Re: [Bug-apl] Question about GNU APL

[Christian Robert]

thanks for the reply (and all others who replyed)

I will tell you the story who brought me here ...

I learned the APL in the 70' years, while I was about 21. (I'm now 59)

Not used the language until may be 5 years ago when I saw APLX for free to 
linux users.

used it (may be 10 times per year to do Loto) or just some calculation (as a 
calculator)

Not really used the language until may be 2 years ago when I discovered NARS2000

It was a huge update compared to the free linux APLX.

I used the free NARS2000 for about 2 years, still using it.

what get me here was indirectly this url:


http://aplwiki.com/SudokuSolver

it's a jewel of APL program to solve a Sudoku

the bug was that NARS2000 can't cope with thing like:

⍝ For squares which are already known, set list of possibles to empty
((,puzzle≠0)/,possibles)←⊂⍬

so, had to recode like this

possibles←,possibles
possibles[(,puzzle≠0)/⍳⍴,puzzle] ← ⊂⍬
possibles←(⍴puzzle) ⍴ possibles

really painfull but it work, I can solve any Sudoku in NARS2000 now

at that time I started to search for free APL who can do that sort of assigment 
... (SelSPEC)
and be relatively new.


found GNU APL

it work, but it lack most of the :if :else :endif stuff and similars

please take a look at http://aplwiki.com/SudokuSolver
as stated above.


Xtian. (Christian)



On 2015-02-19 08:10, Juergen Sauermann wrote:
> Hi Christian,
>
> see my answers inline below...
>
> /// Jürgen
>
>
> On 02/19/2015 03:10 AM, Christian Robert wrote:
> > I was to report that this APL expression
> >
> >       30 2⍴?60⍴2
> >
> > always return a row of "1" and a row of "2" (installed from the source(.tar.gz) 
> > provided on GNU Mirrors)
> >
> > after looking at the "GNU APL" site for a bug report address, I saw that we can 
> > get
> > the "latest" from svn; so I check-it-out, compiled, installed and to my surprise
> > it no longer give me a row of "1" and "2" !
> >
> > great !
>
> I am currently working on the next GNU APL release 1.5 which will include all 
> fixes for bugs
> reported since GNU APL 1,4. The bug above is one of them.
>
> > that said, my real question is:
> >
> > how hard is it to implement the standard/or-not-as-standard-as-it-seems
> >
> > :if {boolean}
> >   do this
> > :else
> >   do that
> > :endif
> >
> > :repeat
> >   do this
> > :until {boolean}
> >
> > :for {var} :in {list}
> >   do this
> > :endfor
> >
> > :forlcl {var} :in {list}
> >   do this
> > :endforlcl
> >
> > I think there is a :while :endwhile  too
> >
> >
> > thoses are really missing (to my point of view).
>
> 1. those things are probably not very hard to implement. However:
>
> 2. I try to minimize non-standard extensions of GNU APL because every such 
> extension
>      creates incompatibilities of APL programs that are using them. My idea of 
> free software
>      is that not only GNU APL itself should be free but also APL programs 
> running on GNU APL.
>      And for a free APL program to be useful it is important that is is 
> portable between different APL interpreters.
>
> > an other thing really missing is a native ")edit function_name"
> > who would open an other xterm and offer editing/modifying/saving a function
> > in a window, ala VI/VIM or ala emacs or ala nano. (I may be able to help in this matter, ps: ala 
> > means "like", not really "with")
>
> I believe Elias has responded to that. I would add that you now can create user 
> defined commands yourself :-) .
> My personal working mode is that I edit an APL script in one *xterm* with *vi 
> *and run that script in a second *xterm*
> from the command line.
>
> > nevertheless I'm quite pleased with "GNU APL" (2 days old installation)
>
> Thanks!
>
> > Christian Robert,
> > Poly.