Proposal: Add isLeft/isRight to Data.Either
gabriel439 at gmail.com
Thu Dec 6 19:46:07 CET 2012
Although I provide "isLeft" and "isRight" in my "errors" package, count
me against adding them to Data.Either. I only include them in "errors"
because it is supposed to be a "everything and the kitchen sink" utility
The API of standard libraries should provide guidance to new users for
how to program idiomatically in Haskell and including those two
functions will very likely lead new users astray from pattern matching,
giving them a poor initial impression of Haskell.
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