Uncurried.Writer

type Writer s = WriterT s Identity

A type synonym for a WriterT with Identity as its base monad.

writer :: forall w a. Monoid w => (a /\ w) -> Writer w a

Create a Writer monad from a pair of a result and an accumulator.

runWriter :: forall w a. Monoid w => Writer w a -> (a /\ w)

Runs a computation inside of Writer.

evalWriter :: forall w a. Monoid w => Writer w a -> a

Runs a computation inside of Writer, discarding the final accumulator.

execWriter :: forall w a. Monoid w => Writer w a -> w

Runs a computation inside of Writer, discarding the final result.

mapWriter :: forall w1 w2 a b. Monoid w1 => Monoid w2 => ((a /\ w1) -> (b /\ w2)) -> Writer w1 a -> Writer w2 b

Modifies the result and accumulator types of a Writer.