In this programming assignment, you will be implementing an interpreter for our small programming...

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In this programming assignment, you will be implementing an interpreter for our small programming language and write a C++ program to test it. You are required to modify the parser you have implemented for the small programming language to implement the simple language interpreter. The syntax definitions and tokens of the programming language were given in Programming Assignment 2, and are given below using EBNF notations.PA 3 Description 1 CS 280 Programming Language Concepts Programming Assignment 3 Implementation of an Interpreter for a  Simple Programming Language Programming Assignment 3 ◼ Objectives  Construction of an interpreter for a simple programming language based on the recursive-descent parser developed in Programming Assignment 2. ◼ Notes:  Read the assignment carefully to understand it.  Understand the functionality of the interpreter, and the required actions to be performed to execute the source code. 3 Given Files ◼ “lex.h” ◼ “lex.cpp”  You can use your implementation, or copy and use my lexical analyzer when I publish it. ◼ “parserIn.h”  Modified version of “parse.h”. ◼ “parse.cpp”  You can use your implementation, or copy and use my parser when I publish it.  This file will should be renamed as “parserInt.cpp” for your submission ◼ “val.h” and “val.cpp”  Specification and implementation of the class Value. 4 Grammar ◼ Modified grammar: Deletion of the ReadStmt and VarList rules Prog = PROGRAM IDENT {Decl} {Stmt} END PROGRAM IDENT Decl = (INTEGER | REAL | CHAR) : IdList IdList = IDENT {,IDENT} Stmt = AssigStmt | IfStmt | PrintStmt PrintStmt = PRINT , ExprList IfStmt = IF (LogicExpr) THEN {Stmt} END IF AssignStmt = Var = Expr ExprList = Expr {, Expr} Expr = Term {(+|-) Term} Term = SFactor {(*|/) SFactor} SFactor = Sign Factor | Factor LogicExpr = Expr (== |  TempsResults;  Each entry of TempsResults is a pair of a string and a Value object, representing a variable name, a constant, or an expression value and its corresponding Value object. ◼ Queue container for Value objects  queue  * ValQue;  Declaration of a pointer variable to a queue of Value objects  Utilized to queue the evaluated list of expressions (ExprList) in a PrintStmt. The values of evaluated expressions are printed out in order from left to right by the PrintStmt. 17 “parserInt.h” Description ◼ “parserInt.h”: includes the prototype definitions of the parser functions as in “parse.h” header file with following applied modifications: extern bool Var(istream& in, int& line, LexItem & tok); extern bool LogicExpr(istream& in, int& line, Value & retVal); extern bool Expr(istream& in, int& line, Value & retVal); extern bool Term(istream& in, int& line, Value & retVal); extern bool SFactor(istream& in, int& line, Value & retVal); extern bool Factor(istream& in, int& line, int sign, Value & retVal); 18 “parserInt.h” Description ◼ NOTE:  All code segments available in “parserInt.h” have to be moved to your “parserInt.cpp” file, except the defined functions prototypes. This process is needed in order to satisfy the requirements for linking program files on Linux when you are submitting your work to Vocareum. 19 Testing Program Requirements ◼ “prog3.cpp”:  You are given the testing program “prog3.cpp” that reads a file name from the command line. The file is opened for syntax analysis and interpretation, as a source code of the language.  A call to Prog() function is made. If the call fails, the program should stop and display a message as "Unsuccessful Interpretation ", and display the number of errors detected. For example: Unsuccessful Interpretation Number of Syntax Errors: 3  If the call to Prog() function succeeds, the program should stop and display the message "Successful Execution", and the program stops. 20 Testing Program Requirements ◼ Vocareum Automatic Grading  You are provided by a set of 14 testing files associated with

Sandeep Kumar · Accepted Answer

lex.cpp
lex.cpp
/*
 * lex.cpp
 *
 * CS280 - Spring 2021
 */
#include 
#include 
#include "lex.h"
using std::map;
using namespace std;
LexItem id_or_kw(const string &lexeme, int linenum)
{
    Token tt = IDENT;
    auto kIt = kwmap.find(lexeme);
    if (kIt != kwmap.end())
        tt = kIt->second;
    return LexItem(tt, lexeme, linenum);
}
LexItem
getNextToken(istream &in, int &linenum)
{
    enum TokState
    {
        START,
        INID,
        INSTRING,
        ININT,
        INREAL,
        INCOMMENT
    } lexstate = START;
    string lexeme;
    char ch, nextch, nextchar, nextch1;
    int strtype = 0; //0 for double quotes and 1 for single quotes
    while (in.get(ch))
    {
        switch (lexstate)
        {
        case START:
            if (ch == '
')
                linenum++;
            if (isspace(ch))
                continue;
            lexeme = ch;
            if (isalpha(ch))
            {
                lexeme = toupper(ch);
                lexstate = INID;
            }
            else if (ch == '"')
            {
                lexstate = INSTRING;
            }
            else if (ch == '\'')
            {
                strtype = 1;
                lexstate = INSTRING;
            }
            else if (isdigit(ch))
            {
                lexstate = ININT;
            }
            else if (ch == '!')
            {
                lexstate = INCOMMENT;
            }
            else
            {
                Token tt = ERR;
                switch (ch)
                {
                case '+':
                    tt = PLUS;
                    break;
                case '-':
                    tt = MINUS;
                    break;
                case '*':
                    tt = MULT;
                    break;
                case '/':
                    nextch1 = in.peek();
                    if (nextch1 == '/')
                    {
                        in.get(ch);
                        tt = CONCAT;
                        break;
                    }
                    tt = DIV;
                    break;
                case '=':
                    nextchar = in.peek();
                    if (nextchar == '=')
                    {
                        in.get(ch);
                        tt = EQUAL;
                        break;
                    }
                    tt = ASSOP;
                    break;
                case '(':
                    tt = LPAREN;
                    break;
                case ')':
                    tt = RPAREN;
                    break;
                case ':':
                    tt = COLON;
                    break;
                case ',':
                    tt = COMA;
                    break;
                case '
#include 
#include 
using namespace std;
//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,

PA 3 Description 1 CS 280 Programming Language Concepts Programming Assignment 3 Implementation of an Interpreter for a Simple Programming Language Programming Assignment 3 ◼ Objectives  Construction...

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