Simulate plugin experience in Helix

12/07/22

09/5/1444

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I like helix, especially multi-cursor supports which unfortunately for nvim seems hard to add

So everyone is waiting for the plugin system, till then here is a not so bad plugin like experience

• Create a folder to hold our scripts

mkdir -p ~/dev/helix/scripts/source

• Make helix aware of our scripts by adding scripts to the PATH only for helix

This example uses fish, other shell have similar abilities

function hx
    set PATH_TMP $PATH
    set PATH ~/dev/helix/scripts/ $PATH
    helix $argv
    set PATH $PATH_TMP
end

funcsave hx

So now hx is aliased to helix that knows about our scripts path

• Create a script

I'm going to use deno here, but any compiled program can work

The advantage of deno, is the programs have 0 permissions by default which works actually very well as a plugin

But realisticly you want a compiled language, for the fastest cold startup time. I prefer Zig for this since it makes the lowest amount of syscalls possible by default in linux for example.

cd ~/dev/helix/scripts

Here is an example for a script I just needed that just simply flips ] to ) and [ to (

source/f.ts

const buf = new Uint8Array(256);
const n = await Deno.stdin.read(buf);

const a = new TextDecoder().decode(buf.slice(0, n!));
let r;
switch (a) {
  case "]":
    r = ")";
    break;
  case "[":
    r = "(";
    break;
  default:
    r = a;
}
Deno.stdout.writeSync(new TextEncoder().encode(r));

Or another script that acts as a snippet (just inserts console.log)

Deno.stdout.writeSync(new TextEncoder().encode("console.log("));

• Compile our scripts

This example uses fish syntax, other shell have similar workflow

for f in (ls source)
    deno compile source/$f
end

That's it, now when running helix, we can pipe a selection to our scripts using the pipe command which is bound to | key by default (can be changed, I have personally "µ" = "shell_pipe" for azerty keyboard)