Performance of nested yield in a tree

Question

I\'ve got a tree-like structure. Each element in this structure should be able to return a Enumerable of all elements it is root to. Let\'s call this method IEnumerabl

Answer 1

It's certainly not ideal in terms of performance - you end up creating a lot of iterators for large trees, instead of a single iterator which knows how to traverse efficiently.

Some blog entries concerning this:

• Wes Dyer: All about iterators
• Eric Lippert: Immutability in C#, part 6
• Eric again: Immutability in C#, part 7

It's worth noting that F# has the equivalent of the proposed "yield foreach" with "yield!"