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, facilating 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 Windows-NT .DLL interface.