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Re: [Pharo-dev] SmallInteger asByteArray for negative numbers

by Nicolas Cellier

One more thing: accessing the integer bytes means accessing the details of internal representation... But if you look a bit deeper, you'll discover that: - SmallInteger use 2-complement internally (not accounting for immediate tag bits) - LargeInteger use sign-magnitude internally. So to maintain some uniformity at Integer level, and having all kind of sub-instances behaving identically, we have to cheet. As Sven said, in 2-complement we could model the high bits as an infinite sequence of 1... Not convenient for converting to a finite ByteArray, so we have chosen to behave as if integers were sign-magnitude encoded... Funnily, for bit-ops (bitAnd: bitOr: etc...) we have chosen another paradigm: behave as if integers were 2-complement encoded. 2015-02-06 15:48 GMT+01:00 Sven Van Caekenberghe <sven(a)stfx.eu>: > Alejandro, > > > On 06 Feb 2015, at 15:10, Alejandro Infante < > alejandroinfante91(a)gmail.com> wrote: > > > > Hello, > > I have just found that calling asByteArray for any negative small > integer returns the same result that the positive small integer. Is it > supposed to be like that or is it a bug? > > > > 1 asByteArray = -1 asByteArray. "true" > > > > (1 to: 100000) allSatisfy: [ :int | int asByteArray = int negated > asByteArray ] âtrue" > > > > Cheers, > > Alejandro > > (These kinds of questions should be asked on pharo-users(a)lists.pharo.org) > > You can only represent positive numbers as ByteArrays, because to > represent negative numbers you have to decide how to do that. The most > common solution is to use 2-complement. To do this you also need to decide > on the number of bytes to use. > > Here is an example using 4 bytes: > > | integer size mask | > integer := -123. > size := 4. > mask := (2 raisedTo: size * 8) - 1. > (mask bitAnd: ((integer abs bitXor: mask) + 1)) > asByteArrayOfSize: 4. > > => #[255 255 255 133] > > => FF FF FF 85 > > The reverse is: > > | integer size mask | > integer := #[255 255 255 133] asInteger. > size := 4. > mask := (2 raisedTo: size * 8) - 1. > (mask bitAnd: ((integer abs bitXor: mask) + 1)) > negated > > This is for negative numbers. > > Positive numbers need not be 2-complemented. > > When decoding, integers < (2 raisedTo: (size * 8) - 1) are negative. > > HTH, > > Sven > > >

Feb. 6, 2015

[pharo-project/pharo-core]

by GitHub

Branch: refs/tags/40479 Home: https://github.com/pharo-project/pharo-core

Feb. 6, 2015

[pharo-project/pharo-core] ccc6b1: 40479

by GitHub

Branch: refs/heads/4.0 Home: https://github.com/pharo-project/pharo-core Commit: ccc6b1a77fe84d7d9b93d031c81095ae0fb5f28a https://github.com/pharo-project/pharo-core/commit/ccc6b1a77fe84d7d9b93d031… Author: Jenkins Build Server <board(a)pharo-project.org> Date: 2015-02-06 (Fri, 06 Feb 2015) Changed paths: A ScriptLoader40.package/ScriptLoader.class/instance/pharo - scripts/script479.st A ScriptLoader40.package/ScriptLoader.class/instance/pharo - updates/update40479.st M ScriptLoader40.package/ScriptLoader.class/instance/public/commentForCurrentUpdate.st A Slot.package/ClassModification.class/instance/accessing/additions.st A Slot.package/ClassModification.class/instance/accessing/removals.st A Slot.package/Slot.class/instance/meta-object-protocol/installingIn_.st A Slot.package/Slot.class/instance/meta-object-protocol/removingFrom_.st M Slot.package/Slot.class/instance/queries/definingClass.st M Slot.package/SlotClassBuilder.class/instance/initialize-release/build.st Log Message: ----------- 40479 14877 InstanceVariableSlot>>#definingClass does not work for vars from the class side https://pharo.fogbugz.com/f/cases/14877 14876 Add call back in ClassBuilder to call slots when building a class https://pharo.fogbugz.com/f/cases/14876 http://files.pharo.org/image/40/40479.zip

