Namespace Lucene.Net.QueryParsers.Flexible.Core

Core classes of the flexible query parser framework.

Flexible Query Parser

This namespace contains the necessary classes to implement a query parser.

A query parser is divided in at least 2 phases, text parsing and query building, and one optional phase called query processing.

First Phase: Text Parsing

The text parsing phase is performed by a text parser, which implements ISyntaxParser interface. A text parser is responsible to get a query string and convert it to a IQueryNode tree, which is an object structure that represents the elements defined in the query string.

Second (optional) Phase: Query Processing

The query processing phase is performed by a query processor, which implements QueryNodeProcessor. A query processor is responsible to perform any processing on a IQueryNode tree. This phase is optional and is used only if an extra processing, validation, query expansion, etc needs to be performed in a IQueryNode tree. The IQueryNode tree can be either be generated by a text parser or programmatically created.

Third Phase: Query Building

The query building phase is performed by a query builder, which implements <xref:Lucene.Net.QueryParsers.Flexible.Core.Builders.IQueryBuilder{Lucene.Net.QueryParsers.Flexible.Core.Nodes.IQueryNode}>. A query builder is responsible to convert a IQueryNode tree into an arbitrary object, which is usually used to be executed against a search index.

Classes

QueryNodeError

A query node error.

QueryNodeException

This exception should be thrown if something wrong happens when dealing with IQueryNodes.

QueryNodeParseException

This should be thrown when an exception happens during the query parsing from string to the query node tree.

QueryParserHelper<TQuery>

This class is a helper for the query parser framework, it does all the three query parser phrases at once: text parsing, query processing and query building.

It contains methods that allows the user to change the implementation used on the three phases.