type-helpers.ts 1.5 KB

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  1. /**
  2. * Copyright (c) 2018-2021 mol* contributors, licensed under MIT, See LICENSE file for more info.
  3. *
  4. * @author Alexander Rose <alexander.rose@weirdbyte.de>
  5. * @author David Sehnal <david.sehnal@gmail.com>
  6. */
  7. export type Mutable<T> = { -readonly [P in keyof T]: T[P] }
  8. export type PartialBy<T, K extends keyof T> = Omit<T, K> & Partial<Pick<T, K>>
  9. export type PickRequired<T, K extends keyof T> = T & Required<Pick<T, K>>
  10. export type TypedIntArray = Int8Array | Int16Array | Int32Array | Uint8Array | Uint16Array | Uint32Array
  11. export type TypedFloatArray = Float32Array | Float64Array
  12. export type TypedArray = TypedIntArray | TypedFloatArray
  13. export type NumberArray = TypedArray | number[]
  14. export type UintArray = Uint8Array | Uint16Array | Uint32Array | number[]
  15. export type ValueOf<T> = T[keyof T]
  16. export type ArrayCtor<T> = { new(size: number): { [i: number]: T, length: number } }
  17. /** assignable ArrayLike version */
  18. export type AssignableArrayLike<T> = { [i: number]: T, length: number }
  19. export type NonNullableArray<T extends any[] | ReadonlyArray<any>> = T extends any[] ? NonNullable<T[0]>[] : ReadonlyArray<NonNullable<T[0]>>
  20. export function ObjectKeys<T extends object>(o: T) {
  21. return Object.keys(o) as (keyof T)[];
  22. }
  23. export interface FiniteArray<T, L extends number = number> extends ReadonlyArray<T> { length: L };
  24. export function assertUnreachable(x: never): never {
  25. throw new Error('unreachable');
  26. }
  27. export function isPromiseLike<T = any>(x: any): x is Promise<T> {
  28. return typeof x?.then === 'function';
  29. }