Please help!

You are given a copy of "lex.h" from Programming Assignment 1, and a file called "tokensListing.cpp" as a driver program. DO NOT CHANGE neither "lex.h" nor "tokensListing.cpp". Your implementation should include the following in another file, called "RAS.cpp": The function Lexitem id_or_kw(const string& lexeme, int linenum); id_or_kw () function accepts a reference to a string of a lexeme and a line number and returns a Lexitem object. It searches for the lexeme in a directory that maps a string value of a keyword to its corresponding Token value, and it returns a Lexitem object containing the keyword Token if it is found. Otherwise, it returns a Lexitem object containing a token for one of the possible types of identifiers (i.e., IDENT, SIDENT, or NIDENT). The overloaded operator function operator at Line NIDENT/SIDENT : ""at Line Keyword token : "" at Line ICONST/ RCONST : () at Line SCONST SCONST: '' at Line Operators : "" at Line ERR ERROR: "" at Line Note that the implementation of operator