[Haskell-cafe] Lists of Existential DT

Yves Parès limestrael at gmail.com
Sun Feb 28 13:49:10 EST 2010

jkff wrote:
> Or like this, with the benefit of using lists.
> data DrawableObj a = forall a.Drawable a => DrawableObj a
> a <,> b = DrawableObj a : b
> drawMany (a<,>b<,>c<,>[])

I like this solution, but it's a pity I think that Haskell doesn't provide a
way to use types like [forall a. (Drawable a) => a], which obligates you to
declare an extra datatype...

Yves Parès

Live long and prosper
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