src/core/merge.js

import siftup from './siftup.js';

/**
 * Merges heaps at intervals [i, j[ and [j, k[ in array *a*
 * into a new heap at interval [i, k[.
 *
 * Hypothesis :
 *
 *   - i <= j <= k
 *   - j - 1 is the last leaf ot the first heap
 *
 * @param {int} arity arity of the heap
 * @param {function} compare the comparison function
 * @param {function} swap the swap function
 * @param {array} a the array where the two heaps are stored
 * @param {int} i is the root of the first heap
 * @param {int} j is the root of the second heap
 * @param {int} k - 1 is the index of the last leaf in the second heap
 */

export default function merge(arity, compare, swap, a, i, j, k) {
	for (; j < k; ++j) {
		siftup(arity, compare, swap, a, i, j + 1, j);
	}
}