openCypher — Grammar and TCK
By Cypher Language Group | 6 October 2016
The openCypher project has produced two significant new features in 2016: an Extended BNF grammar which formally defines the permitted syntax of Cypher, and a TCK (Technology Compatibility Kit).
An XML grammar definition is used to generate an EBNF and an Antlr4 grammar for use by projects who wish to parse Cypher, and “Railroad Diagrams” which document the syntax.
Cypher is a declarative query language which is not tied to any general-purpose programming language or domain-specific language. In line with this approach, the TCK is a Cucumber-based set of tests that can be used for any Cypher implementation in any of the many languages supported by Cucumber.
The grammar specification and the TCK may be downloaded from the Resources page.
Several organizations are already involved in openCypher; read more about them in Current projects.
Furthermore, we have been approaching the growing number of product and service vendors who are offering property graph databases or data storage services, to explore the best way to come together around an open standards process for a declarative property graph query language that occupies the same ecological niche as SQL does for relational query processors.