Oops, I mixed up associative with commutative.
On Tue, Sep 14, 2010 at 1:27 PM, Bas van Dijk <v.dijk....@gmail.com> wrote: > On Mon, Sep 13, 2010 at 4:23 PM, Nick Bowler <nbow...@elliptictech.com> wrote: >> ... not all Num instances have an associative (+). > > Indeed: > > $ cabal install repr # [1] > ... > $ ghci > Prelude> :m Text.Repr > Prelude Text.Repr> show (1 + 2 :: Repr Int) == show (2 + 1 :: Repr Int) > False > > because: > show (1 + 2 :: Repr Int) == "1 + 2" > show (2 + 1 :: Repr Int) == "2 + 1" > > but note: > Prelude Text.Repr> (1 + 2 :: Repr Int) == (2 + 1 :: Repr Int) > True > > Bas > > [1] http://hackage.haskell.org/package/repr > _______________________________________________ Haskell-prime mailing list Haskell-prime@haskell.org http://www.haskell.org/mailman/listinfo/haskell-prime
