Fwd: hasEqualElements:
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2009/12/23 Stéphane Ducasse <[hidden email]>:
> > > > Hi > > (SortedCollection new addAll: #(9 2 3 ); yourself) > hasEqualElements: (OrderedCollection withAll: #(9 2 3)) -> false > > hasEqualElements: otherCollection > "Answer whether the receiver's size is the same as otherCollection's > size, and each of the receiver's elements equal the corresponding > element of otherCollection. > This should probably replace the current definition of #= ." > > | size | > (otherCollection isKindOf: SequenceableCollection) ifFalse: [^ false]. > (size := self size) = otherCollection size ifFalse: [^ false]. > 1 to: size do: > [:index | > (self at: index) = (otherCollection at: index) ifFalse: [^ false]]. > ^ true > > For me the name of this method is misleading and I would really like to > renaming it > hasStructurallyEqualElements: and have new one doing hasEqualElements: > > What do you think? > I would like a beautiful world.... > > Stef (freezing with a flu in my bed.... cool christmax). > > Didn't VW had a #isSameSquenceAs: Nicolas > > > _______________________________________________ > 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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No but I will look because I do not remember where I saw the difference and
we need it. Stef On Dec 23, 2009, at 10:08 AM, Nicolas Cellier wrote: > isSameSquenceAs _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
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In reply to this post by Nicolas Cellier
On Wed, Dec 23, 2009 at 1:08 AM, Nicolas Cellier <[hidden email]> wrote: 2009/12/23 Stéphane Ducasse <[hidden email]>: Yes.
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In reply to this post by Nicolas Cellier
On Wed, Dec 23, 2009 at 1:08 AM, Nicolas Cellier <[hidden email]> wrote:
2009/12/23 Stéphane Ducasse <[hidden email]>: <methods> <class-id>Core.SequenceableCollection</class-id> <category>comparing</category> <body package="Collections-Abstract" selector="isSameSequenceAs:">isSameSequenceAs: otherCollection
"Answer whether the receiver's size is the same as otherCollection's size, and each of the receiver's elements equal the corresponding element of otherCollection."
| size | (size := self size) = otherCollection size ifFalse: [^false]. 1 to: size do: [:index | (self at: index) = (otherCollection at: index) ifFalse: [^false]].
^true</body> </methods> i.e. trust the caller is providing a sequence and if otherCollection doesn't implement at: there will be a run-time error, hence any otherCollection isKindOf: SequenceableCollection is just wasted cycles.
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Excellent the Browser did not find it.
So now I understand where I got used to the idea of having the difference between sameElements and sameStructuralElements. Tx eliot I will read again in VW. Stef On Dec 23, 2009, at 7:10 PM, Eliot Miranda wrote: > > > On Wed, Dec 23, 2009 at 1:08 AM, Nicolas Cellier <[hidden email]> wrote: > 2009/12/23 Stéphane Ducasse <[hidden email]>: > > > > > > > > Hi > > > > (SortedCollection new addAll: #(9 2 3 ); yourself) > > hasEqualElements: (OrderedCollection withAll: #(9 2 3)) -> false > > > > hasEqualElements: otherCollection > > "Answer whether the receiver's size is the same as otherCollection's > > size, and each of the receiver's elements equal the corresponding > > element of otherCollection. > > This should probably replace the current definition of #= ." > > > > | size | > > (otherCollection isKindOf: SequenceableCollection) ifFalse: [^ false]. > > (size := self size) = otherCollection size ifFalse: [^ false]. > > 1 to: size do: > > [:index | > > (self at: index) = (otherCollection at: index) ifFalse: [^ false]]. > > ^ true > > > > For me the name of this method is misleading and I would really like to > > renaming it > > hasStructurallyEqualElements: and have new one doing hasEqualElements: > > > > What do you think? > > I would like a beautiful world.... > > > > Stef (freezing with a flu in my bed.... cool christmax). > > > > > > Didn't VW had a #isSameSquenceAs: > > Nicolas > > > <methods> > <class-id>Core.SequenceableCollection</class-id> <category>comparing</category> > > <body package="Collections-Abstract" selector="isSameSequenceAs:">isSameSequenceAs: otherCollection > "Answer whether the receiver's