Re: [Bug-apl] A suggestion concerning the readline library

[Juergen Sauermann]

Hi Thomas,

welcome to the world of APL!

I did not know rlwrap before, but I just installed it and tried APL with 
it. Cool!

As you may have seen there were some problems in GNU APL recently that seems
to be readline related. The root cause of these problems is still 
unknown. After having
GNU APL ./configured with  --without-readline and then started it from 
rlwrap, it looks
like these problems do not occur (more tests needed, though) and full 
readline functionality
is still there.

As you may have seen as well, Elias is working on emacs integration with 
GNU APL. It would
be good if there were a common solution for emacs, vim, and other 
editors. IBM APL2 has
an )EDITOR command while GNU APL has not (yet).

I personally find it strange to open an editor for a single line of 
input, but it makes sense to
do that for larger objects like APL functions or larger variables. For 
one-liners xterm combined
with middle-mouse-button copy/past is still the fastest way to edit.

I would be interested what is needed to start an editor via libreadline.

Best Regards,
Jürgen Sauermann


On 02/13/2014 05:18 PM, Thomas Baruchel wrote:
> Hi, first of all, I am a new APL user; I wish to learn APL mostly with GNU APL 
> (I installed NGN + nodejs as well as Dyalog APL on my raspberry however).
> Since I have been coding in several other languages for many years, I would be 
> happy to help if I can.
>
> First of all, I started a new blog: http://apl-adventures.tumblr.com/ with all 
> my experiments.
>
> Please, could you have a look at my second "trick" on the following post: 
> http://apl-adventures.tumblr.com/post/76529518369/some-tricks-for-using-apl-under-linux
>
> In two words, I tried to launch GNu APL from rlwrap. It can sound weird since 
> GNU APL has its own readline support, but I
> found something very useful to me. rlwrap uses the readline library with a 
> custom function allowing to launch an editor
> from the readline library at any time for a one-line shot. (you hit 
> Ctrl-something, you get your EDITOR (environment
> variable) launched, Vim, emacs or whatever, you finish editing your line, you 
> save, you leave, and you have your line
> interpreted).
>
> Since an APL line is something more complicated than a line in other languages 
> (unicode characters, etc.), I think it could
> be useful to do the same in GNU APL: define a special readline function (the 
> user can decide to use it or not from his/her
> own ~/.inpurtc file) and launch the EDITOR from the REPL.
>
> I had a look at the GNU readline manual and found it should be quite easy to do 
> it.
>
> What do you think of the idea?
>
> Regards,