/*
   Simple +/-/* expression language;
   parser evaluates constant expressions on the fly
*/

package cup.example;

import java_cup.runtime.*;
import cup.example.Lexer;
import java.io.IOException;
import java.io.File;
import java.io.FileInputStream;

parser code {:
  protected Lexer lexer;
:}

/* define how to connect to the scanner! */
init with {:
  ComplexSymbolFactory f = new ComplexSymbolFactory();
  symbolFactory = f;
  File file = new File("input.txt");
  FileInputStream fis = null;
  try {
    fis = new FileInputStream(file);
  } catch (IOException e) {
    e.printStackTrace();
  }
  lexer = new Lexer(f,fis);
:};
scan with {: return lexer.next_token(); :};

/* Terminals (tokens returned by the scanner). */
terminal            LCB, RCB, LSQB, RSQB, COMMA, COLON, IDENTIFIER;
terminal Integer    NUMBER;
terminal Boolean    BOOLEAN;
terminal String     STRING;

/* Non terminals */
// non terminal            expr_list;
non terminal Integer    value;      // used to store evaluated subexpressions

/* Precedences */
precedence left LCB, RCB, LSQB, RSQB, COMMA, COLON;
precedence left NUMBER, BOOLEAN, STRING;

obj ::= LCB keyValList:k RCB            {: RESULT = new Map :}
      | LCB RCB                       {: RESULT = {}  :}
      ;

keyValList ::= ListElem:l               {: RESULT = l  :}
            | ListElem COMMA          {:  :}
            ;

listElem ::= ListElem COMMA keyValue  {:  :}
          | keyValue                  {:  :}
          ;

keyValue ::= IDENTIFIER COLON value   {:  :}
          | STRING COLON value        {:  :}
          ;

value     ::= NUMBER:n	     		      {: System.out.println(n); RESULT = n;           :}
            | obj:n	     		          {: System.out.println(n); RESULT = n;           :}
            | BOOLEAN:n	     		      {: System.out.println(n); RESULT = n;           :}
            | STRING:n	     		      {: System.out.println(n); RESULT = n;           :}
           ;