add PredicateEvaluator::evaluate_predicate_with_direction

Author: GyulyVGC

src/internals/postfix_stack_item.rs

@@ -6,9 +6,13 @@ pub(crate) enum PostfixStackItem<'a, Predicate> {
 }
 
 impl<Predicate> PostfixStackItem<'_, Predicate> {
-    pub(crate) fn evaluate<Reason>(
+    pub(crate) fn evaluate<Reason, Direction>(
         &self,
-        evaluator: &dyn PredicateEvaluator<Predicate = Predicate, Reason = Reason>,
+        evaluator: &dyn PredicateEvaluator<
+            Predicate = Predicate,
+            Reason = Reason,
+            Direction = Direction,
+        >,
         reasons: &mut Vec<Reason>,
     ) -> bool {
         match self {

src/structs/postfix_expression.rs

@@ -58,9 +58,13 @@ impl<Predicate> PostfixExpression<Predicate> {
         InfixExpression::from_tokens_unchecked(output_stack.remove(0).into())
     }
 
-    pub fn evaluate<Reason>(
+    pub fn evaluate<Reason, Direction>(
         &self,
-        evaluator: &dyn PredicateEvaluator<Predicate = Predicate, Reason = Reason>,
+        evaluator: &dyn PredicateEvaluator<
+            Predicate = Predicate,
+            Reason = Reason,
+            Direction = Direction,
+        >,
     ) -> (bool, Vec<Reason>) {
         let mut stack: Vec<PostfixStackItem<Predicate>> = Vec::new();
         let mut reasons: Vec<Reason> = Vec::new();

src/traits/predicate_evaluator.rs

@@ -1,8 +1,19 @@
 pub trait PredicateEvaluator {
     type Predicate;
     type Reason;
+    type Direction;
 
-    fn evaluate_predicate(&self, predicate: &Self::Predicate) -> bool;
+    fn evaluate_predicate(&self, _predicate: &Self::Predicate) -> bool {
+        false
+    }
+
+    fn evaluate_predicate_with_direction(
+        &self,
+        _predicate: &Self::Predicate,
+        _direction: &Self::Direction,
+    ) -> bool {
+        false
+    }
 
     fn get_reason(&self, predicate: &Self::Predicate) -> Self::Reason;