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regex-case

Description:

An easy to use case construct for matching regular expressions.

Author:

felix

Version:

Usage:

(require-extension regex-case)

Download:

regex-case.egg

Documentation:

[syntax] (regex-case EXPRESSION CLAUSE ...)
Evaluates EXPRESSION and executes the body of the first CLAUSE that matches. Each CLAUSE should be of the form: 
(REGEX LAMBDA-LIST BODY ...)
The variables in LAMBDA-LIST are bound to the results of evaluating the expression 
(string-match REGEX STRING)
The last CLAUSE may also be 
(else BODY ...)
If no CLAUSE matches, the form returns an undefined result.

Examples:

(define (test x)
  (regex-case x
    ["[a-z]+" _ 'word]
    ["[0-9]+" _ 'num]
    [else 'nothing] ) )

; Returns 'num
(test "42")

; Returns 'word
(test "hello")

; Returns 'nothing
(test "???")

; Evaluates to "23"
(regex-case "one23four"
  ["[a-z]+([0-9]+).*" (all num) num] )

; Evaluates to ("http" "www.foo.com" "/index.html" "index.html")
(regex-case "http:www.foo.com/index.html" 
  ["([a-z]+):([a-z0-9.-]+)(/(.*))?" (_ . parts) parts])

License:

Copyright (c) 2003, Felix L. Winkelmann
All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following
conditions are met:

  Redistributions of source code must retain the above copyright notice, this list of conditions and the following
    disclaimer. 
  Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
    disclaimer in the documentation and/or other materials provided with the distribution. 
  Neither the name of the author nor the names of its contributors may be used to endorse or promote
    products derived from this software without specific prior written permission. 

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS
OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
POSSIBILITY OF SUCH DAMAGE.
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