Trying out helix editor

February 15, 2025

This is another February story about text editors similar to the vim one. You might want to ignore this one as well :)

Tl;DR

helix is a nice program: I switched to it from vim as a default text editor. If you never heard of helix editor and are vim or nvim user I suggest you to look at it. hx --tutor is short and yet it covers a few cool things. https://helix-editor.com/ has a nice asciinema intro and shows expected look and feel.

Background

I am a happy 2 years old vim user with a simple ~/.vimrc config. Strong vim features for me are:

I still manage to use vim without any external plugins.

The weak vim points for me are:

To expand a bit on “backwards” model here is a simple example: in vim the key sequence df< will delete (d) everything from current position to < symbol inclusive. But you will not see what exactly vim is about to delete until you press <. Would be nice to see what f< selects first and only then press d with more confidence. As a result I rarely use such shortcuts despite them being very convenient for a common editing use case. vim’s very own vf<d command sequence is a lot more intuitive to what I would expect, but that requires switch to a visual mode (prefixed v).

A fun problem

From time to time I use vim to write markdown files (such as this blog post). I like pasting code snippets here and there for better illustration. Once day I idly wondered if vim could be taught to support syntax highlighting of the code snippets within the markdown files:

# Would it not be magic if it just worked?

An example `c` snippet within `markdown`:

```c
// What's up here with the highlight?
int like_this_one(long long);
```

vim does not do any special highlighting in a c block.

Many days later I encountered a mastodon thread that mentioned vim proposal to use TextMate grammar Issue#9087. It discussed various options of different highlighter engines, their pros, cons, and what vim should use longer term. Tree-sitter was specifically mentioned multiple times there as The Solution to all the highlighting problems an editor could have. It’s a long discussion with many branches. From there I learned about (and started using) a few tree-sitter based programs, like bat, difftastic and helix.

helix editor was mentioned as one of tree-sitter users. I heard about helix before from my friend. At the time I just started my vim journey and I did not give helix a serious try. But this time I felt I was able to compare both.

My setup

I got helix up and running to the state I could use it by default in 2 short evenings. After that I did a few incremental tweaks. My whole configuration right now is one page long:

# $ cat config.toml
[editor]
auto-pairs = false
bufferline = "always"
rulers = [73]
true-color = true # TMUX term does not always agree

[editor.statusline]
# added "file-type", "position-percentage"
right = ["file-type", "diagnostics", "selections", "register", "position", "position-percentage", "file-encoding"]

[editor.whitespace.render]
space = "all"
tab = "all"
nbsp = "all"
nnbsp = "all"

[editor.whitespace.characters]
tab = ">"
tabpad = "-"

[keys.insert]
C-c = "normal_mode"
C-up = ["scroll_up", "move_visual_line_up"]
C-down = ["scroll_down", "move_visual_line_down"]

[keys.normal]
C-c = "normal_mode"
C-up = ["scroll_up", "move_visual_line_up"]
C-down = ["scroll_down", "move_visual_line_down"]
ins = ["insert_mode"]

[keys.select]
C-c = "normal_mode"
C-up = ["scroll_up", "move_visual_line_up"]
C-down = ["scroll_down", "move_visual_line_down"]

On top of that I enabled a few language servers not configured in helix by default:

# $ cat languages.toml

# spell checker
[language-server.harper-ls]
command = "harper-ls"
args = ["--stdio"]

[[language]]
name = "markdown"
language-servers = ["marksman", "harper-ls"]
auto-format = false

[language-server.rust-analyzer.config]
check.command = "clippy"

Niceties

I was surprised to discover how much helix already provides without much extra configuration:

toml configuration language

I grew to like toml compared to other custom .ini-like formats. Custom configurations are sometimes not general enough. For example in nix.conf config there is no way (to my knowledge) to add a trailing whitespace to:

bash-prompt-suffix = dev>

toml on the other hand, is more predictable in this regard. It is quite common and expressive enough to encode simple arrays and strings with any contents.

I’m a bit afraid of the configurations that are programming languages. It’s not too bad for me when they are general-purpose languages with good error messages, well understood semantics, and present introspection for available options and helpers.

Color themes can be set in RGB

Using full RGB range to define color elements is great. helix comes with a nice dark default theme suitable for long editing sessions.

