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scheme (format) question
From: |
Mark Polesky |
Subject: |
scheme (format) question |
Date: |
Sat, 21 Mar 2009 14:33:32 -0700 (PDT) |
;; Hi.
;;
;; How can I change the following code so that
;; it returns "2 0.25 0.3333"? That is: return
;; integers without decimal point, otherwise
;; round to as many decimal places as needed,
;; but not more than 4.
(let ((a 2.0)
(b 1/4)
(c 1/3))
(format #t "~&~a ~a ~a" a b c))
;; After some experimenting, I found the
;; following solution, but I'd rather not have
;; to deal with all the incessant quasiquote
;; and unquote stuff. Is there a more elegant
;; solution?
;;
;; Thanks in advance.
;; - Mark
(define (set-precision n)
(let* ((max-decimals 4)
(k (expt 10.0 max-decimals)))
(if (number? n)
(if (integer? n)
(inexact->exact n)
(/ (round (* n k))
k))
n)))
(define (my-format bool string list-of-nums)
(apply format bool string (map set-precision list-of-nums)))
(let ((a 2.0)
(b 1/4)
(c 1/3))
(my-format #t "~&~a ~a ~a" `(,a ,b ,c)))
- scheme (format) question,
Mark Polesky <=