Feb. 6, 2015

Re: [Pharo-dev] SmallInteger asByteArray for negative numbers

by Ben Coman

On Fri, Feb 6, 2015 at 10:48 PM, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: > Alejandro, > > > On 06 Feb 2015, at 15:10, Alejandro Infante < > alejandroinfante91(a)gmail.com> wrote: > > > > Hello, > > I have just found that calling asByteArray for any negative small > integer returns the same result that the positive small integer. Is it > supposed to be like that or is it a bug? > > > > 1 asByteArray = -1 asByteArray. "true" > > > > (1 to: 100000) allSatisfy: [ :int | int asByteArray = int negated > asByteArray ] âtrue" > > > > Cheers, > > Alejandro > > (These kinds of questions should be asked on pharo-users(a)lists.pharo.org) > > You can only represent positive numbers as ByteArrays, because to > represent negative numbers you have to decide how to do that. The most > common solution is to use 2-complement. To do this you also need to decide > on the number of bytes to use. > > Here is an example using 4 bytes: > > | integer size mask | > integer := -123. > size := 4. > mask := (2 raisedTo: size * 8) - 1. > (mask bitAnd: ((integer abs bitXor: mask) + 1)) > asByteArrayOfSize: 4. > > => #[255 255 255 133] > > => FF FF FF 85 > > The reverse is: > > | integer size mask | > integer := #[255 255 255 133] asInteger. > size := 4. > mask := (2 raisedTo: size * 8) - 1. > (mask bitAnd: ((integer abs bitXor: mask) + 1)) > negated > > This is for negative numbers. > > Positive numbers need not be 2-complemented. > > When decoding, integers < (2 raisedTo: (size * 8) - 1) are negative. > > HTH, > > Sven > > > I was going to complain about expecting such niceties as a built in 2s-complement rather than program it myself (I am a bit rusty on such matters), but when I look what should I find? (-123 asTwosComplement: 16rFFFFFFFF) asByteArray. "=> #[255 255 255 133]" cheers -ben

Feb. 6, 2015

Re: [Pharo-dev] Switching to Pharo from Visualworks

by Ben Coman

> I have a few questions: > > Why don't you all use a 6-paned browser (called the package browser in > Squeak) and control the introduction of top-level meta-categories? > > Because you have tags and you can filter packages. > @Stephen, I don't know of the six panelled browser you refer to, but presumably the tree list in the package pane of Pharo's System Browser accounts for one of those two of those six panes e.g. expand the AST-Core package ? @General, btw is it possible to have more levels in the package pane, so that all the AST packages appear under a single first level entry "AST" ? > I really did like the initial Pharo mission statement of making a > tighter, cleaner open-source ST80 implementation. > > @Stephen, Do you refer to Pharo's general mission or the Pharo Vision document [1] which details a few specific items targeted for improvement, noting that several of those items have already been completed. [1] https://gforge.inria.fr/frs/download.php/30434/*PharoVision*.pdf cheers -ben

Feb. 6, 2015

[Pharo CI] Jenkins down 10/11 Feb

by Marcus Denker

Hi, There will a big update of the Inria CI infrastructure. On 10 Feb the system will go offline 5PM Paris time, it will be online the 12th hopefully latest. Why? For now the system just supports Win and Linux. This update will add the base for MacOS vitual servers. (If you wonder how it works now: we have a non-virtual Mac in our office that runs all mac buildsâ¦) Marcus

Feb. 6, 2015

Re: [Pharo-dev] Switching to Pharo from Visualworks

by Guillermo Polito

El Fri Feb 06 2015 at 4:30:10 PM, Eliot Miranda <eliot.miranda(a)gmail.com> escribiÃ³: > On Feb 6, 2015, at 1:52 AM, Guillermo Polito <guillermopolito(a)gmail.com> > wrote: > > Well, but imagine how complex that bootstrap becomes when you want to add > to your classes: > > - traits > - layouts > - slots > ... > > And expressing all that in C also :) > > > Surely the bootstrap doesn't have to be expressed in C?!?! It can be > expressed in Smalltalk and still be a bootstrap right? > :) Hahaha, that was my point. Expressing it in C would be a mess. That's why we do it in Smalltalk.

