| 'use strict'; |
| var $ = require('../internals/export'); |
| var flattenIntoArray = require('../internals/flatten-into-array'); |
| var toObject = require('../internals/to-object'); |
| var toLength = require('../internals/to-length'); |
| var toInteger = require('../internals/to-integer'); |
| var arraySpeciesCreate = require('../internals/array-species-create'); |
| |
| // `Array.prototype.flat` method |
| // https://github.com/tc39/proposal-flatMap |
| $({ target: 'Array', proto: true }, { |
| flat: function flat(/* depthArg = 1 */) { |
| var depthArg = arguments.length ? arguments[0] : undefined; |
| var O = toObject(this); |
| var sourceLen = toLength(O.length); |
| var A = arraySpeciesCreate(O, 0); |
| A.length = flattenIntoArray(A, O, O, sourceLen, 0, depthArg === undefined ? 1 : toInteger(depthArg)); |
| return A; |
| } |
| }); |