Support of algebraic operations on sets

Bert Freudenberg bert at freudenbergs.de
Fri Jun 15 13:37:40 UTC 2007


I don't get you example - isn't that a difference?

| then now new |
then := #(1 2 3).
now := #(1 2 3 4 5).
new := now difference: then.
new "#(4 5)"


- Bert -

On Jun 15, 2007, at 14:40 , Gary Chambers wrote:

> Yes, I've missed it! Think "things that are here now as opposed to  
> then".
>
> -----Original Message-----
> From: squeak-dev-bounces at lists.squeakfoundation.org
> [mailto:squeak-dev-bounces at lists.squeakfoundation.org] On Behalf Of  
> Bert
> Freudenberg
> Sent: 15 June 2007 1:21 pm
> To: The general-purpose Squeak developers list
> Subject: Re: Support of algebraic operations on sets
>
>
> On Jun 15, 2007, at 13:52 , Gary Chambers wrote:
>
>> Note that #difference: is the relative complement of the two sets,
>> rather
>> than the symmetric difference.
>> Perhaps we could have a method for that too!
>
> IMHO that's not nearly as universally useful as the other operations.
> Has anybody ever missed it before? We're not talking about Set theory
> but actual usefulness as a general Collection protocol.
>
> - Bert -
>
>
>
>





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