// pe_driver.cpp : a postfix evaluator driver
#include <iostream>
#include "Lexer.h"
#include "term_control.h"
#include "error_handling.h"
#include "Postfix_Evaluator.h"
using namespace std;

/**
 * -----------------------------------------------------------------------------
 * just print a prompt.
 * -----------------------------------------------------------------------------
 */
void prompt() {
    cout << term_cc(BLUE) << "> " << term_cc() << flush;
}

/**
 * -----------------------------------------------------------------------------
 * the body
 * -----------------------------------------------------------------------------
 */
int main() {
    Lexer lexer; string line; Postfix_Evaluator pe;

    while (cin) {
        prompt(); getline(cin, line); lexer.set_input(line);
        if (!lexer.has_more_token()) continue;
        try {
            pe.set_expression(lexer);
            cout << term_cc(CYAN) << "= " << pe.eval() << term_cc() << endl;
        } 
        catch (runtime_error &e) {
            error_return(e.what());
        }
    }
    return 0;
}