This was discussed at length on github, have a look there. But essentially to make it easier to create vectors of vectors.
On Mon, 2016-06-06 at 16:35, K leo <cnbiz...@gmail.com> wrote: > Why deprecate array concatenation with "[]" and suggest to use "collect"? > It requires more typing and makes code less elegant. What do we really > gain with inefficiency? > > Also using "[]" directly in REPL does not have problem, but including code > generates warning. Why?
