feat(bool fn trait): began impl BooleanFunction for Expression with i…

…ter methods

src/expressions/traits/boolean_function.rs

@@ -0,0 +1,74 @@
+use crate::expressions::iterators::{
+    ExpressionDomainIterator, ExpressionImageIterator, ExpressionRelationIterator,
+    ExpressionSupportIterator,
+};
+use crate::expressions::Expression;
+use crate::traits::{BooleanFunction, BooleanValuation, Evaluate, GatherLiterals};
+use std::collections::{BTreeMap, BTreeSet};
+use std::fmt::Debug;
+
+impl<T: Debug + Clone + Eq + Ord> BooleanFunction<T> for Expression<T> {
+    type DomainIterator = ExpressionDomainIterator;
+    type RangeIterator = ExpressionImageIterator<T>;
+    type RelationIterator = ExpressionRelationIterator<T>;
+    type SupportIterator = ExpressionSupportIterator<T>;
+
+    fn inputs(&self) -> BTreeSet<T> {
+        self.gather_literals()
+    }
+
+    fn essential_inputs(&self) -> BTreeSet<T> {
+        self.inputs()
+            .into_iter()
+            .filter(|input| {
+                let true_valuation = BTreeMap::from([(input.clone(), true)]);
+                let false_valuation = BTreeMap::from([(input.clone(), false)]);
+                self.evaluate(&true_valuation) != self.evaluate(&false_valuation)
+            })
+            .collect()
+    }
+
+    fn domain(&self) -> Self::DomainIterator {
+        self.into()
+    }
+
+    fn image(&self) -> Self::RangeIterator {
+        self.into()
+    }
+
+    fn relation(&self) -> Self::RelationIterator {
+        self.into()
+    }
+
+    fn support(&self) -> Self::SupportIterator {
+        self.into()
+    }
+
+    fn restrict(&self, _valuation: &BooleanValuation<T>) -> Self {
+        todo!()
+    }
+
+    fn substitute(&self, _mapping: BTreeMap<T, Self>) -> Self {
+        todo!()
+    }
+
+    fn existential_quantification(&self, _variables: BTreeSet<T>) -> Self {
+        todo!()
+    }
+
+    fn universal_quantification(&self, _variables: BTreeSet<T>) -> Self {
+        todo!()
+    }
+
+    fn derivative(&self, _variables: BTreeSet<T>) -> Self {
+        todo!()
+    }
+
+    fn is_equivalent(&self, _other: Self) -> bool {
+        todo!()
+    }
+
+    fn is_implied_by(&self, _other: Self) -> bool {
+        todo!()
+    }
+}

src/expressions/traits/mod.rs

@@ -1,4 +1,5 @@
 mod bit;
+mod boolean_function;
 mod display;
 mod evaluate;
 mod gather_literals;