identifiereither

Identifiereither is a term used in discussions of type systems and language design to describe a construct that distinguishes between two possible variants of a value and exposes a tagged union that encodes which variant is present. The concept is closely related to the sum type and to the common Either type found in many functional languages. In this view, identifiereither refers to the act or utility of producing a value that is either of type A or type B, typically represented as Left(a) or Right(b) in languages with sum types.

Definition: An identifiereither operation takes an input and returns a value that explicitly marks which variant was chosen. This makes the subsequent handling explicit through pattern matching or case analysis.

Usage: Identifiereither is useful in error handling, result propagation, and parsing tasks where two outcomes must be distinguished and handled differently. It reduces reliance on nulls and exceptions by encoding outcomes in the type system.

Relation to existing constructs: The practical effect is the same as using a sum type, discriminated union, or Result/Either type in languages such as Haskell (Either a b), Rust (Result<T, E>), or ML-family languages. Some language design discussions refer to identifiereither as a primitive or as a design pattern rather than a fixed keyword.

Example (pseudocode): result = identifiereither(input); if result is Left(a) then handleA(a); else if result is Right(b) then handleB(b).

See also: Either, sum type, discriminated union, pattern matching, tagged union.