Re: [Gm2] ISO SYSTEM clarification

[Gaius Mulley]

Iztok <address@hidden> writes:

> Gaius Mulley wrote:
> 
> >Hi,
> >
> >I'm currently implementing the ISO SYSTEM module and was wondering
> >whether other compilers support SHIFT and ROTATE on non SYSTEM
> >types. Ie is it permissible to:
> >
> 
> Gardens Point M2: SHIFT,ROTATE (VAR b : BITSET; n : INTEGER);
> 
> StonyBrook: SHIFT, ROTATE (set : PackedSetType; shift : INTEGER) :
> PackedSetType;
> 
> StonyBrook M2 considers sets as having a boolean membership flag for
> each value in the base type. The difference between the SET and the
> PACKEDSET (which is SBM2 extension) is that the PACKEDSET has booleans
> represented as bits while the SET elements can be realized at
> compiletime (by compiler itself) as any possible representation of the
> boolean. PACKEDSET has also determined positions of the bits inside
> the processor word regarding their basetype value.
> 
> So, the answer for your question would be - SBM2 would compile your
> example while the GPM would not. I would say that the operations would
> work for long sets also for SBM2 while I am not so sure for GPM. I
> would have to test it which I (currently) do not have time for.

ok, I think that in light of these answers it would be good for gm2 to
support SHIFT, ROTATE on large sets.. I'm still working on ISO SYSTEM
related issues (getting libraries to link and resolving name clashes
between ISO and PIM libraries). So I'll initially check in the ISO SYSTEM
modifications without this feature in order to allow testing to occur.
Then I'll work on fixing large sets with SHIFT, ROTATE, which should
be a straight forward expansion of the large set code written last Oct..

> 
> Sorry for late answer - I was changing my appartement and was very
> very busy last days.

no problem at all! Thanks for the detail..

Gaius