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34 lines
1.0 KiB
Racket
34 lines
1.0 KiB
Racket
#lang racket/base
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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 pat (pregexp (format "^[\\s~a]+$" (if nbsp-white? #\u00A0 ""))))
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(and (let loop ([x x])
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(cond
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[(string? x) (or (zero? (string-length x)) (regexp-match pat x))] ; empty string is deemed whitespace
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[(symbol? x) (loop (symbol->string x))]
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[(pair? x) (andmap loop x)]
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[(vector? x) (loop (vector->list x))]
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[else #f]))
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#t))
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(define (whitespace? x)
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(whitespace-base x #:nbsp-is-white? #f))
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(define not-whitespace? (λ (x) (not (whitespace? x))))
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(define (whitespace/nbsp? x)
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(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)))) |