PS: *Neither* #flattened nor #flatCollect: can be blamed on 40 years of history. #flatten(ed) arrived in Squeak back in 2015, at which time #flatCollect: did not exist. In fact there is *still* no #flatCollect: in Squeak, although Squeak does have #gather:, since 2002.
#flatCollect: was added to Pharo more recently still, as a new name for the tolerably well established #gather:, apparently in the belief that it was a better name. Given #flattened, it is not. #gather: is not all that helpful, but #flatCollect: is just wrong. Even if #flattened did not exist, the result of #flatCollect: is generally not in any sense flat. I repeat: NONE of this can be blamed on Smalltalk history. #flattened was born crufty in 2015 and #flatCollect: is a recent addition to Pharo. On Thu, 14 Apr 2022 at 02:03, Richard O'Keefe <rao...@gmail.com> wrote: > It would help to know which version of Pharo you are using. > #(1 2 3) flatten > raises an exception in Pharo 9 because there is no #flatten > in Array's protocol. > Collection has > #flatCollect: > -- #gather: was not a terribly helpful name, > -- but #flatCollect: is horribly misleading. > #flatCollect:as: > -- A misplaced method, should be > -- Collection class >> withAll: aCollection gather: aBlock > #flatCollectAsSet: > -- a trivial special case of #flatCollect:as:, > -- not clear why this special case exists. > #flattenOn: > -- aStream nextPutAll: self flattened > -- but without creating the intermediate data structure > #flattened > -- a curiously twisted "flatten" that does not work > -- at all for non-collections. > > #(1 2 3) flattened => #(1 2 3) > 1 flattened => BOOM! > > By the way, we cannot blame the cruftiness of #flattened on > 40 years of history. #flatten/#flattened only entered Squeak > about 7 years ago and it was BORN crufty. I mistakenly thought > Squeak and Pharo agreed on what it meant. They do not. > Squeak: puts it on SequenceableCollection and Stream. > Pharo : puts it on Collection (more general) and not Stream (less so). > Squeak: treats stream elements like nested collections. > Pharo : doesn't. > So my earlier claim bears repeating: of the Smalltalk systems that > have some kind of flattening, no two agree on what it means. > > The one use I have ever had for flattening is to build up a > large string by accumulating characters, strings, symbols, > and sequences of the same in a sequence and then flattening > the tree into a single string, which is something that > Squeak and Pharo flatly refuse to do. > > One improvement I would like to see in Pharo 11 is for these > methods to be deleted. > >
