effect-io-ai

Package: effect
Module: Either

Either.mapLeft

Maps the Left side of an Either value to a new Either value.

Signature

declare const mapLeft: { <E, E2>(f: (left: E) => E2): <A>(self: Either<A, E>) => Either<A, E2>; <A, E, E2>(self: Either<A, E>, f: (left: E) => E2): Either<A, E2>; }

Source

Since v2.0.0