Consider replacing forEach, filter, reduce...

Hi,
when parsing the JavaScript input consider replacing methods like forEach with for constructs in order to improve performance significantly.

For example:
```javascript
const numbers = [ 10, 20, 30, 40, 50 ];
const numbersLessThan30 = numbers.filter(number => number < 30);

// OUT [ 10, 20 ].
```

Should become:

```javascript
const numbers = [ 10, 20, 30, 40, 50 ];
const numbersLessThan30 = [];

for (const number of numbers) {
if (number < 30) {
numbersLessThan30.push(30);
}
}

// OUT [ 10, 20 ].
```

The second solution can be 10x times faster than the first.
This is a publication about a performance test based on all methods: https://hackernoon.com/javascript-performance-test-for-vs-for-each-vs-map-reduce-filter-find-32c1113f19d7.