ariya/esprima — pull request #22 by mathiasbynens (2012-02-25 21:33:07+00:00)
Title: Make the regular expressions for `IdentifierStart` and `IdentifierPart` more compact

This is done by…

(1) not creating a range for consecutive code points;
(2) using hexadecimal escape sequences instead of Unicode escape sequences where possible, by running the generated regexes through http://mothereff.in/js-escapes.

File size savings (bytes):

```
before → after (1) → after (2) | savings
IdentifierStart: 4252 → 4214 → 4198 | 54b
IdentifierPart: 5097 → 5054 → 5038 | 59b
```