[Squeak] Newbie permutations
Brian T. Rice
water at tunes.org
Wed Apr 10 02:28:22 UTC 2002
The compromise is to introduce a way to pipe out permutations one at a
time onto a stream, maybe permutationsOnStream: and have the stream pull
them as necessary, probably at the request of the stream-consumer.
On Tuesday, April 9, 2002, at 07:15 PM, Andrew C. Greenberg wrote:
> Could be. On the other hand, the utility of #permutations is entirely
> unclear to me. Even for small collections, the number of permutations
> gathered rate to be fairly large.
> On Tuesday, April 9, 2002, at 06:48 PM, Bijan Parsia wrote:
>> On Tue, 9 Apr 2002, Andrew C. Greenberg wrote:
>>> It is an implementation concern that should probably be documented. I
>>> imagine it was done this way because it would be inefficient for
>>> applications where copies are not required to have the method make
>>> copies in each instance.
>> Given that the selector is #permutationsDo:, it's perhaps worth
>> having a
>> separate method, #permutations, which would produce a collection of the
>> distinct permuations. Then idioms like foo permutations select:...et al
>> would work as expected.
>> Bijan Parsia.
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