[Moose-dev] Re: [Pharo-project] Collection>>difference: behaviour in 1.4 (was Re: Jenkins build is still unstable: moose-latest-dev #972 )

This discussion originates from Mondrian on Moose 4.7 where layouts which previously were exactly reproducible now randomly alternate between two arrangements. I have cross-posted since upstream behaviour of Collection>>difference: has changed between Pharo 1.3 and 1.4. The issue in Mondrian has been isolated so that it can be observed using the attached changeset 'isolate-unstable-972.2.cs' against a fresh Moose 4.7 image downloaded a few moments ago. After loading the cs, open a Transcript and then <Generate> the following script in Modrian Easel a dozen times. view shape label. view nodes: #(1 2 3 4 ). view edgesFromAssociations: { 1 -> 2. 1 ->3 . 3 -> 4}. view treeLayout At some point you will see a change in the order that nodes are drawn between runs as reflected in lines B2 and A2 shown below... ------------------------------RUN 1 B1>an OrderedCollection(a MONode model: 2 a MONode model: 3) B2>an OrderedCollection(a MONode model: 3 a MONode model: 2) A2>a MONode model: 1 A2>a MONode model: 3 A2>a MONode model: 4 A2>a MONode model: 2 ------------------------------RUN 2 B1>an OrderedCollection(a MONode model: 2 a MONode model: 3) B2>an OrderedCollection(a MONode model: 2 a MONode model: 3) A2>a MONode model: 1 A2>a MONode model: 2 A2>a MONode model: 3 A2>a MONode model: 4 ------------------------------END The cause of this is a change in behaviour of Collection>>#difference: between Pharo 1.3 & 1.4. This can be observed by executing the following in Workspace... 20 timesRepeat: [ one := TextMorph new newContents: '1'. two := TextMorph new newContents: '2'. collection := (OrderedCollection with: one with: two). diff := collection difference: OrderedCollection new. Transcript crShow: diff first text, diff second text. ] In Pharo 1.3 the result never deviates from '12'. In Pharo 1.4 the result is sometimes '21'. Pharo 1.3 has... Collection>>difference: aCollection "Answer the set theoretic difference of two collections." ^ self reject: [:each | aCollection includes: each] Pharo 1.4 has... Collection>>difference: aCollection "Answer the set theoretic difference of two collections." | set| set := self asSet. aCollection do: [ :each| set remove: each ifAbsent: []]. ^ self species withAll: set asArray Your thoughts? cheers -ben Tudor Girba wrote: 'From Pharo1.4 of 18 April 2012 [Latest update: #14438] on 16 May 2012 at 11:15:20 pm'! !MOAbstractRegularTreeLayout methodsFor: 'hook' stamp: 'BenComan 5/16/2012 23:14'! doExecute: node | rootNodes btcdebug| alreadyLayoutedNodes := OrderedCollection new. rootNodes := self rootNodesFor: node nodes. nodesByLayer := OrderedCollection new. self flag: #btcdebug. "Regarding moose-dev(a)iam.unibe.ch emails 'Jenkins build is still unstable: moose-latest-dev #972' To isolate the issue, open a Transcript then generate the following in Mondrian Easel twenty times view shape label. view nodes: #(1 2 3 4 ). view edgesFromAssociations: { 1 -> 2. 1 ->3 . 3 -> 4}. view treeLayout. " btcdebug := rootNodes first. Transcript cr; crShow: '------------------------------'. Transcript crShow: 'B1>', (self childrenFor: btcdebug) asString. Transcript crShow: 'B2>', (self computeChildrenFor: btcdebug) asString. self layout: rootNodes atPoint: self leftGap @ self topGap atLayer: 1. self isLayered ifTrue: [ self rearrangeByLayers: node ]! ! !MOAbstractVerticalTreeLayout methodsFor: 'hook-private' stamp: 'BenComan 5/16/2012 23:02'! layout: aNodeCollection atPoint: aPoint atLayer: aNumber | treeSize childrenPosition x y middleOfTree | aNodeCollection isEmpty ifTrue: [ ^ 0 ]. x := aPoint x. y := aPoint y. alreadyLayoutedNodes addAll: aNodeCollection. self atLayer: aNumber add: aNodeCollection. aNodeCollection do: [ :each | self flag: #btcdebug. Transcript crShow: 'A2>', each asString. childrenPosition := y + each height + self verticalGap. treeSize := each width max: (self layout: (self computeChildrenFor: each) atPoint: x @ childrenPosition atLayer: aNumber + 1). middleOfTree := x + (treeSize / 2.0) - (each width / 2.0). each translateTo: middleOfTree @ y. x := x + treeSize + self horizontalGap ]. ^ x - aPoint x - self horizontalGap! !