change local functions to external functions

src/inputHandling.c

@@ -5,11 +5,6 @@
 
 
 char formulaBuffer[1000];
-void deleteWhitespace(char* formulaString, int length);
-op readFunction(char* formulaString, int length);
-char* getNumbers(char* formulaString, int length, calc_op* formulaRef);
-void showStruct(calc_op* formulaRef);
-
 
 void input(char* formulaString, int length) {
     deleteWhitespace(formulaString, length);

src/inputHandling.h

@@ -17,5 +17,9 @@ double result;
 
 extern void input(char* formulaString, int length);
 extern void showStruct(calc_op* formulaRef);
+extern void deleteWhitespace(char* formulaString, int length);
+extern op readFunction(char* formulaString, int length);
+extern char* getNumbers(char* formulaString, int length, calc_op* formulaRef);
+extern void showStruct(calc_op* formulaRef);
 
 #endif // INPUTHANDLING_H