# phpman > man > Plucene::Analysis::TokenFilter

## NAME
    [Plucene::Analysis::TokenFilter](https://www.chedong.com/phpMan.php/perldoc/Plucene%3A%3AAnalysis%3A%3ATokenFilter/markdown) - base class for token filters

## DESCRIPTION
    This is an abstract base class for token filters.

    A TokenFilter is a TokenStream whose input is another token stream.

## METHODS
  next
    This must be defined in a subclass

  close
    Does nothing.