Hello,
{-# LANGUAGE OverlappingInstances, FlexibleInstances #-}
import Data.Binary
instance Binary [String] where
get = undefined
put = undefined
works fine here on GHC 6.12.3. That being said, it would be safer
perhaps to add a newtype around [String] so you can avoid the orphan
instance as well, i.e.
import Data.Binary
newtype MyType = MyType [String]
instance Binary MyType where
get = undefined
put = undefined
Cheers,
Jasper
On Wed, Jan 5, 2011 at 9:24 AM, Magicloud Magiclouds
Hi, I am using Data.Binary which defined "instance Binary a => Binary [a]". Now I need to define "instance Binary [String]" to make something special for string list. How to make it work? I looked into the chapter of overlappinginstances, nothing works. -- 竹密岂妨流水过 山高哪阻野云飞
_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe