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

Re: [Pharo-users] Pharo and instance variables ...

by ClÃ©ment Bera

On Wed, Oct 18, 2017 at 7:07 AM, James Ladd <ladd.james(a)gmail.com> wrote: > Hey David, > > If you could only access instance variables in the class that defined them > and therefore only in a subclass via an accessor / mutator method w that be > a big problem in your view? > Yes. I don't want to have to define accessors, which are public, just to have the subclasses access the instance variables. > > Sent from my Commodore 64 > > On 18 Oct 2017, at 2:41 pm, David Mason <dmason(a)ryerson.ca> wrote: > > In Pharo, open a browser on OrderedCollection, then click "Variables" in > the top left of the window and then "array"... if you scroll through you > can see that mostly OrderedCollection methods use it, but some > SortedCollection (a subclass) methods also use it. > > The model is similar to protected in Java (see http://docs.oracle.com/ > javase/tutorial/java/javaOO/accesscontrol.html ) except there is no > "Package" column. > > On 17 October 2017 at 23:30, James Ladd <ladd.james(a)gmail.com> wrote: > >> Please could you provide an example? >> >> >> >> On Wed, Oct 18, 2017 at 2:16 PM, David Mason <dmason(a)ryerson.ca> wrote: >> >>> Any instance method in the class where the instance variable is defined >>> or in a subclass can access the instance variable. Similarly for class >>> methods to access class-side variables, and for class and instance methods >>> to access class variables. >>> >>> On 17 October 2017 at 23:04, James Ladd <ladd.james(a)gmail.com> wrote: >>> >>>> Hello Pharo Users, >>>> >>>> I'm wondering about instance variables for support in Redline Smalltalk >>>> and >>>> want to get my understanding straight. >>>> >>>> Are instance variables only accessible (without using #instVarNamed:) >>>> inside >>>> the method with the same name as the instance variable? >>>> >>>> eg: >>>> >>>> myInstVar >>>> ^ myInstVar. >>>> >>>> Or can you reference an instance variable from a method that doesn't >>>> have >>>> the same name ? >>>> >>>> anotherMethod >>>> ^ myInstVar. >>>> >>>> Can someone give me or point me to an example of accessing an instance >>>> variable in Pharo Smalltalk? >>>> >>>> - James. >>>> >>>> >>>> >>>> >>>> -- >>>> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >>>> >>>> >>> >> > -- ClÃ©ment BÃ©ra Pharo consortium engineer https://clementbera.wordpress.com/ BÃ¢timent B 40, avenue Halley 59650 Villeneuve d'Ascq

Oct. 18, 2017

Re: [Pharo-users] Pharo and instance variables ...

by James Ladd

Hey David, If you could only access instance variables in the class that defined them and therefore only in a subclass via an accessor / mutator method w that be a big problem in your view? Sent from my Commodore 64 > On 18 Oct 2017, at 2:41 pm, David Mason <dmason(a)ryerson.ca> wrote: > > In Pharo, open a browser on OrderedCollection, then click "Variables" in the top left of the window and then "array"... if you scroll through you can see that mostly OrderedCollection methods use it, but some SortedCollection (a subclass) methods also use it. > > The model is similar to protected in Java (see http://docs.oracle.com/javase/tutorial/java/javaOO/accesscontrol.html ) except there is no "Package" column. > >> On 17 October 2017 at 23:30, James Ladd <ladd.james(a)gmail.com> wrote: >> Please could you provide an example? >> >> >> >>> On Wed, Oct 18, 2017 at 2:16 PM, David Mason <dmason(a)ryerson.ca> wrote: >>> Any instance method in the class where the instance variable is defined or in a subclass can access the instance variable. Similarly for class methods to access class-side variables, and for class and instance methods to access class variables. >>> >>>> On 17 October 2017 at 23:04, James Ladd <ladd.james(a)gmail.com> wrote: >>>> Hello Pharo Users, >>>> >>>> I'm wondering about instance variables for support in Redline Smalltalk and >>>> want to get my understanding straight. >>>> >>>> Are instance variables only accessible (without using #instVarNamed:) inside >>>> the method with the same name as the instance variable? >>>> >>>> eg: >>>> >>>> myInstVar >>>> ^ myInstVar. >>>> >>>> Or can you reference an instance variable from a method that doesn't have >>>> the same name ? >>>> >>>> anotherMethod >>>> ^ myInstVar. >>>> >>>> Can someone give me or point me to an example of accessing an instance >>>> variable in Pharo Smalltalk? >>>> >>>> - James. >>>> >>>> >>>> >>>> >>>> -- >>>> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >>>> >>> >> >

