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Hi,
Sometimes I wish for python-like string-strip to be a standard
function. For example when I want to parse a list of numbers from a
text-field, I could get the string value of the text-field, strip
space from the beginning and end, split on whitespace, map
string->number over it and check the result with `every'.
Is there a better way? If not then perhaps some form of string-strip
could be added (perhaps under regexp-strip name?) since it isn't
exactly extremely simple unless you're a regexp wizard.
Marijn
Some code (ter leering ende vermaak):
#lang racket
(require rackunit (only-in srfi/1 every))
(define (string-strip string (strip "[:space:]"))
(define rexp
(pregexp (regexp-replace*
"strip"
"^[strip]*(.*?)[strip]*$"
strip)))
(cadr (regexp-match rexp string)))
(check-equal? (string-strip " strip this ") "strip this")
(define (string-split string (split "[[:space:]]+"))
(regexp-split (pregexp split) (string-strip string)))
(check-equal? (string-split " 12. .12
34") '("12." ".12" "34"))
(define (string->number-list string)
(map string->number (string-split string)) )
(check-equal? (string->number-list " 2003 2005 2007\t ") '(2003 2005
2007))
(define (list-of-years? lst)
(every exact-positive-integer? lst))
(check-equal? (string->number "not a number") #f)
(check-equal? (list-of-years? '(2003 3004 43)) #t)
(check-equal? (list-of-years? '(45 #f 20)) #f)
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