24 lines
669 B
Racket
24 lines
669 B
Racket
#lang scribble/doc
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@(require scribble/manual scribble/eval "guide-utils.rkt")
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@title[#:tag "booleans"]{Booleans}
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Racket has two distinguished constants to represent boolean values:
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@racket[#t] for true and @racket[#f] for false. Uppercase
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@racketvalfont{#T} and @racketvalfont{#F} are parsed as the same
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values, but the lowercase forms are preferred.
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The @racket[boolean?] procedure recognizes the two boolean
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constants. In the result of a test expression for @racket[if],
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@racket[cond], @racket[and], @racket[or], etc., however, any value
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other than @racket[#f] counts as true.
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@examples[
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(= 2 (+ 1 1))
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(boolean? #t)
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(boolean? #f)
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(boolean? "no")
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(if "no" 1 0)
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]
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