size is the same as otherCollection's size, and each > of the receiver's elements equal the corresponding element of otherCollection." > > | size | > (size := self size) = otherCollection size ifFalse: [^false]. > 1 to: size do: [:index | > (self at: index) = (otherCollection at: index) ifFalse: [^false]]. > ^true</body> > </methods> > > > i.e. trust the caller is providing a sequence and if otherCollection doesn't implement at: there will be a run-time error, hence any otherCollection isKindOf: SequenceableCollection is just wasted cycles. > _______________________________________________ > 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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In reply to this post by Eliot Miranda-2
Em 23/12/2009 16:10, Eliot Miranda < [hidden email] > escreveu:
> > Core.SequenceableCollection comparing > isSameSequenceAs: otherCollection > > "Answer whether the receiver's size is the same as otherCollection's > size, and each of the receiver's elements equal the corresponding > element of otherCollection." > > | size | > (size := self size) = otherCollection size ifFalse: [^false]. > 1 to: size do: [:index | > (self at: index) = (otherCollection at: index) ifFalse: [^false]]. > ^true > > i.e. trust the caller is providing a sequence and if > otherCollection doesn't implement at: there will be a run-time > error, hence any otherCollection isKindOf: SequenceableCollection is > just wasted cycles. > I don't think that "trusting the caller" makes sense in this case, so I propose instead that you implementation be complemented by: Object>>isSameSequenceAs: otherCollection ^false -- Cesar Rabak _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
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On Wed, Dec 23, 2009 at 10:41 AM, <[hidden email]> wrote: Em 23/12/2009 16:10, Eliot Miranda < [hidden email] > escreveu: We're talking about the argument otherCollection not the receiver. i.e. leaving out isKindOf: in isSameSequenceAs: otherCollection "Answer whether the receiver's size is the same as otherCollection's size, and each | size |of the receiver's elements equal the corresponding element of otherCollection." (otherCollection isKindOf: SequenceableCollection) ifFalse: [^false]. "this is a horrible wart" (size := self size) = otherCollection size ifFalse: [^false]. ^true1 to: size do: [:index | (self at: index) = (otherCollection at: index) ifFalse: [^false]]. You could use double dispatching: SequenceableCollection>>isSameSequenceAs: otherThing ^otherThing isSameSequenceAsSequence: self
SequenceableCollection>> isSameSequenceAsSequence: aSequenceableCollection aSequenceableCollection size ~= self size ifTrue: [^false]. etc Object isSameSequenceAsSequence: aSequenceableCollection
^false but I think in this case it's overkill.
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Ideally what I would like is
= isSameSequenceAs: + same receiver kind (may be overkill) isSameSequenceAs: otherCollection "Answer whether the receiver's size is the same as otherCollection's size, and each of the receiver's elements equal the corresponding element of otherCollection." hasSameElements: "Answer whether the receiver's size is the same as otherCollection's size, and each of the receiver's elements is included in otherCollection and vice versa." Stef On Dec 23, 2009, at 7:58 PM, Eliot Miranda wrote: > > > On Wed, Dec 23, 2009 at 10:41 AM, <[hidden email]> wrote: > Em 23/12/2009 16:10, Eliot Miranda < [hidden email] > escreveu: > > > > > Core.SequenceableCollection comparing > > isSameSequenceAs: otherCollection > > > > "Answer whether the receiver's size is the same as otherCollection's > > size, and each of the receiver's elements equal the corresponding > > element of otherCollection." > > > > | size | > > (size := self size) = otherCollection size ifFalse: [^false]. > > 1 to: size do: [:index | > > (self at: index) = (otherCollection at: index) ifFalse: [^false]]. > > ^true > > > > i.e. trust the caller is providing a sequence and if > > otherCollection doesn't implement at: there will be a run-time > > error, hence any otherCollection isKindOf: SequenceableCollection is > > just wasted cycles. > > > > I don't think that "trusting the caller" makes sense in this case, so > I propose instead that you implementation be complemented by: > > Object>>isSameSequenceAs: otherCollection > ^false > > We're