REPL: running inside emacs crashes (shell, eshell) or prompt is double-printed (term)

[kmsquire]

When running the latest julia (0.3.0-prerelease+2494) inside emacs, julia either crashes (shell, eshell):

$ julia
               _
   _       _ _(_)_     |  A fresh approach to technical computing
  (_)     | (_) (_)    |  Documentation: http://docs.julialang.org
   _ _   _| |_  __ _   |  Type "help()" to list help topics
  | | | | | | |/ _` |  |
  | | |_| | | | (_| |  |  Version 0.3.0-prerelease+2494 (2014-04-04 23:25 UTC)
 _/ |\__'_|_|_|\__'_|  |  Commit 7d495c0* (0 days old master)
|__/                   |  x86_64-linux-gnu

�[?2004h�[0G�[0Kjulia> �[?2004lERROR: integer division error
 in div at promotion.jl:172

$ 

or the prompt is double printed (eterm-color):

julia> 1+1julia> 1+1
2

julia> julia> 2+2julia> 2+2
4

This issue should perhaps be retitled something like "allow use with limited terminals".

Somewhat related: #5271

[farrellm]

I see the same "ERROR: integer division error" with the ESS inferior Julia mode (M-x julia).

[zaphar]

This appears to be because the new LineEditREPL doesn't play nice with emacs.

I've got a really hacky version using StreamREPL working in a branch I'm playing with and it succeeds.

Not sure why yet though.

As a related bug. The StreamREPL in REPL.jl is broken at head right now. run_repl(s::AsyncStream) isn't even valid code.

[StefanKarpinski]

This business of running a REPL inside of emacs' very limited terminal emulation just strikes me as the wrong way to go about things. What about using something like emacs IPython notebook instead?

[kmsquire]

I've actually tried that before (in Python, I think). It's okay, but I
tend to prefer the regular REPL in general.

To be clear, this is not a huge deal to me personally.

On Thu, Apr 10, 2014 at 9:46 AM, Stefan Karpinski
[email protected]:

This business of running a REPL inside of emacs' very limited terminal
emulation just strikes me as the wrong way to go about things. What about
using something like emacs IPython notebookhttp://tkf.github.io/emacs-ipython-notebook/instead?

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/6428#issuecomment-40109061
.

[StefanKarpinski]

I just watch people struggle with the basic REPL in emacs and it's kind of painful. It's just weird that Julia is going to great pains to make the terminal do useful things while emacs is struggling to pretend to be a terminal. Emacs has a programming language, Julia is easy to call. Why isn't this smoother and easier?

[JeffBezanson]

It should be simple to use the REPL in pipe mode, which is already implemented for the case where something is redirected into julia.

[farrellm]

Running Julia through the ESS REPL was a very nice interface for interactive development. Moreover, Org/Babel eval Julia code through the ESS REPL, which I am very interested in using.

If there is a workaround to get IJulia or a pipe mode REPL running through ESS, that's probably sufficient for my purposes. I'd be very happy to help test or debug, just let me know.

[zaphar]

I think the issue is that ess is currently the best way to edit julia code in emacs. Code completion, evaluation, eldoc... All of this makes for a really nice environment. Most of that required having the julia process there though and right now that process has no way go into a basic mode.

The simple fix in the short run is to have a switch perhaps on command line that puts the repl in basic mode. A longer term fix is for someone to tackle a better integration in ess.

As it stands right now if 0.3 is released like this then a whole lot of people are going be frustrated with the experience of editing julia code.

[StefanKarpinski]

It shouldn't be too hard to add a --line-edit=[true|false|auto] option for the julia client.

[zaphar]

That is pretty close to what my "very hacky" change I experiemented with does.

[farrellm]

Julia no longer crashes under emacs! (due to #6419 being fixed?)
Babel now works very well.
Though the ESS REPL works, it is now a mess of duplicate prompts and control characters.