es7.array.flatten.js

'use strict';
// https://tc39.github.io/proposal-flatMap/#sec-Array.prototype.flatten
var $export = require('./_export');
var flattenIntoArray = require('./_flatten-into-array');
var toObject = require('./_to-object');
var toLength = require('./_to-length');
var toInteger = require('./_to-integer');
var arraySpeciesCreate = require('./_array-species-create');

$export($export.P, 'Array', {
  flatten: function flatten(/* depthArg = 1 */) {
    var depthArg = arguments[0];
    var O = toObject(this);
    var sourceLen = toLength(O.length);
    var A = arraySpeciesCreate(O, 0);
    flattenIntoArray(A, O, O, sourceLen, 0, depthArg === undefined ? 1 : toInteger(depthArg));
    return A;
  }
});

require('./_add-to-unscopables')('flatten');