talking about the argument otherCollection not the receiver. i.e. leaving out isKindOf: in > isSameSequenceAs: otherCollection > "Answer whether the receiver's size is the same as otherCollection's size, and each > of the receiver's elements equal the corresponding element of otherCollection." > > | size | > (otherCollection isKindOf: SequenceableCollection) ifFalse: [^false]. "this is a horrible wart" > (size := self size) = otherCollection size ifFalse: [^false]. > 1 to: size do: [:index | > (self at: index) = (otherCollection at: index) ifFalse: [^false]]. > ^true > > You could use double dispatching: > > SequenceableCollection>>isSameSequenceAs: otherThing > ^otherThing isSameSequenceAsSequence: self > > SequenceableCollection>> isSameSequenceAsSequence: aSequenceableCollection > aSequenceableCollection size ~= self size ifTrue: [^false]. > etc > > Object isSameSequenceAsSequence: aSequenceableCollection > ^false > > but I think in this case it's overkill. > > > -- > Cesar Rabak > > _______________________________________________ > 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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2009/12/23 Stéphane Ducasse <[hidden email]>:
> Ideally what I would like is > > = > isSameSequenceAs: + same receiver kind (may be overkill) > > isSameSequenceAs: otherCollection > "Answer whether the receiver's size is the same as otherCollection's size, and each > of the receiver's elements equal the corresponding element of otherCollection." > > hasSameElements: > "Answer whether the receiver's size is the same as otherCollection's size, and each > of the receiver's elements is included in otherCollection and vice versa." > > Stef > like #(2 2 3) hasSameElements: #(2 3 3) -> true but #(2 2 3) asSet hasSameElements: #(2 3 3) -> false ? > > > > On Dec 23, 2009, at 7:58 PM, Eliot Miranda wrote: > >> >> >> On Wed, Dec 23, 2009 at 10:41 AM, <[hidden email]> wrote: >> Em 23/12/2009 16:10, Eliot Miranda < [hidden email] > escreveu: >> >> > >> > Core.SequenceableCollection comparing >> > isSameSequenceAs: otherCollection >> > >> > "Answer whether the receiver's size is the same as otherCollection's >> > size, and each of the receiver's elements equal the corresponding >> > element of otherCollection." >> > >> > | size | >> > (size := self size) = otherCollection size ifFalse: [^false]. >> > 1 to: size do: [:index | >> > (self at: index) = (otherCollection at: index) ifFalse: [^false]]. >> > ^true >> > >> > i.e. trust the caller is providing a sequence and if >> > otherCollection doesn't implement at: there will be a run-time >> > error, hence any otherCollection isKindOf: SequenceableCollection is >> > just wasted cycles. >> > >> >> I don't think that "trusting the caller" makes sense in this case, so >> I propose instead that you implementation be complemented by: >> >> Object>>isSameSequenceAs: otherCollection >> ^false >> >> We're talking about the argument otherCollection not the receiver. i.e. leaving out isKindOf: in >> isSameSequenceAs: otherCollection >> "Answer whether the receiver's size is the same as otherCollection's size, and each >> of the receiver's elements equal the corresponding element of otherCollection." >> >> | size | >> (otherCollection isKindOf: SequenceableCollection) ifFalse: [^false]. "this is a horrible wart" >> (size := self size) = otherCollection size ifFalse: [^false]. >> 1 to: size do: [:index | >> (self at: index) = (otherCollection at: index) ifFalse: [^false]]. >> ^true >> >> You could use double dispatching: >> >> SequenceableCollection>>isSameSequenceAs: otherThing >> ^otherThing isSameSequenceAsSequence: self >> >> SequenceableCollection>> isSameSequenceAsSequence: aSequenceableCollection >> aSequenceableCollection size ~= self size ifTrue: [^false]. >> etc >> >> Object isSameSequenceAsSequence: aSequenceableCollection >> ^false >> >> but I think in this case it's overkill. >> >> >> -- >> Cesar Rabak >> >> _______________________________________________ >> 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 > _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
