Re: Proposal: add new function "check" to Control.Monad

Jón Fairbairn wrote:

Trac ticket #3453. Two week time frame. Add check function to Control.Monad check :: (MonadPlus m) => (a -> Bool) -> a -> m a

I remember needing this on a number of occasions.

  mfilter = (join .) . liftM . check

I might write that as: mFilter = (=<<) . check That is an intriguing dual to filterM. Regards, Yitz