ts-toolbelt
Version:
TypeScript's largest utility library
25 lines (24 loc) • 988 B
TypeScript
import { Key } from '../../Any/Key';
import { Readonly as OReadonly } from '../Readonly';
import { List } from '../../List/List';
import { BuiltIn } from '../../Misc/BuiltIn';
import { Tail } from '../../List/Tail';
import { Depth } from '../_Internal';
/**
* @hidden
*/
declare type ReadonlyAt<O, Path extends List<Key>, depth extends Depth> = O extends BuiltIn ? O : Path extends [Key] ? O extends List ? OReadonly<O, Path[0], depth> : O extends object ? OReadonly<O, Path[0], depth> : O : {
[K in keyof O]: K extends Path[0] ? ReadonlyAt<O[K], Tail<Path>, depth> : O[K];
};
/**
* Make some fields of `O` readonly at `Path` (deeply or not)
* @param O to make readonly
* @param Path to be followed
* @param depth (?=`'flat'`) 'deep' to do it deeply
* @returns [[Object]]
* @example
* ```ts
* ```
*/
export declare type Readonly<O extends object, Path extends List<Key>, depth extends Depth = 'flat'> = Path extends unknown ? ReadonlyAt<O, Path, depth> : never;
export {};