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> 2009/12/23 Stéphane Ducasse <[hidden email]>: >> Ideally what I would like is >> >> = >> isSameSequenceAs: + same receiver kind (may be overkill) >> >> isSameSequenceAs: otherCollection >> "Answer whether the receiver's size is the same as otherCollection's size, and each >> of the receiver's elements equal the corresponding element of otherCollection." >> >> hasSameElements: >> "Answer whether the receiver's size is the same as otherCollection's size, and each >> of the receiver's elements is included in otherCollection and vice versa." >> >> Stef >> > > like #(2 2 3) hasSameElements: #(2 3 3) -> true > but #(2 2 3) asSet hasSameElements: #(2 3 3) -> false no as >> hasSameElements: >> "Answer wether each of the receiver's elements is included in otherCollection and vice versa." Sorry another victim of copy and paste. Stef > > ? > >> >> >> >> On Dec 23, 2009, at 7:58 PM, Eliot Miranda wrote: >> >>> >>> >>> On Wed, Dec 23, 2009 at 10:41 AM, <[hidden email]> wrote: >>> Em 23/12/2009 16:10, Eliot Miranda < [hidden email] > escreveu: >>> >>>> >>>> Core.SequenceableCollection comparing >>>> isSameSequenceAs: otherCollection >>>> >>>> "Answer whether the receiver's size is the same as otherCollection's >>>> size, and each of the receiver's elements equal the corresponding >>>> element of otherCollection." >>>> >>>> | size | >>>> (size := self size) = otherCollection size ifFalse: [^false]. >>>> 1 to: size do: [:index | >>>> (self at: index) = (otherCollection at: index) ifFalse: [^false]]. >>>> ^true >>>> >>>> i.e. trust the caller is providing a sequence and if >>>> otherCollection doesn't implement at: there will be a run-time >>>> error, hence any otherCollection isKindOf: SequenceableCollection is >>>> just wasted cycles. >>>> >>> >>> I don't think that "trusting the caller" makes sense in this case, so >>> I propose instead that you implementation be complemented by: >>> >>> Object>>isSameSequenceAs: otherCollection >>> ^false >>> >>> We're talking about the argument otherCollection not the receiver. i.e. leaving out isKindOf: in >>> isSameSequenceAs: otherCollection >>> "Answer whether the receiver's size is the same as otherCollection's size, and each >>> of the receiver's elements equal the corresponding element of otherCollection." >>> >>> | size | >>> (otherCollection isKindOf: SequenceableCollection) ifFalse: [^false]. "this is a horrible wart" >>> (size := self size) = otherCollection size ifFalse: [^false]. >>> 1 to: size do: [:index | >>> (self at: index) = (otherCollection at: index) ifFalse: [^false]]. >>> ^true >>> >>> You could use double dispatching: >>> >>> SequenceableCollection>>isSameSequenceAs: otherThing >>> ^otherThing isSameSequenceAsSequence: self >>> >>> SequenceableCollection>> isSameSequenceAsSequence: aSequenceableCollection >>> aSequenceableCollection size ~= self size ifTrue: [^false]. >>> etc >>> >>> Object isSameSequenceAsSequence: aSequenceableCollection >>> ^false >>> >>> but I think in this case it's overkill. >>> >>> >>> -- >>> Cesar Rabak >>> >>> _______________________________________________ >>> 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 >> > > _______________________________________________ > 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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In reply to this post by Nicolas Cellier
Em 23/12/2009 19:17, Nicolas Cellier < [hidden email] > escreveu:
> 2009/12/23 Stéphane Ducasse : > > Ideally what I would like is > > > > = isSameSequenceAs: + same receiver kind (may be overkill) > > > > isSameSequenceAs: otherCollection > > "Answer whether the receiver's size is the same as > > otherCollection's size, and each of the receiver's > > elements equal the corresponding element of > > otherCollection." > > > > hasSameElements: > > "Answer whether the receiver's size is the same as > > otherCollection's size, and each of the receiver's > > elements is included in otherCollection and vice versa." > > Stef > > > like #(2 2 3) hasSameElements: #(2 3 3) -> true > but #(2 2 3) asSet hasSameElements: #(2 3 3) -> false Can someone illustrate this less enlightened coder what common programming pattern this wonderful method would of use for? -- Cesar Rabak _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
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In reply to this post by Eliot Miranda-2
Eliot is right: the argument of isSameSequenceAs: should be already of
