code: private void scanOperator() {
          while (true) {
              reader.putChar(false);
              Name newname = reader.name();
              TokenKind tk1 = tokens.lookupKind(newname);
              if (tk1 == TokenKind.IDENTIFIER) {
                  reader.sp--;
                  break;
              }
              tk = tk1;
              reader.scanChar();
              if (!isSpecial(reader.ch)) break;
          }
      }
docs: Read longest possible sequence of special characters and convert
  to token.