November 2018 - Pharo-users

Re: [Pharo-users] how do I send the 2 messsages to the function

by Roelof Wobben

Nov. 25, 2018

Re: [Pharo-users] how do I send the 2 messsages to the function

by Roelof Wobben

Op 25-11-2018 om 19:12 schreef dorellang: > What you want to do is: > > findBasement: input2 > "solution to part1 of this challenge" > > input2 withIndexDo: [ :element :index | |action| action:= > SantaFloorAction getActionFor: element. floor := action > calculateNewFloor: floor index: index ]. > ^ counter > > Notice how I added the 'index: index' bit in the line just above the '^ > counter', so you're actually performing: > > action calculateNewFloor: floor index: index > > If you had a method with three args you would declare it as: > > methodWithArg1: arg1 arg2: arg2 arg3: arg3 > "assume this is in Foo class" > self doSomething. > > and then you would call it in another place with > > ... > "assume obj is some instance of Foo" > obj methodWithArg1: 'some' arg2: 'arguments' arg3: #thatMightChange > ... > > BTW the way you're framing the question makes me think you are not > understanding how Smalltalk works. In Smalltalk (and by extension, in Pharo) > you don't send messages to functions, you send messages to objects (all > values that you can store in variables are objects in Smalltalk). In this > context 'send message' is what in other languages is 'call the object's > instance method with some arguments'. So you may be wondering: what's a > 'message' anyway? A message is a method name (or more properly in the > Smalltalk slang, its 'selector') plus some arguments. The idea is that what > actually happens when a message is received by an object depends on the > concrete implementation that that object has for that message; in other > words, the method the object has; which may vary according the class of the > object that received the message. > > Actually it's not unlike other object oriented languages, but the > terminology and the syntax might be a little weird at first. > > Cheers, > Diego > > > > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html > > I know. Still trying to get a feeling about it and what takes me some time is that the use of if then is a bad smell I try to stretch my mind around that Roelof

Nov. 25, 2018

Re: [Pharo-users] how do I send the 2 messsages to the function

by Nicole de Graaf

Hi Roelof, is not easy to understand the question , without contents. #calculateNewFloor:index: - I assume you implemented the method on an action class (SantaAction). - In the method I see no usage from argument index but to send the method with a index: aFoor := aAction calculateNewFloor: aFloor index: anIndex. the method does not return a floor instance , as you expect in #findBasement: I hope you can solve you Santa puzzel, Nic > On 25 Nov 2018, at 17:42, Roelof Wobben <r.wobben(a)home.nl> wrote: > > Hello, > > I have made this function : > > calculateNewFloor: aFloor index: index > "comment stating purpose of message" > |action floor | > action:= SantaAction getActionFor: aFloor. floor := action doMovementFor: aFloor > > now I want to send a message to this function : > > findBasement: input2 > "solution to part1 of this challenge" > > input2 withIndexDo: [ :element :index | |action| action:= SantaFloorAction getActionFor: element. floor := action calculateNewFloor: floor .. ]. > ^ counter > > but how do I get the second argument in this > > Roelof > > >

Nov. 25, 2018

Re: [Pharo-users] how do I send the 2 messsages to the function

by dorellang

What you want to do is: findBasement: input2 "solution to part1 of this challenge" input2 withIndexDo: [ :element :index | |action| action:= SantaFloorAction getActionFor: element. floor := action calculateNewFloor: floor index: index ]. ^ counter Notice how I added the 'index: index' bit in the line just above the '^ counter', so you're actually performing: action calculateNewFloor: floor index: index If you had a method with three args you would declare it as: methodWithArg1: arg1 arg2: arg2 arg3: arg3 "assume this is in Foo class" self doSomething. and then you would call it in another place with ... "assume obj is some instance of Foo" obj methodWithArg1: 'some' arg2: 'arguments' arg3: #thatMightChange ... BTW the way you're framing the question makes me think you are not understanding how Smalltalk works. In Smalltalk (and by extension, in Pharo) you don't send messages to functions, you send messages to objects (all values that you can store in variables are objects in Smalltalk). In this context 'send message' is what in other languages is 'call the object's instance method with some arguments'. So you may be wondering: what's a 'message' anyway? A message is a method name (or more properly in the Smalltalk slang, its 'selector') plus some arguments. The idea is that what actually happens when a message is received by an object depends on the concrete implementation that that object has for that message; in other words, the method the object has; which may vary according the class of the object that received the message. Actually it's not unlike other object oriented languages, but the terminology and the syntax might be a little weird at first. Cheers, Diego -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Nov. 25, 2018

