Uint32Array Helper Functions

When working with binary data in WebCrypto API and similar contexts, you end up calling new Uint32Array quite often. Writing that lengthy syntax every time gets tedious, so I made a shorter wrapper.

Code

function initUint32(length: number): Uint32Array;
function initUint32(array: ArrayLike<number> | ArrayBufferLike): Uint32Array;
function initUint32(
  buffer: ArrayBufferLike,
  byteOffset?: number,
  length?: number,
): Uint32Array;
function initUint32(
  arg1: number | ArrayLike<number> | ArrayBufferLike,
  arg2?: number,
  arg3?: number,
): Uint32Array {
  return typeof arg1 === "number"
    ? new Uint32Array(arg1)
    : "byteLength" in arg1
      ? new Uint32Array(arg1, arg2, arg3)
      : new Uint32Array(arg1);
}

Usage Examples

Initialize with specified length

const arr = initUint32(8);
// Uint32Array(8) [0, 0, 0, 0, 0, 0, 0, 0]

Convert from array

const arr = initUint32([1, 2, 3, 4]);
// Uint32Array(4) [1, 2, 3, 4]

View a portion of ArrayBuffer

const buffer = new ArrayBuffer(32);
const arr = initUint32(buffer, 8, 4);
// Uint32Array(4) [0, 0, 0, 0] - 4 elements from byte 8

Implementation Notes

Using TypeScript function overloads, this provides type-safe access to all three Uint32Array constructor patterns.

Pass a number to create an array of that length
Pass an array-like object to convert it
Pass ArrayBuffer with offset to create a partial view

Internal type guards determine the argument type and dispatch to the appropriate constructor call.