| Strange, because when i tried it in Dyalog 18, the result is only the number 3, not the matrix you got.
display 3 (1 2) (2 2 ⍴ 0 1 2 3) ┌→──────────────┐ │ ┌→──┐ ┌→──┐ │ │ 3 │1 2│ ↓0 1│ │ │ └~──┘ │2 3│ │ │ └~──┘ │ └∊──────────────┘ display ⊃ 3 (1 2) (2 2 ⍴ 0 1 2 3) 3
Well, for each element that has lower rank than the highest-rank element in the list should be rank-extended by prepending 1.
In other words, in the example I gave, the maximum rank (last element) is 2. The rank-1 element (the second one) should be extended to (1 2) by prepending 1.
Thus, the result from Dyalog is:
┌┌→──┐ ↓↓3 0│ ││0 0│ ││ │ ││1 2│ ││0 0│ ││ │ ││0 1│ ││2 3│ └└~──┘
The current implementation already extends scalars, so it seems to special-case that case anyway.
Regards, Elias
On Wed, 22 Sept 2021 at 23:55, Louis Chretien via Bugs and suggestions for GNU APL < bug-apl@gnu.org> wrote: And what is the correct answer?
I tried it with APL/X 5.1, and i get the same “RANK ERROR” as in GNU APL.
If i understand disclose correctly, the right argument are nested elements, but of a shape that allows for them to be laminated into a matrix as a result. Having a scalar, a vector and a matrix is bound to create difficulty.
The following _expression_ should work, if I'm reading the ISO spec correctly:
⊃ 3 (1 2) (2 2 ⍴ 0 1 2 3)
It does work on Dyalog, and gives the expected result.
Regards, Elias
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