Hi Shaping, Pharo (& Squeak & Cuis) Float subclass BoxedFloat64 maps exactly to VW's Double. In 64-bit SmallFloat64 maps exactly to SmallDouble. But I wonder whether there is any issue here. STON would use the print strings for (PSC) Float / (VW) Double, and so deseerialization on Pharo would automatically produce the right class. Going in the other direction might need some help. APF needs support in PSC before one can port, but are representable as suitably-sized word arrays. There is no support for __float128 anywhere in the VM (e.g. not even in the FFI) on PSC as yet. On Tue, Nov 6, 2018 at 12:56 AM Shaping <shaping@uurda.org> wrote:
STON is able to serialise Pharoâs Floats, what do you mean by double ?
Floating-point numbers in IEEE 64-bit format, 14 or 15 significant digits, with a range between =10^307 and 10^307.
Additionally, I recently asked Sven if t would be possible to store ScaledDecimals (I think it implements what you call ArbitraryPrecisionFloats) without loss of precision.
Iâm referring VWâs Double (and SmallDouble in 64-bit engines/images). APFs are binary representations that can be arbitrarily large, using Integers (LargePositiveIntegers for example) to model the bits of the mantissa.
Before, because STON extends JSON, it was storing all kind of numbers either as float or integer.
Now, thanks to Sven, STON stores ScaledDecimals correctly (without loss of precision through serialisation as float, what was done before).
But I do not know if this change is integrated in recent images yet.
â¦..
Number subclass: #Float
instanceVariableNames: ''
classVariableNames: 'E Epsilon Halfpi Infinity Ln10 Ln2 MaxVal MaxValLn MinValLogBase2 NaN NegativeInfinity NegativeZero Pi RadiansPerDegree Sqrt2 ThreePi Twopi'
poolDictionaries: ''
category: 'Kernel-Numbers'
My instances represent IEEE-754 floating-point double-precision numbers. They have about 16 digits of accuracy and their range is between plus and minus 10^307. Some valid examples are:
8.0 13.3 0.3 2.5e6 1.27e-30 1.27e-31 -12.987654e12
â¦.
I see that Pharoâs Float is VWâs Double. So then I just need to be able to serialize APF.
â¦.
FIFloatType subclass: #FFIFloat128
instanceVariableNames: ''
classVariableNames: ''
poolDictionaries: ''
category: 'UnifiedFFI-Types'
I'm a 128bits (cuadruple precision) float.
It is usually not used, but some compiler modes support it (__float128 in gcc)
THIS IS NOT YET SUPPORTED
â¦.
The class above is also from the Pharo 7 image. This is the largest of the c-type FFIFloats. Any Float classes of this size and larger for the Smalltalk heap on 64-bit Pharo?
Cheers,
Shaping
Le 6 nov. 2018 à 06:58, Shaping <shaping@uurda.org> a écrit :
(Having domain problems recently. Please excuse this posting if you have seen it twice. I've not seen it appear yet on the list.)
Can STON be extended to handle Doubles and ArbitraryPrecisionFloats?
Shaping
-----Original Message----- From: Pharo-dev [mailto:pharo-dev-bounces@lists.pharo.org <pharo-dev-bounces@lists.pharo.org>] On Behalf Of David T. Lewis Sent: Wednesday, October 31, 2018 14:58 To: Pharo Development List <pharo-dev@lists.pharo.org> Subject: Re: [Pharo-dev] [ANN] The STON Specification
This is very clear and well written.
Dave
Hi,
Since there can never be enough documentation I finally took some time to write a more formal description of STON as a data format.
https://github.com/svenvc/ston/blob/master/ston-spec.md
The idea is to let this stabilise a bit and to then update the two other documents describing STON, where necessary:
https://github.com/svenvc/ston/blob/master/ston-paper.md
https://ci.inria.fr/pharo-contribution/job/EnterprisePharoBook/lastSuc cessfulBuild/artifact/book-result/STON/STON.html
Also, the latest changes in STON have to make their way to the Pharo image as well.
https://github.com/svenvc/ston
All feedback is welcome.
Sven
-- Sven Van Caekenberghe Proudly supporting Pharo http://pharo.org http://association.pharo.org http://consortium.pharo.org
-- _,,,^..^,,,_ best, Eliot