Nero Datalog

Nero is Joe's own dialect of the Datalog relational query language. Datalog is often used as a query language for databases; Joe provides it as a means of querying and transforming in-memory collections of data.

Joe provides Nero in two forms:

• As a standalone language, via the joe nero tool.
• As a language embedded in Joe scripts.

The following subsections discuss these in turn.

• The Nero Tutorial describes Nero as a standalone language.
• Embedded Nero describes how Nero is used within a Joe script, and particularly how to use scripted input facts and how to produce outputs in the script's domain types.
• 'ruleset' Reference is a concise statement of the syntax and semantics of Nero rule sets.
• Technical Details places Nero within the larger family of Datalog implementations, and describes specific differences from "standard" Datalog.