October 2019 - Pharo-users - lists.pharo.org

Re: [Pharo-users] help with understanding the visitor pattern
by Richard O'Keefe Oct. 17, 2019

Oct. 17, 2019

First, this is presumably the "Die" exercise from the Pharo track of exercism.io. Second, this is a case where - there is nothing to a Die other than the number of faces, so from a practical point of view there should not be a Die class; - there is nothing to a DieHandle other than a sequence of dice, so from a practical point of view there should not be a DieHandle class (not least because the word "Handle" here makes no sense in English and since it may contain many dice it would be better as DiceHandle, if only Handle made sense here). Once you realise that a Die is just an Integer wearing a burqa and a DIeHandle is just an OrderedCollection or Bag wearing a burqa, it may be easier to figure out how to combine these things. Of course it is most unwise to use #+ for combining dice and/or DieHandles. Both because + is a confusing choice and because we already *have* a selector that means "concatenate these two sequences", namely #, Looking at my own answer to this, and others, I see that you want two operations: aDieHandle addDie: aDie aDieHandle + anotherDieHandle You are not required to define + with either operation a Die. One way to do this is to add a new method DieHandle >> addAllTo: another [ dice do: [:each | another addDie: each]. ^another ] then DieHandle >> + another [ ^another addAllTo: (self addAllTo: DieHandle new)) ] Now if you want to extend this to treat a single Die as if it were a DieHandle containing itself, just do Die >> addAllTo: another [ another addDie: self. ^another ] Die >> + another [ ^another addAllTo: (self addAllTo: DieHandle new)) ] Now that Die and DieHandle have some selectors in common (and an actual method), it might make sense to introduce a common superclass. DiceSet (no data) roll ^self roll: Random default roll: rng diceNumber addAllTo: + another ^another addAllTo: (self addAllTo: DieHandle new) Die < DiceSet (faces) roll: rng ^faces atRandom: rng diceNumber ^1 addAllTo: aHandle aHandle addDie: self. ^aHandle DieHandle < DiceSet (dice) roll: rng ^self detectSum: [:die | did roll: rng] diceNumber ^dice size addAllTo: aHandle dice do: [:die | aHandle addDie: die]. ^aHandle What we have here is pretty close to the Composite pattern, not the Visitor pattern. If a DieHandle could accept DieHandles as elements as well as Die instances, it would be a bona fide example of Composite, and the code would need a few minor changes. The Visitor pattern is a way of dealing with "the Expression Problem". You don't *have* that problem. It doesn't seem like a good idea to apply it here. On Wed, 16 Oct 2019 at 21:33, Roelof Wobben via Pharo-users <pharo-users(a)lists.pharo.org> wrote: > > Hello, > > Im busy with this project: https://github.com/RoelofWobben/Die > > Now I also want to try to add a DieHandler and a Die together. > And I heared you can use the visitor pattern to solve this. > > As far as I understand the pattern I have to make a new class which > contains only the + method. > > But I fail to understand to see how I can make a difference between the > + of a Die and the + of a DieHandler. > > So can someone help me understand this pattern and maybe learn me step > by step how to implement this in my code. > > Regards, > > Roelof > >

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Concurrency Best Practices + Tests
by Noury Bouraqadi Oct. 16, 2019

Oct. 16, 2019

Hi everyone, Can I get your input on the following questions : - What are your best practices and recommendations for developing and testing concurrent software? - How to discover need for synchronization/critical sections/ when doing TDD? - How to write code to avoid dead-locks? Noury

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help with understanding the visitor pattern
by Roelof Wobben Oct. 16, 2019

Oct. 16, 2019

Hello, Im busy with this project: https://github.com/RoelofWobben/Die Now I also want to try to add a DieHandler and a Die together. And I heared you can use the visitor pattern to solve this. As far asÂ I understand the pattern I have to make a new class which contains only the + method. But I fail to understand to see how I can make a difference between the + of a Die and the + of a DieHandler. So can someone help me understand this pattern and maybe learn me step by step how to implement this in my code. Regards, Roelof

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Aconcagua Canonical Repo(s)
by Sean P. DeNigris Oct. 16, 2019

Oct. 16, 2019

It seems that this is now canonical: https://github.com/ba-st/aconcagua I assume its predecessor [1] was a port from this StHub repo [2]. There are two other repos on StHub [3] - the first of which has changes after the last in [1] and the other has changes which may have been/need to be merged. Can anyone shed further light? 1. https://github.com/mtaborda/aconcagua 2. http://smalltalkhub.com/#!/~maxi/Aconcagua 3. http://smalltalkhub.com/#!/~HernanWilkinson/Aconcagua http://smalltalkhub.com/#!/~BenoitAstruc/Aconcagua p.s. IMHO when porting from MCZ to GH, a good practice is to state in the GH README that it's a port, including the URL of the source and a way to clarify the last commit (maybe the date could often be sufficient) ----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

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Transcript: printString or asString
by Samuel Teixeira Santos Oct. 15, 2019

