[racket] [Typed Racket] "define-predicate" in Racket 5.3.4

From: Eric Dobson (eric.n.dobson at gmail.com)
Date: Thu May 9 23:18:42 EDT 2013

That definitely looks like a bug. Can you file one either using the
bug report tool in the menus or at bugs.racket-lang.org.

No you cannot define a predicate like that, because you cannot tell a
functions type with a first order check. But you can use cast, so
(cast <function-expression> (Boolean -> Boolean)) should work.

On Thu, May 9, 2013 at 7:57 PM, Paul Leger <pleger at gmail.com> wrote:
> Hi all,
>     In the Racket 5.3.4, I defined the following predicate
>    >(define-predicate A? Procedure)
>    and later, I tried using as follow:
>    >(A? 'a)
>   But I have the following error:
>   >recursive-contract: contract violation
>   >expected: flat-contract?
>   >given: #<|chaperone-case->|>
> BTW, in this version, Is it possible to define predicate with a specific
> function?
> (define-type A (Boolean -> Boolean))
> (define-predicate A? A)
> Best,
> Paul
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