May 2015 - Pharo-dev - lists.pharo.org

Re: [Pharo-dev] Is there an official JSON parser/writer?

by stepharo

Le 26/5/15 19:14, Guillermo Polito a Ã©crit : > And even if STON is integrated, PostgresV2 configuration should > include a dependency against it (because in the not so remote future > we will need explicit dependency information to build images). + 1000000 Mking dependencies explicit is the only way to not die under complexity!

May 28, 2015

Re: [Pharo-dev] Inconsistent number comparison?

by stepharo

Read fun with numbers in deep into pharo :) Le 27/5/15 05:00, Sean P. DeNigris a Ã©crit : > Why does "1 = 1.0" but "273.15 ~= (5463/20)"? You must send #asFloat to the > fraction to answer true... > > > > ----- > Cheers, > Sean > -- > View this message in context: http://forum.world.st/Inconsistent-number-comparison-tp4828795.html > Sent from the Pharo Smalltalk Developers mailing list archive at Nabble.com. > >

May 28, 2015

Re: [Pharo-dev] Beyond RPackages: RPackageTag and DynamicGroup

by Marcus Denker

> On 28 May 2015, at 01:56, Sergio Fedi <sergio.fedi(a)gmail.com> wrote: > > Hi list! > > As we are adding comments to Packages in Pharo, we stumbled upon the fact that there are other creatures present in the package list. > > These are: > > RPackageTag, which models the tags under the package > DynamicGroup, which model the dynamic categories of LastModifiedClasses, MostViewedClasses and Work > > Objects of these classes WILL have to understand the accessor #comment > > 1 - How do we want RPackageTag and DynamicGroup to handle #comment and #comment: ? The tag could just return the comment that is defined for itâs package. The Nautilus groups maybe could return a description on what they do and how they work? Marcus

May 28, 2015

Re: [Pharo-dev] Beyond RPackages: RPackageTag and DynamicGroup

by stepharo

Le 28/5/15 01:56, Sergio Fedi a Ã©crit : > Hi list! > > As we are adding comments to Packages in Pharo, we stumbled upon the > fact that there are other creatures present in the package list. > > These are: > > RPackageTag, which models the tags under the package > DynamicGroup, which model the dynamic categories of > LastModifiedClasses, MostViewedClasses and Work > > Objects of these classes WILL have to understand the accessor #comment > > 1 - *How do we want RPackageTag and DynamicGroup to handle #comment > and #comment: ?* > 2 - *Are there any other classes present in that list we are not aware > of?* > > Some options we can consider: > > a - Hardcode in an generic answer to #comment, do nothing on #comment, > leave them be for now I would just return an empty string. I think that the problem is that the item list elements should be customized to not send the messages comment to the wrapped items (Tag, DynamicGroup....). Stf > b - Have the object behave as a RPackage, it can have a persistent > comment. In this case, where do we save that data? > > Since the Package Comments case is taking so long, and to keep the > scope of the case in check, we are incline to handle both classes with > option a. > > But we wanted to check with the list first, just in case. > > Ok, now let's hear you feedback. >

May 28, 2015

Re: [Pharo-dev] LinkedIn presence

by Yuriy Tymchuk

yes, here it is: https://www.linkedin.com/grp/home?gid=2558378 <https://www.linkedin.com/grp/home?gid=2558378> Uko > On 28 May 2015, at 01:46, Sergio Fedi <sergio.fedi(a)gmail.com> wrote: > > Hi, does Pharo have a presence on LinkedIn? > > I want to indicate my (tiny) contribution to the Pharo project and I don't find it as an Organization. >

May 28, 2015

Re: [Pharo-dev] Inconsistent number comparison?

