[squeak-dev] Properties of "<" in SortedCollection>>#sortBlock - reflexive, symmetric, transitive required?

Hi,

Is the "<" opertaion in SortedCollection>>#sortBlock required to be reflexive,
symmetric and transitive ?

I have a set of classes with known parent class and try to sort them so they
install into the image in the right order (parent first). The obvious "<"
implementation of parent < child may not be enough because it not transitive
unless I do some more sophisticated manipulation (I only immediate descendant
relationship)..

The sortBlock documentation provides no help on this...

Thanks Milan

Hi,


certainly you would not want all three of these, that would give an
equivalence relation :-)

I think that SortedCollection>>should: a precede: b is the crucial
method here, it uses <= as the default sorting relation. Another
interesting method for you might be sortTopologically.

Cheers

Matthias

On Sun, May 4, 2008 at 12:39 PM, Milan Zimmermann
<[hidden email]> wrote:

On 2008 May 4, Matthias Berth wrote:
> Hi,
> certainly you would not want all three of these, that would give an
> equivalence relation :-)

Oops how embarassing, that is what I get for writing anything just after
waking up and before first coffee. I ment to ask whether the relation defined
by sortBlock must be all of (or only some of) "reflexive, anti-symmetric,
transitive", and/or whether any other condition is required for the sort to
work. I tried to Google for such things as related to Smalltalk but could not
find anything...

> I think that SortedCollection>>should: a precede: b is the crucial
> method here, it uses <= as the default sorting relation.
> Another
> interesting method for you might be sortTopologically.

thanks, i did not realize sortTopologically is on SortedCollection. So far I
ordered my class list manually (for installing classes into image) using an
algorithm that should achieve same as sortTopologically but more cumbersome.

Thanks Milan