> RE patterns can be horribly ugly
It worth to be noted that the verbose flag (re.X or re.VERBOSE in Python) may help to get more readable/friendly regexes (by allowing whitespace and comments).
It worth to be noted that the verbose flag (re.X or re.VERBOSE in Python) may help to get more readable/friendly regexes (by allowing whitespace and comments).
It's a declarative language without symbols or recursion: that means that it's just not well-suited to being "broken down and simplified". You just have to bite the bullet and learn it. With a little practice, the basic features (e.g. beginning/end of line markers, character classes and captures, maybe non-capturing parentheses too) should be readable without trouble.
I agree that for trivial regex it's useless. For instance (directly taken from Python doc) in this case:
a = re.compile(r"""\d + # the integral part
\. # the decimal point
\d * # some fractional digits""", re.X)
b = re.compile(r"\d+\.\d*")
Another point is that even if I can read/write (that's the case) regexes other people may have to deal with my code and it's a well known fact that many people doesn't understand/like regex, so splitting them in small "chunks" may help them.
I'm just saying that 90% of the time when users complain about not being able to read a regex, the solution should be "hit the books" not "rewrite the expression".