/* (c) https://github.com/MontiCore/monticore */

/**
 * This grammar defines several additional literals for Numbers,
 * which are common in computing, such as hexadecimals.
 * The goal of this grammar is to ease the reuse of literals 
 * in Java-like sublanguages
*/

component grammar MCHexNumbers extends
                          MCNumbers, de.monticore.MCBasics {

  /*========================================================================*/
  /*== Hexadecimal =========================================================*/
  /*========================================================================*/

  /** ASTHexadecimal represents a positive Hexadecimal number.
      These numbers start with "0x".
        @attribute source String-representation.
    */
  Hexadecimal implements Number =
    source:HexadecimalToken;

  astrule Hexadecimal =
    method public int getValueInt() {
      return Integer.parseInt(getSource().substring(2),16);
    }
    method public long getValue() {
      return Long.parseLong(getSource().substring(2),16);
    }
  ;

  token HexadecimalToken
    = '0' ('x' | 'X') HexDigit HexDigit*;

  fragment token HexDigit
    = '0'..'9'  | 'a'..'f'  | 'A'..'F' ;

  /*========================================================================*/
  /*== Hexadezimal with negative number ====================================*/
  /*========================================================================*/

  /** ASTHexInteger represents a positive or negative Hexadecimal number.
      These numbers start with "0x" or "-0x".
        @attribute source String-representation.
    */
  HexInteger implements Number =
     (negative:["-"])? hexadecimalpart:HexadecimalToken;

  astrule HexInteger =
    method public int getValueInt() {
      int a = Integer.parseInt(getHexadecimalpart().substring(2),16);
      return negative ? -a : a;
    }
    method public long getValue() {
      long a = Long.parseLong(getHexadecimalpart().substring(2),16);
      return negative ? -a : a;
    }
    // source is handcoded: it adds the "-"
    method public String getSource() {
      String s = getHexadecimalpart();
      return (negative ? "-" +s : s);
    }
  ;

}