Re: [Haskell-cafe] Non Empty List?

data Container a = Container a [a] ? Or, maybe, you need something like zipper. On 5 Jun 2009, at 01:53, GüŸnther Schmidt wrote:

Hi,

I need to design a container data structure that by design cannot be empty and can hold n elements. Something like a non-empty list.

I started with:

data Container a = Single a | Many a [a]

but the problem above is that the data structure would allow to construct a Many 5 [] :: Container Int.

I can't figure out how to get this right. :(

Please help.

Günther

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