Contains Option and Either.
Option
Either
Represents a disjoint union i.e. a type with two possibilities, either Left or Right.
The left case of an Either.
Represents an absent value in terms of Option.
Represents an optional value with map, flatMap, fold and getOrElse to transform it.
The right case of an Either.
Represents a present value in terms of Option.
Returns false on calling.
false
Returns true on calling.
true