scalaz/scalaz-stream — pull request #118 by fthomas (2014-03-01 13:36:01+00:00)
Title: Add unique and uniqueBy to process1

This PR adds `unique` and `uniqueBy` to `process1`. Both remove duplicate elements from the input such that only the first occurrence of each element is emitted. The implementation (ab)uses `scalaz.==>>[A,Unit]` to check for duplicate elements. It can be replaced with `scalaz.ISet` once that is available.