In C++

Given a copy of "lex.h" and a file called "tokensListing.cpp" as a driver program.

Implementation should include the following in another file:

• The function

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

• The overloaded operator function operator<< for LexItem.

ostream& operator<<(ostream& out, const LexItem& tok);

The operator<< function should print out the token of the tok object, followed by its line number. If the token is either an IDENT, ICONST, RCONST, or SCONST, it will print out its token followed by its lexeme between parentheses, and its line number. See the examples below for the output format.

Use the given driver program in "tokensListing.cpp" for testing your implementations. The driver program accepts two command line arguments, "-othertok" and "-idsonly".

The "-othertok" flag is used to test your implementation of the overloaded operator<< function only, and the "-idsonly" is used to test your implementation of both functions.

LEX H

//Definition of all the possible token types

enum Token {

// keywords

PROGRAM, PRINT, READ, INTEGER, END, IF, THEN, REAL, CHAR,

// an identifier

IDENT,

// an integer, real, and string constant

ICONST, RCONST, SCONST,

// the operators, parens, semicolon

PLUS, MINUS, MULT, DIV, ASSOP, LPAREN, RPAREN, COMA,

EQUAL, LTHAN, CONCAT, COLON,

// any error returns this token

ERR,

// when completed (EOF), return this token

DONE

};

static map tokenPrint = {

{PROGRAM, "PROGRAM"},

{READ, "READ"},

{INTEGER, "INTEGER"},

{REAL, "REAL"},

{CHAR, "CHAR"},

{ PRINT, "PRINT" },

{ IF, "IF" },

{ END, "END" },

{THEN, "THEN"},

{ IDENT, "IDENT" },

{ ICONST, "ICONST" },

{ RCONST, "RCONST" },

{ SCONST, "SCONST" },

{ PLUS, "PLUS" },

{ MINUS, "MINUS" },

{ MULT, "MULT" },

{ DIV, "DIV" },

{ ASSOP, "ASSOP" },

{ LPAREN, "LPAREN" },

{ RPAREN, "RPAREN" },

{ COLON, "COLON" },

{COMA, "COMA" },

{ EQUAL, "EQUAL" },

{ LTHAN, "LTHAN" },

{ CONCAT, "CONCAT" },

{ ERR, "ERR" },

{ DONE, "DONE" },

};

static map kwmap = {

{"PROGRAM", PROGRAM},

{"READ", READ},

{ "INTEGER", INTEGER},

{ "REAL", REAL},

{ "CHAR", CHAR},

{ "PRINT", PRINT },

{ "IF", IF },

{"THEN", THEN},

{ "END", END },

};

//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<<(ostream& out, const LexItem& tok);

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

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

#endif /* LEX_H_ */

TokenList

#include

#include

#include "lex.h"

#include

#include

using std::map;

using namespace std;

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

{

LexItem tok;

LexItem kwtok;

LexItem idtoks[] = {

LexItem(IDENT,"PRINT",3),

LexItem(IDENT,"circle",3),

LexItem(IDENT,"square",11),

LexItem(IDENT,"rectangle",12),

LexItem(IDENT,"ellipse",14),

LexItem(IDENT, "PROGRAM", 1),

LexItem(IDENT, "READ", 8),

LexItem(IDENT, "INTEGER",2),

LexItem(IDENT, "REAL",3),

LexItem(IDENT, "CHAR",4),

LexItem(IDENT, "IF", 5),

LexItem(IDENT, "THEN", 5),

LexItem(IDENT, "END", 0)

};

LexItem toks[] = {

LexItem(END,"END",15),

LexItem(ICONST,"579",5),

LexItem(SCONST,"hello NJIT",6),

LexItem(RCONST,"5.79",7),

LexItem(PLUS,"+",3),

LexItem(MINUS,"-",3),

LexItem(MULT,"*",3),

LexItem(DIV,"/",3),

LexItem(ASSOP,"=",3),

LexItem(LPAREN,"(",3),

LexItem(RPAREN,")",3),

LexItem(COLON,":",3),

LexItem(COMA,",",3),

LexItem(COMA,",",3),

LexItem( EQUAL, "EQUAL", 4),

LexItem( LTHAN, "LTHAN", 4 ),

LexItem( CONCAT, "CONCAT", 6 ),

LexItem(ERR, "ERR", 3),

LexItem(DONE,"DONE",3),

};

bool idsflag = false;

bool tokflag = false;

int i;

if (argc == 1)

{

cerr << "No Specified arguments." << endl;

return 0;

}

for( int i=1; i

string arg( argv[i] );

if( arg == "-idsonly" )

idsflag = true;

else if( arg == "-othertok" )

tokflag = true;

else if( arg[0] == '-' ) {

cerr << "UNRECOGNIZED FLAG " << arg << endl;

return 0;

}

}

if(idsflag)

{

cout << "Identifiers and Keywords:" << endl;

for( i = 0; idtoks[i].GetLexeme() != "END"; i++ )

{

kwtok = id_or_kw(idtoks[i].GetLexeme(), toks[i].GetLinenum());

cout << kwtok;

}

kwtok = id_or_kw(idtoks[i].GetLexeme(), toks[i].GetLinenum());

cout << kwtok;

}

if(tokflag)

{

cout << "Other tokens:" << endl;

for( i = 0; toks[i] != DONE; i++ )

{

cout << toks[i];

}

cout << toks[i];

}

return 0;

}