hkt-toolbelt/type/union.d.ts

Functional and composable type utilities

import { Kind } from '..';
/**
 * `_$union` is a type-level function that takes two types `A` and `B`, and
 * returns the union of `A` and `B`.
 *
 * @template A - The first type to union.
 * @template B - The second type to union.
 *
 * @example
 * ```ts
 * type T0 = _$union<[], number> // number
 * type T1 = _$union<string, string> // string
 * ```
 */
export type _$union<A, B> = A | B;
interface Union_T<A extends unknown> extends Kind.Kind {
    f(x: this[Kind._]): _$union<A, typeof x>;
}
/**
 * `Union` is a type-level function that takes two types `A` and `B`, and
 * returns the union of `A` and `B`.
 *
 * @template A - The first type to union.
 * @template B - The second type to union.
 *
 * @example
 * ```ts
 * type T0 = $<Union, [], number> // number
 * type T1 = $<Union, string, string> // string
 * ```
 */
export interface Union extends Kind.Kind {
    f(x: this[Kind._]): Union_T<typeof x>;
}
export {};