Struct RegularPathConstraint 

pub struct RegularPathConstraint { /* private fields */ }

Constrains two variables to be connected by a regular path expression.

Created by the path! macro. The path expression supports concatenation, alternation (|), transitive closure (+), and reflexive-transitive closure (*). Single-attribute hops use direct index scans; multi-step paths use the WCO join engine for concatenation and BFS for closures.

When the start variable is bound, propose enumerates all reachable endpoints. When the end is bound, confirm checks reachability.

Implementations

impl RegularPathConstraint

pub fn new( set: TribleSet, start: Variable<GenId>, end: Variable<GenId>, ops: &[PathOp], ) -> Self

Creates a path constraint from start to end over the given postfix-encoded path operations.

Trait Implementations

impl<'a> Constraint<'a> for RegularPathConstraint

fn variables(&self) -> VariableSet

Returns the set of variables this constraint touches.

fn estimate(&self, variable: VariableId, binding: &Binding) -> Option<usize>

Estimates the number of candidate values for variable given the current partial binding.

fn propose( &self, variable: VariableId, binding: &Binding, proposals: &mut Vec<RawInline>, )

Enumerates candidate values for variable into proposals.

fn confirm( &self, variable: VariableId, binding: &Binding, proposals: &mut Vec<RawInline>, )

Filters proposals to remove values for variable that violate this constraint.

fn satisfied(&self, _binding: &Binding) -> bool

Returns whether this constraint is consistent with the current binding.

fn influence(&self, variable: VariableId) -> VariableSet

Returns the set of variables whose estimates may change when variable is bound or unbound.