🚀 go-pugleaf

What are appropriate data structures for functional languages?
I saw a message from someone talking about arrays in a functional
language.  How can arrays be used in a purely functional manner?
(Or is talking about arrays in a functional language a contradiction
in terms?).  What work is being done on other data structures?
Is anyone using streams, or how about tree structures in languages
other than lisp?  Are there any limitations that have to be placed
on trees to keep them purely functional?

And how about operating systems?  Can one build an operating system
using a purely functional language.  In his turing lecture, Backus
proposes the AST system, which is clearly non-functional.
I guess this boils down to the problem with dealing with the concept
of time in a functional system.

	Any comments, answers, questions?