On Nov 5, 2009, at 8:26 AM, Jason Dagit wrote:
I can't really think of how laziness and polymorphism are related. For me the big win with laziness is composability. Laziness allows us to express things in ways that are more natural. The prelude function 'take' is a perfect example. It allows you to use finite portions of infinite lists. You could then express an infinite series very naturally and then decouple from that the logic to process finite parts. The implication here is that laziness allows you to use data structures for control flow. This all works together to enable separation of concerns. Which is generally a very good thing if you want to reason about your source code.
My bad, I meant polymorphism as the answer as to why things are boxed.
Laziness can also be thought of as a transformation on the time complexity of algorithms. Sure, the worst-case complexity still remains but often you can get a better average case by only computing as much as you need.
I hope that helps,
It does.