Oct. 18, 2017

Re: [Pharo-users] Pharo and instance variables ...

by James Ladd

Ah that is very helpful - thank you. addFirst: newObject "Add newObject to the beginning of the receiver. Answer newObject." firstIndex = 1 ifTrue: [self makeRoomAtFirst]. firstIndex := firstIndex - 1. *array* at: firstIndex put: newObject. ^ newObject On Wed, Oct 18, 2017 at 2:41 PM, David Mason <dmason(a)ryerson.ca> wrote: > In Pharo, open a browser on OrderedCollection, then click "Variables" in > the top left of the window and then "array"... if you scroll through you > can see that mostly OrderedCollection methods use it, but some > SortedCollection (a subclass) methods also use it. > > The model is similar to protected in Java (see http://docs.oracle.com/ > javase/tutorial/java/javaOO/accesscontrol.html ) except there is no > "Package" column. > > On 17 October 2017 at 23:30, James Ladd <ladd.james(a)gmail.com> wrote: > >> Please could you provide an example? >> >> >> >> On Wed, Oct 18, 2017 at 2:16 PM, David Mason <dmason(a)ryerson.ca> wrote: >> >>> Any instance method in the class where the instance variable is defined >>> or in a subclass can access the instance variable. Similarly for class >>> methods to access class-side variables, and for class and instance methods >>> to access class variables. >>> >>> On 17 October 2017 at 23:04, James Ladd <ladd.james(a)gmail.com> wrote: >>> >>>> Hello Pharo Users, >>>> >>>> I'm wondering about instance variables for support in Redline Smalltalk >>>> and >>>> want to get my understanding straight. >>>> >>>> Are instance variables only accessible (without using #instVarNamed:) >>>> inside >>>> the method with the same name as the instance variable? >>>> >>>> eg: >>>> >>>> myInstVar >>>> ^ myInstVar. >>>> >>>> Or can you reference an instance variable from a method that doesn't >>>> have >>>> the same name ? >>>> >>>> anotherMethod >>>> ^ myInstVar. >>>> >>>> Can someone give me or point me to an example of accessing an instance >>>> variable in Pharo Smalltalk? >>>> >>>> - James. >>>> >>>> >>>> >>>> >>>> -- >>>> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >>>> >>>> >>> >> >

Oct. 18, 2017

Re: [Pharo-users] Pharo and instance variables ...

by David Mason

In Pharo, open a browser on OrderedCollection, then click "Variables" in the top left of the window and then "array"... if you scroll through you can see that mostly OrderedCollection methods use it, but some SortedCollection (a subclass) methods also use it. The model is similar to protected in Java (see http://docs.oracle.com/javase/tutorial/java/javaOO/accesscontrol.html ) except there is no "Package" column. On 17 October 2017 at 23:30, James Ladd <ladd.james(a)gmail.com> wrote: > Please could you provide an example? > > > > On Wed, Oct 18, 2017 at 2:16 PM, David Mason <dmason(a)ryerson.ca> wrote: > >> Any instance method in the class where the instance variable is defined >> or in a subclass can access the instance variable. Similarly for class >> methods to access class-side variables, and for class and instance methods >> to access class variables. >> >> On 17 October 2017 at 23:04, James Ladd <ladd.james(a)gmail.com> wrote: >> >>> Hello Pharo Users, >>> >>> I'm wondering about instance variables for support in Redline Smalltalk >>> and >>> want to get my understanding straight. >>> >>> Are instance variables only accessible (without using #instVarNamed:) >>> inside >>> the method with the same name as the instance variable? >>> >>> eg: >>> >>> myInstVar >>> ^ myInstVar. >>> >>> Or can you reference an instance variable from a method that doesn't have >>> the same name ? >>> >>> anotherMethod >>> ^ myInstVar. >>> >>> Can someone give me or point me to an example of accessing an instance >>> variable in Pharo Smalltalk? >>> >>> - James. >>> >>> >>> >>> >>> -- >>> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >>> >>> >> >

