43dc59bea2
Correctly restrict the struct predicate's filter type when a parent struct is mutable but the child is not and they both have polymorphic type variables. See the discussion in GH issue #205
21 lines
360 B
Racket
21 lines
360 B
Racket
#lang typed/racket
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;; The call to `set-foo-x!` below should fail because the
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;; predicate filter on `bar?` has to be restrictive.
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(struct (A) foo ([x : A]) #:mutable)
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(struct (A) baz foo ())
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(define (f [i : Integer]) : (foo Integer)
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(baz i))
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(: x (foo Integer))
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(define x (f 1))
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(: y Any)
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(define y x)
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(if (baz? y) (set-foo-x! y "foo") 2)
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(foo-x x)
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