27 lines
774 B
Scheme
27 lines
774 B
Scheme
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;;; -*-Scheme-*-
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;;;
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;;; Demonstrate the regular expression primitives.
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(require 'regexp)
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;; Returns a list of substrings of string `str' that match the
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;; pattern `pat'
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(define (matches str pat)
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(let loop ((r (make-regexp pat '(extended))) (result '()) (from 0))
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(let ((m (regexp-exec r str from)))
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(if (regexp-match? m)
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(loop r (cons (substring str (+ from (regexp-match-start m 0))
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(+ from (regexp-match-end m 0)))
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result)
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(+ from (regexp-match-end m 0)))
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(reverse result)))))
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(cond
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((feature? ':regular-expressions)
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(print (matches "Hello, world!" "[a-zA-z]+"))
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(print (matches "Hello, world!" ".")))
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(else
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(format #t "Regular expressions not supported by ~a-~a~%"
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site-machine site-os)))
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