Enum Term 

pub enum Term {
    Invocation(Invocation),
    Literal(Literal),
    ExternalConstant(String),
    Parenthesized(Box<Expression>),
}

Represents a basic term in a FHIRPath expression

A term is the most fundamental unit in a FHIRPath expression. It can be a literal value, an invocation, a variable reference, or a parenthesized expression. Terms are the leaves of the expression tree in the abstract syntax tree (AST).

Terms can appear alone or as part of more complex expressions, and they are the starting point for expression evaluation.

Variants

Invocation(Invocation)

An invocation, such as a member access, function call, or special identifier (e.g., name, first(), $this)

Literal(Literal)

A literal value like a number, string, boolean, or date (e.g., 42, 'text', true, @2022-01-01)

ExternalConstant(String)

An external constant or environment variable reference (e.g., %context, %ucum, %terminologies)

Parenthesized(Box<Expression>)

A parenthesized expression (e.g., (1 + 2), (Patient.name))

Trait Implementations

impl Clone for Term

fn clone(&self) -> Term

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Term

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq for Term

fn eq(&self, other: &Term) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for Term