library submission: Data.Either.unzipEithers :: [Either a b] -> ([a],[b])

[JeremyShaw]

This function is like unzip for a list of Eithers instead of tuples.

According to google code search, I am at least the 5th person to implement this function:

 http://www.google.com/codesearch?hl=en&lr=&q=%22%5BEither+a+b%5D+-%3E+%28%5Ba%5D%2C%5Bb%5D%29%22&btnG=Search

I opted for the name unzipEithers because the function is similar to two existing functions: unzip and catMaybes. It seems less similar to partition, because partition does not desconstruct the values, it just divides them into to two groups. I have no particular attachment to the name however.

I modeled the implementation after unzip and partition. Hopefully I made effective use of the irrefutable patterns and laziness, but someone else should verify.

Deadline: October 15

[JeremyShaw]

implementation of Data.Either.unzipEithers

[JeremyShaw]

oops, appears this is a dupe of

 http://hackage.haskell.org/trac/ghc/ticket/974

[igloo]

Reopening as #974 has a wider scope

[igloo]

This ticket is a duplicate of the only part of #974 that isn't decided, so this ticket is no easier to resolve than all of #974. Thus I'm closing it as a duplicate.