ts-data-forge/dist/array/impl/array-utils-element-access.mjs

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import { none } from '../../functional/optional/impl/optional-none.mjs';
import { some } from '../../functional/optional/impl/optional-some.mjs';
import { pipe } from '../../functional/pipe.mjs';
import '@sindresorhus/is';

function at(...args) {
    switch (args.length) {
        case 2: {
            const [array, index$1] = args;
            return pipe(index$1 < 0 ? array.length + index$1 : index$1).map((normalizedIndex) => normalizedIndex < 0 || normalizedIndex >= array.length
                ? none
                : // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
                    some(array[normalizedIndex])).value;
        }
        case 1: {
            const [index] = args;
            return (array) => at(array, index);
        }
    }
}
/**
 * Returns the first element of an array as an Optional.
 *
 * @example
 *
 * ```ts
 * const users = [{ id: 1 }, { id: 2 }];
 *
 * const empty: { id: number }[] = [];
 *
 * const first = Arr.head(users);
 *
 * const none = Arr.head(empty);
 *
 * assert.deepStrictEqual(first, Optional.some({ id: 1 }));
 *
 * assert.deepStrictEqual(none, Optional.none);
 * ```
 */
const head = (array) => 
// eslint-disable-next-line total-functions/no-unsafe-type-assertion
(array.length === 0 ? none : some(array.at(0)));
/**
 * Returns the last element of an array as an Optional.
 *
 * @example
 *
 * ```ts
 * const queue = ['first', 'second'];
 *
 * const emptyQueue: string[] = [];
 *
 * const lastValue = Arr.last(queue);
 *
 * const none = Arr.last(emptyQueue);
 *
 * assert.deepStrictEqual(lastValue, Optional.some('second'));
 *
 * assert.deepStrictEqual(none, Optional.none);
 * ```
 */
const last = (array) => 
// eslint-disable-next-line total-functions/no-unsafe-type-assertion
(array.length === 0 ? none : some(array.at(-1)));
/**
 * Alias for `head`.
 *
 * @see {@link head}
 */
const first = head;

export { at, first, head, last };
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