Map and Flat Map

map takes in a function (A -> B) where A and B are any type.

For example:

>>> from pyeffects.Option import  *
>>> Some("abc").map(lambda s: len(s))
Some(3)

flat_map takes in a function (A -> M[B]) where A and B are any types and M is the container.

For example:

>>> from pyeffects.Option import  *
>>> Some("abc").flat_map(lambda s: Some(len(s)))
Some(3)

flat_map is a more general version of the map function.

Both operations return a container of type B.