# \[ANN\] REPLSmuggler.jl: Send code to your Julia REPL, and get Neo-Vim diagnostics in return

**URL:** <https://discourse.julialang.org/t/ann-replsmuggler-jl-send-code-to-your-julia-repl-and-get-neo-vim-diagnostics-in-return/111420>\
**Category:** Package Announcements\
**Tags:** package, announcement, repl, editors, neovim\
**Created:** [March 10, 2024, 11:47am UTC](https://discourse.julialang.org/t/ann-replsmuggler-jl-send-code-to-your-julia-repl-and-get-neo-vim-diagnostics-in-return/111420 "2024-03-10T11:47:50Z")\
**Posts on this page:** 5\
**Page:** 1

<div class="post-metadata">

**Author:** ![klafyvel](https://avatars.discourse-cdn.com/v4/letter/k/a587f6/32.png) [@klafyvel](https://discourse.julialang.org/u/klafyvel)\
**Post date:** [March 10, 2024, 11:47am UTC](https://discourse.julialang.org/t/ann-replsmuggler-jl-send-code-to-your-julia-repl-and-get-neo-vim-diagnostics-in-return/111420/1 "2024-03-10T11:47:50Z")

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Hi there!  
I have worked a lot with NeoVim and [vim-slime](https://github.com/jpalardy/vim-slime) during my PhD. This workflow is great, but I was missing some features, such as having the correct line numbering in exceptions. I have put together a small Julia package and its companion plugin for NeoVim that fixes this.

[![asciicast](https://asciinema.org/a/W6RTJeVzRL3SvUIHfuauLGDF7.svg)](https://asciinema.org/a/W6RTJeVzRL3SvUIHfuauLGDF7)

It can probably be improved, and contributions are welcome!

> **[GitHub - Klafyvel/REPLSmuggler.jl: Send code to your Julia REPL.](https://github.com/Klafyvel/REPLSmuggler.jl)**
>
> Send code to your Julia REPL. Contribute to Klafyvel/REPLSmuggler.jl development by creating an account on GitHub.

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**Author:** ![fredrikekre](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/fredrikekre/32/1688_2.png) [@fredrikekre](https://discourse.julialang.org/u/fredrikekre)\
**Post date:** [March 10, 2024, 1:15pm UTC](https://discourse.julialang.org/t/ann-replsmuggler-jl-send-code-to-your-julia-repl-and-get-neo-vim-diagnostics-in-return/111420/2 "2024-03-10T13:15:26Z")

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This is great! I have also used vim-slime for a long time and incorrect source location is my main gripe too.

Here are some feedback from just playing around a bit:

- When using vim-slime (or copy-pasting manually) with something like:

```julia
function foo()
    x = 45
    y = x * 3
end

```

the Julia REPL look like this after:

```julia
julia> function foo()
           x = 32
           y = x + foo(x)
           return y
       end
foo (generic function with 1 method)

```

whereas with REPLSmuggler the indentation is off and you end up with

```julia
julia> function foo()
    x = 32
    y = x + foo(x)
    return y
end
foo (generic function with 1 method)

```

Would it be possible to keep the paste-behavior also with REPLSmuggler?
- When smuggling a visual range it would be great to let the cursor stay in its original position (see [vim-slime#354](https://github.com/jpalardy/vim-slime/issues/354) for the same issue in vim-slime).
- One great thing with vim-slime is that you don’t need to do anything in the REPL before sending text. It would be amazing if, when trying to smuggle, `using REPLSmuggler; smuggle()` could be sent to the target REPL automatically somehow.
- With vim-slime I often reconfigure the target window (e.g. two Julia REPLs with different Julia versions running). I have it [configured](https://github.com/fredrikekre/.dotfiles/blob/7bd9a5404198b63e3d6717aba4acedbe2bc5eb99/.vimrc#L115-L120) so that `:SlimeConfig` automatically targets the last visited tmux pane. I see that you can reconfigure also with REPLSmuggler but you then have to remember which socket belong to which pane etc. It would be great to make switching like this easier.
- There seem to be no way to clear the error diagnostics
- I initially thought that calling functions manually in the REPL would also have errors hooked up to show in the editor, do you think this would be possible?
- Do you think REPLSmuggler can be used as a debugger frontend?

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<div class="post-metadata">

**Author:** ![klafyvel](https://avatars.discourse-cdn.com/v4/letter/k/a587f6/32.png) [@klafyvel](https://discourse.julialang.org/u/klafyvel)\
**Post date:** [March 10, 2024, 2:01pm UTC](https://discourse.julialang.org/t/ann-replsmuggler-jl-send-code-to-your-julia-repl-and-get-neo-vim-diagnostics-in-return/111420/3 "2024-03-10T14:01:47Z")

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Hi, thank you for your interest!

> - Would it be possible to keep the paste-behavior also with REPLSmuggler?

Right now, the way REPLSmuggler displays things is a bit hacky: it prints the REPL’s prompt and adds the evaluated line (see [REPLSmuggler.jl/src/eval.jl at 63d811900d4761aa1003ce2db6702155371fba07 · Klafyvel/REPLSmuggler.jl · GitHub](https://github.com/Klafyvel/REPLSmuggler.jl/blob/63d811900d4761aa1003ce2db6702155371fba07/src/eval.jl#L23-L36)). So we could simply offset each line knowing the length of the prompt. However, I wonder if it wouldn’t be better to define a new prompt for REPLSmuggler rather than hacking into julia’s default one. Sadly documentation is a bit lacking here (or I did not find it!). Maybe someone with more experience with Julia’s REPL could point me towards the correct solution here!