Oct. 15, 2019

Hi folks. I'm starting in Pharo studies by FUN Mooc. In Week 03, on An Overview of Essential Collections there is the example below: | days | days := Dictionary new. days at: #January put: 31; at: #February put: 28; at: #March put: 31. days keysAndValuesDo: [ :k :v | Transcript show: k asString, ' has ', v printString, ' days' ; cr ] The code in blue I change for days keysAndValuesDo: [ :k :v | Transcript show: k asString, ' has ', v asString, ' days' ; cr ] And works too on Playground. There is something different about both? There is someone better than other? Thanks in advance, Samuel T. Santos

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OSProcess and CommandShell available on GitHub for Pharo users
by David T. Lewis Oct. 15, 2019

Oct. 15, 2019

Alistair Grant and I, with the support of Feenk, have made GitHub repositories for OSProcess and CommandShell at: https://github.com/dtlewis290/OSProcess-Tonel https://github.com/dtlewis290/CommandShell-Tonel Alistair did the conversions using Peter Uhn??k's migration tool, and I set up the repositories so that they can now be loading in Pharo as follows: Metacello new repository: 'github://dtlewis290/OSProcess-Tonel/src'; baseline: 'OSProcess'; load. Metacello new repository: 'github://dtlewis290/CommandShell-Tonel/src'; baseline: 'CommandShell'; load. Note, the two respositories are named *-Tonel because I also maintain a GitHub repository for OSProcess on Cuis, and will probably do repositories in Squot format in the future. @Thierry Goubier - If you have an account on GitHub I will add you as a collaborator (but my own development work remains on squeaksource so I prefer contributions there anyway). Enjoy, Dave and Alistair

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Re: [Pharo-users] How to install stripe library on Pharo 7 64bit ?
by Paul DeBruicker Oct. 14, 2019

Oct. 14, 2019

Are you sure you're using a released version of Pharo 7? Running the load script in a stable released version of Pharo 7 loads with no errors for me. I'm not in a position to be able to support un-released or non-stable or outdated versions of Pharo (e.g. pharo 8). To get a stable version of Pharo 7 run this from a command line on mac or linux: curl https://get.pharo.org/64/ | bash The missing baseUrl is my fault. I override it in my own code to make nginx do the ssl termination for the https connections. I've uploaded a corrected version. IT should be StripeSystem>>#baseUrl ^'https://api.stripe.com/v1' Also the API reference docs are here: https://stripe.com/docs/api For any Stripe object I haven't created a class for the code should create an instance of a StripeObject class Hope this helps Paul Pharo Smalltalk Users mailing list wrote > OK, did some more testing and here are the results. > > > Pharo 7 > - Image hangs when loading Zinc HTTP Components. I tried loading Zinc > HTTP > Components separately through Metacello with the same results so I don't > think the problem is with your code. > > > Pharo 8 > - Stripe Loads fine, > - 22/29 Stripe tests fail (On debug it says that StripeSystem class does > not > understand #baseUrl message) > - Seaside not launched & can't right click Seaside Control Panel to start > server (Fixed by reloading Seaside3 from Metacello.) > - Stripe example apps (stripe & stripe-form) crash (Seaside Walkback > Error: > Instances of UndefinedObject are not indexable) > > > > > > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

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Running a teapot instance remotely
by sergio ruiz Oct. 13, 2019

Oct. 13, 2019

Hi, all. I am running my teapot instance remotely, but Iâm not sure how to start it up. Just for testing, I am trying this: ./pharo LunchPicker.image eval "server := PickerServer serveOn: 3200. server startâ & But no luck. ideas? Thanks! ---- peace, sergio photographer, journalist, visionary Public Key: http://bit.ly/29z9fG0 #BitMessage BM-NBaswViL21xqgg9STRJjaJaUoyiNe2dV @sergio_101@mastodon.social https://sergio101.com http://www.codeandmusic.com http://www.twitter.com/sergio_101 http://www.facebook.com/sergio101

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Pharo launcher
by ilker Ã¶zcan Oct. 13, 2019

Oct. 13, 2019

When i tried to install pharo 7 and 8 with the launcher on windows 10 there happened a message which says windows can not run 16 bit program.. It seems pharo.exe seems to be 16 bit ( i installed 64bit)..anyone with such a problem and any idea how i can solve this? Thanks all..

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Re: [Pharo-users] How to install stripe library on Pharo 7 64bit ?
by Sven Van Caekenberghe Oct. 11, 2019

Oct. 11, 2019

> On 11 Oct 2019, at 13:45, jmathews via Pharo-users <pharo-users(a)lists.pharo.org> wrote: > > Pharo 7 > - Image hangs when loading Zinc HTTP Components. I tried loading Zinc HTTP > Components separately through Metacello with the same results so I don't > think the problem is with your code. Yes, that is true and very problematic. A new implementation of ZnBufferedReadWriteStream was added to Pharo 7, which gets again (partially) overwritten by Zinc HTTP Components, breaking code loading. In Pharo 8 this was fixed by renaming these special (and now changed) class(es) to SourceFileBufferedReadWriteStream/SourceFileCharacterReadWriteStream so that they are moved out of Zinc HTTP Components and cannot be overwritten/broken. Either the last 3 commits on the Pharo 7 branch must be reversed, or the fixes/renaming/usage of Pharo 8 must be back ported as well. This is urgent. Sven

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