OK, thanks for the explanation, good to hear it. (But, just nitpicking, it still does not say officially 'you can safely save your data in Fuel format and rest assured that you will always be able to read it back').
(Also, if there are compatibility problems between Pharo versions (understandably Pharo's doing), how can there be compatibility with other Smalltalk implementation, not that I expect any, but again, what is the official word ?) > On 16 Dec 2015, at 14:10, Mariano Martinez Peck <marianop...@gmail.com> wrote: > > Hi guys, > > I would like to say a couple of things: > > 1) Fuel format: Sven is right in the sense that Fuel has problems of > migrating to another Fuel version. However.... there is some explanation > needed here. Previously (years ago), a given Fuel version was not compatible > with previous versions because we were still changing/improving what we call > Fuel format, that is, basically, how objects are written and read from the > stream. We have stopped with those optimization/changes years ago. So the > "Fuel format" has been stable so far for a couple of years. > > 2) Fuel gets in the internals: In Pharo 4.0 Fuel was not compatible with > Fuel from 3.0. I don't remember the exact detail but it was a change in > Pharo's Date (or DateAndTime I cannot remember). Now the version that should > work in 5.0 changes the Characater serialization. What I want to make clear > here is that it's NOT that we are changing the fuel format 1) as years ago > when Fuel as still evolving from this point of view. It's Pharo changes that > make our incompatibility. But that doesn't mean we cannot fix it. > > 3) Yes, compromises for speed: I think that both examples that break > compatibility in 4.0 (Date / DateAndTime change) and in 5.0 with Spur > (Character) is because we target speed. We do have special clusters for both > of those cases (Date and Character), and so, we get into it's internals for > performance reasons. If the internals change, then we break. This is why a > text serializer for example may simply not break, because it continues using > text representation that might not have been affected by the underlaying > internal representation. > > We will try to do a Pharo 40 - Pharo 5.0 (or spur actually) compatibility. > > Best, > > > On Wed, Dec 16, 2015 at 9:49 AM, Sven Van Caekenberghe <s...@stfx.eu> wrote: > > > On 16 Dec 2015, at 13:46, Denis Kudriashov <dionisi...@gmail.com> wrote: > > > > Hi. > > > > 2015-12-16 13:33 GMT+01:00 Sven Van Caekenberghe <s...@stfx.eu>: > > > On 16 Dec 2015, at 13:24, Clément Bera <bera.clem...@gmail.com> wrote: > > > > > > I don't know if SqueakV3 - Spur32 support is needed, however, I think it > > > is really important to be able to serialize and materialize objects > > > between 32 bits spur images and 64bits spur images. > > > > I don't know. > > > > Yes it would be nice, but since Fuel cannot even exchange data between > > different version itself (If I understand the situation correctly), why > > should that have to work ? > > > > It is needed to use fuel as communication format between services which run > > on different platforms. For example you can exchange data between 64bits > > server and 32bits android phone. > > What you want might not be the same to what it was designed for. > > I might be wrong, but that is how I understood it from discussion in the past > when moving data from one fuel version to another. > > Let's see what the Fuel guys have to say about this. > > > > -- > Mariano > http://marianopeck.wordpress.com
