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29 lines
1003 B
Racket
29 lines
1003 B
Racket
#lang racket/base
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(require racket/match)
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(provide (all-defined-out))
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(define (whitespace-base x #:nbsp-is-white? nbsp-white?)
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(define white-pat (pregexp (format "^[\\s~a]+$" (if nbsp-white? #\u00A0 ""))))
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(let loop ([x x])
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(match x
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["" #true] ; empty string is deemed whitespace
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[(pregexp white-pat) #true]
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[(? symbol?) (loop (symbol->string x))]
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[(? pair?) (andmap loop x)]
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[(? vector?) (loop (vector->list x))]
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[_ #false])))
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(define (whitespace? x) (whitespace-base x #:nbsp-is-white? #f))
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(define (not-whitespace? x) (not (whitespace? x)))
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(define (whitespace/nbsp? x) (whitespace-base x #:nbsp-is-white? #t))
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(module+ test
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(require rackunit racket/format)
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(check-true (whitespace? " "))
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(check-false (whitespace? (~a #\u00A0)))
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(check-true (whitespace/nbsp? (~a #\u00A0)))
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(check-true (whitespace/nbsp? (vector (~a #\u00A0))))
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(check-false (whitespace? (format " ~a " #\u00A0)))
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(check-true (whitespace/nbsp? (format " ~a " #\u00A0)))) |