[bazoom42]

How would you know if a regex is correct if you dont understand it?

[poisonborz]

You have test strings covering all cases and they match accordingly? The same way you'd know when writing manually.

[bazoom42]

Covering all cases? How would that be possible? Even if we only consider ASCII strings, there are 16.000 possible two-character strings, 2 million possible three-character strings and so on.