/****************************************************************************
** COPYRIGHT (C):    1997 Cay S. Horstmann. All Rights Reserved.
** PROJECT:          Practical OO Development with C++ and Java
** FILE:             TextInputStream.java
** PURPOSE:          input stream that can read ASCII numbers
** VERSION           1.0
** PROGRAMMERS:      Cay Horstmann (CSH)
** RELEASE DATE:     3-15-97 (CSH)
** UPDATE HISTORY:
****************************************************************************/

//package practicaloo;
import java.io.*;

public class TextInputStream extends FilterInputStream
{  public String readLine()
   {  int ch;
      String r = "";
      boolean done = false;
      while (!done)
      {  try
         {  ch = read();
            if (ch < 0)
               done = true;
            else if ((char)ch == '\n')
               done = true;
            else if ((char)ch != '\r')
               r = r + (char) ch;
         }
         catch(java.io.IOException e)
         {  done = true;
         }
      }
      return r;
   }

   private void skipSpace()
   {  int ch;
      for(;;)
      {  try
         {  ch = read();
            if (ch < 0)
               return;
            else if (!java.lang.Character.isWhitespace((char)ch))
            {  unread(ch);
               return;
            }
         }
         catch(java.io.IOException e)
         {  
         }
      }
   }

   public String readString()
   {  skipSpace();
      int ch;
      String r = "";
      boolean done = false;
      while (!done)
      {  try
         {  ch = read();
            if (ch < 0)
               done = true;
            else if (java.lang.Character.isWhitespace((char)ch))
            {  done = true;
               unread(ch);
            }
            else
               r = r + (char) ch;
         }
         catch(java.io.IOException e)
         {  done = true;
         }
      }
      return r;
   }

   public String readChar()
   {  int ch;
      String r = "";
      try
      {  ch = read();
         if (ch >= 0)
            r = r + (char)ch;
      }
      catch(java.io.IOException e)
      {  
      }
      return r;
   }

   private String readDigits()
   {  String r = "";
      try
      {  for(;;)
         {  int ch = read();
            if (ch < 0) return r;
            else if (!java.lang.Character.isDigit((char)ch))
            {  unread(ch);
               return r;
            }
            else
               r = r + (char) ch;
         }
      }
      catch(java.io.IOException e)
      {  return r;
      }
   }

   public int readInt()
   {  skipSpace();
      int ch;
      String r = "";
      boolean done = false;
      boolean digits = false;
      try
      {  ch = read();
         if (ch == '+' || ch == '-')
            r = r + (char)ch;
         else if (ch < 0)
         {  done = true;
         }
         else unread(ch);
         r += readDigits();
      }
      catch(java.io.IOException e)
      {  
      }
      try
      {  return Integer.valueOf(r).intValue();
      } catch(NumberFormatException e)
      {  return 0;
      }
   }

   public double readDouble()
   {  skipSpace();
      int ch;
      String r = "";
      boolean done = false;
      boolean digits = false;
      try
      {  ch = read();
         if (ch == '+' || ch == '-')
            r = r + (char)ch;
         else if (ch < 0)
            return 0;
         else unread(ch);
         r += readDigits();
         ch = read();
         if (ch == '.')
         {  r = r + (char)ch;
            r += readDigits();
         }            
         else if (ch >= 0) unread(ch);
         ch = read();
         if (ch == 'E' || ch == 'e')
         {  r = r + (char)ch;
            ch = read();
            if (ch == '+' || ch == '-')
               r = r + (char)ch;
            else if (ch >= 0) unread(ch);
            r += readDigits();
         }
         else if (ch >= 0) unread(ch);
      }
      catch(java.io.IOException e)
      {  
      }
      try
      {  return Double.valueOf(r).doubleValue();
      } catch(NumberFormatException e)
      {  return 0;
      }
   }

   public TextInputStream(InputStream in)
   {  super(new PushbackInputStream(in));
   }

   public void unread(int x) throws IOException
   {  ((PushbackInputStream)in).unread(x);
   }

}