flScalar InfixToPostfix::evaluate(const std::string postfix,
const std::map<std::string, flScalar>* variables) const {
std::stack<flScalar> stack;
std::stringstream ss(postfix);
std::string token;
while (ss >> token) {
if (isOperand(token)) {
if (isNumeric(token)) {
stack.push(atof(token.c_str()));
} else {
if (!variables) {
throw FuzzyException(FL_AT, "Impossible to compute operand <" + token + "> because no map was supplied");
}
std::map<std::string, flScalar>::const_iterator it = variables->find(token);
if (it == variables->end()) {
throw FuzzyException(FL_AT, "Operand <" + token + "> not found in map");
}
stack.push(it->second);
}
} else if (isOperator(token)) {
if (isUnaryOperator(token)) {
if (stack.empty()) {
throw FuzzyException(FL_AT, "Error evaluating postfix expression <" + postfix + ">");
}
flScalar a = stack.top();
stack.pop();
stack.push(compute(token, a, 0));
} else {
if (stack.size() < 2) {
throw FuzzyException(FL_AT, "Error evaluating postfix expression <" + postfix + ">");
}
flScalar b = stack.top();
stack.pop();
flScalar a = stack.top();
stack.pop();
stack.push(compute(token, a, b));
}
}
}
if (stack.size() == 1){
return stack.top();
}
throw FuzzyException(FL_AT, "Error evaluating postfix expression <" + postfix + ">");
}
flScalar InfixToPostfix::compute(const std::string& op, flScalar a, flScalar b) const {
if (op == "!") {
return !(bool)a;
}
if (op == "and") {
return (bool)a && (bool)b;
}
if (op == "or") {
return (bool)a || (bool)b;
}
if (op == "+") {
return a + b;
}
if (op == "-") {
return a - b;
}
if (op == "*") {
return a * b;
}
if (op == "/") {
return a / b;
}
if (op == "%") {
return (long) a % (long) b;
}
if (op == "^") {
return pow(a, b);
}
if (op == "sin") {
return sin(a);
}
if (op == "cos") {
return cos(a);
}
if (op == "tan") {
return tan(a);
}
if (op == "sinh") {
return sinh(a);
}
if (op == "cosh") {
return cosh(a);
}
if (op == "tanh") {
return tanh(a);
}
throw FuzzyException(FL_AT, "Operator <" + op + "> not defined");
}
void FuzzyException::Assert(const std::string& file, int line,
const std::string& function, bool assert, const std::string message) {
if (!assert) {
throw FuzzyException(file, line, function, message);
}
}
