f: A -> B

g: B -> C

(f . g): A -> C

Function composition:

Just pass an output of f into input of g

f: A -> List[B]

g: B -> C

(f ? g): ?

How do you compose that?

And what will it return?

f: A -> B :: throws Exception

g: B -> C

(f ? g): A -> Safe[C]

How do you compose them in a safe way?

f: A -> B :: returns null sometimes

Pass the result to g only if it is not null and there are no exceptions

Challenge 1