content: package alchemystar.engine.parser.util;
  
  /**
   * CharTypes
   *
   * @Author lizhuyang
   */
  public class CharTypes {
      private final static boolean[] hexFlags = new boolean[256];
      static {
          for (char c = 0; c < hexFlags.length; ++c) {
              if (c >= 'A' && c <= 'F') {
                  hexFlags[c] = true;
              } else if (c >= 'a' && c <= 'f') {
                  hexFlags[c] = true;
              } else if (c >= '0' && c <= '9') {
                  hexFlags[c] = true;
              }
          }
      }
  
      public static boolean isHex(char c) {
          return c < 256 && hexFlags[c];
      }
  
      public static boolean isDigit(char c) {
          return c >= '0' && c <= '9';
      }
  
      private final static boolean[] identifierFlags = new boolean[256];
      static {
          for (char c = 0; c < identifierFlags.length; ++c) {
              if (c >= 'A' && c <= 'Z') {
                  identifierFlags[c] = true;
              } else if (c >= 'a' && c <= 'z') {
                  identifierFlags[c] = true;
              } else if (c >= '0' && c <= '9') {
                  identifierFlags[c] = true;
              }
          }
          //  identifierFlags['`'] = true;
          identifierFlags['_'] = true;
          identifierFlags['$'] = true;
      }
  
      public static boolean isIdentifierChar(char c) {
          return c > identifierFlags.length || identifierFlags[c];
      }
  
      private final static boolean[] whitespaceFlags = new boolean[256];
      static {
          whitespaceFlags[' '] = true;
          whitespaceFlags['\n'] = true;
          whitespaceFlags['\r'] = true;
          whitespaceFlags['\t'] = true;
          whitespaceFlags['\f'] = true;
          whitespaceFlags['\b'] = true;
      }
  
      public static boolean isWhitespace(char c) {
          return c <= whitespaceFlags.length && whitespaceFlags[c];
      }
  
  }