March 2020 - Pharo-users - lists.pharo.org

Pharo float precision vs Python
by Tim Mackinnon March 25, 2020

March 25, 2020

Hi guys - I recall this came up a few months ago, but Iâm curious about the difference of Pharoâs use of Float64 vs Python - as I assumed that if languages use the same IEEE spec (or whatever spec it is) that simple stuff would be quite similar. I am curious why in Python adding these numbers: y = 987.9504418944 + 815.2627636718801 + 1099.3898999037601 + 1021.6996069333198 + 1019.8750146478401 + 1084.5603759764 + 1008.2985131833999 + 1194.9564575200002 + 893.9680444336799 + 1032.85460449136 + 905.9324633786798 + 1024.2805590819598 + 784.5488305664002 + 957.3522631840398 + 1001.7526196294 print(y) print(y / 15) Gives: 14832.682458496522 988.8454972331015 In pharo I have noticed an anomaly which I thought was precision but it may be something odd with iterators. y := 987.9504418944 + 815.2627636718801 + 1099.3898999037601 + 1021.6996069333198 + 1019.8750146478401 + 1084.5603759764 + 1008.2985131833999 + 1194.9564575200002 + 893.9680444336799 + 1032.85460449136 + 905.9324633786798 + 1024.2805590819598 + 784.5488305664002 + 957.3522631840398 + 1001.7526196294. y. y / 15. Gives the same as Python. BUT: z := {987.9504418944 . 815.2627636718801 . 1099.3898999037601 . 1021.6996069333198 . 1019.8750146478401 . 1084.5603759764 . 1008.2985131833999 . 1194.9564575200002 . 893.9680444336799 . 1032.85460449136 . 905.9324633786798 . 1024.2805590819598 . 784.5488305664002 . 957.3522631840398 . 1001.7526196294} sum. z. z / 15. Gives 14832.68245849652 988.8454972331014 Is this correct?

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[ANN] Next Pharo Sprint: March 27
by Marcus Denker March 24, 2020

March 24, 2020

We will organize a Pharo sprint / Moose dojo March 27 Goals of this sprint: - Fix issues from tracker https://github.com/pharo-project/pharo/issues This is a Remote Sprint, it happens on Discord. http://pharo.org/contribute-events We have added a Board to coordinate the work: https://github.com/orgs/pharo-project/projects/9 A list of all Pharo Event of the year an be found here: https://association.pharo.org/events

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Versioning and packaging?
by Rob Raisch March 23, 2020

March 23, 2020

Iâve noticed that the majority of projects in which I have an interest, from any repository, like Moose or PetitParser, fail to load into Pharo 8.0 throwing errors related to missing requirements. For example, filing in Moose into Pharo 8.0 fails with âError: Cannot resolve symbolic version #release1â. In the Catalog browser, Moose is tagged with âPharo3.0â. Does this imply that Moose only works in that version of Pharo only? PetitParser, which Moose requires, is tagged âPharo5.0â and PetitParser2 is tagged âPharo6.0â neither of which will work in Pharo 3.0. So, Iâm left wondering if Iâm doing something wrong, and how requirements are supposed to work when there are so many projects that depend on deprecated versions of Pharo. Thanks. /rr -- Rob Raisch, Internet Handyman

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[ANN] Pharo Newsletter March 2020
by Marcus Denker March 23, 2020

March 23, 2020

[ANN] Pharo Newsletter March 2020 The Pharo Newsletter March 2020 has been sent to subscribers last week: https://mailchi.mp/pharo/pharo-newsletter-march-2020 To get it as soon as it is released, please subscribe here: http://eepurl.com/bykqWn

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Morph Code problem
by shawon58 March 22, 2020

March 22, 2020

i am new in morph code. so i try this code "Color orange asMorph openInWorld" . in my screen it shows a line but i cant able to close that. screen shot added below. thanks <http://forum.world.st/file/t372453/Capture.png> -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

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Json encoding
by Vitor Medina Cruz March 21, 2020

March 21, 2020

Hello, I know two projects of json encoding/decoding â NeoJson and STON. In Java I have two most used ones too: Gson and Jackson. Using those I can simply pass any object and it they can convert to a json string, the former can't deal with cycles, the latter can with some little config. NeoJson seems to be limited to primitives, for example, in Pharo 8 I can't run NeoJSONWriter toString: (Date today) > Since I got: NeoJSONMappingNotFound: No mapping found for Date in NeoJSONWriter > STON works fine with STON toString: (Date today). > but fail with: STON toJsonString: (Date today). > Also, STON fails if I try to serialize an object which contains an instance variable pointing to a block closure. I didn't find out how to ignore these instance variable as it is unnecessary for what I need at the moment. So, which lib for json or some object/string encoding/decoding should I be using on Pharo? Is there something better than those libs? Am I doing something wrong? My experience tells this should be simple, but it is not. Thanks in advance, Vitor

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Slots vs collections
by N. Bouraqadi March 21, 2020

March 21, 2020

Hi, Suppose I have an instance variable referencing a collection of booleans. I want to have all elements of the collection be stored as bits. Is there a way I can express it using slots? This idea can be generalized to other types of slots. Noury

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Morphs with Spec2
by Sebastian Jordan March 20, 2020

March 20, 2020

Hi everyone, I Want to use a StringMorph as a title of a UI created with Spec2. For that, I am using a SpMorhPresenter inside a SpPresenter. But the text inside the morph loses its format as it is shown in the attached image. Does anyone knows how to solve this? What I am doing wrong? It would be very appreciated. Thanks for your time. Here is the code of the example: defaultSpec ^ SpBoxLayout newVertical add: #morphLabel; add: #button1; add: #button2; yourself initializePresenters morphLabel := self obtainSpMorphPresenterwithAStringMorph. button1 := self newButton. button1 label: 'Button one'. button2 := self newButton. button2 label: 'Button two'. self focusOrder add: morphLabel; add: button1; add: button2 obtainSpMorphPresenterwithAStringMorph | morph | morph := StringMorph contents: 'A String Morph' font: (LogicalFont familyName: Smalltalk ui theme labelFont familyName pointSize: Smalltalk ui theme labelFont pointSize + 10). ^ SpMorphPresenter new morph: morph; yourself

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Best ways to retrieve JSON objects from a feed?
by Tim Mackinnon March 20, 2020

March 20, 2020

Hi everyone, Iâm finally finding some space from world chaos and looking more into Pharo, and I have a question about retrieving json data from feeds - how is the best way to elegantly parse it - e.g. I am doing : url := ZnUrl fromString: 'http://climatedataapi.worldbank.org/climateweb/rest/v1/country/annualavg/pr…. url addPathSegments: {aDate1 asString. aDate2 asString. aCountryCode}. result := ZnEasy get: url. content := STONJSON fromString: result contents. ... However I was kind of surprised there wasn't something on a ZnResponse for getting json objects e.g. result getJsonObjects or something like that? Itâs so common I wonder if I am missing some trick? What arenât there helpers in place for this or is there a better way to do this that I havenât found yet? I was kind of thinking something like (which obviously I can add myself) result asJsonObjects sum: [:obj | (obj at: âannualDataâ) first ] Tim

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[ANN] COVID-19 and JRMPC
by Richard Kenneth Eng March 19, 2020

March 19, 2020

https://smalltalk.tech.blog/2020/03/13/covid-19-and-jrmpc/ This is very unfortunate. I was counting on the awards ceremony for a great deal of PR value. A virtual ceremony likely wouldn't have the same impact. Richard

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