[fpc-other] PROLOG written in Pascal

[Nikolay Nikolov]

On 09/21/2014 12:31 AM, Marco van de Voort wrote:
> In our previous episode, Mark Morgan Lloyd said:
>> Is anybody interested in a PROLOG interpreter written in Turbo Pascal,
>> plus a couple of typeset articles which outline how it works internally?
>>
>> When I found it I was wondering whether it could be usefully used to
>> handle inference rules in a Delphi/FPC/Lazarus program, in the same way
>> that MS use Prolog for some of their network configuration stuff.
>> However it turns out that it is coded explicitly for Turbo Pascal with a
>> garbage collector on top of the normal heap, which I think implies that
>> porting it to FPC would need either a mark/release facility or multiple
>> heaps which could be "thrown away" when no longer needed.
> I don't understand why interested people couldn't implement mark/release for
> the base TP compatible level of FPC ?  What is so different between TP and
> FPC there?
Just implemented it in the "tiny" heap manager (the heap manager used 
for i8086-msdos and perhaps in the future - the embedded targets). For 
the regular targets I'd suggest adding it as an unit that replaces the 
standard heap manager with the simple one, as described by Marco. You 
can even use the "tiny" heap manager sources (rtl/inc/tnyheaph.inc and 
rtl/inc/tinyheap.inc) in your unit. They might need some minor patching, 
but nothing too difficult.

Nikolay