/
last.ts
48 lines (44 loc) · 1.04 KB
/
last.ts
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import type { IterableContainer } from "./_types";
import { purry } from "./purry";
import type { LastArrayElement } from "./type-fest/last-array-element";
/**
* Gets the last element of `array`.
*
* @param data - The array.
* @signature
* R.last(array)
* @example
* R.last([1, 2, 3]) // => 3
* R.last([]) // => undefined
* @dataFirst
* @pipeable
* @category Array
*/
export function last<T extends IterableContainer>(data: T): LastArrayElement<T>;
/**
* Gets the last element of `array`.
*
* @signature
* R.last()(array)
* @example
* R.pipe(
* [1, 2, 4, 8, 16],
* R.filter(x => x > 3),
* R.last(),
* x => x + 1
* ); // => 17
* @dataLast
* @pipeable
* @category Array
*/
export function last<T extends IterableContainer>(): (
data: T,
) => LastArrayElement<T>;
export function last(): unknown {
return purry(_last, arguments);
}
function _last<T extends IterableContainer>(
data: T,
): LastArrayElement<T> | undefined {
return data[data.length - 1] as LastArrayElement<T> | undefined;
}