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Diffstat (limited to 'testsuite/tests/typecheck/should_compile/tc221.hs')
-rw-r--r-- | testsuite/tests/typecheck/should_compile/tc221.hs | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/testsuite/tests/typecheck/should_compile/tc221.hs b/testsuite/tests/typecheck/should_compile/tc221.hs new file mode 100644 index 0000000000..903b2bc3ac --- /dev/null +++ b/testsuite/tests/typecheck/should_compile/tc221.hs @@ -0,0 +1,16 @@ +{-# LANGUAGE GADTs #-} + +-- A program very like this triggered a kind error with GHC 6.6 + +module Foo where + +data PatchSeq p a b where + Nil :: PatchSeq p a b + U :: p a b -> PatchSeq p a b + (:-) :: PatchSeq p a b -> PatchSeq p b c -> PatchSeq p a c + +-- is_normal :: PatchSeq p a b -> Bool +is_normal Nil = True +is_normal (U _) = True +is_normal (U _ :- _) = True +is_normal _ = False |