I meant having what Sven mentioned: Collection>>streamContents:
Right now, we only have it in SequeanceableCollection. Doru On Sat, Nov 9, 2013 at 1:27 AM, Stéphane Ducasse <stephane.duca...@inria.fr>wrote: > > On Nov 4, 2013, at 9:40 PM, Tudor Girba <tu...@tudorgirba.com> wrote: > > Indeed, it would be great to have a polymorphic message for constructing > collections. In the meantime, there are three flatCollect: methods: > > > > doru do you have an example of what you mean ? > > > For flaCollect: I let you discuss because I'm not enough concentrated but > I was when we worked on it long time ago. > > > > > > Collection>>flatCollect: aBlock > "Evaluate aBlock for each of the receiver's elements and answer the > list of all resulting values flatten one level. Assumes that aBlock > returns some kind > of collection for each element. Equivalent to the lisp's mapcan" > | stream | > self isEmpty ifTrue: [ ^ self copy ]. > stream := (self species new: 0) writeStream. > self do: [ :each | stream nextPutAll: (aBlock value: each) ]. > ^ stream contents > > Set>>flatCollect: aBlock > ^self flatCollectAsSet: aBlock > > SortedCollection>>flatCollect: aBlock > ^ self flatCollect: aBlock as: OrderedCollection > > Doru > > > On Mon, Nov 4, 2013 at 6:02 PM, Chris Cunningham > <cunningham...@gmail.com>wrote: > >> Right. I hadn't looked closely enough at the Moose one. Actually, if >> you dig it a bit deeper, #writeStream isn't defined in the Collection >> hierarchy until you get to SequenceableCollection in any case, so the Moose >> version is defined too high. >> >> So, if there is a desire for #flatCollect: outside of >> SequenceableColleciton, then this should work (based on Moose version): >> >> Collection>>flatCollect: aBlock >> "Evaluate aBlock for each of the receiver's elements and answer the >> list of all resulting values flatten one level. Assumes that aBlock >> returns some kind >> of collection for each element. Equivalent to the lisp's mapcan" >> "original written by a. Kuhn and released under MIT" >> | result | >> self isEmpty ifTrue: [ ^ self copy ]. >> result := (self species new: 0). >> self do: [ :each | result addAll: (aBlock value: each) ]. >> ^ result >> >> >> SequenceableCollection>>flatCollect: aBlock >> "Evaluate aBlock for each of the receiver's elements and answer the >> list of all resulting values flatten one level. Assumes that aBlock >> returns some kind >> of collection for each element. Equivalent to the lisp's mapcan" >> "original written by a. Kuhn and released under MIT" >> | stream | >> self isEmpty ifTrue: [ ^ self copy ]. >> ^self species streamContents: [ :stream | >> self do: [ :each | stream nextPutAll: (aBlock value: each) ] >> >> >> -Chris >> On Mon, Nov 4, 2013 at 8:46 AM, Sven Van Caekenberghe <s...@stfx.eu>wrote: >> >>> Actually I am still confused about this, for example, >>> >>> Set new writeStream nextPut: 1; contents >>> >>> does not work, so for which non-sequenceable collections would the >>> #flatCollect: code work ? >>> >>> I was thinking that maybe #streamContents: could be put higher up ? >>> If that would not be possible, why not ? >>> And how would the #flatCollect: code then work ? >>> >>> On 04 Nov 2013, at 17:36, Chris Cunningham <cunningham...@gmail.com> >>> wrote: >>> >>> > On Sat, Nov 2, 2013 at 3:52 AM, Tudor Girba <tu...@tudorgirba.com> >>> wrote: >>> > Indeed, it would be more elegant, but streamContents: is only defined >>> in SequeanceableCollection, so it is not generic enough. >>> > >>> > So, then use the generic one where it is defined (Collection), and a >>> more specific one that Sven suggested in SequenceableCollection. >>> > >>> > -Chris >>> > >>> > Doru >>> > >>> > >>> > On Sat, Nov 2, 2013 at 11:21 AM, Sven Van Caekenberghe <s...@stfx.eu> >>> wrote: >>> > BTW, it seems #flatten in 2.0 has become #flattened in 3.0 and that >>> too might needs the #species >>> > >>> > Would it also not be better and more elegant to say >>> > >>> > self species streamContents: [ :stream | >>> > … ] >>> > >>> > ? >>> > >>> > On 02 Nov 2013, at 09:50, Sven Van Caekenberghe <s...@stfx.eu> wrote: >>> > >>> > > >>> > > On 01 Nov 2013, at 23:55, Tudor Girba <tu...@tudorgirba.com> wrote: >>> > > >>> > >> Hi, >>> > >> >>> > >> I see that Pharo 3.0 has a Collection>>flatCollect:. This is great >>> as the method proved to be very valuable in the context of Moose. >>> > >> >>> > >> However, the current Pharo implementation is less ideal: >>> > >> >>> > >> Collection>>flatCollect: aBlock >>> > >> ^ Array streamContents: >>> > >> [:stream | >>> > >> self do: [:ea | stream nextPutAll: (aBlock value: ea)]] >>> > >> >>> > >> The Moose one is: >>> > >> Collection>>flatCollect: aBlock >>> > >> "Evaluate aBlock for each of the receiver's elements and >>> answer the >>> > >> list of all resulting values flatten one level. Assumes that >>> aBlock returns some kind >>> > >> of collection for each element. Equivalent to the lisp's >>> mapcan" >>> > >> "original written by a. Kuhn and released under MIT" >>> > >> >>> > >> | stream | >>> > >> self isEmpty ifTrue: [ ^ self copy ]. >>> > >> stream := (self species new: 0) writeStream. >>> > >> self do: [ :each | stream nextPutAll: (aBlock value: each) ]. >>> > >> ^ stream contents >>> > >> >>> > >> The difference is in the type returned. The Pharo one always >>> returns Array, while the Moose one returns a collection of the same species >>> as the receiver. >>> > > >>> > > Sounds right, returning #species. >>> > > >>> > >> Does anyone have anything against the Moose implementation? >>> > >> >>> > >> Doru >>> > >> >>> > >> -- >>> > >> www.tudorgirba.com >>> > >> >>> > >> "Every thing has its own flow" >>> > >>> > >>> > >>> > >>> > >>> > -- >>> > www.tudorgirba.com >>> > >>> > "Every thing has its own flow" >>> > >>> >>> >>> >> > > > -- > www.tudorgirba.com > > "Every thing has its own flow" > > > -- www.tudorgirba.com "Every thing has its own flow"
