Enum Kind 

pub enum Kind {
    Universal,
    Record(BTreeSet<String>),
}

The kind of a free type variable.

Record(labels) mirrors v0.0.6’s RecordKind: it constrains a variable not yet known to be anything in particular, but which field access (e#lbl) has already shown must resolve to some record type containing (at least) labels. Unlike v0.0.6, which pairs each required label with its field type directly in the kind, this port stores only the label names here — the field types are tracked by the Row the variable eventually binds to (unify::bind_var’s Kind::Record branch). This loses nothing because a concrete record’s structure here is always a first-class Row; v0.0.6 needed field types in the kind because its closed RecordType has no notion of “the type of label l” apart from the whole association list.

Variants

Universal

Record(BTreeSet<String>)

Trait Implementations

impl Clone for Kind

fn clone(&self) -> Kind

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Kind

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

Formats the value using the given formatter.

impl Eq for Kind

impl PartialEq for Kind

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Kind