SequenceableCollection kind , otherwise there is no sense asking , whether some collection has same sequence as another one, which probably not sequencable. By analogy, asking 'isSameColor: anObject' , we already stating, that an argument - anObject having a #color property. Otherwise, if its not, this should lead to error, but not returning 'false'. 2009/12/23 Eliot Miranda <[hidden email]>: > > > On Wed, Dec 23, 2009 at 10:41 AM, <[hidden email]> wrote: >> >> Em 23/12/2009 16:10, Eliot Miranda < [hidden email] > escreveu: >> >> > >> > Core.SequenceableCollection comparing >> > isSameSequenceAs: otherCollection >> > >> > "Answer whether the receiver's size is the same as otherCollection's >> > size, and each of the receiver's elements equal the corresponding >> > element of otherCollection." >> > >> > | size | >> > (size := self size) = otherCollection size ifFalse: [^false]. >> > 1 to: size do: [:index | >> > (self at: index) = (otherCollection at: index) ifFalse: [^false]]. >> > ^true >> > >> > i.e. trust the caller is providing a sequence and if >> > otherCollection doesn't implement at: there will be a run-time >> > error, hence any otherCollection isKindOf: SequenceableCollection is >> > just wasted cycles. >> > >> >> I don't think that "trusting the caller" makes sense in this case, so >> I propose instead that you implementation be complemented by: >> >> Object>>isSameSequenceAs: otherCollection >> ^false > > We're talking about the argument otherCollection not the receiver. i.e. > leaving out isKindOf: in > isSameSequenceAs: otherCollection > "Answer whether the receiver's size is the same as > otherCollection's size, and each > of the receiver's elements equal the corresponding element of > otherCollection." > > | size | > (otherCollection isKindOf: SequenceableCollection) ifFalse: > [^false]. "this is a horrible wart" > (size := self size) = otherCollection size ifFalse: [^false]. > 1 to: size do: [:index | > (self at: index) = (otherCollection at: index) ifFalse: > [^false]]. > ^true > You could use double dispatching: > SequenceableCollection>>isSameSequenceAs: otherThing > ^otherThing isSameSequenceAsSequence: self > SequenceableCollection>> isSameSequenceAsSequence: aSequenceableCollection > aSequenceableCollection size ~= self size ifTrue: [^false]. > etc > Object isSameSequenceAsSequence: aSequenceableCollection > ^false > but I think in this case it's overkill. >> >> -- >> Cesar Rabak >> >> _______________________________________________ >> 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 > -- Best regards, Igor Stasenko AKA sig. _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
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Igor,
Sometimes a fallacy can be written by clever people, by accident. If you pay attention to the line: (size := self size) = otherCollection size ifFalse: [^false]. I all Smalltalks [Except Pharo to what I wrote a comment in issue 1637 http://code.google.com/p/pharo/issues/detail?id=1637] this would return false if self be not Collection or otheCollection isKindOf: Collection not. This happens because in these Smalltalks Object>>size returns zero. In Squeak where the method is implemented slightly different, an UndefinedObject>>size does return the zero for nil Objects but will raise an error for non indexable objects. So except if we are willing to have a very specific dialect of Smalltalk in Pharo, we'll probably have to fix the protocol for Object>>size, and then the line above will for most of the cases automatically return false as soon otherCollection happen to be isKindOf: Collection not. OTOH, if we keep Pharo as is, the above line will also by the automatism already described give the MNU as an error. . . -- Cesar Rabak Em 23/12/2009 20:22, Igor Stasenko <[hidden email]> escreveu: Eliot is right: the argument of isSameSequenceAs: should be already of SequenceableCollection kind , otherwise there is no sense asking , whether some collection has same sequence as another one, which probably not sequencable. By analogy, asking 'isSameColor: anObject' , we already stating, that an argument - anObject having a #color property. Otherwise, if its not, this should lead to error, but not returning 'false'. 