When is a issue too complex for a regular expression?

Question

Please don\'t answer the obvious, but what are the limit signs that tell us a problem should not be solved using regular expressions?

For example: Why is a complete emai

Answer 1

Whenever you can't be sure it really solves the problem, for example:

• HTML parsing
• Email validation
• Language parsers

Especially so when there already exist tools that solve the problem in a totally understandable way.

Regex can be used in the domains I mentioned, but only as a subset of the whole problem and for specific, simple cases.

This goes beyond the technical limitations of regexes (regular languages + extensions), the maintainability and readability limit is surpassed a lot earlier than the technical limit in most cases.