Problem deriving instances
I have the following (reduced to the bare neccessities to produce the error) piece of code:
----
newtype A a = A a
deriving (Eq,Show)
type B = A
type C = B D
--type C = A D
type D = Double
data E = E { a :: C }
deriving (Eq,Show)
----
Compiling with ghc gives me the following error:
test.hs:13:
No instance for `Eq C'
When deriving classes for `E'
When I change the type of C to what I commented out (eg A D instead of B D) it works fine.
I don't think this is an error on my side, and besides hugs loads it without a complaint.
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Bug |
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OtherFailure |
Priority |
normal |
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ResolvedFixed |
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Differential revisions |
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Blocking |
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CC |
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