rambdax/_ts-toolbelt/src/Object/SelectKeys.ts

Extended version of Rambda - a lightweight, faster alternative to Ramda

import {Match} from '../Any/_Internal'
import {Is} from '../Any/Is'

/**
@hidden
*/
export type _SelectKeys<O extends object, M extends any, match extends Match> = {
    [K in keyof O]-?: {
        1: K
        0: never
    }[Is<O[K], M, match>]
}[keyof O]

/**
Get the keys of `O` which fields match `M`
@param O to extract from
@param M to select fields
@param match (?=`'default'`) to change precision
@returns [[Key]]
@example
```ts
```
*/
export type SelectKeys<O extends object, M extends any, match extends Match = 'default'> =
    O extends unknown
    ? _SelectKeys<O, M, match>
    : never