Lazy lists - an implementation.

Sean Hinde <>
Tue Oct 17 20:08:56 CEST 2000


Hi,

> > OK, since noone complained too much, here's a hack of lists.erl,
> > where most functions have been enhanced to operate on both eager
> > and lazy lists.
> 
> And here is my first version of a lazy lists library. Seems 
> to work ok.

Just so I (and I guess others?) understand how all this would be applied to
the original problem (that iterating over very large lists causes large
heaps to be generated)..

If we already have a large list and want to generate another I guess there
would there be no benefit of converting this into a lazy_list first? (would
this make a Huge fun?)

If we already have the list and want to do say a checksum calc on it
(foreach/2) there is no advantage because we still have to run through all
the elements (ok, one at a time)?

So this could be used where the list itself doesn't already exist and we
want to iterate to produce a result which isn't a list? Wouldn't the stack
then fill up with the not yet calculated results of each iteration?

My head is starting to spin. Under what circumstances would this stuff be
very appropriate to use?

Thanks for the code BTW - wow,

Sean



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