STON is able to serialise Pharo���s Floats, what do you mean by double ?

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Floating-point numbers in IEEE 64-bit format, 14 or 15 significant digits, with a range between =10^307 and 10^307.

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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.

��

I���m referring VW���s 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).

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But I do not know if this change is integrated in recent images yet.

��

���..

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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'

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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

���.

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I see that Pharo���s Float is VW���s Double.���� So then I just need to be able to serialize APF.

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���.

FIFloatType subclass: #FFIFloat128

������������������������������ instanceVariableNames: ''

������������������������������ classVariableNames: ''

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������������������������������ category: 'UnifiedFFI-Types'

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I'm a 128bits (cuadruple precision) float.

It is usually not used, but some compiler modes support it (__float128 in gcc)

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THIS IS NOT YET SUPPORTED

���.

��

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 �� 06:58, Shaping <shaping@uurda.org> a ��crit :

��

(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] 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

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