1 files changed, 17 insertions, 3 deletions
diff --git a/impl/Expression.h b/impl/Expression.h
index 105ad28..38a5e65 100644
--- a/impl/Expression.h
+++ b/impl/Expression.h
@@ -1,12 +1,26 @@
 #ifndef EXPRESSION_H
 #define EXPRESSION_H
 
-#include <string>
 #include <map>
+#include <string>
+#include <vector>
+template<typename T>
+struct Expression;
+#include "Operator.h"
 
-template<class T>
+template<typename T>
 struct Expression {
-  virtual T eval(const std::map<std::string, T>&) const = 0;
+  Expression(Operator<T>* o, std::vector< Expression<T> > a)
+    : _operator(o), _arguments(a) { }
+  virtual const T minvalue(std::map<std::string, T> m) const {
+    return _operator->eval(_arguments, m);
+  }
+  virtual const T maxvalue(std::map<std::string, T> m) const {
+    return _operator->eval(_arguments, m);
+  }
+  private:
+  Operator<T>* _operator;
+  std::vector< Expression<T> > _arguments;
 };
 
 #endif