RUNNING REGULUS APPLICATIONS UNDER SICSTUS 4

Regulus is intended to work under both Sicstus 3 and Sicstus 4. If you are trying to port a Sicstus 3 Regulus application to Sicstus 4, here are some initial pointers:

1. Sicstus 4 is NOT downward-compatible with Sicstus 3, so don't expect your app to work unmodified. It almost certainly won't.
2. Before doing anything else, look at the Sicstus 4 release notes. They are in doc/pdf/relnotes.pdf in your Sicstus 4 release directory, and list most of the top-level incompatibilities.
3. Regulus makes heavy use of conditional loading in the code files, and in particular in $REGULUS/PrologLib/utilities. The predicates required to do this conditional loading are defined in $REGULUS/PrologLib/compatibility.pl. You are strongly advised to add the following line at the top of all your Prolog files:

   :- ensure_loaded('$REGULUS/PrologLib/compatibility').

   If you want your app to run both under Sicstus 3 and under Sicstus 4, you are advised to look carefully at $REGULUS/PrologLib/compatibility.pl and $REGULUS/PrologLib/utilities.

4. A couple of specific Sicstus 3/4 compatibility things that are particularly relevant to Regulus applications:

• Replace atom_chars/2 with atom_codes/2 everywhere.
• If you are using sockets to connect to other processes, an easy solution is to use the compatibility predicates in $REGULUS/PrologLib/compatibility.pl.

  Replace server-side sequences like

  current_host(Host),
  socket('AF_INET', Socket),
  socket_bind(Socket, 'AF_INET'(Host, Port)),
  socket_listen(Socket, 5),
  socket_accept(Socket, Client, Stream)

  with

  safe_socket_server_open(Port, Socket),
  safe_socket_server_accept(Socket, Client, Stream)

  You can see an example in $REGULUS/Prolog/dialogue_server.pl.

  Replace client-side sequences like

  socket('AF_INET', Socket),
  socket_connect(Socket, 'AF_INET'(Host, Port), Stream)

  with

  safe_socket('AF_INET', Socket),
  safe_socket_connect(Socket, Host, Port, Stream),

  You can see an example in $REGULUS/Examples/Calendar/Prolog/toy1_app_using_server.pl.

1. The Sicstus 4 port of Regulus is still very new. If you see things that look like problems in the Regulus code, feel free to mail me at Emmanuel.Rayner at issco.unige.ch or (better) submit a Regulus bug at http://sourceforge.net/projects/regulus/ > Tracker > Bugs