So first: as Sven said Sequenceable collection is abstract.
Still I would consider what you found a bug since it provides the implementations that produce the behavior you reported.

I can reproduce it in a 40 with vmLatest, and the proble occurs whenever either #do: or #size is sent.

SequenceableCollection>>do: aBlock
"Refer to the comment in Collection|do:.� 
 1 to: self size do: [:index | aBlock value: (self at: index)]


Collection>>size
size "Answer how many elements the receiver contains.� 

 | tally | 
 tally := 0. 
 self do: [:each | tally := tally + 1]. 
 ^ tally


As you can see, calling either method will produce an infinite loop which eventually crashes the VM.

I couldn�t find an open bug entry so I�ve created one: https://pharo.fogbugz.com/f/cases/14022/Infinite-loop-in-simple-subclasses-of-SequenceableCollection

Cheers,
Max

On 15.09.2014, at 23:12, jdelgado@lsi.upc.edu wrote:

Hi,

A student of mine has accidentaly found something interesting that may be already reported, but I do not have time to check.

The thing is simple:

1) Create a class with accessors for f.

SequenceableCollection subclass: #Foo
    instanceVariableNames: 'f'
    classVariableNames: ''
    category: 'Varios'

2) Foo class >> new: d
    ^self new f: (Array new: d*d)

3) Go to Workspace and inspect the following code

       | m |
        m := Foo new: 2

And Pharo crashes. Always crashes. I am using "Pharo 3.0 3" on OS X 10.6.8. I am pretty sure it is not a Smalltalk error since it works ok in Squeak and VisualWorks.

So, is this a known issue?

Bests,

Jordi