code

code elements must be one of a set of strings

Many code elements require using a specific ValueSet to draw from. For example, Patient.gender requires AdministrativeGender. In Gleam, code elements with a required binding use an enum from r4_valuesets (or r4b/r5).

Other code elements do not have a required binding to a specific ValueSet. In Gleam these have no enum, and are defined as String.

Having stronger and weaker bindings lets FHIR keep interoperability simple and practical but also stay flexible enough to meet many terminology requirements. Required bindings to a specific valueset make it possible to use a type-safe enum, which makes them easy to work with in Gleam. Coding code elements are more powerful in that they can use any system of codes, and in Gleam are not type-safe.

Extension elements similarly let FHIR keep core elements relatively simple by allowing users to define new elements.

//In r4.gleam
pub type Patient {
  Patient(
    ...
    gender: Option(r4_valuesets.Administrativegender),
    ...
  )
}

//In r4_valuesets.gleam
pub type Administrativegender {
  AdministrativegenderMale
  AdministrativegenderFemale
  AdministrativegenderOther
  AdministrativegenderUnknown
}