MathLib: introduce and use calculate() method.

No functional change.

src/mathlib.cpp

@@ -101,6 +101,39 @@ std::string MathLib::multiply(const std::string &first, const std::string &secon
     return toString<double>(toDoubleNumber(first) * toDoubleNumber(second));
 }
 
+std::string MathLib::calculate(const std::string &first, const std::string &second, char action)
+{
+    std::string result("0");
+
+    switch (action)
+    {
+        case '+':
+            result = MathLib::add(first, second);
+            break;
+
+        case '-':
+            result = MathLib::subtract(first, second);
+            break;
+
+        case '*':
+            result = MathLib::multiply(first, second);
+            break;
+
+        case '/':
+            result = MathLib::divide(first, second);
+            break;
+
+        default:
+            std::cout << "##### If you see this, there is a bug: "
+                      << "MathLib::calculate() was called with unknown action '"
+                      << action
+                      << "' #####"
+                      << std::endl;
+            break;
+    }
+
+    return result;
+}
 
 std::string MathLib::sin(const std::string &tok)
 {

src/mathlib.h

@@ -41,6 +41,8 @@ public:
     static std::string subtract(const std::string & first, const std::string & second);
     static std::string multiply(const std::string & first, const std::string & second);
     static std::string divide(const std::string & first, const std::string & second);
+    static std::string calculate(const std::string & first, const std::string & second, char action);
+
     static std::string sin(const std::string & tok);
     static std::string cos(const std::string & tok);
     static std::string tan(const std::string & tok);

src/tokenize.cpp

@@ -2946,21 +2946,7 @@ bool Tokenizer::simplifyCalculations()
             if (Token::simpleMatch(tok->next(), "/ 0"))
                 continue;
 
-            switch (*(tok->strAt(1)))
-            {
-            case '+':
-                tok->str(MathLib::add(tok->str(), tok->strAt(2)));
-                break;
-            case '-':
-                tok->str(MathLib::subtract(tok->str(), tok->strAt(2)));
-                break;
-            case '*':
-                tok->str(MathLib::multiply(tok->str(), tok->strAt(2)));
-                break;
-            case '/':
-                tok->str(MathLib::divide(tok->str(), tok->strAt(2)));
-                break;
-            }
+            tok->str(MathLib::calculate(tok->str(), tok->tokAt(2)->str(), *(tok->strAt(1))));
 
             tok->deleteNext();
             tok->deleteNext();