[Haskell-cafe] a minor bug (memory leak) in ListLike package

Ivan Lazar Miljenovic ivan.miljenovic at gmail.com
Wed Aug 24 03:47:44 CEST 2011

On 24 August 2011 11:10, bob zhang <bobzhang1988 at gmail.com> wrote:
> Hi, John, there is a space leak problem in ListLike typeclass,
> in the method genericLength
> calclen !accum cl =
> calclen accum cl =

I _think_ this may cause problems with some data types (e.g.
) that require the extra laziness (that is, you can do things like ` 3
< genericLength [1..] ' and have it return True).

> --- thank you for your nice library
> btw, is there any way to derive ListLike interface automatically?
> for such type :
> newtype List a = List {[a]}

GeneralizedNewtypeDeriving can do that.

Ivan Lazar Miljenovic
Ivan.Miljenovic at gmail.com

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