1.10 Version 2.0 Release Notes

Version 2.0 is first of all a freeze of all the features added to the various 1.9.x releases. Version 2.0.6 for PC has moved from the WATCOM C 32-bit windows extender to Windows NT and runs under Windows 3.1 using the Win32s NT emulator.

New features offered:

• 32-bit Virtual Machine
  Removes various limits and improves performance.
• Inline foreign functions
  `Simple' foreign predicates no longer build a Prolog stack-frame, but are directly called from the VM. Notably provides a speedup for the test predicates such as var/1, etc.
• Various compatibility improvements
  
• Stream based I/O library
  All SWI-Prolog's I/O is now handled by the stream-package defined in the foreign include file SWI-Stream.h. Physical I/O of Prolog streams may be redefined through the foreign language interface, facilitating much simpler integration in window environments.

Version 2.0.6 offers a few incompatibilities:

• retractall/1
  In previous releases, the definition of retractall/1 was: retractall(Term) :- retract(Term), fail. retractall(_).

  As from version 2.0.6, retractall/1 is implemented as a deterministic foreign predicate compatible with Quintus Prolog. It behaves as:

  retractall(Head) :- retract(Head), fail. retractall(Head) :- retract((Head :- _)), fail. retractall(_).

  I.e. the definition behaves the same when handling predicates consisting of facts. Clauses with a non-true body will be retracted if their head matches.

• Foreign interface types
  All foreign interface types now have names ending in _t to lessen the chance for conflicts. term, atomic, functor and module have #define's for backward compatibility.
• PL_register_foreign()
  The attributes is now a bitwise or of the attribute flags rather than a 0 terminated list. This has no consequences for predicates that have no attributes (99% of them), while predicates with just one attribute will generate a compiler warning, but work properly otherwise. Predicates with more than one attributes must be changed.
• PL_dispatch_events
  This pointer is replaced by PL_dispatch_hook(). A function was necessary for the Win32 .DLL interface.