\Section{Conclusions}
\label{sec:conclusions}

  In this experiment, we added a small macro system to JavaScript to
capture both the syntactic structure and the semantics of textual code into parse tree nodes that are
used as internal representations of the code.
We also described conversions between arbitrary tile scripts and arbitrary textual code, which work in either direction.

  With these facilities, we managed to build a system in which
new kinds of tiles in the tile-scripting system can be defined in a way accessible to end-users.
  All of the constructs of our language are available to the end-user in both tiles
and text, which allows the end-user to explore all aspects of the system in a fairly deep manner.

  This project is still in its infancy.  As discussed in the previous
section, we aim to allow even deeper exploration by defining more parts
of the system in itself, and also to make the system more practical for
real end-users to use effectively.

\section*{Acknowledgement} We would like to express thanks for the
  valuable insights that Alan Kay, Kim Rose, Ted Kaehler, Bert
Freudenberg, Ian Piumarta, and other colleagues have given us.