fhir_mapping

The FHIR Mapping Language, independent of FHIR version: a parser from map text to a StructureMap and back, and the transform engine that runs a StructureMap over a source to build a target.

The engine reads a StructureMap and its ConceptMaps by element name through package:fhir_node, evaluates FHIRPath through package:fhir_path, and builds the target through FhirNodeBuilder, the mutable side of the node contract. A version binding (fhir_r4_mapping, fhir_r5_mapping, fhir_r6_mapping) supplies a MappingModel: its generated builders, its fhir_path binding, and the few places where the versions spell a StructureMap or ConceptMap differently (R4B's contextType, equivalence and dependent.variable; R5's relationship and dependent.parameter).

final parser = await StructureMapParser.create(model);
final map = parser.parse(mapText, 'my-map');
final engine = await FhirMapEngine.create(cache, model);
final target = await engine.transform('', source, map, null);

Use a binding for everyday work; it hands back typed resources. This package is what the bindings share.

Ported from the Java reference implementation (org.hl7.fhir.r5.utils.structuremap.StructureMapUtilities); comments in the parser and engine cite it where a version differs.