Skip to main content
Using Deno in production at your company? Earn free Deno merch.
Give us feedback


Deno standard library
Go to Latest
// Ported from js-yaml v3.13.1:// Copyright 2011-2015 by Vitaly Puzrin. All rights reserved. MIT license.// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
// deno-lint-ignore no-explicit-anyexport type Any = any;
export function isNothing(subject: unknown): subject is never { return typeof subject === "undefined" || subject === null;}
export function isArray(value: unknown): value is Any[] { return Array.isArray(value);}
export function isBoolean(value: unknown): value is boolean { return typeof value === "boolean" || value instanceof Boolean;}
export function isNull(value: unknown): value is null { return value === null;}
export function isNumber(value: unknown): value is number { return typeof value === "number" || value instanceof Number;}
export function isString(value: unknown): value is string { return typeof value === "string" || value instanceof String;}
export function isSymbol(value: unknown): value is symbol { return typeof value === "symbol";}
export function isUndefined(value: unknown): value is undefined { return value === undefined;}
export function isObject(value: unknown): value is Record<string, unknown> { return value !== null && typeof value === "object";}
export function isError(e: unknown): boolean { return e instanceof Error;}
export function isFunction(value: unknown): value is () => void { return typeof value === "function";}
export function isRegExp(value: unknown): value is RegExp { return value instanceof RegExp;}
export function toArray<T>(sequence: T): T | [] | [T] { if (isArray(sequence)) return sequence; if (isNothing(sequence)) return [];
return [sequence];}
export function repeat(str: string, count: number): string { let result = "";
for (let cycle = 0; cycle < count; cycle++) { result += str; }
return result;}
export function isNegativeZero(i: number): boolean { return i === 0 && Number.NEGATIVE_INFINITY === 1 / i;}
export interface ArrayObject<T = Any> { [P: string]: T;}