import java_cup.runtime.*;
import adder.*;

parser code {: 
/* these variables must be declared here: */
String intext;    // concrete syntax typed in by user
Yylex scanner;    // scanner object
:};

init with {:
try {			/* Get Input, form lexer: */
  java.io.InputStreamReader lr = 
     new java.io.InputStreamReader(System.in);
  java.io.BufferedReader lineinput = 
     new java.io.BufferedReader(lr);
/* didn't figure out how to pass in input from the main program: */
  System.out.print("Enter arithmetic expression: ");
  intext = lineinput.readLine();
} catch (Exception ee) {}
/* scanner needs an input stream */
scanner = new Yylex(new java.io.StringBufferInputStream(intext)); 

:};

scan with {: return scanner.next_token(); :};

terminal String		CONST;
terminal 		TIMES, PLUS, LPAREN, RPAREN;

non terminal expr	EXP;

precedence left PLUS;
precedence left TIMES;

EXP ::= CONST:c1  {: RESULT = new constexp(c1); :}
    |   EXP:e1 PLUS EXP:e2
         {: RESULT = new sumexp("",e1,e2); :}
    |   EXP:e1 TIMES EXP:e2
         {: RESULT = new multexp("",e1,e2); :}
    |   LPAREN EXP:e1 RPAREN {: RESULT = e1; :};