Published on 2020-07-14 2018 Martin Odersky less than a minute

Functional program design in scala

Thee cheat sheet recaps the course.

For expression and monads

Monads

for expression can always be translated into high order functions (map, flatmap, filters...)

A monad is a type which implement flatMap and a unit.

def flatMap[U](f: T => M[U]): M[U]
def unit[T](x :T): M[T]

Moreover a monad must conform to 3 laws:

• associativity.

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

• left unit

unit(x) flatMap f == f(x)

• right unit

m flatMap unit == m