You do know that SequenceableCollection is an abstract class, right ? But there should be a nice exception not a crash, on the other hand, this happens for many abstract classes. On 05 May 2014, at 19:27, Ben Coman <btc@openInWorld.com> wrote:

Just reporting, while looking into a query on [pharo-users] (which is attached for initial context only and can probably be deleted from any replies) I managed to crash the VM by evaluating the following in Workspace:

a := SequenceableCollection new. a add: 1. a , SequenceableCollection new.

Now the interesting thing is that while the system becomes immediately sluggish, Pharo.exe crashes about 20 seconds later.

This is with Pharo 3.0 Release (30846) http://files.pharo.org/platform/Pharo3.0-win.zip (dated 2014-04-30) on Windows Home Premium 64-bit SP1.

cheers -ben

Ben Coman wrote:

...

Thanks. That info made it much easier to try. Sorry I didn't end up with an answer for you, but I confirm there is some issue here, or something new I can learn when other chip in.

Here is what I tried.

* Installed XMLParser (monty.58) from Configuration Browser in Pharo 3.

* Ran your code. Got the same error.

* From the call stack I observed that XMLOrderedCollection(SequenceableCollection)>>copyReplaceFrom:to:with: has the line "newSequenceableCollection := self species new: newSize." such that it seems your error might be reduced to the question of why the following two snippets fail: d := OrderedCollection new: 1. d at: 1 put: 1.

e := OrderedCollection new: 3. e at: 2 put: 1.

However I'm sorry that is beyond my knowledge, and I'm hoping someone else can chip in so I can learn something.

Pushing on, I noticed that XMLOrderedList has an instance variable /collection/ which holds the OrderedCollection.

Now I wonder (without great experience and hoping to learn something) if it smells funny that XMLOrderedList inherits all of SequencableCollection methods that can not operate on /collection/.

I noticed that XMLOrderedList was using an inherited SequenceableCollection>>copyReplaceFrom:to:with while OrderedCollection overrode that method with its own. So taking inspiration XMLOrderedList>>copyFrom:to: to override SequencableCollection>>copyReplaceFrom:to:with: to work with /collection/ seems to solve your problem: XMLOrderedList>>copyReplaceFrom: start to: stop with: replacementCollection ^ self newWithCollection: (collection copyReplaceFrom: start to: stop with: replacementCollection )

Along the way I noticed a few (possible) bugs that seems not related to your problem:

* When stepping through XMLOrderedList>>setCollection: there is a red-box-of-death for the instance variables, which can be solved by defining the following. XMLOrderedList>>size ^ collection ifNil: [ 0 ] ifNotNil: [ collection size]

* In the debugger the /collection/ instance variable is not shown! (e.g. line XMLOrderedList>>at:put:). Can someone confirm this should show?

HTH cheers -ben

Thushar G R wrote:

...

XMLOrderedList belongs to package XML-Parser-Nodes.

a := XMLOrderedList new. a add:'1'. a , XMLOrderedList new.

Here select all and Do it. On line 3 (a , XMLOrderedList new.) i am expected to get a copy of 'a' , but instead it throws an error SubscriptOutOfBounds.

OrderedCollection(Object)>>errorSubscriptBounds: OrderedCollection>>ensureBoundsFrom:to: OrderedCollection>>at:put: OrderedCollection(SequenceableCollection)>>replaceFrom:to:with:startingAt: XMLOrderedList>>replaceFrom:to:with:startingAt: XMLOrderedList(SequenceableCollection)>>copyReplaceFrom:to:with: XMLOrderedList(SequenceableCollection)>>, UndefinedObject>>DoIt OpalCompiler>>evaluate SmalltalkEditor>>evaluateSelectionAndDo: PluggableTextMorph>>inspectIt in Block: [ textMorph editor evaluateSelectionAndDo: [ :resu...etc... PluggableTextMorph>>handleEdit: in Block: [ result := editBlock value ] TextMorphForEditView(TextMorph)>>handleEdit: PluggableTextMorph>>handleEdit: PluggableTextMorph>>inspectIt SmalltalkEditor class>>buildSmalltalkEditorKeymappingsOn: in Block: [ :morph | morph inspectIt ] BlockClosure>>cull: BlockClosure>>cull:cull: BlockClosure>>cull:cull:cull: KMCategoryBinding>>completeMatch:buffer: KMKeymap>>notifyCompleteMatchTo:buffer: in Block: [ :l | l completeMatch: self buffer: aBuffer ] Array(SequenceableCollection)>>do: KMKeymap>>notifyCompleteMatchTo:buffer: KMKeymap>>onMatchWith:notify:andDo: KMCategory>>onMatchWith:notify:andDo: in Block: [ :entry | entry onMatchWith: anEventBuffer notify...etc... Set>>do: KMCategory>>onMatchWith:notify:andDo: KMCategoryBinding>>verifyMatchWith:notifying:thenDoing: KMDispatcher>>dispatch: in Block: [ :aTarget | ... OrderedCollection>>do:

Plese refer to the above stack.

Thanks in advance.

thushar

On Mon, May 5, 2014 at 6:28 PM, Ben Coman <btc@openinworld.com> wrote: Thushar G R wrote: Hi,

I am getting an error while doing this.

a := XMLOrderedList new. a add:'1'. a , XMLOrderedList new.

Thanks,

Thushar I could give you "an answer" ;) - but it would be what you wanted. It would help if you told what the error was, where it occurs (which of the three lines), and what you expect each line is doing (especially the third line).

Also I don't see XMLOrderedList in the default Pharo image, so it would help if you describe where you got that from and how you installed it.

cheers -ben