Control.Logger

newtype Logger m r

A logger receives records and potentially performs some effects.

Constructors

• Logger (r -> m Unit)

Instances

• Contravariant (Logger m)
• (Apply m) => Divide (Logger m)
• (Applicative m) => Divisible (Logger m)
• (Apply m) => Decide (Logger m)
• (Applicative m) => Decidable (Logger m)
• (Apply m) => Semigroup (Logger m r)
• (Applicative m) => Monoid (Logger m r)

log :: forall r m. Logger m r -> r -> m Unit

Log a record to the logger.

cfilter :: forall r m. Applicative m => (r -> Boolean) -> Logger m r -> Logger m r

Transform the logger such that it ignores records for which the predicate returns false.

hoist :: forall r m' m. (m ~> m') -> Logger m r -> Logger m' r

Apply a natural transformation to the underlying functor.