Enum Supplier 

pub enum Supplier {
    Annotation,
    AnnotationVariable,
    Body,
}

What could supply the record type an ErrorKind::RecordTypeUnknown is missing — which is what its note tells the reader to do about it. unifier::unknown decides it.

“Part of the declaration’s type” means a variable of the declaration’s solved type — a parameter’s, the result’s, or inside either — or the field type of another use whose record type is one: an annotation, unified with that type, would solve the variable, and reading the use would solve the next.

Variants

Annotation

The declaration has no annotation, and the record type is part of its type: an annotation writing a record type there would supply it.

AnnotationVariable

The record type is part of the declaration’s type, and the declaration’s annotation writes a type variable there — f : a -> Int with body r.x — or around it.

Body

The record type is not part of the declaration’s type — .x passed where any value is taken, as in first n .x — so no annotation on the declaration could supply it, and only its body can.

Trait Implementations

impl Clone for Supplier

fn clone(&self) -> Supplier

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for Supplier

impl Debug for Supplier

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

Formats the value using the given formatter.

impl Eq for Supplier

impl PartialEq for Supplier

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Supplier