This is a definition and reference implementation for MRA (Multidimensional Relational Algebra), the core calculus for Quasar, an analytics engine for semi-structured data.
Quasar's support for SQL2 is layered atop MRA, and many features of the SQL dialect have a natural and high-level mapping to MRA.
Tests for the reference implementation (such as they are) are located in src/Test.purs.
TODO: A higher-level mathematical specification of the work contained herein which elides irrelevant details of this implementation.