2017-11-07 9:23 GMT+01:00 Nicolas Cellier <nicolas.cellier.aka.nice@gmail.com>:

I have other ideas yet.

The selector undefinedFirst is good, but the implementation not so.
I don't like the UndefinedSortFunction: too specific, compose oddly...

If we defined <=> in Boolean (orWhatEverTheLongSelectorYouPreferBecausePharoHasTheFreedomToHaveOwnTaste:)
in order to have true sorted first, then we can generalize.

�� "sort by absolute value, but put the negative first"
�� numbers sorted: #negative sortedFirst, #abs

sortedFirst in this case would be a synonym for ascending (or asSortFunction).
Alternatively, if we don't want <=> in Boolean because it's not natural (the fact that we need a synonym is a clue)
then we can have sortedFirst answering a specialized BooleanSortFunction.

I like this idea. And I think it is better to add threeWayCompare: to Boolean because it allows to avoid extra selector:

#negative ascending, #abs

#isNil descending, #name

From the other side it will force remembering convention for boolean order. So maybe it should be explicit:

#negative trueFirst, #abs
#isNil trueLast, #name