The only caveat of a default theme is that some colors are not unique for cases where it matters. For example, to work around a bug in default theme I needed to pick a different color for secondary selection:

# $ cat themes/sf.toml
inherits = "default"

# workaround https://github.com/helix-editor/helix/issues/12601
"ui.selection" = { bg = "#540020" }
"ui.selection.primary" = { bg = "#540099" }

Using RGB is so much better than picking a pre-defined color. I did not know I need it until I tried :)

Selection and multi-selection feels intuitive

helix does show what navigation commands select before I about to do an action. An example would be vim df" sequence compared to helix f"d sequence. Before pressing d I am more confident what it is about to delete.

After using helix for a while I am actually more comfortable using vim f / t (and similar) navigation commands because I understand better what they actually do.

Multi-selection is also very natural: you create a bunch of cursors based on you search (s command) in your selection (or by extending a column with C command) and start modifying text interactively at each active cursor at the same time. In multi-selection mode it’s more natural to use navigation commands like f, t and w to do bulk edits. In vim I used to use arrow keys more and did not see much use for more complex navigation commands. But now once I’m used to then I’m using them in vim as well.

IDE experience is unexpectedly good

The LSPs provide you a navigation, hints, symbol search and so much more. It’s so easy to explore new and existing projects for various cross-references. Before jumping into the target you can look at the bit of context in preview and it might be enough for a thing you are looking for!

Even in this post <space>s (symbol lookup) provides a Table Of Contents output with a preview.

For development projects <space>f provides you a file picker with a fuzzy search. Now I have to rely a lot less on mashing <TAB> in the shell to get to a file I want to edit. I even installed fzf to emulate similar fuzzy search experience when I need it in bash to pass a file to other programs.

To make clangd to work (a C or C++ LSP) one needs a compile_commands.json file. meson-based projects just create it unconditionally, cmake-based projects do it after -DCMAKE_EXPORT_COMPILE_COMMANDS=YES option is enabled and for autotools-based projects there is a bear hack to wrap make and extract the commands after the build.

bear is not able to handle projects like gcc where local gcc is used to compile most of the code. But smaller ones work good enough.

https://github.com/helix-editor/helix/wiki/Language-Server-Configurations has tips for many more language servers.

Snags

Over past month of helix use as a default editor I encountered a few limitations I had to work around or just accept the limitation.

Trailing whitespace highlighting (minor)

Whitespace highlighting is a bit blunt: I would prefer spaces to be highlighted only in trailing context while highlighting tabs everywhere. https://github.com/helix-editor/helix/issues/2719.

But it’s not a big deal. I need to be careful to copy text into clipboard buffer not with a mouse selection but via <space>y

Spell checking (minor)

I was surprised to see that helix does not yet have spell checking integration and was afraid I could not use it as I make huge amount of typos and rely on aspell so much. The integration is tracked by https://github.com/helix-editor/helix/issues/11660.

But luckily there are a few language servers that do implement spell checking. I’m using harper as:

[language-server.harper-ls]
command = "harper-ls"
args = ["--stdio"]

It works reasonably well for English but does not support anything else. Having an LSP based on something like aspell would be nice.

Default theme colors (minor)

helix tutorial has section that demonstrates primary and secondary selections via ( and ) navigation. But the colors of both selection types are identical in the default theme. That was very confusing. The issue is 2.5 years old: https://github.com/helix-editor/helix/issues/12601.

Luckily the workaround is trivial: you can modify default theme just for selection distinct colors:

inherits = "default"

"ui.selection" = { bg = "#540020" }
"ui.selection.primary" = { bg = "#540099" }

Saving last cursor position in the file

I like the save/restore of the file cursor in edited file. It was a default vim setting. helix does not have an equivalent yet: https://github.com/helix-editor/helix/issues/1133

Buffer search only highlights current search, not all

In vim I was using set hlsearch option to highlight (and keep highlighted) all the occurrences that match the search. Not just the current one. helix is yet to implement it: https://github.com/helix-editor/helix/issues/1733.

Generic autocomplete

I like autocompletion of arbitrary words in a text file. So far helix only ever does LSP autocompletion.

https://github.com/helix-editor/helix/issues/1063 tracks the addition of a simple keyword-based completer.

Parting words

helix feels like a good modern vim successor for my use cases. It’s extensive use of RGB colors and unicode characters gives a look and feel of a program beyond a terminal application. A ton of pre-configured LSPs makes it a nice lightweight code navigator on par with IDE experience.

Have fun!