Re: [Bug-apl] Lambda valence error

[Christian Robert]

address@hidden:/home/xtian] $ apl

                    ______ _   __ __  __    ___     ____   __
                   / ____// | / // / / /   /   |   / __ \ / /
                  / / __ /  |/ // / / /   / /| |  / /_/ // /
                 / /_/ // /|  // /_/ /   / ___ | / ____// /___
                 \____//_/ |_/ \____/   /_/  |_|/_/    /_____/

                     Welcome to GNU APL version 1.5 / 734

                Copyright (C) 2008-2015  Dr. Jürgen Sauermann
                       Banner by FIGlet: www.figlet.org

                This program comes with ABSOLUTELY NO WARRANTY;
                          for details run: apl --gpl.

     This program is free software, and you are welcome to redistribute it
         according to the GNU Public License (GPL) version 3 or later.

      ∇z←OMEGA n
[1] z←n
[2] ∇
      1 OMEGA 2
VALENCE ERROR
      1 OMEGA 2
      ^ ^
      1 (OMEGA 2)
1 2

so, it's not related to Lambda functions at all. The parser may be, or working 
as designed ...

Xtian.


On 2016-06-04 02:58, Daniel H. Leidisch wrote:
> Hello!
>
> On r734:
>
>       1 {⍵} 2
> VALENCE ERROR
>       1 λ1 2
>       ^ ^
>
> Unless I'm mistaken, this used to work. I assumed it to be a regression,
> but reading the info section about lambdas, it actually seems to be
> intended behavior. ("If only ⍵ is present then it is monadic, and if
> neither ⍺ nor ⍵ is present then the lambda is niladic.")
>
> I can get around it using something like {⍺ ⊢ ⍵}, but it feels clumsy
> and isn't needed in Dyalog and NGN. Is it intended behavior, and if yes,
> what was the rationale behind it?
>
>
> Regards,
>
> Daniel