On Fri, 16 Jun 2017, Nicolai Hess wrote:

> Does this even work ?
> Set does not preserve ordering.

The receiver is not a Set but a SequenceableCollection, so yes, it does 
work:

 	| set |
 	set := Set new.
 	#(1 1 2 1 2 3 1 2 3 4) select: [ :each | set addNewElement: each ]

 	"==> #(1 2 3 4)"

Levente

> 
> Item was added:
> + ----- Method: SequenceableCollection>>withoutDuplicates (in category 'copying') -----
> + withoutDuplicates
> +       "Answer a copy of the receiver that preserves order but eliminates any duplicates."
> +       | seen |
> +       seen := Set new: self size.
> +       ^self select: [:each|
> +                                 (seen includes: each)
> +                                       ifTrue: [false]
> +                                       ifFalse: [seen add: each. true]]!
> 
> 
>