On Sat, Jun 8, 2013 at 9:02 AM, Peter Hall <peter.hall@memorphic.com> wrote:

This is confusing me, and I'm wondering if it's a compiler bug. I have this:

   foo = (++) `on` show

I'm expecting the type to be:

    foo :: Show a => a -> a -> String

But GHCI is inferring:

    foo :: () -> () -> String

No bug; it's the monomorphism restriction combining with extended defaulting to infer a monomorphic type. If you want to keep the monomorphism restriction and throw a type error, disable ExtendedDefaultRules.

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brandon s allbery kf8nh                               sine nomine associates

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