21 lines
568 B
Racket
21 lines
568 B
Racket
#lang s-exp "../cur.rkt"
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(require "sugar.rkt")
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(provide Maybe none some)
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(data Maybe : (forall (A : Type) Type)
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(none : (forall (A : Type) (Maybe A)))
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(some : (forall* (A : Type) (a : A) (Maybe A))))
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(module+ test
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(require rackunit "bool.rkt")
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;; Disabled until #22 fixed
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#;(check-equal?
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(case* Maybe Type (some Bool true) (Bool)
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(lambda* (A : Type) (x : (Maybe A)) A)
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[(none (A : Type)) IH: ()
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false]
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[(some (A : Type) (x : A)) IH: ()
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;; TODO: Don't know how to use dependency yet
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(if x true false)])
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true))
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