code: private int next() throws IOException {
          int c = get();
          if (c == '/') {
              switch (peek()) {
                  case '/':
                      for (; ; ) {
                          c = get();
                          if (c <= '\n') {
                              break;
                          }
                      }
                      break;
                  case '*':
                      get();
                      while (c != ' ') {
                          switch (get()) {
                              case '*':
                                  if (peek() == '/') {
                                      get();
                                      c = ' ';
                                  }
                                  break;
                              case EOF:
                                  error("Unterminated comment.");
                          }
                      }
                      break;
              }
          }
          theY = theX;
          theX = c;
          return c;
      }
docs: /* next -- get the next character, excluding comments. peek() is used to see
  if a '/' is followed by a '/' or '*'.