Hi Richard.

I agree with your proposal.��
But it force me to think that we should completely move to SortFunction's.��
In that case SortCollection will have sortFunction variable instead of sortBlock. And for your scenario reverse operation will be simple expression: "sortFunction := sortFunction reversed".



2018-04-23 3:09 GMT+02:00 Richard O'Keefe <raoknz@gmail.com>:
Test case:
���� #(1 2 4) asSortedCollection reverse add: 3; yourself
<print it>
The answer *should* be aSortedCollection(4 3 2 1)
but *is* aSortedCollection(4 2 1 3).
This works in Squeak.
The problem is that SortedCollection does not define
#reverse[d] but simply inherits it(them), and the
inherited code pays no attention to the sortBlock.

I propose adding the following two methods to
SortedCollection:

reverseInPlace
������ |a z|
������ a := firstIndex.
������ z := lastIndex.
������ [a < z] whileTrue: [array swap: a with: z. a := a + 1. z := z - 1].
������ sortBlock := sortBlock
������ ������ ifNil: [[:x :y | y <= x]]
������ ������ ifNotNil: [[:x :y | sortBlock value: y value: x]].
������ ^self

reversed
������ ^self copy reverseInPlace

The ANSI method is #reverse, not #reversed, but Pharo
defines #reverse to call #reversed, and OrderedCollection overrides #reversed, so SortedCollection *must* override #reversed.

#reverseInPlace is the name Squeak uses for the other
method.�� It also has a definition in SequenceableCollection, which is not but is
equivalent to

reverseInPlace
������ |a z|
������ a := 1.
������ z := self size.
������ [a < z] whileTrue: [self swap: a with: z. a := a + 1. z := z - 1].l
������ ^self

r