[Haskell-cafe] Stream-fusion without the lists

[Roman Leshchinskiy]

On 12/05/2009, at 14:45, Reiner Pope wrote:

> The Stream datatype seems to be much better suited to representing
> loops than the list datatype is. So, instead of programming with the
> lists, why don't we just use the Stream datatype directly?

I think the main reason is that streams don't store data and therefore  
don't support sharing. That is, in

let xs = map f ys in (sum xs, product xs)

the elements of xs will be computed once if it is a list but twice if  
it is a stream.

Roman