fn check_operator(&mut self, operator: &str) -> bool {
        if !self.peek_operator(operator) {
            return false;
        }
        for _ in operator.chars() {
            self.pop();
        }
        true
    }
/// Check if the input starts with the operator and if yes consume it.
Check if the input starts with the operator and if yes consume it.
Check if the input starts with the operator and if yes consume it .
fn check_operator(&mut self, operator: &str) -> bool {
        if !self.peek_operator(operator) {
            return false;
        }
        for _ in operator.chars() {
            self.pop();
        }
        true
    }
fn check_operator ( & mut self , operator : & str ) -> bool { if ! self . peek_operator ( operator ) { return false ; } for _ in operator . chars ( ) { self . pop ( ) ; } true }
Check if the input starts with the operator and if yes consume it.
Check if the input starts with the operator and if yes consume it .
&mut self
operator
&str