pub trait VariableSelector<Var> {
// Required method
fn select_variable(&mut self, context: &SelectionContext<'_>) -> Option<Var>;
// Provided methods
fn on_conflict(&mut self) { ... }
fn on_unassign_literal(&mut self, _literal: Literal) { ... }
fn on_unassign_integer(&mut self, _variable: DomainId, _value: i32) { ... }
fn on_appearance_in_conflict_literal(&mut self, _literal: Literal) { ... }
fn on_appearance_in_conflict_integer(&mut self, _variable: DomainId) { ... }
fn is_restart_pointless(&mut self) -> bool { ... }
}Expand description
A trait containing the interface for VariableSelectors,
specifying the appropriate hooks into the solver and the methods required for selecting
variables.
Required Methods§
sourcefn select_variable(&mut self, context: &SelectionContext<'_>) -> Option<Var>
fn select_variable(&mut self, context: &SelectionContext<'_>) -> Option<Var>
Determines which variable to select next if there are any left to branch on.
Should only return None when all variables which have been passed to the
VariableSelector have been assigned. Otherwise it should return the variable to
branch on next.
Provided Methods§
sourcefn on_conflict(&mut self)
fn on_conflict(&mut self)
A function which is called after a conflict has been found and processed but (currently) does not provide any additional information.
sourcefn on_unassign_literal(&mut self, _literal: Literal)
fn on_unassign_literal(&mut self, _literal: Literal)
sourcefn on_unassign_integer(&mut self, _variable: DomainId, _value: i32)
fn on_unassign_integer(&mut self, _variable: DomainId, _value: i32)
sourcefn on_appearance_in_conflict_literal(&mut self, _literal: Literal)
fn on_appearance_in_conflict_literal(&mut self, _literal: Literal)
A function which is called when a Literal appears in a conflict during conflict
analysis.
sourcefn on_appearance_in_conflict_integer(&mut self, _variable: DomainId)
fn on_appearance_in_conflict_integer(&mut self, _variable: DomainId)
A function which is called when a variable appears in a conflict during conflict analysis.
sourcefn is_restart_pointless(&mut self) -> bool
fn is_restart_pointless(&mut self) -> bool
This method returns whether a restart is currently pointless for the VariableSelector.
For example, if a VariableSelector is using a static strategy (e.g. Smallest) then a
restart is pointless; however, for a VariableSelector like Vsids which
changes throughout the search process restarting is not pointless.
Note that even if the VariableSelector has indicated that a restart is pointless, it
could be that the restart is still performed.