[project @ 2005-07-27 08:04:02 by simonpj]
Try MERGE to STABLE GHC does not do type subsumption in patterns. But it should be fine if the expected type and the pattern have the same type, even if they are polymorphic. But that test (in TcUnify.tcSubPat) wasn't implemented right, which gave rise to perplexing messages like: Couldn't match `forall a. a -> b' against `forall a. a -> b' This fixes the bug. tc198 tests it, while tcfail145 tests the non-matching case.
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