## org.apache.lucene.queryParser.ext
Class ParserExtension

    java.lang.Object
      org.apache.lucene.queryParser.ext.ParserExtension

    public abstract class ParserExtension

extends Object

This class represents an extension base class to the Lucene standard `QueryParser`. The `QueryParser` is generated by the JavaCC parser generator. Changing or adding functionality or syntax in the standard query parser requires changes to the JavaCC source file. To enable extending the standard query parser without changing the JavaCC sources and re-generate the parser the `ParserExtension` can be customized and plugged into an instance of `ExtendableQueryParser`, a direct subclass of `QueryParser`.

See Also:
  `Extensions`, `ExtendableQueryParser`

Constructor Summary
`ParserExtension()`

Method Summary
`abstract org.apache.lucene.search.Query` `parse(ExtensionQuery query)` Processes the given `ExtensionQuery` and returns a corresponding `Query` instance.

Methods inherited from class java.lang.Object
`clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait`

Constructor Detail

### ParserExtension

    public ParserExtension()

Method Detail

### parse

    public abstract org.apache.lucene.search.Query parse(ExtensionQuery query)
                                                  throws org.apache.lucene.queryParser.ParseException

  Processes the given `ExtensionQuery` and returns a corresponding `Query` instance. Subclasses must either return a `Query` instance or raise a `ParseException`. This method must not return `null`.

  Parameters:
    `query` - the extension query
  Returns:
    a new query instance
  Throws:
    `org.apache.lucene.queryParser.ParseException` - if the query can not be parsed.