Implict parameters and monomorphism

[Marcin 'Qrczak' Kowalczyk]

Thu, 03 May 2001 06:29:35 -0400, Lennart Augustsson <lennart@mail.augustsson.net> pisze:

> Try this program:
> -- Try commenting out this type signature.
> fun:: (Num a) => a -> Int

Test.hs:7:
    Ambiguous type variable(s) `a' in the constraint `Num a'
    arising from use of `fun' at Test.hs:7
    In the first argument of `g', namely `fun'
    In the definition of `ii': g fun

Test.hs:18:
    Ambiguous type variable(s) `a' in the constraint `C a'
    arising from use of `m' at Test.hs:18
    In the first argument of `putStrLn', namely `(m ii)'
    In the definition of `main': putStrLn (m ii)

Defaulting applies only when all classes involved are Haskell 98.
hbc, nhc98 and Hugs are not conforming.

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 __("<  Marcin Kowalczyk * qrczak@knm.org.pl http://qrczak.ids.net.pl/
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