Feb. 6, 2015

Re: [Pharo-dev] Switching to Pharo from Visualworks

by Sven Van Caekenberghe

Yes, but that is not really provided as a #catalog* method, is it ? There is #catalogDescription, but that is some lines of text. There should be something like #catalogLabel for a sjort one-line title style label. > On 06 Feb 2015, at 16:26, Esteban Lorenzano <estebanlm(a)gmail.com> wrote: > > there should be both: a name and a category > > Seaside - Web framework > Zinc - HTTP server > etc. > > Esteban > >> On 06 Feb 2015, at 16:16, Marcus Denker <marcus.denker(a)inria.fr> wrote: >> >> Yes, we need to improve that. Names are nice, but they make it harder to explore the system. >> >>> On 06 Feb 2015, at 12:43, Sean P. DeNigris <sean(a)clipperadams.com> wrote: >>> >>> Markus Fritsche-4 wrote >>>> +1 to that one. >>> >>> Yes, I also find it difficult - much more so when I was new to the >>> community, but even still a bit now. Coral, Zinc, Seaside, Opal - may be >>> catchy, but when I'm browsing the system, I just want to see where the darn >>> WebClient is, not mine for minerals or go to the beach!! ;) j/k. But >>> seriously, it's one thing to have "sexy" names at the top level - Pharo, >>> Squeak, Ruby, Python; but inside the system, it definitely creates >>> confusion. It's perhaps extra difficult for us because some of these >>> projects have both an outside and inside identity. It's an interesting open >>> problem... maybe some metadata at the MetaC/package level could help? Like >>> some standard tags like #WebClient, #Compiler, etc to say logically what >>> role a project fills... >>> >>> >>> >>> ----- >>> Cheers, >>> Sean >>> -- >>> View this message in context: http://forum.world.st/Switching-to-Pharo-from-Visualworks-tp4803811p4804142… >>> Sent from the Pharo Smalltalk Developers mailing list archive at Nabble.com. >>> >> >> > >

Feb. 6, 2015

Re: [Pharo-dev] Switching to Pharo from Visualworks

by Eliot Miranda

On Feb 6, 2015, at 1:52 AM, Guillermo Polito <guillermopolito(a)gmail.com> wrote: > Well, but imagine how complex that bootstrap becomes when you want to add to your classes: > > - traits > - layouts > - slots > ... > > And expressing all that in C also :) Surely the bootstrap doesn't have to be expressed in C?!?! It can be expressed in Smalltalk and still be a bootstrap right? > > El Fri Feb 06 2015 at 10:47:19 AM, Markus Fritsche <mfritsche(a)reauktion.de> escribiÃ³: >> >> On 06.02.2015 09:33, stepharo wrote: >>> In the coming months we will work on putting in place our bootstrapping kernel. >>> There are no Smalltalk able to do that right now. >> >> GNU Smalltalk does just that, if it doesn't find an image, it will be bootstrapped by using the shipped .st fileouts. >> >> A bit of cheating is involved, a compiler & initialization is implemented on the VM side. >> >> So I would say "there are no Smalltalk that are able to do that right now the way we want to do it" :-P >> >> (Pissing at the door contest, to refer to another unquoted metaphor :-D)

Feb. 6, 2015

Re: [Pharo-dev] Switching to Pharo from Visualworks

by Esteban Lorenzano

there should be both: a name and a category Seaside - Web framework Zinc - HTTP server etc. Esteban > On 06 Feb 2015, at 16:16, Marcus Denker <marcus.denker(a)inria.fr> wrote: > > Yes, we need to improve that. Names are nice, but they make it harder to explore the system. > >> On 06 Feb 2015, at 12:43, Sean P. DeNigris <sean(a)clipperadams.com> wrote: >> >> Markus Fritsche-4 wrote >>> +1 to that one. >> >> Yes, I also find it difficult - much more so when I was new to the >> community, but even still a bit now. Coral, Zinc, Seaside, Opal - may be >> catchy, but when I'm browsing the system, I just want to see where the darn >> WebClient is, not mine for minerals or go to the beach!! ;) j/k. But >> seriously, it's one thing to have "sexy" names at the top level - Pharo, >> Squeak, Ruby, Python; but inside the system, it definitely creates >> confusion. It's perhaps extra difficult for us because some of these >> projects have both an outside and inside identity. It's an interesting open >> problem... maybe some metadata at the MetaC/package level could help? Like >> some standard tags like #WebClient, #Compiler, etc to say logically what >> role a project fills... >> >> >> >> ----- >> Cheers, >> Sean >> -- >> View this message in context: http://forum.world.st/Switching-to-Pharo-from-Visualworks-tp4803811p4804142… >> Sent from the Pharo Smalltalk Developers mailing list archive at Nabble.com. >> > >

Feb. 6, 2015