Formating for pcre regx patterns

[photodude]

After some performance testing and consideration for readability, I think that patterns like [0-9] or [[:digit:]] is better than \d as the meaning is more clear. Since there seems to be no performance difference between any of these patterns; readability is prefered over the more condensed version.

Expression	Meaning	Prefered option 1	Prefered option 2
\d	any decimal digit	[0-9]	[[:digit:]]
\D	any character that is not a decimal digit	[^0-9]	--
\w	any alphanumeric character (aka word character)	[a-zA-Z0-9_]	[[:word:]]
[a-z]	Lowercase letters	[a-z]	[[:lower:]]
[A-Z]	Uppercase letters	[A-Z]	[[:upper:]]
\xYY	Hexadecimal character YY	[0-9a-fA-F]	[[:xdigit:]]

Preference to readability for pcre/regx patterns should be included in the coding standard.

[photodude]

I think something should be done in regards to a rule for pcre regx patterns. but as I don't have the time or skills to address I will Suggest voting to close as a Stale issue. @wilsonge @mbabker