From 579d78aa88e6fbebbb51aa74a3441b4a5b7ef72d Mon Sep 17 00:00:00 2001 From: Sam Tobin-Hochstadt Date: Sun, 18 Jan 2015 15:14:08 -0500 Subject: [PATCH] Add discussion of `define-predicate` to contract caveats. --- .../typed-racket/scribblings/guide/caveats.scrbl | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/typed-racket-doc/typed-racket/scribblings/guide/caveats.scrbl b/typed-racket-doc/typed-racket/scribblings/guide/caveats.scrbl index c5ad0c2a..ad1f559c 100644 --- a/typed-racket-doc/typed-racket/scribblings/guide/caveats.scrbl +++ b/typed-racket-doc/typed-racket/scribblings/guide/caveats.scrbl @@ -90,6 +90,13 @@ of type precision at use sites: (object-name #rx"a regexp") ] +Use of @racket[define-predicate] also involves contract generation, and +so some types cannot have predicates generated for them. The following +illustrates a type for which a predicate can't be generated: + +@interaction[#:eval the-eval + (define-predicate p? (All (A) (Listof A)))] + @section{Unsupported features} Units are not currently supported at all in Typed Racket, but they