[Accepted with modifications] SE-0240: Ordered Collection Diffing

Hello Swift Community,

The review of SE-0240 "Ordered Collection Diffing" ran from January 14...22, 2019. The review thread is available here. The proposal is accepted with modifications, specifically:

  • The algorithm's semantic guarantees have been weakened to specify that it will produce a difference to get from the self state to the other state, but not guarantee the shortest such difference. The intent is to allow the standard library to provide a balanced algorithm that provides the shortest difference when possible (e.g., for inputs with fewer differences) but won't exhibit quadratic behavior for large inputs with many differences.
  • The name of the algorithm itself is changed from shortestEditScript(from:) to difference(from:).
  • The name of the collection of differences is changed from OrderedCollectionDifference to CollectionDifference.

Thank you to the authors and everyone who participated in the review.

Doug Gregor
Review Manager