Inferred type is less polymorphic than expected?

Thomas Jäger thjaeger at
Fri Jul 29 19:46:54 EDT 2005


This is not a bug, the restriction is actually mentioned in the
Haskell Report, section 4.5.2. However, the restriction was recently
lifted, so your code compiles fine with the current cvs ghc, see


On 7/29/05, Benjamin Franksen <benjamin.franksen at> wrote:
> Bug.lhs:27:0:
>     Contexts differ in length
>     When matching the contexts of the signatures for
>       printer :: Viewer
>       printCatalog :: forall c. (Catalog c) => View c
>     The signature contexts in a mutually recursive group should all be
> identical

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