2 Oct
2001
2 Oct
'01
8:01 a.m.
On Tue, 2 Oct 2001, Cagdas Ozgenc wrote:
Do I ALWAYS need to create a new instance if I want to modify the state of an instance? For example, if I design an index for a simple database with an recursive algebric Tree type, do I need to recreate the whole Tree if I insert or remove an element? How can I improve performance, what are common idioms in these situations?
No, you don't have to copy the whole tree node by node, fortunately: you can "re-use" most of it. I don't fully understand just how good things can get, but I'd heartily recommend Chris Okasaki's "Purely Functional Data Structures" book if you want to. (-: He launches into judging efficiency early on. -- Mark