Collection>>select: aBlock ifNoneTakeAsDefault: aDefaultValue
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Collection>>select: aBlock ifNoneTakeAsDefault: aDefaultValue
 
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Dear all, While developing some code, I made following extension of the Collection protocol: select: aBlock ifNoneTakeAsDefault: aDefaultValue |result| result := self select: aBlock. (result isEmpty) ifTrue: [^self class with: aDefaultValue] ifFalse: [^result]. Maybe this could be added to the Pharo 1.1 Collection clazz? Or do we want to keep the interface of Collection as small as possible (which is also a good idea!).
Kind Regards, Bart -- imagination is more important than knowledge - Albert Einstein Logic will get you from A to B. Imagination will take you everywhere - Albert Einstein Learn from yesterday, live for today, hope for tomorrow. The important thing is not to stop questioning. - Albert Einstein The true sign of intelligence is not knowledge but imagination. - Albert Einstein Gravitation is not responsible for people falling in love. - Albert Einstein _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: Collection>>select: aBlock ifNoneTakeAsDefault: aDefaultValue
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Personally, I would rather see #ifEmpty: modified to return self in
the false case like #ifNil: does. The only in-image sender I can find that even uses the return value seems to actually expect this behaviour anyway. :) Then you could simply write: (aCollection select: [:ea | ...]) ifEmpty: [ ... ] Julian 2009/12/26 Bart Gauquie <[hidden email]>: > Dear all, > > While developing some code, I made following extension of the Collection > protocol: > select: aBlock ifNoneTakeAsDefault: aDefaultValue > |result| > result := self select: aBlock. > (result isEmpty) > ifTrue: [^self class with: aDefaultValue] > ifFalse: [^result]. > > Maybe this could be added to the Pharo 1.1 Collection clazz? Or do we want > to keep the interface of Collection as small as possible (which is also a > good idea!). > Kind Regards, > Bart > -- > imagination is more important than knowledge - Albert Einstein > Logic will get you from A to B. Imagination will take you everywhere - > Albert Einstein > Learn from yesterday, live for today, hope for tomorrow. The important thing > is not to stop questioning. - Albert Einstein > The true sign of intelligence is not knowledge but imagination. - Albert > Einstein > Gravitation is not responsible for people falling in love. - Albert Einstein > > _______________________________________________ > Pharo-project mailing list > [hidden email] > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: Collection>>select: aBlock ifNoneTakeAsDefault: aDefaultValue
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Hi, that seems like a very good suggestion. Is more general usable also. Regards, Bart On Sat, Dec 26, 2009 at 11:44 PM, Julian Fitzell <[hidden email]> wrote: Personally, I would rather see #ifEmpty: modified to return self in -- imagination is more important than knowledge - Albert Einstein Logic will get you from A to B. Imagination will take you everywhere - Albert Einstein Learn from yesterday, live for today, hope for tomorrow. The important thing is not to stop questioning. - Albert Einstein The true sign of intelligence is not knowledge but imagination. - Albert Einstein Gravitation is not responsible for people falling in love. - Albert Einstein _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: Collection>>select: aBlock ifNoneTakeAsDefault: aDefaultValue
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In reply to this post by Julian Fitzell-2
On Dec 26, 2009, at 11:44 PM, Julian Fitzell wrote: > Personally, I would rather see #ifEmpty: modified to return self in > the false case like #ifNil: does. The only in-image sender I can find > that even uses the return value seems to actually expect this > behaviour anyway. :) what is the behavior in other dialects ? :) Do you have some nice tests to cover the semantics? Did you do the change and see what break? Stef > > Then you could simply write: > > (aCollection select: [:ea | ...]) ifEmpty: [ ... ] > > Julian > > 2009/12/26 Bart Gauquie <[hidden email]>: >> Dear all, >> >> While developing some code, I made following extension of the Collection >> protocol: >> select: aBlock ifNoneTakeAsDefault: aDefaultValue >> |result| >> result := self select: aBlock. >> (result isEmpty) >> ifTrue: [^self class with: aDefaultValue] >> ifFalse: [^result]. >> >> Maybe this could be added to the Pharo 1.1 Collection clazz? Or do we want >> to keep the interface of Collection as small as possible (which is also a >> good idea!). >> Kind Regards, >> Bart >> -- >> imagination is more important than knowledge - Albert Einstein >> Logic will get you from A to B. Imagination will take you everywhere - >> Albert Einstein >> Learn from yesterday, live for today, hope for tomorrow. The important thing >> is not to stop questioning. - Albert Einstein >> The true sign of intelligence is not knowledge but imagination. - Albert >> Einstein >> Gravitation is not responsible for people falling in love. - Albert Einstein >> >> _______________________________________________ >> Pharo-project mailing list >> [hidden email] >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >> > > _______________________________________________ > Pharo-project mailing list > [hidden email] > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: Collection>>select: aBlock ifNoneTakeAsDefault: aDefaultValue
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In reply to this post by Julian Fitzell-2
I forgot open a bug tracker entry because we should not lose the suggestion.
