void var::greater_than(const var &v) {
// (this > v) == (v < this)
auto v_copy = m_gen.new_var("_copy_" + v.m_name);
v_copy->copy(v);
v_copy->lower_than(*this);
this->move(*v_copy);
}
int calculate(string s) {
int digit_start_idx = -1;
vector<string> tokens;
for (int i = 0; i < s.length(); ++i) {
switch (s[i]) {
case '+':
case '-':
case '*':
case '/':
case ' ':
{
if (digit_start_idx != -1) {
tokens.push_back(s.substr(digit_start_idx, i-digit_start_idx));
digit_start_idx = -1;
}
if (s[i] != ' ')
tokens.push_back(s.substr(i,1));
break;
}
default:
{
if (digit_start_idx == -1)
digit_start_idx = i;
}
}
}
if (digit_start_idx != -1)
tokens.push_back(s.substr(digit_start_idx, s.length()-digit_start_idx));
stack<long> operands;
stack<char> operators;
for (int i = 0; i < tokens.size(); ++i) {
if (tokens[i] == "+" || tokens[i] == "-" || tokens[i] == "*" || tokens[i] == "/") {
while (!operators.empty() && lower_than(tokens[i][0], operators.top())) {
char op = operators.top();
operators.pop();
long num2 = operands.top();
operands.pop();
long num1 = operands.top();
operands.pop();
operands.push(calc(num1, num2, op));
}
operators.push(tokens[i][0]);
} else {
operands.push(stol(tokens[i]));
}
}
while (!operators.empty()) {
char op = operators.top();
operators.pop();
long num2 = operands.top();
operands.pop();
long num1 = operands.top();
operands.pop();
operands.push(calc(num1, num2, op));
}
return operands.top();
}
