Is this multisort feature available for Pharo somewhere? Regards!
Esteban A. Maringolo 2014-03-12 7:45 GMT-03:00 Nicolas Cellier <nicolas.cellier.aka.n...@gmail.com>: > I presume you all know about Griggs work on the subject > > http://stackoverflow.com/questions/8204826/smalltalk-sort-a-collection-by-two-criteria > http://objology.blogspot.com/2010/11/tag-sortfunctions.html > > > 2014-03-12 11:23 GMT+01:00 carlo.t <snoob...@yahoo.ie>: > >> Hi Otto >> >> I think the main reason is to support the second usage scenario: >> SequenceableCollection withAllSubclasses sortedAs: [:class | class >> methodDict size]. >> We could try and unify the sort: method to take only blocks while >> sortedAs: >> a symbol but then at the same time we could just put everything into one >> method and use cull: perhaps to handle all the scenarios. >> >> Personally I don't feel too comfortable with the code below, apart from >> the >> performance penalties it also feels like code that is too 'clever' for >> itself which obviously makes it complicated to understand and modify. I >> wrote it mainly for people to voice opinions and get ideas flowing. I'd >> have >> 2 separate sort methods so that users can choose if they want the runtime >> characteristics of either. >> >> Example which can handle all current scenarios i.e. symbol or block taking >> 1 >> or 2 arguments: >> SequenceableCollection>>sort: aSortBlock >> self >> mergeSortFrom: 1 >> to: self size >> by: (self createSortBlock: aSortBlock) >> >> >> SequenceableCollection>>createSortBlock: aSortBlockOrSymbol >> ^ aSortBlockOrSymbol numArgs < 2 >> ifTrue: [[ :a :b | (#(true false ) >> includes: (aSortBlockOrSymbol >> value: a)) >> ifTrue: [ aSortBlockOrSymbol value: a] >> ifFalse: [(aSortBlockOrSymbol value: a) < >> (aSortBlockOrSymbol value: >> b)]]] >> ifFalse: [[:a :b | aSortBlockOrSymbol cull: a cull: b]] >> >> >> BTW the previous versions had a bug where it fails when called on an empty >> collection as the true/false check is done eagerly. >> >> Cheers >> Carlo >> >> >> >> -- >> View this message in context: >> http://forum.world.st/Sort-by-property-tp4748500p4748757.html >> Sent from the Pharo Smalltalk Developers mailing list archive at >> Nabble.com. >> >
