-whitespace? #\space)
+
+(define (char->integer c) c)
+(define (integer->char c) char-integer)
+
+(define (char-upcase c) (if (char-lower-case? c) (+ c (- #\A #\a)) c))
+
+(char-upcase #\a)
+(char-upcase #\B)
+(char-upcase #\0)
+(char-upcase #\space)
+
+(define (char-downcase c) (if (char-upper-case? c) (+ c (- #\a #\A)) c))
+
+(char-downcase #\a)
+(char-downcase #\B)
+(char-downcase #\0)
+(char-downcase #\space)
+
+(define string (lambda chars (list->string chars)))
+
+(display "apply\n")
+(apply cons '(a b))
+
+(define map
+  (lambda (proc . lists)
+	 (define (args lists)
+	   (cond ((null? lists) ())
+		 (else
+		  (cons (caar lists) (args (cdr lists)))
+		  )
+		 )
+	   )
+	 (define (next lists)
+	   (cond ((null? lists) ())
+		 (else
+		  (cons (cdr (car lists)) (next (cdr lists)))
+		  )
+		 )
+	   )
+	 (define (domap lists)
+	   (cond ((null? (car lists)) ())
+		 (else
+		  (cons (apply proc (args lists)) (domap (next lists)))
+		  )
+		 )
+	   )
+	 (domap lists)
+	 )
+  )
+
+(map cadr '((a b) (d e) (g h)))
+
+(define for-each (lambda (proc . lists)
+			(apply map proc lists)
+			#t))
+
+(for-each display '("hello" " " "world" "\n"))
+
+(define (_string-ml strings)
+  (if (null? strings) ()
+    (cons (string->list (car strings)) (_string-ml (cdr strings)))
+    )
+  )
+
+(define string-map (lambda (proc . strings)
+			  (list->string (apply map proc (_string-ml strings))))))
+
+(string-map (lambda (x) (+ 1 x)) "HAL")
+
+(define string-for-each (lambda (proc . strings)
+			       (apply for-each proc (_string-ml strings))))
+
+(string-for-each write-char "IBM\n")
+
+(define (newline) (write-char #\newline))
+
+(newline)
+
+(call-with-current-continuation
+ (lambda (exit)
+   (for-each (lambda (x)
+	       (write "test" x)
+	       (if (negative? x)
+		   (exit x)))
+	     '(54 0 37 -3 245 19))
+   #t))
+
+
+					; `q -> (quote q)
+					; `(q) -> (append (quote (q)))
+					; `(a ,(+ 1 2)) -> (append (quote (a)) (list (+ 1 2)))
+					; `(a ,@(list 1 2 3) -> (append (quote (a)) (list 1 2 3))
+
+
+
+`(hello ,(+ 1 2) ,@(list 1 2 3) `foo)
+
+
+(define repeat
+  (macro (count . rest)
+	 (define counter '__count__)
+	 (cond ((pair? count)
+		(set! counter (car count))
+		(set! count (cadr count))
+		)
+	       )
+	 `(let ((,counter 0)
+		(__max__ ,count)
+		)
+	    (while (< ,counter __max__)
+	      ,@rest
+	      (set! ,counter (+ ,counter 1))
+	      )
+	    )
+	 )
+  )
+
+(repeat 2 (write 'hello))
+(repeat (x 3) (write 'goodbye x))
+
+(define case
+  (macro (test . l)
+					; construct the body of the
+					; case, dealing with the
+					; lambda version ( => lambda)
+
+	 (define (_unarrow l)
+	   (cond ((null? l) l)
+		 ((eq? (car l) '=>) `(( ,(cadr l) __key__)))
+		 (else l))
+	   )
+
+					; Build the case elements, which is
+					; simply a list of cond clauses
+
+	 (define (_case l)
+
+	   (cond ((null? l) ())
+
+					; else case
+
+		 ((eq? (caar l) 'else)
+		  `((else ,@(_unarrow (cdr (car l))))))
+
+					; regular case
+		 
+		 (else
+		  (cons
+		   `((eqv? ,(caar l) __key__)
+		     ,@(_unarrow (cdr (car l))))
+		   (_case (cdr l)))
+		  )
+		 )
+	   )
+
+					; now construct the overall
+					; expression, using a lambda
+					; to hold the computed value
+					; of the test expression
+
+	 `((lambda (__key__)
+	     (cond ,@(_case l))) ,test)
+	 )
+  )
+
+(case 12 (1 "one") (2 "two") (3 => (lambda (x) (write "the value is" x))) (12 "twelve") (else "else"))
+
+;(define number->string (lambda (arg . opt)
+;			      (let ((base (if (null? opt) 10 (car opt)))
+					;
+;
+				
diff --git a/src/scheme/ao_scheme_float.c b/src/scheme/ao_scheme_float.c
index 541f0264..99249030 100644
--- a/src/scheme/ao_scheme_float.c
+++ b/src/scheme/ao_scheme_float.c
@@ -39,6 +39,10 @@ const struct ao_scheme_type ao_scheme_float_type = {
 	.name = "float",
 };
 
+#ifndef FLOAT_FORMAT
+#define FLOAT_FORMAT "%g"
+#endif
+
 void
 ao_scheme_float_write(ao_poly p)
 {
@@ -54,7 +58,7 @@ ao_scheme_float_write(ao_poly p)
 			printf("+");
 		printf("inf.0");
 	} else
-		printf ("%g", f->value);
+		printf (FLOAT_FORMAT, v);
 }
 
 float
diff --git a/src/scheme/ao_scheme_read.c b/src/scheme/ao_scheme_read.c
index 6b1e9d66..30e29441 100644
--- a/src/scheme/ao_scheme_read.c
+++ b/src/scheme/ao_scheme_read.c
@@ -151,7 +151,7 @@ static const uint16_t	lex_classes[128] = {
 static int lex_unget_c;
 
 static inline int
-lex_get()
+lex_get(void)
 {
 	int	c;
 	if (lex_unget_c) {
@@ -244,7 +244,7 @@ lex_quoted(void)
 	}
 }
 
