| > | (case undefined of Foo GadtValue -> ()) :: () -- is rigid ... | | But the first compiles fine, so it seems that the scrutinee doesn't | have to always be rigid?
Not for me! Either with 6.8.3 or HEAD. What compiler are you using?
HEAD from last Thursday. The code I'm using is slightly different to your code, and is attached at the end of the message. Is matching Foo causing its argument to become rigid? Thanks Neil {-# LANGUAGE GADTs, ScopedTypeVariables #-} module Test where data E x = E x data Foo where Foo :: Gadt a -> Foo data Gadt a where GadtValue :: Gadt (E a) g :: () g = case undefined of Foo GadtValue -> () ============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ==============================================================================