# sct-ecl
The SNOMED CT Expression Constraint Language.
A `logos` lexer and a `winnow` parser faithful to the official ECL ANTLR
grammar ([the ECL specification](https://docs.snomed.org/snomed-ct-specifications/snomed-ct-expression-constraint-language)),
a syntax tree named after the grammar's rules, a printer whose output parses
back to the same tree, and an evaluator that compiles a constraint to set
algebra over a [`concept-graph`](https://crates.io/crates/concept-graph).
## Where it sits
`sct-ecl` is one crate of [FerroTERM](https://github.com/rubentalstra/FerroTERM),
a pure-Rust FHIR terminology server for SNOMED CT, LOINC, and other clinical
code systems. The crates are published so other projects can reuse them; the
API is pre-1.0 and moves with the FerroTERM release train. Documentation:
<https://docs.rs/sct-ecl>.
## Licence
Apache License, Version 2.0 (`LICENSE`). Clinical terminology content (SNOMED
CT, LOINC, RxNorm, ICD, the Dutch national code systems) is licensed by its
publisher and is never part of this crate.