how do I send the 2 messsages to the function

by Roelof Wobben

Hello, I have made this function : calculateNewFloor: aFloor index: index Â Â Â "comment stating purpose of message" Â Â |action floor | Â Â action:= SantaAction getActionFor: aFloor. floor := action doMovementFor: aFloor now I want to send a message to this functionÂ : findBasement: input2 Â Â Â "solution to part1 of this challenge" Â Â Â Â input2 withIndexDo: [ :element :index | |action| action:= SantaFloorAction getActionFor: element. floor := action calculateNewFloor: floor ..Â ]. Â Â Â Â ^ counter but how do I get the second argument in this Roelof

Nov. 25, 2018

Questions about NewValueHolder and Model

by dorellang

Hi everyone! I was trying to find out how to propagate changes through widgets in the Spec UI framework, and so far it seems to me that using NewValueHolder objects is the most proper way right now. Am I wrong? However I have some questions regarding this class: (BTW I am using a Pharo 7 image) First, you may notice that NewValueHolder extends the Model class, whose class comment simply says "Provides optimized model support". The first thing I thought coming from a non-Smalltalk background was like "What is that supposed to mean?". Then I tried to make sense of it, but you know, this has been hard because Model has a lot of methods that aren't too related IMHO. For instance let's take all the methods under the 'stepping' and 'stepping-window' protocols ...what are they intended to do? After doing some research I think they are some kind of mechanism from the Morphic framework to setup actions that will be performed periodically, probably for supporting animations or something, but what does this have to do with being a Model anyway? All of this has been pretty confusing, but I think I've understood it better after reading this post about Smalltalk MVC: http://peter.michaux.ca/articles/smalltalk-mvc-translated-to-javascript . I know this may be a bit obvious for veteran Smalltalkers, but now it has become clearer to me that this Model class is the M of the MVC framework that was used in ye olden days to build Smalltalk UIs. Which is weird because as far as I know MVC doesn't exist in Pharo. So I asked myself: "Shouldn't this be killed? Why is it kept? (at least it should be cleaned up I think)". And after searching the references and senders of the methods I think it mostly comes down to Morphs. Is it feasible to clean this up? I think all of this should be explicitely documented at least, you know, all this Model API. Currently it's too implicit, not friendly for newcomers and too mixed up with random Morphic stuff (which should be dying soon anyway). Some other thing that bothers me it's that that most of the methods in Model are defined in Object too. I understand that that was made in the original MVC to have the ability to use anything as a Model, but I don't think that's necessarily the best option. It would be cleaner perhaps to have an asModel message which creates a ProxyModel object which implements all the Model API methods and then proxies the rest to the underlying instance; or maybe a more pragmatic approach would be like moving all these Model methods in object to an extension protocol; or ...hey, it's 2018! Today we have traits, we could create a Trait with all those methods and then just let the current Model class use it. That's are my thoughts about the Model class. Now I'm not an expert, so they should be taken with a grain of salt ;) Coming back to the NewValueHolder, other two issues came to my mind: - What's the deal with the old ValueHolder class? Apparently it's not used anywhere. I think it should be removed, and NewValueHolder should be renamed to ValueHolder. - Some messages of NewValueHolder are also in the Model class in the 'announcing' protocol... What's the point of this polymorphism? This is not like the classical Model API at all, which uses the dependents and updating protocols. All these methods under the 'announcing' protocol use a totally unrelated way of propagating changes. This breaks SRP, shouldn't we have instead like a NewModel class which uses this new Announcement-based mechanism for propagating changes and don't conflate the two things? - In the same fashion, I don't think there isn't any good reason for having the NewValueHolder as a Model subclass; at least the Model that implements the behavior from the old MVC framework. For the record in my image I've done 'Object subclass: #NewValueHolder (...)', copied all the announcing methods to NewValueHolder and added an announcer instance variable and it's going fine so far, but that might be because all Objects can be used as models in the MVC sense. Anyway, after some use 'Object classVariableNamed: #DependentsFields' still prints "#DependentsFields->a WeakIdentityKeyDictionary()" :P I think that's it, or maybe I forgot something I don't know haha -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Nov. 25, 2018

