openehr-query

A hand-written openEHR AQL 1.1 front end for Rust: lexer, parser, and typed AST for the Archetype Query Language — native logos + chumsky, no ANTLR runtime.

What it provides

• A complete AQL 1.1 lexer and parser producing a typed AST (SELECT, FROM/CONTAINS, WHERE, ORDER BY, LIMIT, path expressions with predicates, parameters, functions), corpus-validated against the official grammar's example set.
• Typed parse errors with source positions — a refusal names what and where.
• The AST is engine-agnostic: this crate deliberately stops at parsing, so any execution engine (SQL generation, in-memory evaluation) can build on it.

Versioning

The package version is the crate's own independent SemVer line — it tracks this implementation's code and moves freely with fixes and improvements, never with the vendored openEHR specification (QUERY (AQL) 1.1.0). The implemented spec version is always available at runtime as openehr_query::SPEC_VERSION ("1.1.0"), independent of the package version.

Minimum supported Rust version

Rust 1.96 (edition 2024).

License

MIT (LICENSE-MIT). The crate is hand-written; the openEHR specification text it implements is the authority but is not embedded in the package.

Part of FerroEHR

This crate is the query-language layer of FerroEHR, a pure-Rust, openEHR-spec-conformant Clinical Data Repository (ITS-REST 1.1.0 + AQL 1.1 on PostgreSQL 18). The crates are usable standalone; FerroEHR is the reference consumer.