On Dec 25, 2007 4:27 PM, Henning Thielemann <[EMAIL PROTECTED]> wrote: > test :: (Integral a, RealFrac a) => a > test = > let c = undefined > in asTypeOf (round c) c > > > When compiling I get: > > Compiling StorableInstance ( src/StorableInstance.hs, interpreted ) > > src/StorableInstance.hs:38:17: > Warning: Defaulting the following constraint(s) to type `Double' > `RealFrac a' arising from use of `round' at > src/StorableInstance.hs:38:17-21 > In the first argument of `asTypeOf', namely `(round c)' > In the definition of `test1': test1 = let c = undefined in > asTypeOf (round c) c
Interesting, I don't see this behaviour at all. $ cat t.hs module Main where instance Integral Double test :: (Integral a, RealFrac a) => a test = let c = undefined in asTypeOf (round c) c main = print (test :: Double) $ ghc --make t.hs [1 of 1] Compiling Main ( t.hs, t.o ) t.hs:3:0: Warning: No explicit method nor default method for `quotRem' In the instance declaration for `Integral Double' t.hs:3:0: Warning: No explicit method nor default method for `toInteger' In the instance declaration for `Integral Double' Linking t ... $ ./t t: Prelude.undefined $ ghc --version The Glorious Glasgow Haskell Compilation System, version 6.6.1 -- Felipe. _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe