stringcl.cc

this is a lp0 compilator new

/***********************************************************************
   Gerald Carter
   cse 525
   Spring 1994
   stringcl.cc
   
   DESCRIPTION : This file contains all the method defintion for the string
                 class from "stringcl.h".  Each method is documented 
                 individually.
***********************************************************************/

// INCLUDE FILES
#include <iostream.h>         // cout, cin, cerr, etc...
#include <string.h>           // strcmp(), strdup(), etc...
#include "logic.h"            // boolean typedefs
#include "stringcl.h"         // string class declaration

// Initialize static data members
const string string::empty_string = string ("");

// CONSTRUCTORS
// Initializes the text to a string of 'set_char' of length 'size'
string::string (char set_char, int size)
{
   int       i = 0;

   if (size > MAX_BUF_SIZE)
      cerr << "String to long for buffer.  Unable to create string object.\n";
   else
   {
      text = new char[size+1];
      for (; i<=size; ++i)
	 text[i] = set_char;
      text[size+1] = '\0';
   }
}

// Initializes 'this' to another string
string::string (const string& instring)
{
   text = strdup (instring.text);
   length = instring.length;
}

// Initializes the text to a null terminated string given by 'char_text'
string::string (char* char_text)
{
   int    i = 0;

   if (strlen(char_text) > MAX_BUF_SIZE)
      cerr << "String to long for buffer.  Unable to create string object.\n";
   else
   {
      length = strlen(char_text);
      text = new char[length+1];
      for (; i<length; ++i)
	 text[i] = *(char_text++);
      text[length] = '\0';
   }
}

// Initializes the string to NULL
string::string (void)
{
   length = 0;
   text = 0;
}

// OVERLOADED OPERATORS
// Add character to end of text
string string::operator+ (char add_char)
{
   char    temp[MAX_BUF_SIZE];
   int     i = 0;

   for (; i<length; ++i)
      temp[i] = text[i];
   temp[length] = add_char;
   temp[length+1] = '\0';
   ++length;

   return string(temp);
}

// Catenates two strings
string string::operator+ (const string& add_string)
{
   int     i = 0;
   int     j = 0;
   char    temp[(MAX_BUF_SIZE*2)+1];

   for (; i<length; ++i)
      temp[i] = text[i];
   while (j<add_string.length)
      temp[i++] = add_string.text[j++];
   temp[i] = '\0';
   
   return string(temp);
}

// Delete all instances of the given character from the string
string string::operator- (char delete_char)
{
   char   temp[MAX_BUF_SIZE];
   int    i = 0;
   int    index = 0;
   
   for (; i<length; ++i)
      if (text[i] != delete_char)
	 temp[index++] = text[i];
   temp[index] = '\0';
   
   return string(temp);
}

// Delete character in the position indicated by the integer given
//    position ranges 0..length-1
string string::operator- (int delete_pos)
{
   int   i = 0;
   char  temp[MAX_BUF_SIZE];
   
   if ((delete_pos<0) OR (delete_pos>length))
   {
      cerr << "Position to delete not within range.\n";
      cerr << "      Position..." << delete_pos << "\n";
      cerr << "    " << text << "\n";
      return *this;
   }
   
   while (i<delete_pos)
   {
      temp[i] = text[i];
      ++i;
   }
   ++delete_pos;
   while (delete_pos<length)
      temp[i++] = text[delete_pos++];
   temp[i] = '\0';

   return string(temp);
}

// Assignment operator
string& string::operator= (const string& item)
{
   int     i = 0;
   
   delete []text;
   length = item.length;
   text = new char[length+1];
   for (; i<length; ++i)
      text[i] = item.text[i];
   text[length] = '\0';

   return *this;
}

// Simple ASCII comparison of the two string.text`s
int string::operator< (const string& item) const
{
   int    i = 0;
   int    limit;

   if (length<item.length)
      limit = length;
   else
      limit = item.length;

   for (; i<limit; ++i)
      if (text[i]<item.text[i])
	 return TRUE;
      else if (text[i]>item.text[i])
	 return FALSE;

   if (length < item.length)
      return TRUE;
   else
      return FALSE;
}

// Simple ASCII comparison of the two string.text`s
int string::operator> (const string& item)  const
{
   int    i = 0;
   int    limit;

   if (length<item.length)
      limit = length;
   else
      limit = item.length;

   for (; i<limit; ++i)
      if (text[i]>item.text[i])
	 return TRUE;
      else if (text[i]<item.text[i])
	 return FALSE;

   if (length > item.length)
      return TRUE;
   else
      return FALSE;
}

// Simple ASCII comparison of the two string.text`s
int string::operator== (const string& item) const
{
   int    i = 0;

   if (length!=item.length)
      return FALSE;

   for (; i<length; ++i)
      if (text[i]!=item.text[i])
	 return FALSE;

   return TRUE;
}

// Simple ASCII comparison of the two string.text`s
int string::operator!= (const string& item) const
{
   int	  i = 0;

   if (length!=item.length)
      return TRUE;

   for (; i<length; ++i)
      if (text[i]!=item.text[i])
	 return TRUE;

   return FALSE;
}

// Divide the string into 2 strings at the first occurence of the character
//   given.  Returns the first half excluding the characted divided at
string string::operator/ (const char split_char)
{
   char      temp[MAX_BUF_SIZE];
   char      *point = text;
   int       i = 0;

   while ((*point!=split_char) AND (*point!='\0') AND (i<MAX_BUF_SIZE))
       temp[i++] = *(point++);
   temp[i] = '\0';
   return string(temp);
}

// Diviide the string into 2 strings at the first occurence of the character
//   given.  Returns the second half of the string including the character
//   divided at
string string::operator% (const char split_char)
{
   char         temp[MAX_BUF_SIZE];
   char         *point = text;
   int          i = 0;
   
   while ((*point!=split_char) AND (*point!='\0'))
     ++point;
   while ((*point!='\0') AND (i<MAX_BUF_SIZE))
      temp[i++] = *point++;
   temp[i] = '\0';
   return string(temp);
}

// Subsrcipt operator that works identically to the subscript operator on arrays
char& string::operator[] (int index) const
{
   int	      i = 0;
   char       *point = text;

   if (NOT ((0<=index) AND (i<length)))
   {
      cerr << "Invalid index reference to string object.\n";
      return *text;
   }

   while (i!=index)
   {
      ++point;
      ++i;
   }
   return *point;
}


// print the string
ostream& operator<< (ostream& S, const string& item)
{
   int      index = 0;
  
   for (; index<item.length; ++index)
      S << item.text[index];
   return S; 
}


// Get from operator that reads a character string into the string object
istream& operator>> (istream& S, string& item)
{
   char     buf[MAX_BUF_SIZE];
   int      i = 0;

   delete []item.text;
   S.getline (buf, 255, '\n');
   item.length = strlen(buf);
   item.text = new char[item.length+1];
   for (; i<item.length; ++i)
      item.text[i] = buf[i];
   item.text[item.length] = '\0';

   return S;
}