Oct. 18, 2017

Re: [Pharo-users] Pharo and instance variables ...

by James Ladd

Please could you provide an example? On Wed, Oct 18, 2017 at 2:16 PM, David Mason <dmason(a)ryerson.ca> wrote: > Any instance method in the class where the instance variable is defined or > in a subclass can access the instance variable. Similarly for class > methods to access class-side variables, and for class and instance methods > to access class variables. > > On 17 October 2017 at 23:04, James Ladd <ladd.james(a)gmail.com> wrote: > >> Hello Pharo Users, >> >> I'm wondering about instance variables for support in Redline Smalltalk >> and >> want to get my understanding straight. >> >> Are instance variables only accessible (without using #instVarNamed:) >> inside >> the method with the same name as the instance variable? >> >> eg: >> >> myInstVar >> ^ myInstVar. >> >> Or can you reference an instance variable from a method that doesn't have >> the same name ? >> >> anotherMethod >> ^ myInstVar. >> >> Can someone give me or point me to an example of accessing an instance >> variable in Pharo Smalltalk? >> >> - James. >> >> >> >> >> -- >> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >> >> >

Oct. 18, 2017

Re: [Pharo-users] Pharo and instance variables ...

by David Mason

Any instance method in the class where the instance variable is defined or in a subclass can access the instance variable. Similarly for class methods to access class-side variables, and for class and instance methods to access class variables. On 17 October 2017 at 23:04, James Ladd <ladd.james(a)gmail.com> wrote: > Hello Pharo Users, > > I'm wondering about instance variables for support in Redline Smalltalk and > want to get my understanding straight. > > Are instance variables only accessible (without using #instVarNamed:) > inside > the method with the same name as the instance variable? > > eg: > > myInstVar > ^ myInstVar. > > Or can you reference an instance variable from a method that doesn't have > the same name ? > > anotherMethod > ^ myInstVar. > > Can someone give me or point me to an example of accessing an instance > variable in Pharo Smalltalk? > > - James. > > > > > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html > >

Oct. 18, 2017

Pharo and instance variables ...

by James Ladd

Hello Pharo Users, I'm wondering about instance variables for support in Redline Smalltalk and want to get my understanding straight. Are instance variables only accessible (without using #instVarNamed:) inside the method with the same name as the instance variable? eg: myInstVar ^ myInstVar. Or can you reference an instance variable from a method that doesn't have the same name ? anotherMethod ^ myInstVar. Can someone give me or point me to an example of accessing an instance variable in Pharo Smalltalk? - James. -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Oct. 18, 2017

