JSONiq

JSONiq is a query and functional programming language that is designed to declaratively query and transform collections of hierarchical and heterogeneous data in format of JSON, XML, as well as unstructured, textual data. JSONiq is an open specification published under the Creative Commons Attribution-ShareAlike 3.0 license. It is based on the XQuery language, with which it shares the same core expressions and operations on atomic types. JSONiq comes in two syntactical flavors, which both support JSON and XML natively. The JSONiq syntax (a superset of JSON) extended with XML support through a compatible subset of XQuery. The XQuery syntax (native XML support) extended with JSON support through a compatible subset (the JSONiq extension to XQuery) of the above JSONiq syntax. JSONiq primarily provides means to extract and transform data from JSON documents or any data source that can be viewed as JSON (e.g. relational databases or web services). The major expression for performing such operations is the SQL-like “FLWOR expression” that comes from XQuery. A FLWOR expression is constructed from the five clauses after which it is named: FOR, LET, WHERE, ORDER BY, RETURN. However, it also supports clauses for doing grouping and windowing. The language also provides syntax for constructing new JSON documents where either the field names and values are known in advance or can be computed dynamically. The JSONiq language (not the extension to XQuery) is a superset of JSON. That is, each JSON document is a valid JSONiq program. Additionally, the language also supports a navigational syntax for extracting field names and values out of JSON objects as well as values out of JSON arrays. Navigation is resilient in the absence of values, or if values are heterogeneous, in that it silently ignores unforeseen values without raising errors. All constructs are defined as expressions within the language and can be arbitrarily nested. JSONiq does not include features for updating JSON or XML documents, it does not have full text search capabilities, and has no statements.