(aSortFunction value: x value: y) returns a Boolean; (aSortFunction value: x value: x) returns true. So you can already set up a SortedCollection using a SortFunction. So yes, that would work. But there is no reason why #reversed (or my preference, #converse) could not work on sortBlocks.
On 25 April 2018 at 23:27, Denis Kudriashov <dionisi...@gmail.com> wrote: > 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 <rao...@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 >> >> >
