/**
 * JavaCC template file created by SF JavaCC plugin 1.5.17+ wizard for JavaCC 1.5.0+
 */
options
{
  JDK_VERSION = "1.5";
  static = true;
}

PARSER_BEGIN(eg1)
import java.util.*;
public class eg1
{
  static Stack st;
  public static void main(String args []) throws ParseException
  {
    st=new Stack();
    eg1 parser = new eg1(System.in);

    while (true)
    {
      try
      {
      //System.out.print("Write a valid variable: ");
      //eg1.input();
      //System.out.println("Variable is valid.");
      System.out.print("Write an expression: ");
      eg1.calc();
      for(int i=0;i<st.size();i++){
			System.out.println(st.get(i));
		}
    }catch(Exception e)
    {
      System.out.println("Variable not valid");
    }

    }
  }
}

PARSER_END(eg1)

SKIP :
{
  " "
| "\r"
| "\t"
| "\n"
}

TOKEN : /* KEYWORDS */
{
  < PLUS : "+" >
| < MINUS : "-" >
| < MULTIPLY : "*" >
| < DIVIDE : "/" >
| < EQUALS : "=" >
| < TYPE : "BYTE" | "SHORT" | "INT" | "LONG" | "FLOAT" | "DOUBLE" | "BOOLEAN" | "CHAR" >
| < EOS : ";" >

}
/* LITERALS */

TOKEN :
{
  < INTEGER_LITERAL:
        <DECIMAL_LITERAL> (["l","L"])?
      | <HEX_LITERAL> (["l","L"])?
      | <OCTAL_LITERAL> (["l","L"])?
  >
|
  < #DECIMAL_LITERAL: ["1"-"9"] (["0"-"9"])* >
|
  < #HEX_LITERAL: "0" ["x","X"] (["0"-"9","a"-"f","A"-"F"])+ >
|
  < #OCTAL_LITERAL: "0" (["0"-"7"])* >
|
  < FLOATING_POINT_LITERAL:
        <DECIMAL_FLOATING_POINT_LITERAL>
      | <HEXADECIMAL_FLOATING_POINT_LITERAL>
  >
|
  < #DECIMAL_FLOATING_POINT_LITERAL:
        (["0"-"9"])+ "." (["0"-"9"])* (<DECIMAL_EXPONENT>)? (["f","F","d","D"])?
      | "." (["0"-"9"])+ (<DECIMAL_EXPONENT>)? (["f","F","d","D"])?
      | (["0"-"9"])+ <DECIMAL_EXPONENT> (["f","F","d","D"])?
      | (["0"-"9"])+ (<DECIMAL_EXPONENT>)? ["f","F","d","D"]
  >
|
  < #DECIMAL_EXPONENT: ["e","E"] (["+","-"])? (["0"-"9"])+ >
|
  < #HEXADECIMAL_FLOATING_POINT_LITERAL:
        "0" ["x", "X"] (["0"-"9","a"-"f","A"-"F"])+ (".")? <HEXADECIMAL_EXPONENT> (["f","F","d","D"])?
      | "0" ["x", "X"] (["0"-"9","a"-"f","A"-"F"])* "." (["0"-"9","a"-"f","A"-"F"])+ <HEXADECIMAL_EXPONENT> (["f","F","d","D"])?
  >
|
  < #HEXADECIMAL_EXPONENT: ["p","P"] (["+","-"])? (["0"-"9"])+ >
|
  < CHARACTER_LITERAL:
      "'"
      (   (~["'","\\","\n","\r"])
        | ("\\"
            ( ["n","t","b","r","f","\\","'","\""]
            | ["0"-"7"] ( ["0"-"7"] )?
            | ["0"-"3"] ["0"-"7"] ["0"-"7"]
            )
          )
      )
      "'"
  >
|
  < STRING_LITERAL:
      "\""
      (   (~["\"","\\","\n","\r"])
        | ("\\"
            ( ["n","t","b","r","f","\\","'","\""]
            | ["0"-"7"] ( ["0"-"7"] )?
            | ["0"-"3"] ["0"-"7"] ["0"-"7"]
            )
          )
      )*
      "\""
  >
}

TOKEN :
{
	< IDENTIFIER : ["a"-"z","A"-"Z","_"] ( ["a"-"z","A"-"Z","0"-"9","_"] )* >
}
/*FOR EXPRESSION HANDLING */



void input() :
{
Token t1; String name;
Token t2; String type;
}
{
 t1=< TYPE >
 {type=t1.image.toString();}
 {System.out.println("type="+type); }
 t2=<IDENTIFIER>
 < EOS >
 {name=t2.image.toString();}
 {System.out.println("variable name="+name); }
}

int calc() :
{}
{


  sum() ";"
  {
    return 0;
  }
|

";"
  {
    return 1;
  }
}


void sum() :
{Token t;}
{
  term()
  (
    (
      t=< PLUS >{st.add(t.image);}
    | t=< MINUS > {st.add(t.image);}

    )
    term()
  )*
}

void term() :
{Token t;}
{
  unary()
  (
    (
      t=< MULTIPLY > {st.add(t.image);}
    | t=< DIVIDE > {st.add(t.image);}

    )
    unary()
  )*
}

void unary() :
{Token t;}
{
  t=< MINUS >
  {st.add(t.image);  } element()
| element()
}

void element() :
{Token t;}
{
  t=< INTEGER_LITERAL >
  {
    st.add(t.image);
  }
| < IDENTIFIER >
| "(" sum() ")"

}