How can I optimize this C# regex? “^\s?([-*]|\d+[.])\s+”

Question

I am not an expert at regular expression and have a regular expression

^\s?([-*]|\d+[.])\s+

I wonder if anyone has ideas about shortening/optimizing/simplifying the above regular expression?

Answer 1

You can save one entire character (yay!) by writing:

^\s?([-*]|\d+\.)\s+

Other than that there's not much to do here. If you don't need the contents of the alternation, you could make the group non-capturing and maybe shave a nanosecond or two off by writing

^\s?(?:[-*]|\d+\.)\s+

but that's very probably the most extreme form of premature optimization you can do. Plus, you need more characters...

Answer 2

As Regexes go, that one is pretty darn short and simple as it is. Does it work as you expect? If so, leave it alone.

Answer 3

Why would you want to optimize it? The contents of your regular expressions are already made of nonredundant atoms. You cannot simplify this more…