Dan Sugalski <[EMAIL PROTECTED]> wrote: > Okay, I'm about ready to just bite the bullet and declare that > INTVALs have to be 64 bit integers. > > Does anyone know of a platform that has neither native nor emulated > 64 bit integers? (One we're likely to run on, rather)
I'm fairly new to Parrot, but I've spent a while following standards tracks for languages such as C and C++, and also using Perl, so hopefully I'm not too far off the mark here... I was wondering if anyone else followed the discussion in comp.std.c about integer types, prior to the adoption of the C99 standard? There was a substantial paper put out by Frank Farance, entitled "specification based extended integer range" or SBEIR for short; see http://wwwold.dkuug.dk/JTC1/SC22/WG14/docs/c9x/extended-integers/. It wasn't adopted at the time, mostly because it was too big a lump to swallow, too late in the standardisation process, but it looks like it might be timely for Parrot to consider the concepts involved. The basic idea is to express the requirements that a program has for its integers, and let the compiler choose the best option; minimum size trap-on-overflow, take-modulus-on-overflow, exactness of size (for modulus operation), compactness speed There were objections that this was too complex, and that some combinations didn't make sense. To address the complexity, I proposed that integers should be subcategorised as "classical" versus "logical". "Classical" integers included all the existing C integer types, while "logical" integers were those based on usage specification rather than storage specification. In practice a logical specification would be something like an exact range of values with trap-on-overflow, whereas a classical or low level specification would be something like the range held by a CPU register, with host-specific handling of overflows. The relevance to Parrot is that, rather than opting for a short-list of integer sizes like [8, 16, 32 and 64 bit], we should if possible allow an extensible type system, possibly including optional automatic promotion to a library-implemented integer type (BigNum, Complex, or whatever). -Martin (I find it quiet disappointing that "modern" languages like Java and C# rely entirely on storage-based integer specifications "64 bit", when languages like Pascal and Algol had range-specified integers 20 years ago.) -- CAUTION: The information contained in this message is consequential and subject to legacy provenance. If you are the intended recipient you are hereby notified that reading this message is permitted. If you have not received this message please notarise the sender and destroy the originator.
