A truly lazy OrderBy in LINQ

Written by: Jayson Bradley

Jon Skeet recently discussed what it means to be “lazy” (in the context of LINQ to Objects). He introduced some new definitions based on how the operator processes the source sequence. Another aspect (which Jon didn’t cover) is how lazily the operator produces output when its results are enumerated.

Let’s take a concrete example: what’s the difference in running time between these two statements?