Monad

(Note - don’t use this, use cats)

Simple implementation of a Monad type class. Subclasses only need to override apply and flatMap, but they should override map, join, joinWith, and sequence if there are better implementations.

Laws Monad instances must follow:

identities:

flatMap(apply(x))(fn) == fn(x)
flatMap(m)(apply _) == m

associativity on flatMap (you can either flatMap f first, or f to g):

flatMap(flatMap(m)(f))(g) == flatMap(m) { x => flatMap(f(x))(g) }

Documentation Help

We’d love your help fleshing out this documentation! You can edit this page in your browser by clicking this link. These links might be helpful:

• Monad.scala
• MonadProperties.scala