2009/12/23 Eliot Miranda : > > > On Wed, Dec 23, 2009 at 10:41 AM, wrote: >> >> Em 23/12/2009 16:10, Eliot Miranda < [hidden email] > escreveu: >> >> > >> > Core.SequenceableCollection comparing >> > isSameSequenceAs: otherCollection >> > >> > "Answer whether the receiver's size is the same as otherCollection's >> > size, and each of the receiver's elements equal the corresponding >> > element of otherCollection." >> > >> > | size | >> > (size := self size) = otherCollection size ifFalse: [^false]. >> > 1 to: size do: [:index | >> > (self at: index) = (otherCollection at: index) ifFalse: [^false]]. >> > ^true >> > >> > i.e. trust the caller is providing a sequence and if >> > otherCollection doesn't implement at: there will be a run-time >> > error, hence any otherCollection isKindOf: SequenceableCollection is >> > just wasted cycles. >> > >> >> I don't think that "trusting the caller" makes sense in this case, so >> I propose instead that you implementation be complemented by: >> >> Object>>isSameSequenceAs: otherCollection >> ^false > > We're talking about the argument otherCollection not the receiver. i.e. > leaving out isKindOf: in > isSameSequenceAs: otherCollection > "Answer whether the receiver's size is the same as > otherCollection's size, and each > of the receiver's elements equal the corresponding element of > otherCollection." > > | size | > (otherCollection isKindOf: SequenceableCollection) ifFalse: > [^false]. "this is a horrible wart" > (size := self size) = otherCollection size ifFalse: [^false]. > 1 to: size do: [:index | > (self at: index) = (otherCollection at: index) ifFalse: > [^false]]. > ^true > You could use double dispatching: > SequenceableCollection>>isSameSequenceAs: otherThing > ^otherThing isSameSequenceAsSequence: self > SequenceableCollection>> isSameSequenceAsSequence: aSequenceableCollection > aSequenceableCollection size ~= self size ifTrue: [^false]. > etc > Object isSameSequenceAsSequence: aSequenceableCollection > ^false > but I think in this case it's overkill. >> >> -- >> Cesar Rabak >> >> _______________________________________________ >> 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 > -- Best regards, Igor Stasenko AKA sig. _______________________________________________ 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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2009/12/24 <[hidden email]>:
> Igor, > > Sometimes a fallacy can be written by clever people, by accident. > > If you pay attention to the line: > > (size := self size) = otherCollection size ifFalse: [^false]. > > I all Smalltalks [Except Pharo to what I wrote a comment in issue 1637 http://code.google.com/p/pharo/issues/detail?id=1637] this would return false if self be not Collection or otheCollection isKindOf: Collection not. > > This happens because in these Smalltalks Object>>size returns zero. > Not so sure. Try 1.0 size, then 1.0 at: 1.0 size in you favourite dialect. Nicolas > In Squeak where the method is implemented slightly different, an UndefinedObject>>size does return the zero for nil Objects but will raise an error for non indexable objects. > > So except if we are willing to have a very specific dialect of Smalltalk in Pharo, we'll probably have to fix the protocol for Object>>size, and then the line above will for most of the cases automatically return false as soon otherCollection happen to be isKindOf: Collection not. > > OTOH, if we keep Pharo as is, the above line will also by the automatism already described give the MNU as an error. . . > > -- > Cesar Rabak > > Em 23/12/2009 20:22, Igor Stasenko <[hidden email]> escreveu: > > > Eliot is right: the argument of isSameSequenceAs: should be already of > SequenceableCollection kind , > otherwise there is no sense asking , whether some collection has same > sequence as another one, which probably not sequencable. > > By analogy, asking 'isSameColor: anObject' , we already stating, that > an argument - anObject having a #color property. > Otherwise, if its not, this should lead to error, but not returning 'false'. > > > 2009/12/23 Eliot Miranda : >> >> >> On Wed, Dec 23, 2009 at 10:41 AM, wrote: >>> >>> Em 23/12/2009 16:10, Eliot Miranda < [hidden email] > escreveu: >>> >>> > >>> > Core.SequenceableCollection comparing >>> > isSameSequenceAs: otherCollection >>> > >>> > "Answer whether the receiver's size is the same as otherCollection's >>> > size, and each of the receiver's elements equal the corresponding >>> > element of otherCollection." >>> > >>> > | size | >>> > (size := self size) = otherCollection size ifFalse: [^false]. >>> > 1 to: size do: [:index | >>> > (self at: index) = (otherCollection at: index) ifFalse: [^false]]. >>> > ^true >>> > >>> > i.e. trust the caller is