Hi,
Round #1 was mostly about sets containing nil, and the winner seems to be the object-oriented solution implemented by Igor: http://bugs.squeak.org/file_download.php?file_id=3829&type=bug
What about the other ideas?
- create a common superclass (HashedCollection) for Set and Dictionary
- implement #valuesDo: only in Dictionary as a single self send of #do: and remove other implementations from it's subclasses
- add Andres' changes (or something similar) http://lists.gforge.inria.fr/pipermail/pharo-project/2009-November/015464.ht... which help with weak hash values (#identityHash).
- add #keySet to dictionaries which returns a set with the keys, since #keys now returns an Array
If you have anything against these ideas, please let us know.
Cheers, Levente
2009/11/17 Levente Uzonyi leves@elte.hu:
Hi,
Round #1 was mostly about sets containing nil, and the winner seems to be the object-oriented solution implemented by Igor: http://bugs.squeak.org/file_download.php?file_id=3829&type=bug
What about the other ideas?
- create a common superclass (HashedCollection) for Set and Dictionary
+1 http://lists.squeakfoundation.org/pipermail/squeak-dev/2007-June/117894.html (biased opinion)
- implement #valuesDo: only in Dictionary as a single self send of #do: and
remove other implementations from it's subclasses
+1
- add Andres' changes (or something similar)
http://lists.gforge.inria.fr/pipermail/pharo-project/2009-November/015464.ht... which help with weak hash values (#identityHash).
+1
- add #keySet to dictionaries which returns a set with the keys, since #keys
now returns an Array
If it add something to keys asSet, why not. For large collections a clever trick could be to not rehash the keys (Use a Set of same capacity...).
cheers Nicolas
If you have anything against these ideas, please let us know.
Cheers, Levente
+1 for dissecting Set & Dictionary. and of course +1 for improving the hashing.
2009/11/17 Nicolas Cellier nicolas.cellier.aka.nice@gmail.com:
2009/11/17 Levente Uzonyi leves@elte.hu:
Hi,
Round #1 was mostly about sets containing nil, and the winner seems to be the object-oriented solution implemented by Igor: http://bugs.squeak.org/file_download.php?file_id=3829&type=bug
What about the other ideas?
- create a common superclass (HashedCollection) for Set and Dictionary
+1 http://lists.squeakfoundation.org/pipermail/squeak-dev/2007-June/117894.html (biased opinion)
- implement #valuesDo: only in Dictionary as a single self send of #do: and
remove other implementations from it's subclasses
+1
- add Andres' changes (or something similar)
http://lists.gforge.inria.fr/pipermail/pharo-project/2009-November/015464.ht... which help with weak hash values (#identityHash).
+1
- add #keySet to dictionaries which returns a set with the keys, since #keys
now returns an Array
If it add something to keys asSet, why not. For large collections a clever trick could be to not rehash the keys (Use a Set of same capacity...).
cheers Nicolas
If you have anything against these ideas, please let us know.
Cheers, Levente
On Tue, 17 Nov 2009, Nicolas Cellier wrote:
2009/11/17 Levente Uzonyi leves@elte.hu:
- add #keySet to dictionaries which returns a set with the keys, since #keys
now returns an Array
If it add something to keys asSet, why not. For large collections a clever trick could be to not rehash the keys (Use a Set of same capacity...).
The idea is to (ab)use the fact that every dictionary has a set which is hashed the same way as the dictionary's keys. So a dictionary can create a set stub without an array, collect it's keys into an array and inject it into the set. This way creating a set with the keys is basically just a #collect: of the dictionary's array.
Levente
cheers Nicolas
On Mon, Nov 16, 2009 at 7:11 PM, Levente Uzonyi leves@elte.hu wrote:
Hi,
Round #1 was mostly about sets containing nil, and the winner seems to be the object-oriented solution implemented by Igor: http://bugs.squeak.org/file_download.php?file_id=3829&type=bug
What about the other ideas?
- create a common superclass (HashedCollection) for Set and Dictionary
I think a better solution is to give Set and Dictionary a common component, a HashTable. I've seen this done several times and it always resulted in a clean design. The major drawback is that MethodDictionary doesn't fit that design, and the VM needs to know the format of MethodDictionary.
-Ralph
On Tue, 2009-11-17 at 07:48 -0600, Ralph Johnson wrote:
On Mon, Nov 16, 2009 at 7:11 PM, Levente Uzonyi leves@elte.hu wrote:
Hi,
Round #1 was mostly about sets containing nil, and the winner seems to be the object-oriented solution implemented by Igor: http://bugs.squeak.org/file_download.php?file_id=3829&type=bug
What about the other ideas?
- create a common superclass (HashedCollection) for Set and Dictionary
I think a better solution is to give Set and Dictionary a common component, a HashTable. I've seen this done several times and it always resulted in a clean design. The major drawback is that MethodDictionary doesn't fit that design, and the VM needs to know the format of MethodDictionary.
MethodDictionary already uses a different implementation, it uses two arrays one being part of the MethodDictionary and accessed via basicAt:. Dictionary uses one Array and Associations.
Bryce
On Tue, 17 Nov 2009, Ralph Johnson wrote:
On Mon, Nov 16, 2009 at 7:11 PM, Levente Uzonyi leves@elte.hu wrote:
Hi,
Round #1 was mostly about sets containing nil, and the winner seems to be the object-oriented solution implemented by Igor: http://bugs.squeak.org/file_download.php?file_id=3829&type=bug
What about the other ideas?
- create a common superclass (HashedCollection) for Set and Dictionary
I think a better solution is to give Set and Dictionary a common component, a HashTable. I've seen this done several times and it always resulted in a clean design. The major drawback is that MethodDictionary doesn't fit that design, and the VM needs to know the format of MethodDictionary.
I've been thinking about this a lot before I uploaded the latest changes, but I came to a decision that if were using encapsulation instead of inheritance, we would have to duplicate the common interface methods. Also performance would be worse (extra message sends) mainly because HashTable would have to behave differently in Set and Dictionary. So I decided to sacrifice a bit of clarity for simplicity and performance.
Levente
-Ralph
squeak-dev@lists.squeakfoundation.org
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Bryce Kampjes -
Igor Stasenko -
Levente Uzonyi -
Nicolas Cellier -
Ralph Johnson -
Tobias Pape