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pollen/pollen/private/whitespace.rkt

34 lines
1.0 KiB
Racket

#lang racket/base
(provide (all-defined-out))
(define (whitespace-base x #:nbsp-is-white? nbsp-white?)
(define pat (pregexp (format "^[\\s~a]+$" (if nbsp-white? #\u00A0 ""))))
(and (let loop ([x x])
(cond
[(string? x) (or (zero? (string-length x)) (regexp-match pat x))] ; empty string is deemed whitespace
[(symbol? x) (loop (symbol->string x))]
[(pair? x) (andmap loop x)]
[(vector? x) (loop (vector->list x))]
[else #f]))
#t))
(define (whitespace? x)
(whitespace-base x #:nbsp-is-white? #f))
(define not-whitespace? (λ(x) (not (whitespace? x))))
(define (whitespace/nbsp? x)
(whitespace-base x #:nbsp-is-white? #t))
(module+ test
(require rackunit racket/format)
(check-true (whitespace? " "))
(check-false (whitespace? (~a #\u00A0)))
(check-true (whitespace/nbsp? (~a #\u00A0)))
(check-true (whitespace/nbsp? (vector (~a #\u00A0))))
(check-false (whitespace? (format " ~a " #\u00A0)))
(check-true (whitespace/nbsp? (format " ~a " #\u00A0))))