Re: [Bug-apl] Major dimension problem

[Blake McBride]

Thanks for verifying my observation.  Since we get different versions of the same problem depending on environment, there must be a memory clobber going on that acts differently depending on memory layout.

--blake

On Sat, May 24, 2014 at 2:30 PM, David B. Lamkins <address@hidden> wrote:

(I'm adding Jürgen to the Cc: list. I have evidence that this may not be
related to gnu-apl-mode, but rather to gnu-apl itself.)

It appears that reshape is somehow mutating certain empty objects to
which is applied.

      0 0⍴⍬
      ⍴⍬
0 0
      0 0⍴''
      ⍴''
0

The above is from my gnu-apl-mode session. Interestingly, I *do* see the
bug when reshaping zilde, but *not* when reshaping the empty character.

Here's the interesting bit: I *can* reproduce the reshape zilde bug
without gnu-apl-mode. The transcript in GNU APL by itself (started in a
Bash shell as `$ apl`) is identical to the transcript shown above.

Furthermore, here's evidence to suggest that the bug may only be tickled
by a reshape of a constant value. (This is a transcript of a
gnu-apl-mode session after having restarted APL to clear the mutated
zilde.)

      b←⍬
      ⍴b
0
      0 0⍴b
      ⍴b
0
      ⍴⍬
0
      0 0⍴⍬
      ⍴⍬
0 0
      ⍴b
0

On Sat, 2014-05-24 at 10:57 -0500, Blake McBride wrote:
> More interesting facts in emacs mode:
>
>
>       ⍴''
> 0
>       1 1⍴' '
>
>       ⍴''
> 0
>       0 0⍴' '  ⍝ reshape of space
>       ⍴''
> 0
>       0 0⍴''  ⍝  reshape of quote quote
>       ⍴''
> 0 0
>       )CLEAR
> CLEAR WS
>       ⍴''
> 0 0
>
>
>
>
>
>