Lex-h -- - lex-h - - CS280 - Spring 2023 -- #ifndef LEX_H_ #define L.pdf

Lex.h
/*
* lex.h
*
* CS280
* Spring 2023
*/
#ifndef LEX_H_
#define LEX_H_
#include <string>
#include <iostream>
#include <map>
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<<(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_ */
tokensListing.cpp
#include "lex.h"
extern ostream operator <<(ostream & out, const tok & tok)
{
out<< "Token: "<< tok.GetToken( )<< "lex:" << tok.Getlexeme( )<< "Line No: "
<<tok.linenum( );
}
#ifndef LEX_H_
#define LEX_H_
#include<string>
#include<iostream>

using std:: string;
using std:: istream;
using std:: ostream;
Enum Token {
//Keywords
PRINT,PRINTLN, REPEAT, BEGIN, END
// an identifier
INDENT,
// an Integer and String constant
ICONST, SCONST,
//Operators, Parens, semicolon
PLUS, MINUS, STAR, SLASH, EQ, LPAREN, RPAREN, SC,
// any error returns this token
ERR,
//When completed (EDF), return this token
DONE
};
Class Tok
{
Token token;
String lexeme;
int inum;
public
Tok( ){
token = ERR;
lnum = -1;
}
Token( 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 Tok &tok);
extern Tok getNextToken (istream&in, int & line num);
#endif /*LEX_H_*/
#include 'lex.h'
int main( )
{
Tok toks[ ] = {
TOK(PRINT, "PRINT", 3);
TOK(PRINTLN, "PRINTLN",3);
TOK(REPEAT, "REPEAT", 3);
TOK(BEGIN, "BEGIN",3);
TOK(END, "END", 3);
TOK(IDENT, "foo", 3);
TOK(CONST,"347",3);
TOK(SCONST, "Hello world", 3);
TOK(PLUS, " +" , 3);
TOK(MINUS, "-", 3);
TOK(STAR, "*",3);
TOK(SLASH, "/",3);
TOK(EQ, "=",3);
TOK(LPAREN, "(",3);
TOK(RPAREN, ")", 3);
TOK(SC, ":",3);
TOK(DONE,"DONE",3);
};
for (int i = 0; toks[i]! = DONE; i++)
cout<< toks[i] <<endl;
return 0;
}
Case 1 input
IDENT PROGRAM 0
IDENT $PROG1 3
IDENT INT 2

IDENT _X1 2
COMMA , 2
IDENT @Y_1 2
COMMA , 2
IDENT Z 2
MINUS - 2
COMMA , 2
IDENT W234 2
SEMICOL ; 2
IDENT FLOAT 3
IDENT Z 3
ASSOP = 3
RCONST 0.75 3
SEMICOL ; 3
IDENT $BOOL 4
IDENT @FLAG 4
ASSOP = 4
SEMICOL ; 4
IDENT R 6
ERR $ 6
IDENT FLAG 7
ASSOP = 7
SEMICOL ; 7
IDENT IF 8
LPAREN ( 8
IDENT FLAG 8
RPAREN ) 8
IDENT THEN 8
IDENT Y_1 9
ASSOP = 9
ICONST 5 9
SEMICOL ; 9
IDENT ELSE 10
IDENT Y_1 11
ASSOP = 11
RCONST 7.5 11
SEMICOL ; 11
IDENT END 12
IDENT IF 12
IDENT PRINT 13
SCONST 8 "Value = " 13
COMMA , 13
IDENT R 13
COMMA , 13
SCONST 4 "z = " 13
COMMA , 13

IDENT Z 13
SEMICOL ; 13
IDENT END 14
IDENT PROGRAM 14
Case 1 output
IDENTIFIER: PROGRAM at Line 0
NIDENT: "$PROG1" at Line 3
IDENTIFIER: INT at Line 2
IDENTIFIER: _X1 at Line 2
COMMA: "," at Line 2
SIDENT: "@Y_1" at Line 2
IDENTIFIER: Z at Line 2
MINUS: "-" at Line 2
IDENTIFIER: W234 at Line 2
SEMICOL: ";" at Line 2
IDENTIFIER: FLOAT at Line 3
ASSOP: "=" at Line 3
RCONST: (0.75) at Line 3
NIDENT: "$BOOL" at Line 4
SIDENT: "@FLAG" at Line 4
IDENTIFIER: R at Line 6
Error: : "$" at Line 6
IDENTIFIER: FLAG at Line 7
IF: "IF" at Line 8
LPAREN: "(" at Line 8
IDENTIFIER: FLAG at Line 8
RPAREN: ")" at Line 8
IDENTIFIER: THEN at Line 8
IDENTIFIER: Y_1 at Line 9
ICONST: (5) at Line 9
ELSE: "ELSE" at Line 10
IDENTIFIER: Y_1 at Line 11
RCONST: (7.5) at Line 11

IDENTIFIER: END at Line 12
IF: "IF" at Line 12
IDENTIFIER: PRINT at Line 13
SCONST: 'Value = ' at Line 13
IDENTIFIER: R at Line 13
SCONST: 'z = ' at Line 13
IDENTIFIER: END at Line 14
IDENTIFIER: PROGRAM at Line 14

Lex-h -- - lex-h - - CS280 - Spring 2023 -- #ifndef LEX_H_ #define L.pdf

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Lex-h -- - lex-h - - CS280 - Spring 2023 -- #ifndef LEX_H_ #define L.pdf