helix-term.md (3052B)
1 ---
2 author: "JayVii"
3 title: "REPL Support for Helix"
4 date: "2024-10-16"
5 summary: "An easy process to send code from inside the Helix editor to console"
6 tags: ["development", "helix", "tech"]
7 ---
8
9 ## Motivation
10
11 For almost a year now, I am an avid user of the "post-modern text editor"
12 [Helix](https://helix-editor.com/), which replaced [NeoVim](https://neovim.io/)
13 for me entirely. In Helix I write all kinds of configs, texts and code,
14 primarily in [R](https://cran.r-project.org/). Helix works flawlessly with it,
15 especially with the built-in LSP. The only gripe I had with this was, that there
16 was no easy way to write R-code in Helix and send it directly and interactively
17 to R's REPL, as you would in typical R IDEs like
18 [RStudio](https://posit.co/products/open-source/rstudio/).
19
20 So earlier this year, I tried to workaround that issue by experimenting with
21 [TMUX](https://github.com/tmux/tmux/wiki) and its `send-keys` feature. The
22 results of this are available as installable script(s)
23 [in my git-repository](https://src.jayvii.de/pub/helix-term/).
24
25 ## Functionality
26
27 The idea behind it is quite simple: A TMUX session with a pre-defined name is
28 spawned that runs the REPL we want to send our code to. This could be R, Python,
29 Bash, ... Next, Helix sends code in its selection to some process
30 [via its `pipe-to` command](https://docs.helix-editor.com/commands.html). This
31 process' job is to send the highlighted text to tmux line-by-line.
32
33 In its simplest form, the REPL in tmux could be started as:
34
35 ```bash
36 tmux new-session -s "my_repl" /usr/bin/R
37 ```
38
39 The process that send text to this tmux session, let's call it `send-to-tmux.sh`
40 could be as easy as:
41 ```bash
42 #!/usr/bin/env bash
43
44 # read piped input
45 readarray -t lines
46
47 # send input to tmux line by line
48 for line in "${lines[@]}"; do
49 tmux send-keys -t "my_repl" "$line" "Enter"
50 done
51 ```
52
53 We could set up a keyboard shortcut for this in Helix in selection mode (hitting
54 Ctrl-C twice):
55
56 ```toml
57 [keys.select]
58 C-c = { C-c = [":pipe-to send-to-tmux.sh"] }
59 ```
60
61 ## Using helix-term
62
63 The final script(s) in my
64 [git-repository](https://src.jayvii.de/pub/helix-term/) are slightly more
65 complicated to allow a more streamlined workflow, such as sending the current
66 code-paragraph in insert or normal mode from Helix and setting launching a
67 separate tmux-session for each working-directory, so you can run multiple such
68 processes at the same time.
69
70 In short, you can use my `helix-term` setup by running `helix-term /usr/bin/R`
71 in the same working directory as the Helix process and hitting `Ctrl-C` twice
72 for the code chunk you would like to send to the `R`-process.
73
74 ## Noteworthy alternatives
75
76 In a conversation
77 [with another Helix user](https://social.jayvii.de/objects/VHQJgjNndkY/thread),
78 we found that we might have different use-cases. This user came up with another,
79 yet similar approach that tries to turn Helix a little bit more into an IDE:
80 [hide](https://codeberg.org/landesfeind/hide). If `helix-editor` is too bare
81 bones for your use-case, maybe `hide` is a better approach for you.
