From cde59bd4365945b9c2383c263e9866fb9cfddb74 Mon Sep 17 00:00:00 2001
From: TimQu <tim.quatmann@cs.rwth-aachen.de>
Date: Fri, 31 Mar 2017 15:56:31 +0200
Subject: [PATCH] added Expression::evaluateAsRational

---
 src/storm/storage/expressions/Expression.cpp | 4 ++++
 src/storm/storage/expressions/Expression.h   | 9 +++++++++
 2 files changed, 13 insertions(+)

diff --git a/src/storm/storage/expressions/Expression.cpp b/src/storm/storage/expressions/Expression.cpp
index 97e7046ab..7f204d0c1 100644
--- a/src/storm/storage/expressions/Expression.cpp
+++ b/src/storm/storage/expressions/Expression.cpp
@@ -59,6 +59,10 @@ namespace storm {
             return this->getBaseExpression().evaluateAsDouble(valuation);
         }
         
+        storm::RationalNumber Expression::evaluateAsRational() const {
+            return this->getBaseExpression().evaluateAsRational();
+        }
+        
         Expression Expression::simplify() const {
             return Expression(this->getBaseExpression().simplify());
         }
diff --git a/src/storm/storage/expressions/Expression.h b/src/storm/storage/expressions/Expression.h
index 874a1ecda..d694017a7 100644
--- a/src/storm/storage/expressions/Expression.h
+++ b/src/storm/storage/expressions/Expression.h
@@ -134,6 +134,15 @@ namespace storm {
              * @return The double value of the expression under the given valuation.
              */
             double evaluateAsDouble(Valuation const* valuation = nullptr) const;
+                        
+            /*!
+             * Evaluates the expression and returns the resulting rational number.
+             * If the return type of the expression is not a rational an exception is thrown.
+             *
+             * @param valuation The valuation of unknowns under which to evaluate the expression.
+             * @return The double value of the expression under the given valuation.
+             */
+            storm::RationalNumber evaluateAsRational() const;
             
             /*!
              * Simplifies the expression according to some basic rules.