Module flavor 

StructureMap as FHIR R4 (and R4B) shape it, and back.

The model follows R5 and the Mapping Language IG. R4 differs in a few elements, converted here the way the HL7 version converter (StructureMap40_50, ConceptMap40_50) does:

R5 / IG	R4
dependent.parameter (valueId, …)	dependent.variable (strings)
source.defaultValue (a FHIRPath literal)	source.defaultValue[x] ('a' → defaultValueString, true → defaultValueBoolean, numbers)
target with a context	contextType: variable
group.typeMode absent	typeMode: none (required in R4)
const	not in R4: the R4 output has none, to_r4 reports it
parameter valueDate/valueTime/valueDateTime	valueString
ConceptMap relationship	equivalence
ConceptMap unmapped.mode: use-source-code	provided

Structs

R4Map

A StructureMap in R4 JSON, and the R5 content R4 cannot hold.

Functions

from_json

Reads a StructureMap in R4 or R5 JSON. R4 elements are converted to the model; R5 content passes through.

to_r4

Converts a StructureMap to its R4 JSON form.