in packages/runtime/runtime.js [455:480]
exports.keys = function(object) {
var keys = [];
for (var key in object) {
keys.push(key);
}
keys.reverse();
// Rather than returning an object with a next method, we keep
// things simple and return the next function itself.
return function next() {
while (keys.length) {
var key = keys.pop();
if (key in object) {
next.value = key;
next.done = false;
return next;
}
}
// To avoid creating an additional object, we just hang the .value
// and .done properties off the next function object itself. This
// also ensures that the minifier will not anonymize the function.
next.done = true;
return next;
};
};