#28 min and max (in)exactness

closed-fixed
nobody
None
5
2011-08-29
2011-08-27
Doug Currie
No

min and max are required to return inexact when any argument is inexact; here is a patch:

--- /Users/e/Dev/scheme/tinyscheme/tinyscheme/trunk/init.scm (revision 73)
+++ /Users/e/Dev/scheme/tinyscheme/tinyscheme/trunk/init.scm (working copy)
@@ -70,10 +70,19 @@
(define (abs n) (if (>= n 0) n (- n)))
(define (exact->inexact n) (* n 1.0))
(define (<> n1 n2) (not (= n1 n2)))
+; min and max must return inexact if any arg is inexact; use (+ n 0.0)
(define (max . lst)
- (foldr (lambda (a b) (if (> a b) a b)) (car lst) (cdr lst)))
+ (foldr (lambda (a b)
+ (if (> a b)
+ (if (exact? b) a (+ a 0.0))
+ (if (exact? a) b (+ b 0.0))))
+ (car lst) (cdr lst)))
(define (min . lst)
- (foldr (lambda (a b) (if (< a b) a b)) (car lst) (cdr lst)))
+ (foldr (lambda (a b)
+ (if (< a b)
+ (if (exact? b) a (+ a 0.0))
+ (if (exact? a) b (+ b 0.0))))
+ (car lst) (cdr lst)))

Discussion

  • Kevin Cozens
    Kevin Cozens
    2011-08-29

    Committed as revision 78.

     
  • Kevin Cozens
    Kevin Cozens
    2011-08-29

    • status: open --> closed-fixed