         case CallUndeclaredMethodError
         case SyntaxError
         case NullPointerError
+        case EditConstantError
     }
 }
        methods["blackAndWhite"] = blackAndWhite
        methods["toLower"] = toLower
        methods["toUpper"] = toUpper
        methods["toCap"] = toUpper
        // MARK: parse
        var commands: [(Int, String)] = []
        for line in 0..<lines.count {

        return constants[name] != nil || properties[name] != nil
    }
    
    func set(name: String, value: String) throws {
        if properties[name] != nil {
            properties[name] = value
        } else if constants[name] != nil {
            print("Tried to edit a constant value")
            throw ExecErrors.EditConstantError
        }
    }
    
