import java.util.*;

public class InputString {
    public String buffer;
    public int current;
    
    public InputString() {
    		buffer = new String();
    		current = 0;
    }
    
    public InputString(String b) {
    	 	buffer = b;
    }
    
    public int getCurrent() {
    		return current; 	
    }
    
    public void setCurrent(int c) {
    		current = c;
    }
    
    public String getBuffer() {
    		return buffer;
    }
    
    public void setBuffer(String b) {
    		buffer = b;
    }
    
    public boolean hasMoreTokens() {
    		return (current < buffer.length());
    }
    
    
    public void readInput() {
    		Scanner sc = new Scanner(System.in);
    		buffer = sc.nextLine();
    }
    
    
    public Token getID() {
    		Token t = new Token();
    		String buf = "";

    		while (current < buffer.length() &&
			(Character.isLetterOrDigit(buffer.charAt(current))))
    		{
    			buf += buffer.charAt(current);
    			current++;
    		}
    		t.setType(Token.IDENTIFIER);
    		t.setValue(buf);
		return t;
    	}
	

    public Token getInt() {
    		Token t = new Token();
    		String buf = "";

    		while (current < buffer.length() && 
	       Character.isDigit(buffer.charAt(current))) {
    			buf += buffer.charAt(current);
    			current++;
    		}
    		if ((current == buffer.length()) || 
    				!(Character.isLetter(buffer.charAt(current)))) {
    			t.setType(Token.INTEGER);
        		t.setValue(buf);
        		return t;
    		} else {
    			while (current < buffer.length() && 
    					Character.isLetter(buffer.charAt(current))) {
    				buf += buffer.charAt(current);
    			    	current++;
    			}
    			t.setType(Token.UNKNOWN);
    			t.setValue(buf);
    			return t;
    		}
    		
    }

    public Token getSymbol() {
    		Token t = new Token();
    		if (buffer.charAt(current) == '=') {
    			t.setType(Token.EQUALSSIGN);
    			t.setValue("=");
    		} else if (buffer.charAt(current) == '+') {
    			t.setType(Token.PLUSSIGN);
    			t.setValue("+");  
    		} else if (buffer.charAt(current) == '-') {
    			t.setType(Token.MINUSSIGN);
    			t.setValue(";");
	} else {
	    t.setType(Token.UNKNOWN);
	    t.setValue(Character.toString(buffer.charAt(current)));
	}
	current++;
	return t;
    }
    
    public Token getNextToken() {

       
	   while (buffer.charAt(current) == ' ') {
	       current++;
	   }
	   if (Character.isDigit(buffer.charAt(current))) {
	       return getInt();
	   } else if (Character.isLetter(buffer.charAt(current))) {
	       return getID();
	   } else {
	       return getSymbol();
	   }
     }
    
    public static void testGetInt() {
		boolean done = false;
		Scanner sc = new Scanner(System.in);
		String tempbuf, ans;
		InputString is = new InputString();
		Token t;
		
		while (!done) {
			System.out.print("Enter a buffer: ");
			tempbuf = sc.next();
			is.setBuffer(tempbuf);
			is.setCurrent(0);
			t = is.getInt();
			System.out.println(t);
			System.out.print("Would you like to keep testing? (y/n)");
			ans = sc.next();
			if (ans.equals("n") || ans.equals("N")) {
				done = true;
			}	
		}
    }
    
    public static void testGetID() {
		boolean done = false;
		Scanner sc = new Scanner(System.in);
		String tempbuf, ans;
		InputString is = new InputString();
		Token t;
		
		while (!done) {
			System.out.print("Enter a buffer: ");
			tempbuf = sc.next();
			is.setBuffer(tempbuf);
			is.setCurrent(0);
			t = is.getID();
			System.out.println(t);
			System.out.print("Would you like to keep testing? (y/n)");
			ans = sc.next();
			if (ans.equals("n") || ans.equals("N")) {
				done = true;
			}	
		}
    }
    
    public static void testGetSymbol() {
		boolean done = false;
		Scanner sc = new Scanner(System.in);
		String tempbuf, ans;
		InputString is = new InputString();
		Token t;
		
		while (!done) {
			System.out.print("Enter a buffer: ");
			tempbuf = sc.next();
			is.setBuffer(tempbuf);
			is.setCurrent(0);
			t = is.getSymbol();
			System.out.println(t);
			System.out.print("Would you like to keep testing? (y/n)");
			ans = sc.next();
			if (ans.equals("n") || ans.equals("N")) {
				done = true;
			}	
		}
    }
    
    public static void testGetNextToken() {
		boolean done = false;
		Scanner sc = new Scanner(System.in);
		String tempbuf, ans;
		InputString is = new InputString();
		Token t;
		
		while (!done) {
			System.out.print("Enter a buffer: ");
			tempbuf = sc.next();
			is.setBuffer(tempbuf);
			is.setCurrent(0);
			t = is.getNextToken();
			System.out.println(t);
			System.out.print("Would you like to keep testing? (y/n)");
			ans = sc.next();
			if (ans.equals("n") || ans.equals("N")) {
				done = true;
			}	
		}
    }
    public static void testHasMoreTokens() {
		boolean done = false;
		Scanner sc = new Scanner(System.in);
		String tempbuf, ans;
		int c;
		InputString is = new InputString();
		
		while (!done) {
			System.out.print("Enter a buffer: ");
			tempbuf = sc.next();
			System.out.print("Enter a counter position: ");
			c = sc.nextInt();
			sc.nextLine();
			is.setBuffer(tempbuf);
			is.setCurrent(c);
			if (is.hasMoreTokens()) {
				System.out.println("More tokens available");
			} else {
				System.out.println("No more tokens available.");
			}
			System.out.print("Would you like to keep testing? (y/n)");
			ans = sc.next();
			if (ans.equals("n") || ans.equals("N")) {
				done = true;
			}	
		}
    }
    public static void main(String args[]) {
    		testGetInt();
    		testGetID();
    		testGetSymbol();
    		testGetNextToken();
    		testHasMoreTokens();
    }
 }