readstdio.java

一个JAVA编写的简单编译器

package codegen;

public class ReadStdIO {
  private static java.io.BufferedReader b = null;
  private static int c = ' ';
  static {
    b = new java.io.BufferedReader (new java.io.InputStreamReader (System.in));
  }
  private static void nextChar () throws java.io.IOException {
    c = b.read ();
  }
  public static String readToken () {
    if (c < 0)
      return null;
    StringBuffer buffer = new StringBuffer ();
    boolean stop = false;
    try {
      // jump over blank
      while (c > 0 && Character.isWhitespace ((char)c))
        nextChar ();
      if (c < 0)
        return null;
      do {
        buffer.append ((char)c);      
        nextChar ();
        stop = ((c < 0) || Character.isWhitespace ((char)c));
      } while (!stop);
    } catch (java.io.IOException io) {
      util.Error.e3 ("errors in input");
    }
    return buffer.toString ();
  }
  public static String readString () {
    try {
      return b.readLine ();
    } catch (java.io.IOException io) {
      util.Error.e3 ("errors in input");
    }
    return null;
  }
  public static double readDouble () {
    String s = readToken ();
    if (s == null)
      util.Error.e3 ("EOF");
    return new Double (s).doubleValue (); 
  }
  public static float readFloat () {
    String s = readToken ();
    if (s == null)
      util.Error.e3 ("EOF");
    return new Float (s).floatValue (); 
  }
  public static long readLong () {
    String s = readToken ();
    if (s == null)
      util.Error.e3 ("EOF");
    return new Long (s).longValue (); 
  }
  public static int readInteger () {
    String s = readToken ();
    if (s == null)
      util.Error.e3 ("EOF");
    return new Integer (s).intValue (); 
  }
  public static short readShort () {
    String s = readToken ();
    if (s == null)
      util.Error.e3 ("EOF");
    return new Short (s).shortValue (); 
  }
  public static byte readByte () {
    String s = readToken ();
    if (s == null)
      util.Error.e3 ("EOF");
    return new Byte (s).byteValue (); 
  }
  public static char readCharacter () {
    try {
    nextChar ();
    int cc = c;
    if (cc < 0)
      util.Error.e3 ("EOF");
    else
      nextChar ();
    return (char)cc;
    } catch (java.io.IOException io) {
      util.Error.e3 ("errors in input");
    }
    return 0;
  }
}