NAME

       Search::Xapian::MatchSpy - abstract base class for match spies.

DESCRIPTION

       This is an abstract base class for match spies in Xapian.

       The subclasses will generally accumulate information seen during the match, to calculate
       aggregate functions, or other profiles of the matching documents.

METHODS

       operator() <Document> <weight>
           Virtual - needs to be implemented in extending classes. Registers a document with the
           match spy.

           This is called by the matcher once with each document seen by the matcher during the
           match process. Note that the matcher will often not see all the documents which match
           the query, due to optimisations which allow low-weighted documents to be skipped, and
           allow the match process to be terminated early.

       get_description
           Return a string describing this object.

           This default implementation returns a generic answer, to avoid forcing those deriving
           their own MatchSpy subclasses from having to implement this (they may not care what
           get_description() gives for their subclass).

           Reimplemented in Xapian::ValueCountMatchSpy.

       name
           Return the name of this match spy.

           This name is used by the remote backend. It is passed with the serialised parameters
           to the remote server so that it knows which class to create. Return the full
           namespace-qualified name of your class here. If you don't want to support the remote
           backend in your match spy, you can use the default implementation which simply throws
           Xapian::UnimplementedError.

           Reimplemented in Xapian::ValueCountMatchSpy.

SEE ALSO

       Search::Xapian, Search::Xapian::ValueCountMatchSpy, Search::Xapian::PerlMatchSpy