Struct ConstraintSet 

pub struct ConstraintSet {
    pub lower_bounds: Vec<TypeId>,
    pub upper_bounds: Vec<TypeId>,
}

Constraint set for an inference variable. Tracks both lower bounds (L <: α) and upper bounds (α <: U).

Fields

lower_bounds: Vec<TypeId>

Lower bounds: types that must be subtypes of this variable e.g., from argument types being assigned to a parameter

upper_bounds: Vec<TypeId>

Upper bounds: types that this variable must be a subtype of e.g., from extends constraints on type parameters

Implementations

impl ConstraintSet

pub const fn new() -> Self

pub fn from_info(info: &InferenceInfo) -> Self

pub fn add_lower_bound(&mut self, ty: TypeId)

Add a lower bound constraint: L <: α

pub fn add_upper_bound(&mut self, ty: TypeId)

Add an upper bound constraint: α <: U

pub const fn is_empty(&self) -> bool

Check if there are any constraints

pub fn merge_from(&mut self, other: Self)

pub fn transitive_reduction(&mut self, interner: &dyn TypeDatabase)

Perform transitive reduction on upper bounds to remove redundant constraints.

If we have constraints (T <: A) and (T <: B) and we know (A <: B), then (T <: B) is redundant and can be removed.

This reduces N² pairwise checks in detect_conflicts to O(N * reduced_N).

pub fn detect_conflicts( &self, interner: &dyn TypeDatabase, ) -> Option<ConstraintConflict>

Detect early conflicts between collected constraints. This allows failing fast before full resolution.

Trait Implementations

impl Clone for ConstraintSet

fn clone(&self) -> ConstraintSet

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for ConstraintSet

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

Formats the value using the given formatter.

impl Default for ConstraintSet

fn default() -> ConstraintSet

Returns the “default value” for a type.