92d1dd1c5e
This enables contract generation in the negative direction (untyped->typed) for row polymorphic types (basically mixin types). Depends on `class-seal` and `class-unseal` in the racket/class library.
27 lines
574 B
Racket
27 lines
574 B
Racket
#lang racket/base
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(module u racket
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(define state #f)
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(define (mixin cls)
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(class cls
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(super-new)
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(define/public (n x) x)))
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(provide mixin))
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(module t typed/racket
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(require/typed (submod ".." u)
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[mixin
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(All (r #:row)
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(-> (Class #:row-var r)
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(Class #:row-var r [n (-> Integer Integer)])))])
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;; ok to call mixin with different types
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(mixin (class object% (super-new)))
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(mixin (class object%
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(super-new)
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(define/public (m x) x))))
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(require 't)
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