We could indeed, but it offends my sense of value (excuse the pun), since Symbol>>value: is implemented in terms of #perform: and so is slower. Since this is a general library routine performance is an issue (the sort block is used N log N times in sorting the collection) and so I prefer the use of perform: when the arg is a symbol and value: when it's a block.
Eliot (phone) On Mar 11, 2014, at 3:54 PM, Carlo <snoob...@gmail.com> wrote: > Hi > > Since Symbol and Blocks are polymorphic could we not simplify the code to be: > > SequenceableCollection>>sortedAs: aSortBlockOrSymbol > "Answer a SortedCollection whose elements are the elements of the > receiver. The sort order is defined by the argument, aSortBlockOrSymbol. The > receiver cannot be empty. Answer a new collection. This method does not side > effect the receiver. e.g. > SequenceableCollection withAllSubclasses sortedAs: > #name. > SequenceableCollection withAllSubclasses sortedAs: > [:class | class methodDict size]." > | aSortBlock | > aSortBlock := (#(true false ) > includes: (aSortBlockOrSymbol value: > self first)) > ifTrue: [[:a :b | aSortBlockOrSymbol value: a]] > ifFalse: [[:a :b | (aSortBlockOrSymbol value: > a) < (aSortBlockOrSymbol value: b)]]. > ^ (SortedCollection new: self size) sortBlock: aSortBlock; > addAll: self; > yourself > > > > > <SequenceableCollection-sortedAs.st> > > Cheers > Carlo > > > > > On 12 Mar 2014, at 12:32 AM, Pharo4Stef <pharo4s...@free.fr> wrote: > > Thanks eliot. > > > On 11 Mar 2014, at 20:51, Eliot Miranda <eliot.mira...@gmail.com> wrote: > >> and here's one with a better comment that includes examples >> >> >> On Tue, Mar 11, 2014 at 12:19 PM, Eliot Miranda <eliot.mira...@gmail.com> >> wrote: >>> Hi Alexandre, >>> >>> IMO the isKindOf:, apart from being ugly, will hurt performance badly. >>> Why not apply aSortBlockOrSymbol to the first element and then choose the >>> block appropriately? e.g. >>> >>> aSortBlockOrSymbol isSymbol >>> ifTrue: >>> [(#(true false) includes: (self first perform: >>> aSortBlockOrSymbol) >>> ifTrue: >>> [[:a :b | (a perform: aSortBlockOrSymbol)]] >>> ifFalse: >>> [[:a :b | (a perform: aSortBlockOrSymbol) < (b >>> perform: aSortBlockOrSymbol)]]] >>> ... >>> >>> Nicer to read and faster, no? >>> >>> On Tue, Mar 11, 2014 at 8:17 AM, Alexandre Bergel <alexandre.ber...@me.com> >>> wrote: >>>> hi Uko, >>>> >>>> For Roassal, we have a #sortedAs: defined on all collections >>>> >>>> -=-=-=-=-=-=-=-=-=-=-=-=-=-=-= >>>> SequenceableCollection>>sortedAs: aSortBlockOrSymbol >>>> "Answer a SortedCollection whose elements are the elements of the >>>> receiver. The sort order is defined by the argument, aSortBlock." >>>> "Return a new collection. This method does not do a side effect" >>>> >>>> | aSortedCollection aSortBlock | >>>> aSortedCollection := SortedCollection new: self size. >>>> aSortBlock := >>>> aSortBlockOrSymbol isSymbol >>>> ifTrue: [ [:a :b | |t1 t2| >>>> t1 := (a perform: >>>> aSortBlockOrSymbol). >>>> t2 := (b perform: >>>> aSortBlockOrSymbol). >>>> ((t1 isKindOf: >>>> Boolean) and: [t2 isKindOf: Boolean]) >>>> ifTrue: [ >>>> t1 ] >>>> ifFalse: [ >>>> t1 < t2 ] ] ] >>>> ifFalse: [ >>>> (aSortBlockOrSymbol numArgs = 1) >>>> ifTrue: [ [ :v1 :v2 | >>>> (aSortBlockOrSymbol value: v1) < (aSortBlockOrSymbol value: v2) ] ] >>>> ifFalse: [ aSortBlockOrSymbol ] ]. >>>> aSortedCollection sortBlock: aSortBlock. >>>> aSortedCollection addAll: self. >>>> ^ aSortedCollection >>>> -=-=-=-=-=-=-=-=-=-=-=-=-=-=-= >>>> >>>> You can use it for example: >>>> (1 to: 4) sortedAs: #odd >>>> => a SortedCollection(1 3 2 4) >>>> >>>> Collection withAllSubclasses sortedAs: #numberOfMethods >>>> => a SortedCollection(HashBag IdentityHashBag …) >>>> >>>> This is really handy. It should be part of Pharo I believe. >>>> >>>> Cheers, >>>> Alexandre >>>> >>>> >>>> On Mar 11, 2014, at 5:19 AM, Yuriy Tymchuk <yuriy.tymc...@me.com> wrote: >>>> >>>> > Hi guys. >>>> > >>>> > This is a thing that I encounter quite often. >>>> > >>>> > Eg I have a collection of projects and I want to sort them by creation >>>> > date. It would be nice to be able to do something like: >>>> > >>>> > projects sortByProp: #creationDate >>>> > >>>> > or by birth date of the author >>>> > >>>> > projects sortByProp: [ :proj | proj author birthDate ] >>>> > >>>> > Maybe I’m wrong, but as I’ve told already I encounter it quite often and >>>> > writing something like >>>> > >>>> > projects sortBy: [ :prev :next | prev creationDate <= next creationDate ] >>>> > >>>> > is boring for me. >>>> > >>>> > Cheers. >>>> > Uko >>>> >>>> -- >>>> _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: >>>> Alexandre Bergel http://www.bergel.eu >>>> ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. >>> >>> >>> >>> -- >>> best, >>> Eliot >> >> >> >> -- >> best, >> Eliot >> <SequenceableCollection-sortedAs.st> > >
