type-plus
Version:
Provides additional types for TypeScript.
57 lines • 2.63 kB
TypeScript
import type { NeverType } from '../never/never_type.js';
import type { TupleType } from '../tuple/tuple_type.js';
import type { MergeOptions } from '../utils/options.js';
import type { ElementMatch } from './array_plus.element_match.js';
/**
* 🦴 *utilities*
* 🔢 *customizable*
*
* Finds the type in array `A` that matches `Criteria`.
*
* @example
* ```ts
* type R = ArrayPlus.Find<Array<string>, string> // string
* type R = ArrayPlus.Find<Array<1 | 2 | 'x'>, number> // 1 | 2 | undefined
* type R = ArrayPlus.Find<Array<string | number>, number | string> // string | number
* type R = ArrayPlus.Find<Array<number>, 1> // widen: 1 | undefined
* type R = ArrayPlus.Find<Array<string | number>, number> // unionMiss: number | undefined
*
* type R = ArrayPlus.Find<string[], number> // never
* ```
*
* @typeParam Options['widen'] performs widen match.
* Default to `true`.
* With widen match, a narrowed type will match its widen type.
* e.g. matching `1` against `number` yields `1 | undefined`
*
* The widen behavior can be customized by `Options['caseWiden']`
*
* @typeParam Options['caseNever'] return type when `A` is `never`. Default to `never`.
*
* @typeParam Options['caseNotMatch'] Return value when `T` does not match `Criteria`.
* Default to `never`.
*
* @typeParam Options['caseTuple'] return type when `A` is a tuple. Default to `not supported` message.
*
* @typeParam Options['caseWiden'] return type when `T` in `A` is a widen type of `Criteria`.
* Default to `Criteria | undefined`.
* Set it to `never` for a more type-centric behavior
*
* @typeParam Options['caseUnionNotMatch'] Return value when a branch of the union `T` does not match `Criteria`.
* Default to `never`.
*
* If you want the type to behave more like JavaScript,
* you can override it to return `undefined`.
*
* Since it is a union, the result will be joined to the matched branch as union.
*/
export type Find<A extends unknown[], Criteria, Options extends Find.Options = Find.DefaultOptions<Criteria>> = MergeOptions<Options, Find.DefaultOptions<Criteria>> extends infer O extends Find.Options ? TupleType<A, O['caseTuple'], A extends Array<infer T> ? ElementMatch<T, Criteria, O> : never, O> : never;
export declare namespace Find {
interface Options extends ElementMatch.Options, NeverType.Options {
caseTuple?: unknown;
}
interface DefaultOptions<Criteria> extends ElementMatch.DefaultOptions<Criteria>, NeverType.DefaultOptions {
caseTuple: 'does not support tuple. Please use `FindFirst` or `TuplePlus.Find` instead.';
}
}
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