[Pharo-project] Set with nil

Andres Valloud avalloud at smalltalk.comcastbiz.net
Sat May 21 22:33:02 CEST 2011

Why this defensive approach to code that adds duplicate entries to a 
menu?  Why not avoid the duplicated entries from being added to begin with?

On 5/20/11 2:58 , Bernat Romagosa wrote:
> You may want the collection from which you build a menu to be a Set
> because you don't want to have repeated entries in a menu, and you'd
> want nil to be there if your field can be empty. When the menu items are
> automatically generated, it'd be nice to be able to do Whatever
> buildMenuFrom: (myCollection asSet add: nil; yourself).
> IMO this would be more elegant than doing myCollection asSet
> asOrderedCollection add: nil; yourself, or any other way to ensure the
> elements are unique and the collection includes nil.
> 2011/5/20 Henrik Sperre Johansen <henrik.s.johansen at veloxit.no
> <mailto:henrik.s.johansen at veloxit.no>>
>     On 20.05.2011 11:36, Bernat Romagosa wrote:
>         On a dropdown menu where you can choose between 'apple' ->
>         #apple, 'orange' -> #orange or 'nothing' -> nil, for example :)
>     Huh?
>     How does a Set figure into that?
>     Cheers,
>     Henry

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