[Haskell-cafe] Collections

Andrew Coppin andrewcoppin at btinternet.com
Wed Jun 20 15:04:25 EDT 2007

Lennart Augustsson wrote:
> I don't think the collection type (a,b) is best thought of as a loop.

True. That's a rather special type; I haven't seen anything remotely 
like it in any other language.

> Neither is a (non-trivial) tree.

Erm... Depends on your idea of "loop" I suppose.

A tree represents a recursive loop quite nicely. ;-)

My point of course was that an array is a loop just as much as a list 
is. Same goes for a set. Or even a dictionary (looping over key/value 
pairs), whichever way it's implemented internally.

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