_array-methods.js
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// 0 -> Array#forEach
// 1 -> Array#map
// 2 -> Array#filter
// 3 -> Array#some
// 4 -> Array#every
// 5 -> Array#find
// 6 -> Array#findIndex
var ctx = require('./_ctx');
var IObject = require('./_iobject');
var toObject = require('./_to-object');
var toLength = require('./_to-length');
var asc = require('./_array-species-create');
module.exports = function (TYPE, $create) {
var IS_MAP = TYPE == 1;
var IS_FILTER = TYPE == 2;
var IS_SOME = TYPE == 3;
var IS_EVERY = TYPE == 4;
var IS_FIND_INDEX = TYPE == 6;
var NO_HOLES = TYPE == 5 || IS_FIND_INDEX;
var create = $create || asc;
return function ($this, callbackfn, that) {
var O = toObject($this);
var self = IObject(O);
var f = ctx(callbackfn, that, 3);
var length = toLength(self.length);
var index = 0;
var result = IS_MAP ? create($this, length) : IS_FILTER ? create($this, 0) : undefined;
var val, res;
for (;length > index; index++) if (NO_HOLES || index in self) {
val = self[index];
res = f(val, index, O);
if (TYPE) {
if (IS_MAP) result[index] = res; // map
else if (res) switch (TYPE) {
case 3: return true; // some
case 5: return val; // find
case 6: return index; // findIndex
case 2: result.push(val); // filter
} else if (IS_EVERY) return false; // every
}
}
return IS_FIND_INDEX ? -1 : IS_SOME || IS_EVERY ? IS_EVERY : result;
};
};