On Dec 26, 2009, at 11:44 PM, Julian Fitzell wrote: > Personally, I would rather see #ifEmpty: modified to return self in > the false case like #ifNil: does. The only in-image sender I can find > that even uses the return value seems to actually expect this > behaviour anyway. :) > > Then you could simply write: > > (aCollection select: [:ea | ...]) ifEmpty: [ ... ] > > Julian > > 2009/12/26 Bart Gauquie <[hidden email]>: >> Dear all, >> >> While developing some code, I made following extension of the Collection >> protocol: >> select: aBlock ifNoneTakeAsDefault: aDefaultValue >> |result| >> result := self select: aBlock. >> (result isEmpty) >> ifTrue: [^self class with: aDefaultValue] >> ifFalse: [^result]. >> >> Maybe this could be added to the Pharo 1.1 Collection clazz? Or do we want >> to keep the interface of Collection as small as possible (which is also a >> good idea!). >> Kind Regards, >> Bart >> -- >> imagination is more important than knowledge - Albert Einstein >> Logic will get you from A to B. Imagination will take you everywhere - >> Albert Einstein >> Learn from yesterday, live for today, hope for tomorrow. The important thing >> is not to stop questioning. - Albert Einstein >> The true sign of intelligence is not knowledge but imagination. - Albert >> Einstein >> Gravitation is not responsible for people falling in love. - Albert Einstein >> >> _______________________________________________ >> Pharo-project mailing list >> [hidden email] >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >> > > _______________________________________________ > Pharo-project mailing list > [hidden email] > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: Collection>>select: aBlock ifNoneTakeAsDefault: aDefaultValue
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In reply to this post by Stéphane Ducasse
>> Personally, I would rather see #ifEmpty: modified to return self in
>> the false case like #ifNil: does. The only in-image sender I can find >> that even uses the return value seems to actually expect this >> behaviour anyway. :) +1 > what is the behavior in other dialects ? :) > Do you have some nice tests to cover the semantics? > Did you do the change and see what break? I don't think anybody else has this method. Lukas -- Lukas Renggli http://www.lukas-renggli.ch _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: Collection>>select: aBlock ifNoneTakeAsDefault: aDefaultValue
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In reply to this post by Julian Fitzell-2
On Sat, Dec 26, 2009 at 11:44 PM, Julian Fitzell <[hidden email]> wrote: Personally, I would rather see #ifEmpty: modified to return self in Julian: we (stef and I) have something we don't understand. The implementation of ifEmpty: is like this in Pharo: Collection >> ifEmpty: aBlock "Evaluate the block if I'm empty" self isEmpty ifTrue: [ ^aBlock value ] In this case, in the false case, nothing is expressively returned, so self is returned. Did I miss something ? cheers mariano Then you could simply write: _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: Collection>>select: aBlock ifNoneTakeAsDefault: aDefaultValue
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> Julian: we (stef and I) have something we don't understand. The
> implementation of ifEmpty: is like this in Pharo: > > Collection >> ifEmpty: aBlock > "Evaluate the block if I'm empty" > > self isEmpty ifTrue: [ ^aBlock value ] In Pharo 1.0rc1 it looks like this: Collection>>ifEmpty: aBlock "Evaluate the block if I'm empty" ^ self isEmpty ifTrue: aBlock Lukas -- Lukas Renggli http://www.lukas-renggli.ch _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: Collection>>select: aBlock ifNoneTakeAsDefault: aDefaultValue
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2009/12/27 Lukas Renggli <[hidden email]>:
>> Julian: we (stef and I) have something we don't understand. The >> implementation of ifEmpty: is like this in Pharo: >> >> Collection >> ifEmpty: aBlock >> "Evaluate the block if I'm empty" >> >> self isEmpty ifTrue: [ ^aBlock value ] > > In Pharo 1.0rc1 it looks like this: > > Collection>>ifEmpty: aBlock > "Evaluate the block if I'm empty" > > ^ self isEmpty ifTrue: aBlock > > Lukas > It sounds stupid to return nil if not empty. Should the change in 1.1 be backported ? Nicolas > -- > Lukas Renggli > http://www.lukas-renggli.ch > > _______________________________________________ > Pharo-project mailing list > [hidden email] > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
Re: Collection>>select: aBlock ifNoneTakeAsDefault: aDefaultValue
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The question is how much will we have to backport.
Because we do not have that horse power to do that for each little details. I would only backport really important fixes. Stef On Dec 27, 2009, at 7:58 PM, Nicolas Cellier wrote: > 2009/12/27 Lukas Renggli <[hidden email]>: >>> Julian: we (stef and I) have something we don't understand. The >>> implementation of ifEmpty: is like this in Pharo: >>> >>> Collection >> ifEmpty: aBlock >>> "Evaluate the block if I'm empty" >>> >>> self isEmpty ifTrue: [ ^aBlock value ] >> >> In Pharo 1.0rc1 it looks like this: >> >> Collection>>ifEmpty: aBlock >> "Evaluate the block if I'm empty" >> >> ^ self isEmpty ifTrue: aBlock >> >> Lukas >> > > It sounds stupid to return nil if not empty. > Should the change in 1.1 be backported ? > > Nicolas > >> -- >> Lukas Renggli >> http://www.lukas-renggli.ch >> >> _______________________________________________ >> Pharo-project mailing list >> [hidden email] >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >> > > _______________________________________________ > Pharo-project mailing list > [hidden email] > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
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