Hi

ppi_dumper is great at hints

$ ppi_dumper foo.pl
PPI::Document
  PPI::Statement::Compound
    PPI::Token::Word    'if'
    PPI::Structure::Condition   ( ... )
      PPI::Statement::Expression
        PPI::Token::Symbol      '$CPC_stop_type'
        PPI::Structure::Subscript       [ ... ]
          PPI::Statement::Expression
            PPI::Token::Symbol          '$i'
        PPI::Token::Whitespace          ' '
        PPI::Token::Operator    '!~'
        PPI::Token::Whitespace          ' '
        PPI::Token::Regexp::Match       '/not stop/'
    PPI::Structure::Block       { ... }
      PPI::Token::Whitespace    '\n'
[download]

So lets see, a Token::Operator ... Regexp::Match ... journey begins at perlop