-#define AO_SCHEME_TOKEN_MAX	32
+#define AO_SCHEME_TOKEN_MAX	128
 
 static char	token_string[AO_SCHEME_TOKEN_MAX];
 static int32_t	token_int;
@@ -470,6 +470,7 @@ static inline int lex(void)
 
 static int parse_token;
 
+int			ao_scheme_read_list;
 struct ao_scheme_cons	*ao_scheme_read_cons;
 struct ao_scheme_cons	*ao_scheme_read_cons_tail;
 struct ao_scheme_cons	*ao_scheme_read_stack;
@@ -479,11 +480,11 @@ struct ao_scheme_cons	*ao_scheme_read_stack;
 #define READ_DONE_DOT	0x04
 
 static int
-push_read_stack(int cons, int read_state)
+push_read_stack(int read_state)
 {
 	RDBGI("push read stack %p 0x%x\n", ao_scheme_read_cons, read_state);
 	RDBG_IN();
-	if (cons) {
+	if (ao_scheme_read_list) {
 		ao_scheme_read_stack = ao_scheme_cons_cons(ao_scheme_cons_poly(ao_scheme_read_cons),
 						       ao_scheme__cons(ao_scheme_int_poly(read_state),
 								     ao_scheme_cons_poly(ao_scheme_read_stack)));
@@ -496,10 +497,10 @@ push_read_stack(int cons, int read_state)
 }
 
 static int
-pop_read_stack(int cons)
+pop_read_stack(void)
 {
 	int	read_state = 0;
-	if (cons) {
+	if (ao_scheme_read_list) {
 		ao_scheme_read_cons = ao_scheme_poly_cons(ao_scheme_read_stack->car);
 		ao_scheme_read_stack = ao_scheme_poly_cons(ao_scheme_read_stack->cdr);
 		read_state = ao_scheme_poly_int(ao_scheme_read_stack->car);
@@ -523,19 +524,18 @@ ao_scheme_read(void)
 {
 	struct ao_scheme_atom	*atom;
 	char			*string;
-	int			cons;
 	int			read_state;
 	ao_poly			v = AO_SCHEME_NIL;
 
-	cons = 0;
+	ao_scheme_read_list = 0;
 	read_state = 0;
 	ao_scheme_read_cons = ao_scheme_read_cons_tail = ao_scheme_read_stack = 0;
 	for (;;) {
 		parse_token = lex();
 		while (parse_token == OPEN) {
-			if (!push_read_stack(cons, read_state))
+			if (!push_read_stack(read_state))
 				return AO_SCHEME_NIL;
-			cons++;
+			ao_scheme_read_list++;
 			read_state = 0;
 			parse_token = lex();
 		}
@@ -543,7 +543,7 @@ ao_scheme_read(void)
 		switch (parse_token) {
 		case END:
 		default:
-			if (cons)
+			if (ao_scheme_read_list)
 				ao_scheme_error(AO_SCHEME_EOF, "unexpected end of file");
 			return _ao_scheme_atom_eof;
 			break;
@@ -577,9 +577,9 @@ ao_scheme_read(void)
 		case QUASIQUOTE:
 		case UNQUOTE:
 		case UNQUOTE_SPLICING:
-			if (!push_read_stack(cons, read_state))
+			if (!push_read_stack(read_state))
 				return AO_SCHEME_NIL;
-			cons++;
+			ao_scheme_read_list++;
 			read_state = READ_IN_QUOTE;
 			switch (parse_token) {
 			case QUOTE:
@@ -597,16 +597,16 @@ ao_scheme_read(void)
 			}
 			break;
 		case CLOSE:
-			if (!cons) {
+			if (!ao_scheme_read_list) {
 				v = AO_SCHEME_NIL;
 				break;
 			}
 			v = ao_scheme_cons_poly(ao_scheme_read_cons);
-			--cons;
-			read_state = pop_read_stack(cons);
+			--ao_scheme_read_list;
+			read_state = pop_read_stack();
 			break;
 		case DOT:
-			if (!cons) {
+			if (!ao_scheme_read_list) {
 				ao_scheme_error(AO_SCHEME_INVALID, ". outside of cons");
 				return AO_SCHEME_NIL;
 			}
@@ -620,7 +620,7 @@ ao_scheme_read(void)
 
 		/* loop over QUOTE ends */
 		for (;;) {
-			if (!cons)
+			if (!ao_scheme_read_list)
 				return v;
 
 			if (read_state & READ_DONE_DOT) {
@@ -647,8 +647,8 @@ ao_scheme_read(void)
 				break;
 
 			v = ao_scheme_cons_poly(ao_scheme_read_cons);
-			--cons;
-			read_state = pop_read_stack(cons);
+			--ao_scheme_read_list;
+			read_state = pop_read_stack();
 		}
 	}
 	return v;
diff --git a/src/scheme/test/ao_scheme_test.c b/src/scheme/test/ao_scheme_test.c
index 15c71203..686e7169 100644
--- a/src/scheme/test/ao_scheme_test.c
+++ b/src/scheme/test/ao_scheme_test.c
@@ -78,7 +78,7 @@ ao_scheme_getc(void)
 		return getc(ao_scheme_file);
 
 	if (newline) {
-		if (ao_scheme_read_stack)
+		if (ao_scheme_read_list)
 			printf("+ ");
 		else
 			printf("> ");