+ forall_tyvars = nub [ tv | ty <- tys,
+ tv <- extractHsTyRdrTyVars ty,
+ not (tv `elemFM` name_env)
+ ]
+ -- The 'nub' is important. For example:
+ -- f (x :: t) (y :: t) = ....
+ -- We don't want to complain about binding t twice!
+
+ located_tyvars = [(tv, loc) | tv <- forall_tyvars]
+ doc_sig = text "In a pattern type-signature"