Assignment3.cpp

#include "std_lib_facilities.h"

class Token{
public:
    char kind;
    double value;
};

Token get_token();
vector<Token> tokens;

int main(){
    for(Token t = get_token(); t.kind != 'q'; t = get_token()){
        tokens.push_back(t);
    }
    for(Token token: tokens){
        if (token.kind == '#')
            cout << "A number token with val= "<< token.value << "\n";
        else if(token.value == 0)
            cout << "A token of kind " << token.kind << "\n";
        else
            cout << "We received an invalid token of value " << token.kind << "\n";
    }
}

Token get_token(){
    char ch;
    cin >> ch;
    switch(ch){
    case 'q':
    case ';':
    case '(':
    case ')':
    case '+':
    case '-':
    case '*':
    case '/':
    case '%':
    return Token{ch};

    case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': case '.':
        {
           cin.putback(ch);
           double val;
           cin >> val;
           return Token{'#', val};
        }

    default:
        return Token{ch, 1};

    }

}