negate

function

Creates a function that negates the result of the predicate func.

Installation

Import

import { negate } from '@tulx/utils';

Source Code

Implementation

/**
 * Creates a function that negates the result of the predicate func.
 *
 * @param predicate - The predicate to negate.
 * @returns Returns the new negated function.
 *
 * @example
 * ```ts
 * const isEven = (n: number) => n % 2 === 0;
 * filter([1, 2, 3, 4, 5, 6], negate(isEven)); // [1, 3, 5]
 * ```
 */
export function negate<T extends (...args: unknown[]) => boolean>(
  predicate: T
): (...args: Parameters<T>) => boolean {
  return function (this: unknown, ...args: Parameters<T>): boolean {
    return !predicate.apply(this, args);
  };
}

Example

import { negate } from '@tulx/utils';

const isEven = (n: number) => n % 2 === 0;
filter([1, 2, 3, 4, 5, 6], negate(isEven)); // [1, 3, 5]

Related Functions

after

The opposite of before; this method creates a function that invokes func once it's called n or more times.

ary

Creates a function that invokes func, with up to n arguments, ignoring any additional arguments.

before

Creates a function that invokes func, with the this binding and arguments of the created function, while it's called less than n times.

bind

Creates a function that invokes func with the this binding of thisArg and partials prepended to the arguments it receives.

bindKey

Creates a function that invokes the method at object[key] with partials prepended to the arguments it receives.

curry

Creates a function that accepts arguments of func and either invokes func returning its result, or returns a function that accepts the remaining arguments.