/(?(DEFINE)
   (?<sigil>       [\$\@%&*])
   (?<name_atom>   (?: [_A-Za-z][_A-Za-z0-9]* | [0-9]+) )
   (?<separator>   (?: :: | '))
   (?<name>        (?: (?&separator)? (?&name_atom) 
                    (?:(?&separator)  (?&name_atom))*))
   (?<punct>       \S))
 (?&sigil) \s* (?:(?&name) | (?&punct))
/x