Fix identity for relation in C++

Author: favu100

btypes_big_integer/src/main/cpp/BRelation.hpp

@@ -967,6 +967,22 @@ class BRelation : public BObject {
             return BRelation<T,T>(resultMap);
         }
 
+        static BRelation<BTuple<S,T>,BTuple<S,T>> identity2(const BRelation<S,T>& relation) {
+            immer::map<BTuple<S,T>,immer::set<BTuple<S,T>, typename BSet<BTuple<S,T>>::Hash, typename BSet<BTuple<S,T>>::HashEqual>,
+                                                               typename BSet<BTuple<S,T>>::Hash,
+                                                               typename BSet<BTuple<S,T>>::HashEqual> resultMap;
+            for(const std::pair<S,immer::set<T, typename BSet<T>::Hash, typename BSet<T>::HashEqual>>& pair : relation.map) {
+                T domainElement = pair.first;
+                immer::set<T, typename BSet<T>::Hash, typename BSet<T>::HashEqual> range = pair.second;
+                for(const T& rangeElement : range) {
+                    immer::set<BTuple<S,T>, typename BSet<BTuple<S,T>>::Hash, typename BSet<BTuple<S,T>>::HashEqual> range;
+                    range = range.insert(BTuple<S,T>(domainElement, rangeElement));
+                    resultMap = resultMap.set(BTuple<S,T>(domainElement, rangeElement), range);
+                }
+            }
+            return BRelation<BTuple<S,T>,BTuple<S,T>>(resultMap);
+        }
+
     	BRelation<S,S> iterate(const BInteger& n) const {
     		BRelation<S,S> thisRelation = (BRelation<S,S>) *this;
             BRelation<S,S> result = BRelation<S,S>::identity(this->domain()._union(thisRelation.range()));

btypes_primitives/src/main/cpp/BRelation.hpp

@@ -967,6 +967,23 @@ class BRelation : public BObject {
             return BRelation<T,T>(resultMap);
         }
 
+
+        static BRelation<BTuple<S,T>,BTuple<S,T>> identity2(const BRelation<S,T>& relation) {
+            immer::map<BTuple<S,T>,immer::set<BTuple<S,T>, typename BSet<BTuple<S,T>>::Hash, typename BSet<BTuple<S,T>>::HashEqual>,
+                                                               typename BSet<BTuple<S,T>>::Hash,
+                                                               typename BSet<BTuple<S,T>>::HashEqual> resultMap;
+            for(const std::pair<S,immer::set<T, typename BSet<T>::Hash, typename BSet<T>::HashEqual>>& pair : relation.map) {
+                T domainElement = pair.first;
+                immer::set<T, typename BSet<T>::Hash, typename BSet<T>::HashEqual> range = pair.second;
+                for(const T& rangeElement : range) {
+                    immer::set<BTuple<S,T>, typename BSet<BTuple<S,T>>::Hash, typename BSet<BTuple<S,T>>::HashEqual> range;
+                    range = range.insert(BTuple<S,T>(domainElement, rangeElement));
+                    resultMap = resultMap.set(BTuple<S,T>(domainElement, rangeElement), range);
+                }
+            }
+            return BRelation<BTuple<S,T>,BTuple<S,T>>(resultMap);
+        }
+
     	BRelation<S,S> iterate(const BInteger& n) const {
     		BRelation<S,S> thisRelation = (BRelation<S,S>) *this;
             BRelation<S,S> result = BRelation<S,S>::identity(this->domain()._union(thisRelation.range()));

src/main/java/de/hhu/stups/codegenerator/generators/ExpressionGenerator.java

@@ -794,8 +794,13 @@ private String generateTupleProjection(ExpressionOperatorNode node) {
     */
     private String generateIdentity(List<String> expressionList, BType type) {
         ST identity = currentGroup.getInstanceOf("identity");
+        if(type instanceof CoupleType) {
+            TemplateHandler.add(identity, "leftType", typeGenerator.generate(((CoupleType) type).getLeft()));
+            TemplateHandler.add(identity, "rightType", typeGenerator.generate(((CoupleType) type).getRight()));
+        }
         TemplateHandler.add(identity, "type", typeGenerator.generate(type));
         TemplateHandler.add(identity, "arg", expressionList.get(0));
+        TemplateHandler.add(identity, "relationalArg", type instanceof CoupleType);
         return identity.render();
     }
 

src/main/resources/de/hhu/stups/codegenerator/CppTemplate.stg

@@ -779,8 +779,12 @@ projection_tuple(arg, isProjection1) ::= <<
 (<arg>.<if(isProjection1)>projection1<else>projection2<endif>())
 >>
 
-identity(type, arg) ::= <<
+identity(leftType, rightType, type, arg, relationalArg) ::= <<
+<if(relationalArg)>
+(BRelation\<<leftType>, <rightType> >::identity2(<arg>))
+<else>
 (BRelation\<<type>, <type> >::identity(<arg>))
+<endif>
 >>
 
 cartesian_product(leftType, rightType, arg1, arg2) ::= <<