Hi Werner, I don't know what you are trying to achieve, but it looks like you want to do conversions. Have you considered this ?
(Bag with: 1 with: 2) asArray. (Bag with: 1 with: 2) asOrderedCollection. These both work. I personally never noticed or used #newFrom: As for #as: some people consider it not the cleanest way to do things. But since the API is there, it should work I guess. Sven On 05 Mar 2014, at 16:28, Werner Kassens <wkass...@libello.com> wrote: > Hi, > > 1. i do this in pharo 2.0: > b:=Bag newFrom: #(1 2). > OrderedCollection newFrom: b."works nicely" > Array newFrom: b."error" > the error happens because ArrayedCollection>>newFrom: inherited by Array > expects a SequenceableCollection that has 'at:' implemented. but the first > line of ArrayedCollection>>newFrom: says: > newFrom: aCollection > it would be more clear,if it would say: > newFrom: aSequenceableCollection > > 2. this also produces an error: > b as: Array. > because Object>>as: uses newFrom:. and since as: is a very general method, > i'd guess that ArrayedCollection>>newFrom: should have an implementation that > does not throw an exception. if changing a Bag to an OrderedCollection works, > this should also work with an Array. or does this make much sense: <grin> > (b as: OrderedCollection) as:Array "this way it works" > > 3. withAll: does essentially the same as newFrom: and has the same problem > with the argument naming. but Array>>withAll: is much much faster than > Array>>newFrom:. try: > b:=Array new:100000. > [Array withAll: b]timeToRun. > [Array newFrom: b]timeToRun. > perhaps one could differentiate the two methods in such a way, that withAll: > is the occasionally faster method that for some collections only accepts > aSequenceableCollection as argument and newFrom: accepts any aCollection. > This way also Object>>as: would work as expected. if one does not want to > change this in my opinion slightly inconsistent behaviour, then <grin> it > would make sense to implement > Array>>newFrom: aSequenceableCollection > ^Array withAll: aSequenceableCollection. > simply for speed reasons. and of course a consistent argument naming would be > nice. > werner >
