var aFunction = require('./_a-function');
var toObject = require('./_to-object');
var IObject = require('./_iobject');
var toLength = require('./_to-length');
module.exports = function (that, callbackfn, aLen, memo, isRight) {
aFunction(callbackfn);
var O = toObject(that);
var self = IObject(O);
var length = toLength(O.length);
var index = isRight ? length - 1 : 0;
var i = isRight ? -1 : 1;
if (aLen < 2) for (;;) {
if (index in self) {
memo = self[index];
index += i;
break;
}
index += i;
if (isRight ? index < 0 : length <= index) {
throw TypeError('Reduce of empty array with no initial value');
}
}
for (;isRight ? index >= 0 : length > index; index += i) if (index in self) {
memo = callbackfn(memo, self[index], index, O);
}
return memo;
};