/
repeat.ts
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/
repeat.ts
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// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
// This module is browser compatible.
import { copy } from "./copy.ts";
/**
* Returns a new byte slice composed of `count` repetitions of the `source`
* array.
*
* @param source Source array to repeat.
* @param count Number of times to repeat the source array.
* @returns A new byte slice composed of `count` repetitions of the `source`
* array.
*
* @example Basic usage
* ```ts
* import { repeat } from "https://deno.land/std@$STD_VERSION/bytes/repeat.ts";
*
* const source = new Uint8Array([0, 1, 2]);
*
* repeat(source, 3); // Uint8Array(9) [0, 1, 2, 0, 1, 2, 0, 1, 2]
*
* repeat(source, 0); // Uint8Array(0) []
*
* repeat(source, -1); // Throws `RangeError`
* ```
*/
export function repeat(source: Uint8Array, count: number): Uint8Array {
if (count < 0 || !Number.isInteger(count)) {
throw new RangeError("Count must be a non-negative integer");
}
const repeated = new Uint8Array(source.length * count);
let offset = 0;
while (offset < repeated.length) {
offset += copy(source, repeated, offset);
}
return repeated;
}