Module Either_intf

module Either_intf: sig .. end
Many functions in Either focus on just one constructor. The Focused signature abstracts over which constructor is the focus. To use these functions, use the First or Second modules in S.

module type Focused = sig .. end
Many functions in Either focus on just one constructor.
module type S = sig .. end

Many functions in Either focus on just one constructor. The Focused signature abstracts over which constructor is the focus. To use these functions, use the First or Second modules in S.

This type represents values with two possibilities. Either can be seen as a generic sum type, the dual of Tuple. First is neither more important nor less important than Second.

first and second are First.return and Second.return.