A hand-written, recursive descent parser of the Contextual Query Language as used in the standardized information retrieval protocol—Search/Retrieval via URL (SRU).
The parser can be used in places where the front-end query analysis is required (e.g search UIs, etc).
Based on the original work of Jakub Skoczen, with updates from Jason Stafford to make it a node package and move it into the ES6 world.
CQL specification, including the grammar and detailed description of the language: CQL specs
There is a slightly modified version of the specification, which has been taken over by OASIS available at searchRetrieve: Part 5. CQL