void CConditionalFormulaParser::startParsing(std::string formula)
{
std::regex exp("^\\((([A-Z]|[0-9\\-]+)([<>=!]+)([A-Z]|[0-9\\-]+))\\)\\?([^:]+):(.+)$");
std::smatch result;
if (!std::regex_match(formula, result, exp))
throw "Wrong Conditional Statement";
_preparedFormula.operandA = makeOperand(result[2].str());
_preparedFormula.operandB = makeOperand(result[4].str());
std::function<bool(double, double)> func;
std::string actions[] = { ">","<","=","!=",">=","<=" };
std::function<bool(double, double)> functions[] = { isgreater<double,double>,isless<double,double>,std::equal_to<double>(),std::not_equal_to<double>(),isgreaterequal<double,double>,islessequal<double,double> };
for (int i = 0; i < 6; i++)
{
if (result[3].str()==(actions[i]))
{
func = functions[i];
break;
}
}
if (func == NULL)
{
throw "Wrong Conditional Statement";
}
_preparedFormula.function = func;
_preparedFormula.trueFormula = makePolandNotation(result[5].str());
_preparedFormula.falseFormula = makePolandNotation(result[6].str());
}
std::string CFormulaParser::makePolandNotation(std::string formula)
{
std::stack<char> stack;
std::string result,num;
std::map<char, std::map<char, char>> priorities = makePriorityList();
char signs_raw[] = { '+','-','*','/','^','(',')' };
std::vector<char> signs(signs_raw, signs_raw + 7);
bool stacked=false;
for (std::string::iterator it = formula.begin(); it != formula.end(); it++)
{
if (*it >= '0' && *it <= '9' || *it == '.' || (*it=='-' && (it==formula.begin() || std::find(signs.begin(), signs.end(), *(it-1)) != signs.end())))
{
num.push_back(*it);
} else {
if (num.length() > 0)
{
result.push_back(makeOperand(num));
num.erase();
}
if (std::find(signs.begin(), signs.end(), *it) != signs.end())
{
stacked = false;
while (!stacked)
{
switch (priorities[!stack.empty() ? stack.top() : 0][*it])
{
case 4:
throw "Error in parsing formula";
break;
case 1:
stack.push(*it);
stacked = true;
break;
case 2:
result.push_back(stack.top());
stack.pop();
break;
case 3:
stack.pop();
stacked = true;
break;
default:
throw "Error in parsing formula";
}
}
}
else {
result.push_back(*it);
}
}
}
if (num.length() > 0)
{
result.push_back(makeOperand(num));
num.erase();
}
while (!stack.empty())
{
result.push_back(stack.top());
stack.pop();
}
return result;
}
int main() {
char char_response = 0;
unsigned int first_operand = 0;
unsigned int second_operand = 0;
int end_of_operand_flag = 0;
int operand_success = 0;
int operation_success = 0;
char operation = 0;
printf("Let's test some simple expressions. Type \'N\' at any time to exit.\nPlease input an expression: ");
while ((char_response = getchar()) != EOF) {
putchar(char_response);
if (char_response == 'N') {
printf("\nThanks for playing. Goodbye.\n");
break;
}
if (isNumChecker(char_response)) {
if (operand_success == 0) {
first_operand = makeOperand(char_response, first_operand);
// printf("\nfirst_operand = %d\n", first_operand);
}
if (operand_success == 1) {
second_operand = makeOperand(char_response, second_operand);
// printf("\nsecond_operand = %d\n", second_operand);
}
end_of_operand_flag = 1;
}
if (!isNumChecker(char_response) && end_of_operand_flag == 1) {
operand_success++;
end_of_operand_flag = 0;
}
if (isOperator(char_response)) {
if (operation_success == 0 && operand_success == 1) operation = char_response;
// printf ("\noperator = %c\n", operation);
operation_success++;
}
if (char_response == '\n') {
// printf("Successful operands = %d\nSuccessful operations = %d\n", operand_success, operation_success);
if (operation == 0 || operation_success > 1) printf("Invalid expression.\n");
if (operand_success == 2 && operation_success == 1) {
if (operation == '+') add(first_operand, second_operand);
if (operation == '-') subtract(first_operand, second_operand);
if (operation == '*') multiply(first_operand, second_operand);
if (operation == '/') divide(first_operand, second_operand);
if (operation == '%') modulo(first_operand, second_operand);
}
printf("Please input a valid expression: ");
/* Reset all variables */
first_operand = 0;
second_operand = 0;
end_of_operand_flag = 0;
operand_success = 0;
operation_success = 0;
operation = 0;
}
}
return 0;
}
