Core classes of the flexible query parser framework.
This package 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.
The text parsing phase is performed by a text parser, which implements xref:Lucene.Net.QueryParsers.Flexible.Core.Parser.SyntaxParser interface. A text parser is responsible to get a query string and convert it to a xref:Lucene.Net.QueryParsers.Flexible.Core.Nodes.QueryNode tree, which is an object structure that represents the elements defined in the query string.
The query processing phase is performed by a query processor, which implements xref:Lucene.Net.QueryParsers.Flexible.Core.Processors.QueryNodeProcessor. A query processor is responsible to perform any processing on a xref:Lucene.Net.QueryParsers.Flexible.Core.Nodes.QueryNode tree. This phase is optional and is used only if an extra processing, validation, query expansion, etc needs to be performed in a xref:Lucene.Net.QueryParsers.Flexible.Core.Nodes.QueryNode tree. The xref:Lucene.Net.QueryParsers.Flexible.Core.Nodes.QueryNode tree can be either be generated by a text parser or programmatically created.
The query building phase is performed by a query builder, which implements xref:Lucene.Net.QueryParsers.Flexible.Core.Builders.QueryBuilder. A query builder is responsible to convert a xref:Lucene.Net.QueryParsers.Flexible.Core.Nodes.QueryNode tree into an arbitrary object, which is usually used to be executed against a search index.