Playing with Pharo 7

by Konrad Hinsen

Hi everyone, after finishing the Pharo MOOC, I have started to play with a simple project of my own, initially using Pharo 6.1. Since Pharo 7 seems to be coming soon, I wanted to try it out, and that lead to a few practical questions. 1) How do you move your personal environment to a new image? If I have to re-do my settings and re-load one by one the packages I use, I won't be trying out new images more than strictly necessary. 2) My test project lives on GitHub, so I fired up Iceberg under Pharo 7 to load it. Works fine... but I cannot commit and push under Pharo 7. Iceberg pretends that there are no changes. With Pharo 6.1, this works very well. Has the operation of Iceberg changed significantly? If so, what would be the best place to learn about this? Any pointers would be appreciated! Cheers, Konrad.

Nov. 25, 2018

Re: [Pharo-users] Windows 10 double-click issue + solution

by PBKResearch

John Many thanks for the tip. I have always found double click very erratic on Windows 7 and now on W10. It would eventually work, but was critically dependent on getting the right timing for the click interval. Pushing the pointer towards 'slow' on the mouse settings has improved things a lot. Peter Kenny From: Pharo-users <pharo-users-bounces(a)lists.pharo.org> On Behalf Of John Kimber via Pharo-users Sent: 24 November 2018 23:06 To: pharo-users(a)lists.pharo.org Cc: John Kimber <jk4aiest(a)yahoo.com> Subject: [Pharo-users] Windows 10 double-click issue + solution

Nov. 25, 2018

Re: [Pharo-users] Pharo 7 - RFB

by Sanjay Minni

OK loaded RFB in pharo 7.0 Thru Monticello is there any documentation somewhere Sanjay Minni wrote > what is RFB used for ? and can I load it in Pharo 7. > I could not find any documentation anywhere > > When migrating an earlier application (pharo 6.1 to 7.0) > RFB was loaded in the ConfigurationOfApplication,(in 6.1) > However in Pharo 7, I manually loaded the required packages and loading > seems complete without RFB so am trying to figure out what is RFB and what > was it used for (application loaded fine). > > any inputs pls how to go about it > (off course I can try running and just see if anything crashes while > running > but so many things may cause crashes and want to know before proceeding) > > > > ----- > cheers, > Sanjay > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html ----- cheers, Sanjay -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Nov. 25, 2018

Re: [Pharo-users] Pharo 7 - RFB

by Sanjay Minni

what is RFB used for ? and can I load it in Pharo 7. I could not find any documentation anywhere When migrating an earlier application (pharo 6.1 to 7.0) RFB was loaded in the ConfigurationOfApplication,(in 6.1) However in Pharo 7, I manually loaded the required packages and loading seems complete without RFB so am trying to figure out what is RFB and what was it used for (application loaded fine). any inputs pls how to go about it (off course I can try running and just see if anything crashes while running but so many things may cause crashes and want to know before proceeding) ----- cheers, Sanjay -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Nov. 25, 2018