package rpn;

import java.util.*;
import java.io.*;

//Throw a ParseException if the token is not recognized
class ParseException extends IOException {
  ParseException(String s) {
    super(s);
  }
}

public class FormStream extends StreamTokenizer {

  // short names for StreamTokenizer codes
  public static int NUM = StreamTokenizer.TT_NUMBER;
  public static int EOF = StreamTokenizer.TT_EOF;
  private RPNEngine _rPNEngine;

  public FormStream(Reader reader, RPNEngine rPNEngine) throws IOException {
      super(new BufferedReader(reader));
      _rPNEngine = rPNEngine;
      ordinaryChar((int)'/');   // make sure '/' is treated like any other char
  }  

  public void parse() throws IOException {
    int token = nextToken();

    while(token != EOF) {
      if (token == NUM) {
	// Push something...but what?
	// Hint: it is a field within StreamTokenizer.
	// Check the API or the example tokenizer from tutorial 9.
      }
      else if (token == '+') {
	// Do add operation
      }
      // Need more if-else statements for the other operators ...
      // ...
      else {
	throw new ParseException("Come again?");
      }
      token = nextToken();
    }
  }
}