StringRecipeRemovingWhiteSpace - Cookbook - s c h e m a t i c s : c o o k b o o k

Removing white space from the ends of a string

Problem

Remove possible white spaces from the beginning and end of a string.

Solution

; strip : string -> string
;  remove white space from the beginning and end of a string
(define strip
  (let ([r-strip (regexp "^[ \t\r]*(.*?)[ \t\r]*$")])
    (lambda (s)
      (cadr (regexp-match r-strip s)))))

> (strip " foo ")
"foo"
> (strip " foo bar ")
"foo bar"
> (strip " foo bar")
"foo bar"
> (strip "foo bar")
"foo bar"
> (strip "")
""
> (strip "   ")
""

Discussion

The solution uses a regular expression to pick out the middle of the string. The regular expression is compiled only once, namely when strip is defined.

Comments about this recipe

TrimmingSpace has another version of this, using SRFI-13. It was classified in the wrong place, so it wasn't showing up under StringRecipes.

Contributors

-- JensAxelSoegaard - 07 Sep 2004

CookbookForm
TopicType:	Recipe
ParentTopic:	StringRecipes
TopicOrder:	999

Current Rev: r1.2 - 08 Sep 2004 - 17:47 GMT - GordonWeakliem, Revision History:Diffs | r1.2 | > | r1.1

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Other than such compilations, this material can be redistributed and/or modified under the terms of the GNU Lesser General Public License (LGPL), version 2.1, as published by the Free Software Foundation.
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