Mon Oct 16 12:56:00 CEST 2000
On Mon, 16 Oct 2000, Ulf Wiger wrote:
> We (a few lunatics at AXD 301) would like to see the lists module
> support an alternative formulation of lists.
> A list could be expressed in the following manner:
> [Head | fun(Head, F)]
> What'ya think? Awful? Elegant?
> BTW, Joe already posted something like this on the erlang-questions
> list in March '99, but he was using zero-argument funs.
They are indeed elegant, and Joe was correct - they're called lazy lists,
and should be implemented using zero-argument funs. To give a type
declaration of sorts:
LazyList ::  | [term() | fun() -> LazyList]
Writing a module 'lazy_lists' should be a doddle. In fact, I might do it
Richard Carlsson () (This space intentionally left blank.)
E-mail: WWW: http://www.csd.uu.se/~richardc/
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