> - When smuggling a visual range it would be great to let the cursor stay in its original position (see [vim-slime#354](https://github.com/jpalardy/vim-slime/issues/354) for the same issue in vim-slime).

I am not able to reproduce this, and the selection of areas is done without moving the cursor within nvim-smuggler (I’m using neovim’s api). Can you give me a more specific example?

> - One great thing with vim-slime is that you don’t need to do anything in the REPL before sending text. It would be amazing if, when trying to smuggle, `using REPLSmuggler; smuggle()` could be sent to the target REPL automatically somehow.

The problem is nvim-smuggler cannot communicate with the REPL at all before these lines are executed. The simplest way to do it would be to add theses to your `startup.jl` file I guess?

> - With vim-slime I often reconfigure the target window (e.g. two Julia REPLs with different Julia versions running). I have it [configured](https://github.com/fredrikekre/.dotfiles/blob/7bd9a5404198b63e3d6717aba4acedbe2bc5eb99/.vimrc#L115-L120) so that `:SlimeConfig` automatically targets the last visited tmux pane. I see that you can reconfigure also with REPLSmuggler but you then have to remember which socket belong to which pane etc. It would be great to make switching like this easier.
> - There seem to be no way to clear the error diagnostics

These are important features, could you open an issue please?

> - I initially thought that calling functions manually in the REPL would also have errors hooked up to show in the editor, do you think this would be possible?

That’s a current limitation. I think it is feasible, but we need to define our own REPL, or at least modify the default REPL to catch exceptions.

> - Do you think REPLSmuggler can be used as a debugger frontend?

The protocol used by REPLSmuggler.jl is fairly extensible (see [here](https://klafyvel.github.io/REPLSmuggler.jl/dev/#Protocol)), so I think it could be achieved if we define the correct endpoints. However, some thoughts are needed to give a good user experience on the editor’s side: how do you mark breakpoints, how do you keep track of modifications… I am open to adding that, but I lack the experience to make it great (I am a physicist, not a software engineer!), so I would need help adding and maintaining such a feature.

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<div class="post-metadata">

**Author:** ![fredrikekre](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/fredrikekre/32/1688_2.png) [@fredrikekre](https://discourse.julialang.org/u/fredrikekre)\
**Post date:** [March 10, 2024, 11:45pm UTC](https://discourse.julialang.org/t/ann-replsmuggler-jl-send-code-to-your-julia-repl-and-get-neo-vim-diagnostics-in-return/111420/4 "2024-03-10T23:45:57Z")

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> [@klafyvel](#):
>
> Right now, the way REPLSmuggler displays things is a bit hacky: it prints the REPL’s prompt and adds the evaluated line […]

Just offsetting the lines would be a nice improvement to begin with at least. Relatedly, it could be nice if smuggled code were inserted into the REPL history.

> [@klafyvel](#):
>
> I am not able to reproduce this, and the selection of areas is done without moving the cursor within nvim-smuggler (I’m using neovim’s api). Can you give me a more specific example?

I am talking about `:SmuggleRange` from `VISUAL` or `VISUAL-LINE` mode; for example with my `foo` function above, entering visual mode on the first line, move down the the `end` line and then smuggle the selection. Afterwards the cursor moves back up to the first line.

> [@klafyvel](#):
>
> The problem is nvim-smuggler cannot communicate with the REPL at all before these lines are executed. The simplest way to do it would be to add theses to your `startup.jl` file I guess?

Yea, or use another mechanism like vim-slime to send the code if there is no REPL server running.

> [@klafyvel](#):
>
> These are important features, could you open an issue please?

[Done](https://github.com/Klafyvel/REPLSmuggler.jl/issues/10), and [done](https://github.com/Klafyvel/REPLSmuggler.jl/issues/11).

> [@klafyvel](#):
>
> That’s a current limitation. I think it is feasible, but we need to define our own REPL, or at least modify the default REPL to catch exceptions.

Another option could be to hack into the display system and smuggle back errors when they are being displayed.

> [@klafyvel](#):
>
> The protocol used by [REPLSmuggler.jl](https://juliahub.com/ui/Packages/General/REPLSmuggler) is fairly extensible (see [here](https://klafyvel.github.io/REPLSmuggler.jl/dev/#Protocol)), so I think it could be achieved if we define the correct endpoints. […]

Yea would probably take some work, but since you already have the two-way communication going it might not be too bad. Perhaps one can take inspiration from how the VS code plugin does it.

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<div class="post-metadata">

**Author:** ![klafyvel](https://avatars.discourse-cdn.com/v4/letter/k/a587f6/32.png) [@klafyvel](https://discourse.julialang.org/u/klafyvel)\
**Post date:** [July 20, 2024, 5:46pm UTC](https://discourse.julialang.org/t/ann-replsmuggler-jl-send-code-to-your-julia-repl-and-get-neo-vim-diagnostics-in-return/111420/5 "2024-07-20T17:46:33Z")

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Hi there,  
I just released v0.3 of REPLSmuggler.jl. This release adds some interesting features such as appending smuggled commands to REPL’s history, smuggling of arbitrary diagnostics (with a JET.jl extension!). It also corrects some bugs related to line numbering and unicode characters.