@extra-array/rotate-update/index.js

Rotates values in array.

'use strict';
function mod(x, y) {
    return x - y * Math.floor(x / y);
}
function index(x, i = 0) {
    return i < 0 ? Math.max(x.length + i, 0) : Math.min(i, x.length);
}
function indexRange(x, i = 0, I = x.length) {
    i = index(x, i);
    I = Math.max(i, index(x, I));
    return [i, I];
}
function copy$(x, y, j = 0, i = 0, I = y.length) {
    var j = index(x, j);
    var [i, I] = indexRange(y, i, I);
    for (; i < I; i++, j++)
        x[j] = y[i];
    return x;
}
function rotate$(x, n = 0) {
    var n = mod(n, x.length);
    var y = x.slice(0, n);
    x.copyWithin(0, n);
    return copy$(x, y, x.length - n);
}
module.exports = rotate$;