Is there already a list class?

Bulat Ziganshin bulat.ziganshin at
Wed Jan 10 07:27:40 EST 2007

Hello David,

Wednesday, January 10, 2007, 5:35:03 AM, you wrote:

>> class List l e, l -> e where

> (But I don't like functional dependencies, because they confuse me, and
> hope that associated types end up making it into Haskell'...)

well, it is pretty studied design space, you can look the chapter about
fundeps in ghc 6.6 manual which describes various solutions for containers
class problem

generally, we need either FD (which is not a part of Haskell') or AT (which
is supported only by GHC HEAD)

about existing implementations:

1) Stringable class in fps-soc project. it is aimed to generalize
interface of String and ButeString

2) numerous classes in Collections [2] and Edison [3] libraries


Best regards,
 Bulat                            mailto:Bulat.Ziganshin at

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