PARSER_BEGIN(Q3)

class Q3 {


  /** Standard code to call the parser
   */
  public static void main(String args[]) 
  {
    Q3 parser;

    System.out.println("Reading from standard input . . .");
    parser = new Q3(System.in);
    try {
      parser.prog();
     } catch (ParseException e) {
      System.out.println("Encountered errors during parse.");
    }
  }   /* End of function "main" */


}

PARSER_END(Q3)



/******************/
/***** TOKENS *****/
/******************/

SKIP : /* WHITE SPACE */
{
  " " 
| "\t"
| "\n"
| "\r"
}

TOKEN : 
{
  < SEMIC : ";" >
| < NAME : ( ["A"-"Z"] )+ >
| < VAR : ["a"-"z"] >
| < FN : "fn" >
| < EL : "=>" >
| < EQUALS : "=" >
| < LBR : "(" >
| < RBR : ")" >
}
 

/*************************/
/***** GRAMMAR RULES *****/
/*************************/

void prog() : 
{
  String s;
}
{
  s=stat() { System.out.print("\n"+s); }
  ( 
    <SEMIC> s=stat()
    { System.out.print(";"+s); }
  )* <EOF> 
}

String stat() : 
{
  String e;
  Token n;
}
{
  n=<NAME> <EQUALS> e=expr()
  { return n.image + "=" + e; }
}
    
String expr() : 
{
  String v, e;
}
{
  v=var()
  { return v; }
| <LBR> <FN> v=var() <EL> e=expr() <RBR>  
  { return "(fn" + v + "=>" + e + ")"; }
}


String var() :
{
  Token v;
}
{
  v=<VAR>
  { return String.valueOf(v.image.charAt(0)-'a'); }
}