On May 3, 2010, at 9:31 PM, Germán Leiva wrote:
Hi, this is my first post (please be gentle xD)
Thanks!
The #collect: message commonly return a new collection like the receiver, but this is really unpractical in some cases
e.g. col := Set with: 'one'->1 with: 'two'->2 with: 'dos'->2. (col collect: [:each | each value ]) sum
In VW you get the same.
In this example #sum will return 3 instead of 5 (I searched a test for #sum but I didn´t find it).
Ok, I can use the message #asBag (or something like that) but does the second line have to depend on the type of the receiver (i.e. the type of col)?
I think that this is the invariant for collect: ?
For example, the implementation of #collect: in SortedCollection returns an OrderedCollection (in the current image)
in VW too
and in other dialects the message #collect: when the receiver is a Set returns a Bag ...
which ones?
Basically, what do you think of an implementation like this?
Set >> collect: aBlock "Evaluate aBlock with each of the receiver's elements as the argument. Collect the resulting values into a Bag. Answer the new collection." | newBag | newBag := Bag new: self size. array do: [:each | each ifNotNil: [newBag add: (aBlock value: each)]]. ^ newBag
Cordially, -- Germán Leiva LeivaGerman@gmail.com _______________________________________________ Pharo-project mailing list Pharo-project@lists.gforge.inria.fr http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project