diff --git a/uppsrc/TCore/CalcNode.cpp b/uppsrc/TCore/CalcNode.cpp
index f02eda156..e5df8d077 100644
--- a/uppsrc/TCore/CalcNode.cpp
+++ b/uppsrc/TCore/CalcNode.cpp
@@ -579,22 +579,22 @@ Value CalcContext::Get(String name) const
 	return Value();
 }
 
-Value CalcContext::Evaluate(String expr)
+Value CalcContext::TryEvaluate(String expr)
 {
-	CalcParser parser;
-	try
-	{
-		CalcNodePtr cn = parser.ScanVoid(expr);
-		if(!cn)
-			return Value();
-		return cn->Calc(*this);
+	try {
+		return Evaluate(expr);
 	}
-	catch(Exc e)
-	{
+	catch(Exc e) {
 		return ErrorValue(e);
 	}
 }
 
+Value CalcContext::Evaluate(String expr)
+{
+	CalcNodePtr node = CalcParser().ScanVoid(expr);
+	return !!node ? node->Calc(*this) : Value();
+}
+
 double CalcContext::EvaluateDouble(String expr)
 {
 	CalcNodePtr node = CalcParser().ScanVoid(expr);
diff --git a/uppsrc/TCore/CalcNode.h b/uppsrc/TCore/CalcNode.h
index af9aed940..0f1da2bd4 100644
--- a/uppsrc/TCore/CalcNode.h
+++ b/uppsrc/TCore/CalcNode.h
@@ -342,6 +342,8 @@ public:
 	CalcContext(const CalcContext& context, int);
 	virtual ~CalcContext();
 
+	Value               TryEvaluate(String expr);
+
 	Value               Evaluate(String expr);
 	double              EvaluateDouble(String expr);
 	String              EvaluateString(String expr);