fhir_path 0.13.0

Model-independent FHIRPath engine — a Dart port of the Java reference. Navigates any FHIR version through the FhirNode contract; bindings are fhir_r4/r5/r6_path.

0.13.0

Complete rewrite. Versions up to 0.12.0 were the original petitparser-based FHIRPath library (walkFhirPath). From 0.13.0 the package is the fhir-fli family's standalone, model-independent FHIRPath engine — a new codebase with a new API, developed at fhir-fli/fhir_path. Users of the legacy API should either stay on 0.12.0 or migrate to FHIRPathEngine via a version binding (fhir_r4_path / fhir_r5_path / fhir_r6_path), which is the recommended entry point.

First release of the standalone, model-independent FHIRPath engine, extracted from fhir_r4_path (which is now a thin binding over this package, alongside fhir_r5_path and fhir_r6_path).

• Architecture: no FHIR model dependency. Data is navigated through the FhirNode reflection contract (package fhir_node); FHIR-version knowledge (type metadata, terminology, value construction) enters through the IWorkerContext / IFhirValueFactory boundary interfaces that each binding implements. A port of the Java reference engine (org.hl7.fhir.core FHIRPathEngine); conformance is verified by the official FHIRPath test suite run in all three bindings (1070 tests each).
• Curated public API: the barrel exports the engine surface (FHIRPathEngine, ExpressionNode, the boundary interfaces, exceptions, type machinery, FHIRLexer — public because the FHIR Mapping Language parser lexes with it, as in Java). The implementation collaborators are src-internal and not exported.
• Exceptions: PathEngineException is the catchable root for all expression failures; FHIRLexerException extends it (Java parity via the shared FHIRException root). PathEngineError (an Error) is reserved for programming errors.
• Java-parity fix: parse(String) rejects trailing tokens ("Premature ExpressionNode termination"), while parseLexer(FHIRLexer) remains the lenient overload for embedded parsing.
• Performance contract: the engine is deliberately cache-free, like the Java reference — parse once, evaluate many; cache ExpressionNodes in the caller (bindings' WorkerContext layers are the right home for an expression cache). Parsed nodes are tied to the IFhirValueFactory that parsed them.
• Known pre-1.0 work: several engine methods that exist for the internal collaborator classes are still public on FHIRPathEngine; they will be narrowed before 1.0.