[Pharo-project] difference between Sequenceable and Ordered
Does anybody can explain the difference between a Sequenceable Collection and an Ordered Collection? Thanks. Tristan Bourgois. -- View this message in context: http://forum.world.st/difference-between-Sequenceable-and-Ordered-tp2231718p... Sent from the Pharo Smalltalk mailing list archive at Nabble.com.
Tristan, SequenceableCollection abstracts using integers to index a collection; from there, subclasses (OrderedCollection is one of them) specialize the behavior to create growable and non-growable collections, collections specific to certain types of objects, etc. The Squeak/Pharo hierarchy browsers are **terrible** which greatly complicates building an understanding of such things. If you use or have access to Windows, you might grab the Community Edition of Dolphin Smalltalk if only to use their class hierarchy browser to look around the collections hierarchy. Dolphin has the best IDE in the business. Another question you might be asking is which collection class to use? The workhorses include Dictionary, Bag, SortedCollection, OrderedCollection, and sometimes Array; String and ByteArray count too, though they and things like FloatArray hold only specific types of objects for speed, gc efficiency, external calls, etc.. For reasons completely inscrutable to me after more than 15 years of Smalltalk use, streams like to work with and grow an Array far more than an OrderedCollection. Some things are best tolerate than understood :) Does that help? Bill ________________________________________ From: pharo-project-bounces@lists.gforge.inria.fr [pharo-project-bounces@lists.gforge.inria.fr] On Behalf Of Tristan Bourgois [tr.bourgois@laposte.net] Sent: Wednesday, May 26, 2010 10:19 AM To: pharo-project@lists.gforge.inria.fr Subject: [Pharo-project] difference between Sequenceable and Ordered Does anybody can explain the difference between a Sequenceable Collection and an Ordered Collection? Thanks. Tristan Bourgois. -- View this message in context: http://forum.world.st/difference-between-Sequenceable-and-Ordered-tp2231718p... Sent from the Pharo Smalltalk mailing list archive at Nabble.com. _______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project
Thanks, that's very interesting but not really help me sorry! Sorry may be the question are not very precise. My question is about the behavior so I put it in the context: I refactoring the collection in trait and I search if there are a difference between a Sequenceable and Ordered behavior. Because if there are not difference I don't create trait for the Ordered behavior. So do you think there are difference between the two behavior? -- View this message in context: http://forum.world.st/difference-between-Sequenceable-and-Ordered-tp2231718p... Sent from the Pharo Smalltalk mailing list archive at Nabble.com.
Ordered have the capability of adding/removing elements, Sequenceable not necessarily (think of Arrayed) Nicolas 2010/5/27 Tristan Bourgois <tr.bourgois@laposte.net>:
Thanks, that's very interesting but not really help me sorry! Sorry may be the question are not very precise. My question is about the behavior so I put it in the context:
I refactoring the collection in trait and I search if there are a difference between a Sequenceable and Ordered behavior. Because if there are not difference I don't create trait for the Ordered behavior.
So do you think there are difference between the two behavior?
-- View this message in context: http://forum.world.st/difference-between-Sequenceable-and-Ordered-tp2231718p... Sent from the Pharo Smalltalk mailing list archive at Nabble.com.
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Take a look at the ANSI standard - it has the collection behaviour already broken up into "traits" that are multiply-inherited to define the protocols of each class. Julian On Thu, May 27, 2010 at 10:32 AM, Tristan Bourgois <tr.bourgois@laposte.net> wrote:
Thanks, that's very interesting but not really help me sorry! Sorry may be the question are not very precise. My question is about the behavior so I put it in the context:
I refactoring the collection in trait and I search if there are a difference between a Sequenceable and Ordered behavior. Because if there are not difference I don't create trait for the Ordered behavior.
So do you think there are difference between the two behavior?
-- View this message in context: http://forum.world.st/difference-between-Sequenceable-and-Ordered-tp2231718p... Sent from the Pharo Smalltalk mailing list archive at Nabble.com.
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Hi, I took a look on the ANSI standard. I base my work on the paper of Wiliam R. Cook "Interfaces and Specifications for the Smalltalk- Collection Classes" http://carlstrom.com/stanford/cs242/readings/12.pdf I prefer this paper because dictionary is not a protocol a single protocol. It takes the behavior of Indexed and I think that's logical. But ANSI standard is very interesting and we could use the 2! I think Nicolas is right about the 2 differences. I think I blocked on the literal sense of Sequenceable and Ordered. Tristan. -- View this message in context: http://forum.world.st/difference-between-Sequenceable-and-Ordered-tp2231718p... Sent from the Pharo Smalltalk mailing list archive at Nabble.com.
participants (4)
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Julian Fitzell -
Nicolas Cellier -
Schwab,Wilhelm K -
Tristan Bourgois