Yes it's documented in the user manual
http://www.haskell.org/ghc/docs/latest/html/users_guide/data-type-extensions...
Since you didn't find it, despite looking, can you suggest how we could improve the manual so that you would?
Thanks
Simon
From: glasgow-haskell-users-bounces@haskell.org [mailto:glasgow-haskell-users-bounces@haskell.org] On Behalf Of Conal Elliott
Sent: 01 April 2009 00:54
To: glasgow-haskell-users@haskell.org
Subject: Re: GADTs with strict fields?
I got an answer: precede the argument types by a "!". I didn't realize that type applications then have to be parenthesized.
On Tue, Mar 31, 2009 at 4:18 PM, Conal Elliott