Re: [Pharo-users] NeoJSONObject convenience method hint

by Sven Van Caekenberghe

Hi, > On 17 Oct 2017, at 11:46, Herby VojÄÃk <herby(a)mailbox.sk> wrote: > > newFromAccessors: aCollection ofObject: anObject > "Performs supplied accessors on anObject > and returns my instance with accessor -> result pairs." > > ^ self newFrom: (aCollection collect: [ :each | each -> (anObject perform: each) ]) > > "I use it for example in this piece of code: > NeoJSONObject > newFromAccessors: #(good bad) > ofObject: self dao sumOfAllAnswers > " If (but see further) I would add this kind of functionality, I would go for the following methods in a 'copying' protocol on the instance side (in analogy with Object>>#copyFrom:) : NeoJSONObject>>#copyFrom: anObject accessors: accessors accessors do: [ :each | self at: each put: (anObject perform: each) ] NeoJSONObject>>#copyFrom: anObject instVarNames: instVarNames instVarNames do: [ :each | self at: each put: (anObject instVarNamed: each) ] NeoJSONObject>>#copyFrom: aDictionary keys: keys keys do: [ :each | self at: each put: (aDictionary at: each) ] NeoJSONObject>>#copyAllInstVarsFrom: anObject self copyFrom: anObject instVarNames: anObject class allInstVarNames Which would allow you to write stuff like: NeoJSONObject new copyFrom: NeoJSONTestObject2 example1 accessors: #(id height width). NeoJSONObject new copyFrom: NeoJSONTestObject2 example1 instVarNames: #(id height width). NeoJSONObject new copyAllInstVarsFrom: NeoJSONTestObject2 example1. NeoJSONObject new copyFrom: { #id->1. #height->200. #width->100 } asDictionary keys: #(width height). However, there are a couple of reasons why I am not so enthusiastic. - You want conversions to/from NeoJSONObject and your domain objects, by creating one for the other, that is exactly why mapping exists: to do this without copying (i.e. directly & more efficiently) - Mapping is also better because it can be applied to values as well (recursively) - I would rather put the responsibility of conversion to the domain objects (say in #toNeoJSONObject and #fromNeoJSONObject:) - I would prefer NeoJSONObject to keep very simple Just some comments, thinking aloud. Sven

Oct. 17, 2017

Re: [Pharo-users] SpecColumnLayout not behaving as expected

by Steven R. Baker

Oh! I remember fighting with this last week too. Am I the only who who struggled with that? If not, perhaps we could call #add: #addRow: ? -Steven On 17/10/17 18:00, Peter UhnÃ¡k wrote: > Because it is the other way around: in the block ([ :col | ... ]) you > are describing the content of the column. > > So what you are actually doing is you create a Column > (SpecColumnLayout), inside which you create another column > (newColumn), and to that column you add two rows (add:, add:). > > On Tue, Oct 17, 2017 at 4:32 PM, Steven R. Baker > <steven(a)stevenrbaker.com <mailto:steven@stevenrbaker.com>> wrote: > > Heya folks, > > I'm sure I'm doing something wrong, I just don't know what it is. > > I have the following: > > defaultSpec > Â Â Â ^ SpecColumnLayout composed > Â Â Â Â Â Â newColumn: [ :col | > Â Â Â Â Â Â Â Â Â col > Â Â Â Â Â Â Â Â Â Â Â Â add: #sideBar; > Â Â Â Â Â Â Â Â Â Â Â Â add: #listView ]; > Â Â Â Â Â Â yourself > > In the resulting window, I get the widgets stacked one on top of the > other, and I expected them to be next to each other (two columns > in a row.) > > What am I missing? > > Thanks! > > -Steven > > >

Oct. 17, 2017

Re: [Pharo-users] SpecColumnLayout not behaving as expected

by Peter UhnÃ¡k

Because it is the other way around: in the block ([ :col | ... ]) you are describing the content of the column. So what you are actually doing is you create a Column (SpecColumnLayout), inside which you create another column (newColumn), and to that column you add two rows (add:, add:). On Tue, Oct 17, 2017 at 4:32 PM, Steven R. Baker <steven(a)stevenrbaker.com> wrote: > Heya folks, > > I'm sure I'm doing something wrong, I just don't know what it is. > > I have the following: > > defaultSpec > ^ SpecColumnLayout composed > newColumn: [ :col | > col > add: #sideBar; > add: #listView ]; > yourself > > In the resulting window, I get the widgets stacked one on top of the > other, and I expected them to be next to each other (two columns in a row.) > > What am I missing? > > Thanks! > > -Steven > > >

Oct. 17, 2017