14 lines
349 B
Racket
14 lines
349 B
Racket
#lang typed-scheme
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(define-type-alias number Number)
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(define-type-alias boolean Boolean)
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(define-type-alias symbol Symbol)
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(define-type-alias top Any)
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(define-type-alias list-of Listof)
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(define: l : (list-of number)
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(cons 1 (cons 2 (cons 3 #{'() : (list-of number)}))))
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(define: (g [x : number]) : number
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(cond [(memv x l) => car]
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[else 0]))
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