CODEWITHSUNDEEP
c#.netlinqoptimization
LBushkin
LBushkin

Reputation: 131756

LINQ Optimizations for IOrderedEnumerable

Is anyone aware of whether there are there any built-in capabilities in the LINQ library (or a publicly available utility library) for optimized operations on IOrderedEnumerable<T>, as opposed to IEnumerable<T>?

For example, in theory, the Contains<T>() extension could potentially be optimized to use binary search when it is applied to a finite IOrderedEnumerable<T> and T is IComparable.

Another example, would be an optimized version of Distinct<T>() that would be deferred and streamable (since on an ordered, comparable collection you can always use skip/match techniques to produce a distinct set).

Upvotes: 3

Views: 1402

Answers (1)

Marc Gravell
Marc Gravell

Reputation: 1063423

There are problems there...

  • A binary search can't be executed on an IOrderedEnumerable<T>, as it ideally needs indexer access into a list/array. So it would have to call something like ToList()/ToArray() first
  • Distinct works on the T items, but OrderBy works on some facet of each T - it isn't quite the same, unless you happen to know that it is ordered by item=>item; which is rarely the case (and hard to prove).

Upvotes: 7

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