Question

Soreland, a software company, is planning on releasing its first C++ compiler with the hopes of putting MiniSoft's Visual C++ out of business (that reminds me of another story). Consequently, Soreland has contracted with the Fruugle Corporation to design and build part of their compiler. Of course, since Fruugle gets all of its labor by exploiting El Camino undergraduate students, you'll be doing all of the programming. For Fruugle, you will write a C++ program to test the "balance" of certain features of C++ programs. This is a task that is done by C++ compilers. The technique you will use is similar to the technique used by a typical C++ compiler. Requirements There are many features in C++ programs that must be "balanced" to be syntactically correct. For example, every ( must be balanced by a corresponding ). Similarly for {} and (). There are other (somewhat more complex) situations. • Block comments must be balanced. Each /* must be balanced by a */ The complication here is that the tokens being balanced are not composed of single characters. Moreover, the closing comment" */ starts with a character that is used in other ways (pointers, multiplication). • Quotes must be balanced. This applies to single quotes and double quotes. The complication here is that all the material between the matching quotes can contain any characters. The characters between the quotes do not require balancing. For example, the string "This is a /*'* quote" is legal, and the comment and single-quote need not be balanced. Inline comments are not balanced. Anything that comes after a comment is ignored until you get to the end of the line that's read in. There are some balanced C++ programs you need not test. For example, some balanced C++ programs contain character constants such as 'l" or "". These are inherently unbalanced and would require a bit more work to catch. You need not worry about such problems for the compiler (unless you like the modest challenge). You must write these two functions with the exact same function signature (include case): void printFile(istream &dictfile); Prints the file with preceding line numbers for each line. bool balanceFile(istream &dictfile); Takes a file dictfile and prints the matching code elements. Returns true if the file is balanced, false otherwise.

$17 x = y + z; 18 y = x/ z; 19 cout << Hello world\n; // :) 20 } 21 pair matching /* and */ pair matching and pair matchin$

The last 3 cases are tests .cpp files to test the code. The language of this code must be C++ because that is the only I am familiar with.

Answer 1

program code to copy

main.cpp

#include <iostream>
#include <stack>
#include <fstream>
#include <string>
#include <iomanip>
#include <cassert>
#include <sstream>
using namespace std;

void printFile(istream &dictfile);
bool balanceFile(istream &dictfile);
bool Matching(char, char);
void getChar(char& c, istream&infile, int& i);

struct charAndLine
{
   int line;
   char openCharacter;
};

int main()
{
   //checkings();
   ifstream infile;
   string filename;
   cout << "Please enter filename for C++ code: ";
   cin >> filename;
   infile.open(filename.c_str());
   if (!infile)
   {
       cout << "File not found!" << endl;
       return (1);
   }
   printFile(infile);
   if (balanceFile(infile))
       cout << "balance ok" << endl;
   else
       cout << "Balance baaaaadddddd";
}

void printFile(istream& infile)
{
   int i = 1;
   string a;
   while (infile.peek() != EOF)
   {
       cout << i << " ";
       getline(infile, a);
       cout << setw(3) << a << endl;
       i++;
   }
   infile.clear();
   infile.seekg(0, infile.beg);
}

bool balanceFile(istream &infile)
{
   stack <charAndLine> stack1;
   char c, d, e, f;
   bool match = true;
   int numberOfLine = 1;
   while (infile.peek() != EOF)
   {
       //infile.get(c);
       getChar(c, infile, numberOfLine);
       if (c == '/'&&infile.peek() == '*')
       {
           infile.get(c); //this must be a *
           int matchLine = numberOfLine;
           getChar(c, infile, numberOfLine); //this is what we're checking
           while ((c != '*' || infile.peek() != '/') && infile.peek() != EOF)
           {
               getChar(c, infile, numberOfLine);
           }
           if (infile.peek() == EOF)
           {
               match = false;
               cout << "unmatched /* symbol on line " << matchLine << endl;
               break;
           }
           cout << "pair matching /* and */" << endl;
       }
       else
       {
           if (c == '/'&&infile.peek() == '/')
           {
               string newLine;
               getline(infile, newLine);
           }
       }