by Florin Mateoc

On 5/27/2015 1:29 PM, Nicolas Cellier wrote: > > > 2015-05-27 14:24 GMT+02:00 Sean P. DeNigris <sean(a)clipperadams.com <mailto:sean@clipperadams.com>>: > > Nicolas Cellier wrote > > Also because it's good to know that 1/10 ~= 0.1 > > Why? It's an implementation detail. #= unlike #== is IIUC supposed to be > logical to the domain, and math doesn't make any distinction about how bits > are stored ;) > > > > Nope, it's more than a detail. > It's what every engineer should know about floating point. > If you think float == real number then you'll be screwed by many unexpected behavior, like why 0.1+0.1+0.1 ~= 0.3 etc... Totally agree until now :) > So you have to somehow unlearn what you were teached in math, because it's simply not true with float. I think this is not well formulated and it might actually deepen the misunderstanding. There is no math to be unlearned. There is just some extra info that has to be remembered about computers. I don't think anybody was ever taught in math class that 0.33 equals 1/3. Not even that 0.3333333333333333 equals 1/3. Not even in the US (although there is a state where a guy introduced a law to change the value of Pi to 3, to make things simpler :)). Here we have the same situation. For these particular floats, their literal value, as expressed in base 10 digits (which is what we do when we input them in source code), has no exact representation (in binary, which is how they are actually compiled/stored), so from the very start these floats are just an approximation. Perhaps the compiler should warn people every time they write such a literal. This would be easy to do and I think it would save people a lot of heartburn. It is very revealing to look at 0.1 asTrueFraction or at 273.15 asTrueFraction , and then it will become obvious why these floats are not equal with those fractions. Whereas if you take the very same base 10 literals, but not in float format but as scaledDecimals, the comparisons evaluate to true, as they should: 1/10 = 0.1s and 273.15s = (5463/20). Florin

May 28, 2015

Beyond RPackages: RPackageTag and DynamicGroup

by Sergio Fedi

Hi list! As we are adding comments to Packages in Pharo, we stumbled upon the fact that there are other creatures present in the package list. These are: RPackageTag, which models the tags under the package DynamicGroup, which model the dynamic categories of LastModifiedClasses, MostViewedClasses and Work Objects of these classes WILL have to understand the accessor #comment 1 - *How do we want RPackageTag and DynamicGroup to handle #comment and #comment: ?* 2 - *Are there any other classes present in that list we are not aware of?* Some options we can consider: a - Hardcode in an generic answer to #comment, do nothing on #comment, leave them be for now b - Have the object behave as a RPackage, it can have a persistent comment. In this case, where do we save that data? Since the Package Comments case is taking so long, and to keep the scope of the case in check, we are incline to handle both classes with option a. But we wanted to check with the list first, just in case. Ok, now let's hear you feedback.

May 27, 2015

LinkedIn presence

by Sergio Fedi

Hi, does Pharo have a presence on LinkedIn? I want to indicate my (tiny) contribution to the Pharo project and I don't find it as an Organization.

May 27, 2015

Pharo running on Pi - video

by Torsten Bergmann

Made a video of Pharo running on a Raspberry Pi with small Tontec 3,5'' display: https://www.youtube.com/watch?t=16&v=sfxFqQIuawg

May 27, 2015

Re: [Pharo-dev] Inconsistent number comparison?

by Nicolas Cellier

2015-05-27 14:15 GMT+02:00 Sean P. DeNigris <sean(a)clipperadams.com>: > Nicolas Cellier wrote > > we want to have this property a=b & (a=c) ==> (b=c). > > If IUC it sounds more inconsistent because > (5463/20) = (10926/40) "true" > > > What is less consistent is that these fractions are all different: fractions := (101 to: 200) collect: [:n | 1<<n+1/(1<<n)]. [fractions asSet size = 100] assert. But they are all "equal" to the same float: [fractions allSatisfy: [:f | f asFloat = 1.0]] assert. [(fractions collect: #asFloat as: Set) size = 1] assert. Don't you see a problem now? > ----- > Cheers, > Sean > -- > View this message in context: > http://forum.world.st/Inconsistent-number-comparison-tp4828795p4828890.html > Sent from the Pharo Smalltalk Developers mailing list archive at > Nabble.com. > >

May 27, 2015