Regular Expressions Special Pattern Macros

A set of special pattern macros can be used for convenience

Macro	Represents
\d	A digit character, same as [0-9]
\D	A non-digit character
\s	A whitespace character, same as [ \t\n\r\f]
\S	A non-whitespace character
\w	A word character (alphanumeric), same as [a-zA-Z_0-9]
\W	A non-word character