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 RA5.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

ostream& operator

The operator

lex.h from

/*

* lex.h

*

* CS280

* Spring 2023

*/

#ifndef LEX_H_

#define LEX_H_

#include

#include

#include

using namespace std;

//Definition of all the possible token types

enum Token {

// keywords

WRITELN, IF, ELSE,

// identifiers

IDENT, NIDENT, SIDENT,

// an integer, real, and string constant

ICONST, RCONST, SCONST,

// the numeric operators, assignment, numeric and string comparison operators

PLUS, MINUS, MULT, DIV, EXPONENT, ASSOP, NEQ,

NGTHAN, NLTHAN, CAT, SREPEAT, SEQ, SLTHAN, SGTHAN,

//Delimiters

COMMA, SEMICOL, LPAREN, RPAREN, LBRACES, RBRACES,

// any error returns this token

ERR,

// when completed (EOF), return this token

DONE,

};

//Class definition of LexItem

class LexItem {

Token token;

string lexeme;

int lnum;

public:

LexItem() {

token = ERR;

lnum = -1;

}

LexItem(Token token, string lexeme, int line) {

this->token = token;

this->lexeme = lexeme;

this->lnum = line;

}

bool operator==(const Token token) const { return this->token == token; }

bool operator!=(const Token token) const { return this->token != token; }

Token GetToken() const { return token; }

string GetLexeme() const { return lexeme; }

int GetLinenum() const { return lnum; }

};

extern ostream& operator

extern LexItem id_or_kw(const string& lexeme, int linenum);

extern LexItem getNextToken(istream& in, int& linenum);

#endif /* LEX_H_ */

\

tokensListing.cpp as a driver program.

#include

#include

#include

#include

#include

#include "lex.h"

//#include "ra5.cpp"

/*

* CS280 - Spring 2023

*/

using std::map;

using namespace std;

istream& operator>>(istream& in, LexItem& tok) {

map StrToTok = {

{"WRITELN", WRITELN},

{ "IF", IF },

{ "ELSE", ELSE },

{ "IDENT", IDENT },

{ "NIDENT", NIDENT },

{ "SIDENT", SIDENT },

{ "ICONST", ICONST },

{ "RCONST", RCONST },

{ "SCONST", SCONST },

{ "PLUS", PLUS },

{ "MINUS" , MINUS },

{ "MULT" , MULT },

{ "DIV" , DIV },

{ "EXPONENT" , EXPONENT },

{ "ASSOP", ASSOP },

{ "NEQ", NEQ },

{ "NGTHAN" , NGTHAN },

{ "NLTHAN", NLTHAN },

{ "CAT", CAT },

{ "SREPEAT" , SREPEAT },

{ "SEQ", SEQ },

{ "SGTHAN", SGTHAN },

{ "SLTHAN", SLTHAN },

{ "COMMA", COMMA },

{ "LPAREN", LPAREN },

{ "RPAREN", RPAREN },

{ "LBRACES", LBRACES },

{ "RBRACES", RBRACES },

{ "SEMICOL", SEMICOL },

{ "ERR",ERR },

{ "DONE", DONE },

};

Token tt;

string tokstr, lexeme, str2;

char ch;

int i, line, strlen;

in >> tokstr ;

if(!in)

{

return in;

}

auto ttitr = StrToTok.find(tokstr);

//cout

if(ttitr != StrToTok.end())

{

tt = ttitr->second;

if(tt == IDENT)

{

in >> lexeme >> line;

tok = id_or_kw(lexeme, line);

}

else if (tt == ICONST || tt == RCONST )

{

in >> lexeme >> line;

LexItem item(tt, lexeme, line);

tok = item;

}

else if (tt == SCONST)

{

in >> strlen;

str2 = ""; i = 0;

ch = in.get();

while (ch != '\"')

{

ch = in.get();

}

ch = in.get();

while ( (ch != '\"') && (i

{

str2 += ch;

ch = in.get();

i++;

}

in >> line;

LexItem item(tt, str2, line);

tok = item;

}

else

{

in >> lexeme >> line;

LexItem item(tt, lexeme, line);

tok = item;

}

}

return in;

}

int main(int argc, char *argv[])

{

LexItem item(ERR, "", 0);

LexItem& tokItem = item;

LexItem kwtok;

ifstream file ;

string str1;

if (argc == 1)

{

cerr

return 0;

}

else

{

if(argv[1][0] == '-')

{

cerr

return 0;

}

file.open(argv[1]);

if( file.is_open() == false ) {

cerr

return 0;

}

}

while (file >> tokItem)

{

cout

}

return 0;

}