       if (c == '"' || c == '\'')
       {
           char save;
           save = c;
           getChar(c, infile, numberOfLine);
           while (c != save && infile.peek() != EOF)
           {
               getChar(c, infile, numberOfLine);
               if (c == '\n')
               {
                   match = false;
                   cout << "unmatched " << save << " symbol on line " << numberOfLine << endl;
                   break;
               }
           }
           if (c != save && infile.peek() == EOF && infile.peek() != '\n')
           {
               match = false;
               cout << "unmatched " << save << " symbol on line " << numberOfLine << endl;
               break;
           }
           cout << "pair matching " << save << " and " << save << endl;
       }
       if (c == '(' || c == '{' || c == '[')
       {
           charAndLine a;
           a.line = numberOfLine;
           a.openCharacter = c;
           stack1.push(a);
       }
       else if (c == ')' || c == '}' || c == ']')
       {
           if (stack1.empty())
           {
               cout << "unmatched " << c << " symbol on line " << numberOfLine << endl;
               match = false;
               break;
           }
           charAndLine openChar;
           openChar = stack1.top();
           stack1.pop();
           if (!Matching(openChar.openCharacter, c))
           {
               match = false;
               cout << "unmatched " << openChar.openCharacter << " symbol on line " << openChar.line << endl;
               break;
           }
           else
               cout << "pair matching " << openChar.openCharacter << " and " << c << endl;
       }
   }
   if (!stack1.empty() && match == true)
   {
       cout << "unmatched " << stack1.top().openCharacter << " symbol on line " << stack1.top().line << endl;
       match = false;
   }
   return match;
}

bool Matching(char a, char b)
{
   if (a == '{')
   {
       if (b == '}')
           return true;
       else
           return false;
   }
   if (a == '(')
   {
       if (b == ')')
           return true;
       else
           return false;
   }
   if (a == '[')
   {
       if (b == ']')
           return true;
       else
           return false;
   }
   return false;
}

void getChar(char& c, istream&infile, int& i)
{
   infile.get(c);
   if (c == '\n')
       i++;
}

=============================================================

bad_balance2.cpp

/*
   bad_balance2.cpp
   Test data for CS2 Project 4

   Created: 24 October 1997
   Modified: 3 November 2017
*/

#define FOO   '"* /* */ foo'
#define BAR   " /* ' "

int main(int argc, char * argv[])
{
char c = {'a';}
y = 3; '
z = 4;
x = y * z;
y = x / z;
cout << "Hello world\n"; // :)
}

================================================================================

sample output

input 2 bad balance2.cpp Test data for CS2 Project 4 4 5 Created: 24 October 1997 6 Modified: 3 November 2017 */ 8 9 #define FOO ""* /* */ foo' 10 #define BAR 11 12 int main(int arge, char * argv[]) 13 14 char c = {'a'; } 15 y 3; 16 z = 4; 17 y 18 y = x / z; 19 cout << "Hello world\n"; // :) 20 pair matching /* and */ pair matching pair matching pair matching [ and ] pair matching ( and ) pair matching pair matching { and } unmatched symbol on line 17 pair matching } and ! and and

< 7 8 9 #define FOO /* */ foo' 10 #define BAR 11 12 int main(int argc, char * argv[]) 13 14 char c = {'a'; } 15 y = 3; 16 z = 4; 17 y z; 18 y = x/ z; 19 cout << "Hello world\n"; // :) 20 } pair matching /* and */ pair matching and' pair matching pair matching [ and ] pair matching ( and ) pair matching pair matching { and } unmatched symbol on line 17 pair matching pair matching pair matching { and } Balance baaaaadddddd and ! and and "