# TODO

## 1. Add `Follow` set for each kind of `Token` (Finished)

This will be extremely useful while handling `error sync`.

## 2. Add `Follow` set for each kind of `Field` (Finished)

## 3. Add `totally support` of `error sync` (Finished)

It's **mainly for**

- [x] l-exp
- [x] exp
- [x] term
- [x] factor
- [x] lop
- [x] aop
- [x] mop
- [x] id
- [x] integer

## 4. Deal with `Token::LexicalError` while `<id> / <integer>` appeared as the `first generation` of any `sub formula` (Finished)

Only need to consider:

- [x] id
- [x] integer
- [x] statement
- [x] factor

## 5. Automatic-First-Follow-Table-Generator

## 6. Optimizer