providing a sequence and if >>> > otherCollection doesn't implement at: there will be a run-time >>> > error, hence any otherCollection isKindOf: SequenceableCollection is >>> > just wasted cycles. >>> > >>> >>> I don't think that "trusting the caller" makes sense in this case, so >>> I propose instead that you implementation be complemented by: >>> >>> Object>>isSameSequenceAs: otherCollection >>> ^false >> >> We're talking about the argument otherCollection not the receiver. i.e. >> leaving out isKindOf: in >> isSameSequenceAs: otherCollection >> "Answer whether the receiver's size is the same as >> otherCollection's size, and each >> of the receiver's elements equal the corresponding element of >> otherCollection." >> >> | size | >> (otherCollection isKindOf: SequenceableCollection) ifFalse: >> [^false]. "this is a horrible wart" >> (size := self size) = otherCollection size ifFalse: [^false]. >> 1 to: size do: [:index | >> (self at: index) = (otherCollection at: index) ifFalse: >> [^false]]. >> ^true >> You could use double dispatching: >> SequenceableCollection>>isSameSequenceAs: otherThing >> ^otherThing isSameSequenceAsSequence: self >> SequenceableCollection>> isSameSequenceAsSequence: aSequenceableCollection >> aSequenceableCollection size ~= self size ifTrue: [^false]. >> etc >> Object isSameSequenceAsSequence: aSequenceableCollection >> ^false >> but I think in this case it's overkill. >>> >>> -- >>> Cesar Rabak >>> >>> _______________________________________________ >>> 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 >> > > > > -- > Best regards, > Igor Stasenko AKA sig. > > _______________________________________________ > 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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Em 23/12/2009 22:51, Nicolas Cellier <[hidden email]> escreveu:
> 2009/12/24 : > > Igor, > > Sometimes a fallacy can be written by clever people, by accident. > > If you pay attention to the line: > > (size := self size) = otherCollection size ifFalse: [^false]. > > I all Smalltalks [Except Pharo to what I wrote a comment in issue > > 1637 http://code.google.com/p/pharo/issues/detail?id=1637] this > > would return false if self be not Collection or otheCollection > > isKindOf: Collection not. > > This happens because in these Smalltalks Object>>size returns > > zero. > > > Not so sure. Try 1.0 size, then 1.0 at: 1.0 size in you favourite > dialect. Nicolas, In Squeak 3.10.2-7179: 1.0 size -> 2 "OK I'm surprised here" 1.0 at: 1.0 size -> 0 "this will not work anymore in Pharo because indices have to be Integer in Pharo right now" HTH -- Cesar Rabak _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
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2009/12/24 <[hidden email]>:
> Em 23/12/2009 22:51, Nicolas Cellier <[hidden email]> escreveu: > >> 2009/12/24 : >> > Igor, >> > Sometimes a fallacy can be written by clever people, by accident. >> > If you pay attention to the line: >> > (size := self size) = otherCollection size ifFalse: [^false]. >> > I all Smalltalks [Except Pharo to what I wrote a comment in issue >> > 1637 http://code.google.com/p/pharo/issues/detail?id=1637] this >> > would return false if self be not Collection or otheCollection >> > isKindOf: Collection not. >> > This happens because in these Smalltalks Object>>size returns >> > zero. >> > >> Not so sure. Try 1.0 size, then 1.0 at: 1.0 size in you favourite >> dialect. > > Nicolas, > > In Squeak 3.10.2-7179: > > 1.0 size -> 2 "OK I'm surprised here" > > 1.0 at: 1.0 size -> 0 "this will not work anymore in Pharo because > indices have to be Integer in Pharo right now" > I mean in VW, size would be > 0 but #at: would raise a debugger. Nicolas > HTH > > -- > Cesar Rabak > > > _______________________________________________ > 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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In reply to this post by csrabak
On Thu, 24 Dec 2009, [hidden email] wrote:
