October 2017 - Pharo-users - lists.pharo.org

Re: [Pharo-users] Glorp: #includesKey:
by Herby VojÄÃk Oct. 25, 2017

Oct. 25, 2017

Tom Robinson wrote: > Hi Herby, > > In my opinion, the way you found to make it work is the way it should > be. The reason is that the first way doesn't translate into SQL and the > second one does. It might be possible to add includesKey: functionality > but resolving that to SQL would be more complex. I would not call this a I think I disagree with this, but correct me if I am wrong. With DictionaryMapping, you map a set of (key, value) pairs into appropriate fields in a table. In essence, it does not differ at all to mapping any other collection containing objects with fields (actually, from what I understood, it does internal tricks to do just that - create internal "class mapping" for an association of that particular dictionary mapping). In case of primitive value dictionaries, it even _is_ the same: key is mapped to one field, value is mapped to different field. If I want to create subquery using value, I can freely use things like #anySatisfy: to filter on that value (which I did in my case, but I come to that later). Since Dictionary enumerates values in do:, select:, collect: (and anySatisfy:), writing each tools anySatisfy: [...] is the same as writing each tools values anySatisfy: [...] but what if I wanted to write each tools keys anySatisfy: [...] ? I cannot, Glorp fails on 'keys' (I tried to use `keys includes:` instead of `includesKey:`, to no avail). So what I want to point here is, that in DictionaryMapping I map keys and values to different fields in table (values can be complex, in which keys they are mapped to more fields, but that is not important distinction here), but Glorp only allows me to use values (and only implicitly) in where clauses; I have no way to use keys at all there. So I assert here that "resolving that to SQL would be more complex" is not true. Key is mapped the same way value is; if I can use where clause that uses value in certain way, I should be able to use key as well - SQL generating from one or the other have same level of difficulty (in fact, I think key is easier, as you do not actually need to join the foreign table); the generated SQL could be something like SELECT * FROM AGENT a WHERE a.tool_id = <toolId asDbValue> The fact that I found a each tools anySatisfy: [ :tool | tool id = aToolId ] is in fact only because non-primitive mappings are processed differently in DictionaryMapping, a non-primitive values are _required_ to have a field defined (not in table, that is understandable, I need to be able to make a join, but in descriptor) a mapping that contains the key. So in essence, that could be represented as SELECT * FROM AGENT a WHERE a.tool_id IN (SELECT * FROM TOOL t WHERE t.agent_id = a.id AND t.id = a.tool_id AND t.id = <aToolId asDbValue>) which is basically same as above, as actually, "a.tool_id = <aToolId asDbValue>" is executed here as well (plus checking that such dictionary actually exists at all; maybe that should be present in previous case as well, but Glorp can generate the join, that's not the question here). It is actually interesting question what SQL Glorp actually generated for "TgAgent readOneOf: [:a|a tools anySatisfy: [:t|t id = toolId]]". Point here is: 1. Why do I need to work it around via [:tool | tool id = aToolId] when I am only interested on "which tools the agent uses" (in fact, give me all agents using this tool). 2. Should this be key -> primitive value mapping, I have simple _no way_ to ask the equivalent of #includesKey: at all (as the value is, for example, a String or an Integer, so no `tool id` is available). > bug. I would call it a limitation of the implementation. I don't know of > anyone planning to add this feature to Glorp right now. That's why I would say #keys (and, ideally, #includesKey:) are actually needed addition to Glorp's set of known-and-translated selectors in case of DictionaryMapping. > Regards, > > Tom Thanks, Herby

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CodeCity like visualization in Linux
by Rafael Luque Oct. 25, 2017

Oct. 25, 2017

Hi all, I'm working on an introductory talk about Pharo for a software craftsmanship local meetup. The presentation will be mainly driven by demos and I'd like to show a CodeCity-like visualization. I've been able to load it in Pharo 5, but it get an error when select the "City" tag in GTInspector. It seems that NBOpenGL does not work in Linux. Do you know any way to make it work in Linux? Thank you. â

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[ANN] LAM Research upgraded to Platinum Membership
by Marcus Denker Oct. 25, 2017

Oct. 25, 2017

The Pharo Consortium is very happy to announce that LAM Research has upgraded to Platinum Member status. About - LAM Research: http://www.lamresearch.com - Pharo Consortium: http://consortium.pharo.org The goal of the Pharo Consortium is to allow companies and institutions to support the ongoing development and future of Pharo. Individuals can support Pharo via the Pharo Association: http://association.pharo.org

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Re: [Pharo-users] Dynamically changing code in a safe way
by Richard Sargent Oct. 25, 2017

