id	summary	reporter	owner	description	type	status	priority	milestone	component	version	resolution	keywords	cc	os	architecture	failure	difficulty	testcase	blockedby	blocking	related
2112	Bad error message for malformed GADTs	tim	igloo	"Compiling the following code:

{{{
data Foo a where
   Bar :: a -> a
}}}

results in the following error message:
{{{
$ ghc-6.8.1 gadt.hs -XGADTs

gadt.hs:5:3:
    Malformed constructor result type: a
    In the result type of a data constructor: a
    In the data type declaration for `Foo'
$ 
}}}

It would be nice if the error message mentioned the name of the offending data constructor ({{{Bar}}} in this case) -- since there might be more than one."	merge	closed	normal		Compiler (Type checker)	6.8.1	fixed			Unknown/Multiple	Unknown/Multiple		Unknown	tcfail146