> Em 23/12/2009 22:51, Nicolas Cellier <[hidden email]> escreveu: > >> 2009/12/24 : >>> Igor, >>> Sometimes a fallacy can be written by clever people, by accident. >>> If you pay attention to the line: >>> (size := self size) = otherCollection size ifFalse: [^false]. >>> I all Smalltalks [Except Pharo to what I wrote a comment in issue >>> 1637 http://code.google.com/p/pharo/issues/detail?id=1637] this >>> would return false if self be not Collection or otheCollection >>> isKindOf: Collection not. >>> This happens because in these Smalltalks Object>>size returns >>> zero. >>> >> Not so sure. Try 1.0 size, then 1.0 at: 1.0 size in you favourite >> dialect. > > Nicolas, > > In Squeak 3.10.2-7179: > > 1.0 size -> 2 "OK I'm surprised here" It's not surprising since Float is a variable word subclass of Number. :) > > 1.0 at: 1.0 size -> 0 "this will not work anymore in Pharo because > indices have to be Integer in Pharo right now" The index is 2, so it will work. Btw, I wonder how pharo can force Integer indices if the vm accepts Floats too. Levente > > HTH > > -- > Cesar Rabak > > > _______________________________________________ > 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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Em 24/12/2009 01:21, Levente Uzonyi < [hidden email] > escreveu:
> On Thu, 24 Dec 2009, [hidden email] wrote: > > > Em 23/12/2009 22:51, Nicolas Cellier escreveu: > > > >> 2009/12/24 : > >>> Igor, Sometimes a fallacy can be written by clever people, by > >>> accident. If you pay attention to the line: (size := self size) > >>> = otherCollection size ifFalse: [^false]. I all Smalltalks > >>> [Except Pharo to what I wrote a comment in issue 1637 > >>> http://code.google.com/p/pharo/issues/detail?id=1637] this would > >>> return false if self be not Collection or otheCollection > >>> isKindOf: Collection not. This happens because in these > >>> Smalltalks Object>>size returns zero. > >>> Not so sure. Try 1.0 size, then 1.0 at: 1.0 size in you > >> favourite > >> dialect. > > Nicolas, > > In Squeak 3.10.2-7179: > > 1.0 size -> 2 "OK I'm surprised here" > It's not surprising since Float is a variable word subclass of > Number. :) > > > 1.0 at: 1.0 size -> 0 "this will not work anymore in Pharo because > > indices have to be Integer in Pharo right now" > The index is 2, so it will work. Btw, I wonder how pharo can force > Integer indices if the vm accepts Floats too. > In fact VM _does_ _not_ accept Floats as indices. There is a hack in Squeak code (which in fact contradicts the comment in the method) in the #at: methods that make a conversion from Number to Integer. If you comment that code out you'll see the VM #at: (via the primitive) will fail with Floats. -- Cesar Rabak _______________________________________________ Pharo-project mailing list [hidden email] http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project |
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On Thu, 24 Dec 2009, [hidden email] wrote:
> Em 24/12/2009 01:21, Levente Uzonyi < [hidden email] > escreveu: > >> On Thu, 24 Dec 2009, [hidden email] wrote: >> >>> Em 23/12/2009 22:51, Nicolas Cellier escreveu: >>> >>>> 2009/12/24 : >>>>> Igor, Sometimes a fallacy can be written by clever people, by >>>>> accident. If you pay attention to the line: (size := self size) >>>>> = otherCollection size ifFalse: [^false]. I all Smalltalks >>>>> [Except Pharo to what I wrote a comment in issue 1637 >>>>> http://code.google.com/p/pharo/issues/detail?id=1637] this would >>>>> return false if self be not Collection or otheCollection >>>>> isKindOf: Collection not. This happens because in these >>>>> Smalltalks Object>>size returns zero. >>>>> Not so sure. Try 1.0 size, then 1.0 at: 1.0 size in you >>>> favourite >>>> dialect. >>> Nicolas, >>> In Squeak 3.10.2-7179: >>> 1.0 size -> 2 "OK I'm surprised here" >> It's not surprising since Float is a variable word subclass of >> Number. :) >> >>> 1.0 at: 1.0 size -> 0 "this will not work anymore in Pharo because >>> indices have to be Integer in Pharo right now" >> The index is 2, so it will work. Btw, I wonder how pharo can force >> Integer indices if the vm accepts Floats too. >> > Levente, > > In fact VM _does_ _not_ accept Floats as indices. There is a hack in > Squeak code (which in fact contradicts the comment in the method) in > the #at: methods that make a conversion from Number to Integer. > > If you comment that code out you'll see the VM #at: (via the primitive) > will fail with Floats. True, and cool, since this hack can be removed. Now I wonder why did I assume that the vm has this hack. :) Levente > > -- > Cesar Rabak > > _______________________________________________ > 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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