> Linked lists stink as a manifested in-memory data structure. However, if what your linked list is is "{concrete value} : {code to generate the rest of the list}" and you walk it once, never having the whole thing at once, it isn't necessarily bad. That is the point cryptonector is making. The memory inefficiency of a linked list doesn't matter if you never really have it "in memory".

Yes, exactly. A lazy list is just another term for generator. If you hold on to a reference to the head of such a list as you run the generator, then you'll consume a lot of memory and will end up with a strict list, and also you'll be sad. But if you don't hold on to that reference, then it will be very efficient.

> That said, the ready availability of linked lists in Haskell does mean that you end up with rather more strictly-manifested linked lists than you might like, since any of them can be manifested as actual linked lists. If you're using Haskell though, while you haven't exactly completely given up on that sort of performance, it must not be foremost on your mind.

Especially strings as lists of characters. That was a mistake. Well, in some sense, character data has to be a list, since with Unicode you really can't efficiently index a string... unless it's a rope and you apply the sorts of tools that xi does (e.g., keeping track of character counts per rope segment, etc.). But strings should be sufficiently opaque that arrays, lists, and ropes are all equally able to implement their semantics.