22 lines
644 B
Racket
22 lines
644 B
Racket
#lang typed/racket
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(require typed-struct-props
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typed/rackunit)
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(struct/props (A) foo ([f : A]) #:transparent
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#:property prop:custom-write
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(λ (this out mode)
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(fprintf out "#<an-instance ~a>" (foo-f this))))
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(test-not-exn "The structure's constructor and type work properly"
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(λ () (ann (foo "b") (foo String))))
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(test-equal? "The structure's constructor and accessor work properly"
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(ann (foo-f (foo "b")) String)
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"b")
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(test-equal? "The prop:custom-write is taken into account"
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(format "~a" (foo 1))
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"#<an-instance 1>")
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