Added function to retrieve range DD for meta variable.

Former-commit-id: 32ef6715f4

src/storage/dd/CuddDdManager.cpp

@@ -39,6 +39,16 @@ namespace storm {
             
             return result;
         }
+        
+        Dd<CUDD> DdManager<CUDD>::getRange(std::string const metaVariableName) {
+            storm::dd::DdMetaVariable<CUDD> const& metaVariable = this->getMetaVariable(metaVariableName);
+            
+            Dd<CUDD> result = this->getZero();
+            for (int_fast64_t value = metaVariable.getLow(); value <= metaVariable.getHigh(); ++value) {
+                result.setValue(metaVariableName, value - metaVariable.getLow(), static_cast<double>(value));
+            }
+            return result;
+        }
 
         void DdManager<CUDD>::addMetaVariable(std::string const& name, int_fast64_t low, int_fast64_t high) {
             if (high == low) {

src/storage/dd/CuddDdManager.h

@@ -62,6 +62,15 @@ namespace storm {
              */
             Dd<CUDD> getEncoding(std::string const& metaVariableName, int_fast64_t value);
             
+            /*!
+             * Retrieves the DD representing the range of the meta variable, i.e., a function that maps all legal values
+             * of the range of the meta variable to one.
+             *
+             * @param metaVariableName The name of the meta variable whose range to retrieve.
+             * @return The range of the meta variable
+             */
+            Dd<CUDD> getRange(std::string const metaVariableName);
+            
             /*!
              * Adds a meta variable with the given name and range.
              *