Oct. 25, 2017

This is a great question, Abdelghani. It comes down to the meaning of the phrase "everything is an object". When you wrote "currentBloc value", that caused the block *[ 1 to:50 do: [:index |Transcript show: index. 100 milliSeconds asDelay wait]. Transcript cr. 1000 milliSeconds asDelay wait ]* to evaluate. The fact that you hold a reference to that block elsewhere and change what object is referenced at some point does not change the fact that the block itself is executing. Until your code executes *currentBloc value* again, it won't start the new block executing. Imagine if I were to hand you a loaf of bread and tell you to feed it to the dog. If I were then to hand you another loaf of bread, the dog would continue eating the first loaf. We never told the dog to do anything else. On Mon, Oct 23, 2017 at 1:53 PM, abdelghani ALIDRA via Pharo-users < pharo-users(a)lists.pharo.org> wrote: > > > ---------- Forwarded message ---------- > From: abdelghani ALIDRA <alidrandco(a)yahoo.fr> > To: <pharo-users(a)lists.pharo.org> > Cc: > Bcc: > Date: Mon, 23 Oct 2017 20:53:51 +0000 (UTC) > Subject: Dynamically changing code in a safe way > Hi, > > If I create a class HotSwapping with the instance variable currentBLoc > (and the corresponding accessors) and the following methods : > > HotSwapping>>initialize > currentBloc := [ 1 to:50 do: [:index |Transcript show: index. 100 > milliSeconds asDelay wait]. Transcript cr. 1000 milliSeconds asDelay wait ] > > HotSwapping>>run > [10 timesRepeat: [ currentBloc value ]] fork > > I then do : obj := HotSwapping new run > The âfunnyâ thing is that, when Transcript starts showing numbers, lets > say : 12345678910 (i.e. the bloc is in the middle of its execution), I do > obj currentBloc: [Transcript show: âHelloâ;cr. 1000 milliSeconds asDelay > wait ] > > The Transcript does not stop showing numbers. It shows the Hello message > only after the old bloc has finished executing (the entire line of number > form 0 to 50 has been printed in the Transcript) > > So why does not this happen this way? Why the assignment of the new code > is delayed until the end of the bloc execution? is it something related to > threads execution or does Pharo implement some safety hot swapping > mechanisms? > > Thanks in advance. > Abdelghani > > >

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Can we halt on memory growth beyond a limit?
by PAUL DEBRUICKER Oct. 25, 2017

Oct. 25, 2017

I'm trying to get some understanding about a process that uses a lot of RAM when it runs. Is there a way to halt if/when RAM use doubles ? Thanks Paul

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using mocketry to mock subcall
by Peter UhnÃ¡k Oct. 24, 2017

Oct. 24, 2017

Hi, maybe I am missing something fundamental, because this seems like an obvious scenario I have a class Something with two methods Something>>askForName ^ UIManager default request: 'Name' Something>>name ^ self askForName , ' suffix' Now I want to mock out askForName, so I can run it automatically in tests... I've tried just stubbing it... SomethingTest>>testRenameStub Something stub askForName willReturn: 'new'. Something new name should be: 'new suffix' however it still opens the window to ask for the name, so the original method is being called. Right now I have to stub it with metalinks, which doesn't play well with some tools (hapao) SomethingTest>>testRenameMeta | link newName | link := MetaLink new metaObject: [ 'new' ]; control: #instead. (Something >> #askForName) ast link: link. [ newName := Something new name ] ensure: [ link uninstall ]. self assert: newName equals: 'new suffix' Thanks, Peter

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Multi-core Software Concurrency
by horrido Oct. 24, 2017

Oct. 24, 2017

With todayâs powerful multi-core processors, the demand for efficient software concurrency is high. We find strong support for such concurrency in the latest crop of âmodernâ languages such as Clojure, Elixir, Go, Haskell, and Scala. Whenever I present Smalltalk (Pharo) as a great language option, inevitably someone asks me about multi-core software concurrency. I have no response for them. Do I just say that if you need concurrency, Pharo is the wrong choice? After all, no programming language can be good at everything. You must always choose the right tool for the job. Do I say that doing concurrency right is very, very tough, even for the most experienced of developers? Let's focus on Pharo's strengths, instead. Sounds like an excuse. Can we safely ignore the multi-core reality? I welcome your feedback. -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

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Zinc HTTP Component HTTP/2?
by Volkert Oct. 24, 2017

Oct. 24, 2017

Dear all, the world is moving to http/2. Any plans for Zinc HTTP Components to support this standard? BW, Volkert

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[ANN] Pharo Consortium New Platinum Member: IngenieurbÃ¼ro fÃ¼r Bauwesen Schmidt GmbH
by Marcus Denker Oct. 24, 2017

Oct. 24, 2017

The Pharo Consortium is very happy to announce that IngenieurbÃ¼ro fÃ¼r Bauwesen Schmidt GmbH has joined the Consortium as a Platinum Member. About - IngenieurbÃ¼ro fÃ¼r Bauwesen Schmidt GmbH: http://bauing-schmidt.de - Pharo Consortium: http://consortium.pharo.org The goal of the Pharo Consortium is to allow companies and institutions to support the ongoing development and future of Pharo. Individuals can support Pharo via the Pharo Association: - http://association.pharo.org

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[ANN] SeasideTesting recovered from oblivion
by Esteban Lorenzano Oct. 24, 2017

Oct. 24, 2017

Hi, I spend some days last week woking with the guys of AFI (http://afi-sa.fr <http://afi-sa.fr/>, yes they also use Pharo in some of their projects) and together we recovered SeasideTesting from Davis Shaffer to be used for their TDD experience. you can check it out here: https://github.com/Afibre/SeasideTesting <https://github.com/Afibre/SeasideTesting> Whatâs SeasideTesting? A package to test Seaside components. Why we do not use Parasol? Because it is based on selenium and that makes the process slow. Where can I know more? - there is some documentation here (for VW, I think): http://www.shaffer-consulting.com/david/Seaside/TestingComponents/TestingCo… <http://www.shaffer-consulting.com/david/Seaside/TestingComponents/TestingCo…> - some slides here (on squeak): http://esug.org/data/ESUG2005/Wednesday/2005-ESUG-Shaffer.pdf <http://esug.org/data/ESUG2005/Wednesday/2005-ESUG-Shaffer.pdf> but all that is old. Best way is to just install and see the tests, as always, cheers! Esteban

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