[Newbies] Re: Recap: How to empty a collection

Janko Mivšek janko.mivsek at eranova.si
Wed Feb 20 09:53:53 UTC 2008

This is the last change, I promise :) Previous solution was for 
collections in general, while for OrderedCollection you can simply do:

    self setCollection: Array new.

A bit optimized method will therefore be:

    "remove all elements quickly"
     self setCollection: (Array new: 10). "Squeak specific"
     self become: OrderedCollection new " "VW specific"


Janko Mivšek wrote:
> Ok, I reimplemented this method as Bert suggested and in the next 
> version of Aida/Web it will be:
> OrderedCollection>>removeAll
>    "remove all elements quickly"
>     self removeAllSuchThat: [:each | true]. "Squeak specific"
> "   self become: OrderedCollection new " "VW specific"
> Note that this method is still an extension of Aida and it must 
> therefore be portable among dialects, which is the reason of commented 
> code for VW above.
> Best regards
> Janko
> Bert Freudenberg wrote:
>> On Feb 20, 2008, at 2:01 , nicolas cellier wrote:
>>>> One thing I wasn't clear on is whether Bert's suggestion:
>>>> aColl removeAllSuchThat: [:anElement| true].
>>>> Is okay, and why it's okay while many of the other similar 
>>>> approaches were not.
>>> Bert's suggestion is simple and works well.
>>> The only question is about efficiency.
>>> Up to (Down to?) subclasses to optimize it.
>> #removeAllSuchThat: is actually optimized in subclasses (look at its 
>> implementation in OrderedCollection).

Janko Mivšek
Smalltalk Web Application Server

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