On Fri, 25 Dec 2009, Stéphane Ducasse wrote:
Hi levente
Reading your changes I was wondering if resetTo: should not be moved into OrderedCollection class >> new: and why only have it for the default new?
The patch below had the purpose to speed up #asOrderedCollection in general. But I think #resetTo: can be moved to #new: or even to #setCollection: on the instance side, since I don't see any benefit for using array size // 3 for firstIndex. I guess the original idea was to leave enough space on both sides of the array, so adding to both sides has good performance, though in general this is not the case, because #makeRoomAtFirst and #makeRoomAtLast doesn't leave space on both sides. o := OrderedCollection new. [ 1 to: 10000 do: [ :each | o addFirst: each; addFirst: each ] ] timeToRun ===> 4 o := OrderedCollection new. [ 1 to: 10000 do: [ :each | o addLast: each; addLast: each ] ] timeToRun ===> 3 o := OrderedCollection new. [ 1 to: 10000 do: [ :each | o addFirst: each; addLast: each ] ] timeToRun ===> 20067 Levente
OrderedCollection class >>newFrom: aCollection "Answer an instance of me containing the same elements as aCollection."
+ ^(self new: aCollection size) + resetTo: 1; + addAll: aCollection; + yourself - | newCollection | - newCollection := self new: aCollection size. - newCollection addAll: aCollection. - ^newCollection
I did OrderedCollection new: 100. and contrary to what I expected firstIndex is not 1 but 33. Now when you add resetTo: 1 firstIndex get 1.
new: anInteger "Create a collection with enough room allocated to contain up to anInteger elements. The new instance will be of size 0 (allocated room is not necessarily used)." ^self basicNew setCollection: (Array new: anInteger)
setCollection: anArray array := anArray. self reset
reset firstIndex := array size // 3 max: 1. lastIndex := firstIndex - 1
_______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project