[project @ 2004-10-11 16:12:58 by simonpj]

---------------------------------
	Fix bug in derivable type classes
	---------------------------------

		MERGE TO STABLE (if poss)

The test for not-supported method types for derivable type classes
was broken. This fixes it.

diff --git a/ghc/compiler/typecheck/TcTyClsDecls.lhs b/ghc/compiler/typecheck/TcTyClsDecls.lhs
index 0c2054e..1c9447d 100644 (file)
--- a/ghc/compiler/typecheck/TcTyClsDecls.lhs
+++ b/ghc/compiler/typecheck/TcTyClsDecls.lhs
@@ -650,7 +650,7 @@ checkValidClass cls
 
                -- Check that for a generic method, the type of 
                -- the method is sufficiently simple
 
                -- Check that for a generic method, the type of 
                -- the method is sufficiently simple

-       ; checkTc (dm /= GenDefMeth || validGenericMethodType op_ty)
+       ; checkTc (dm /= GenDefMeth || validGenericMethodType tau)

                  (badGenericMethodType op_name op_ty)
        }
        where
                  (badGenericMethodType op_name op_ty)
        }
        where