This was a breaking change in APL2 (previously 1 2 3[2] was valid and returned 2) but I think it was the right decision for a language with stranding. It means that A[1] B[2] parses as (A[1])(B[2]) which seems sane.
The alternative (ISO, Dyalog) is that A[1] B[2] parses as (A[1] B)[2], which is pretty counter-intuitive. Jay. On 15 February 2017 at 20:22, Juergen Sauermann < juergen.sauerm...@t-online.de> wrote: > Hi Xiao-Yong, > > IBM APL2. > > *[]* binds stronger than anything else. > > Thus *3[1 2]* is evaluated first, giving the *RANK ERROR*. > > /// Jürgen > > > On 02/15/2017 09:14 PM, Xiao-Yong Jin wrote: > > Feature or bug? > > 1 2 3[2 1 3] > RANK ERROR > 1 2 3[2 1 3] > ^^ > )sic > (1 2 3)[2 1 3] > 2 1 3 > > > > > >
