fml-check

Type checker for the FHIR Mapping Language: finds what a map gets wrong before it runs.

It follows every rule with the types of its variables and reports:

elements that do not exist on the type they are read from or written to, including inherited ones, backbone elements and content references (Questionnaire.item.item);
type annotations that are not a type of the element (src.deceased : string);
unknown variables and writes into source variables;
unknown or abstract types in create('Type'), and transforms with the wrong number of arguments;
calls to groups that are not declared, or with the wrong number of arguments;
element paths inside FHIRPath (where, check, (…)), as warnings, since a wrong path there gives an empty result instead of an error;
what the Mapping Language IG requires of a map: a url and a name, groups that extend another with its parameters (mode, name and type), unique constant names; and, as warnings because the HL7 maps themselves break them, default groups that are not a typed source and target, rule names used twice, and reserved keywords used as names.

Groups without parameter types are checked with the types they are called with, which is how the cross-version maps are written. Those maps (R2–R5) check without errors; on other public maps it found a typo in the FHIR test cases, a parameter a group uses without declaring it, and a condition that is never true because it reads system and code from a CodeableConcept instead of its codings.

Definitions come through a small Definitions trait. With the fhirschema feature, CoreDefinitions provides FHIR R4, R4B, R5 and R6 (6.0.0-ballot5), including the version-specific URLs the cross-version maps use (http://hl7.org/fhir/4.0/StructureDefinition/…). PackageDefinitions puts the StructureDefinitions of FHIR packages (profiles, extensions, logical models) in front of them.

use fml_check::{CoreDefinitions, Release, check};

let parse = fml_syntax::parse(source);
for diagnostic in check(&parse.tree(), &CoreDefinitions::new(Release::R5)) {
    eprintln!("{:?}: {}", diagnostic.severity, diagnostic.message);
}

Part of fml-rs. Licensed under MIT or Apache-2.0.

fml-check 0.2.0

fml-check