completing the C++ parser program

// CS4303 Programming Language Concepts// Lab exercise - Parser//// Name ______________________ ID _____________________//// A simple parser for C/C++-style variable declarations.// THe grammar is as follows://// ::= ; | = ;// ::= int | float// ::= A | B | C | D | E// ::= | // ::= | // ::= 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9// ::= . // // Input is entered at the keyboard.// If the input is correct, the program should print// "no error found", otherwise, it should print the type// of error and terminate its execution. There are four// possible errors:// // "unrecognizable type"// "illegal variable name"// "unexpected number"// "; expected"//// Error message is printed out by calling function // "error". An error code ranging from 0 to 4 can be// passed as an argument to the function indicating what// message is to be printed. The mapping from the error// code to the message can be found by looking at the// definition of function "error".//// The following are some sample input and the response// from the program://// Please enter a declaration in format [= number] ;// int A;// no error found//// Please enter a declaration in format [= number] ;// int a;// illegal variable name//// Please enter a declaration in format [= number] ;// short B;// unrecognizable type// // Please enter a declaration in format [= number] ;// float C = 0.5;// no error found// // Please enter a declaration in format [= number] ;// int A = 10,// unexpected token#include #include using namespace std;string token;string GetToken();void error(int);int main() { cout [= number] ;" token = GetToken(); // Write the code here error(0); return 0;}string GetToken() {// Write the code here}void error(int code) { switch (code) { case 0: cout case 1: cout case 2: cout case 3: cout case 4: cout } return;}