Enum UnresolvedRef 

pub enum UnresolvedRef {
    Path(IdentPath),
}

Unresolved reference, produced by the parser before HIR lowering.

Carried by ExprKind::UnresolvedRef. The parser emits these when the meaning of an identifier path cannot be determined from syntax alone; HIR expression lowering (crate::hir::lower_expr) classifies and resolves them in a single pass against the lexical scope and the module-aware resolver.

This indirection is necessary because the same token shape can mean different expression kinds depending on declarations and local scopes. For example, the dotted expression Foo.Bar is parsed as the unresolved path Foo.Bar in both of these programs:

index Foo = { Bar };
node x: Dimensionless = Foo.Bar;

and:

node x: Dimensionless = Foo.Bar;

Only after collecting names from the file can resolution know whether Foo is an index. In the first program Foo.Bar becomes a HIR variant literal; in the second it becomes a qualified constant-like reference.

Bare identifiers have the same issue. PI parses as the unresolved path PI both when it denotes the built-in constant:

node x: Dimensionless = PI;

and when a local binding shadows that constant:

index I = { A };
node x: Dimensionless[I] = for PI: I { PI };

HIR lowering turns the first PI into a built-in constant reference, but the loop body PI in the second program into a local reference.

The payload is a path rather than separate “bare” and “qualified” variants so the parser records the complete syntactic structure uniformly: Foo, Foo.Bar, and Foo.Bar.Baz are all identifier paths. Segment-count restrictions, such as index variants currently being two-segment paths, are semantic rules enforced by HIR lowering rather than parser artifacts.

Variants

Path(IdentPath)

Unresolved identifier path: Foo, Foo.Bar, or Foo.Bar.Baz.

Implementations

impl UnresolvedRef

pub fn span(&self) -> Span

Returns the source span of the underlying identifier path.

Trait Implementations

impl Clone for UnresolvedRef

fn clone(&self) -> UnresolvedRef

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for UnresolvedRef

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

Formats the value using the given formatter.

impl FormatEquivalent for UnresolvedRef

fn format_equivalent(&self, other: &Self) -> bool

Returns true if self and other are equivalent up to formatting.