I can't fix the slowness.

[trusktr]

When I was using <style lang="stylus"></style>, it was fairly zippy. However, when I modified it to lang="less" or lang="css", it became extremely slow!

I tried to do let g:vue_disable_pre_processors=1, and this time it became alright, but not zippy like with lang="stylus". But this doesn't work. No matter what lang I put, the syntax is highlighted like CSS it seems. And I have lang="pug" for the template, and now that's not highlighted.

Basically, it seems like let g:vue_disable_pre_processors=1 makes it work alright, at the expense of not working ideally. It effectively means I can just set the .vue file type to ft=html to achieve basically the same thing, without installing this plugin.

If that's the case, there's no point of using vim-vue with let g:vue_disable_pre_processors=1 because I can just use ft=html.

[posva]

vim-vue doesn't get slower because you set a different lang, it gets slower because some preprocessors are slow. It isn't slow on my end when using plain css or less

[trusktr]

I have a TON of plugins. I'm on a Chromebook Pro. Adding this plugin caused extreme slowness, and removing it made neovim zippy again. It could possibly be a conflict with another plugin?

Anyway, not sure yet. I'll post back later if/when I try it out again, as for now I'm using ft=html with no specials langs.

[Odaeus]

I use "slm" and "scss" in my Vue components. I also had to disable the pre-processors because it was too slow. However, I just tried deleting all the preprocessors I don't use in the syntax file and it seems to be fast enough again. Admittedly my test is not very scientific, the most obvious issue was pressing O in SCSS and having it take maybe 500 ms to add a new line.

Perhaps the pre-processors could be enabled/disable via an array of names?

[chearon]

Deleting the register_language lines didn't help that much for me, I ended up turning all of them off with let g:vue_disable_pre_processors=1, but even with that it's hard to bear how slow the cursor is.

It doesn't look like neovim is going to start working on a new syntax engine any time soon. I read the entire discussion referenced in the issue @trusktr made in neovim, and some people have made asynchronous highlighting work with c/c++/objc mainly by using vim's matchaddpos() and another process to get the AST.

I wonder if that's the solution for multi-syntax files? I may take a shot at it.

[tetreault]

Chiming in here - I have a fairly barebones vimrc file. The only time vim is slow for me, when using my vimrc file, is if i'm ssh'd into a server and my wifi is bad. Confirming I have good wifi right now, having added this plugin also makes my .vue files load up in vim with about a 10 second delay. To add to that, I'm just learning vue so while I have SCSS in my particular App.vue file it is no more than 20 lines.

The plugin works great when it loads and I definitely appreciate your work on this! Just wanted to add my experience to the relevant thread.

[ryangalamb]

One way to work around this: Separate your vue components into MyComponent.vue, MyComponent.vue.js and MyComponent.vue.scss (replacing .scss with the appropriate extension for your style preprocessor). The .vue file only has your <template> and imports your other files with

<script src="./MyComponent.vue.js"></script>
<style lang="scss" src="./MyComponent.vue.scss"></style>

<template>
<!-- just do this part like a normal single file component vue template -->
</template>

It's not ideal, but I think it's the best way to accommodate 3 filetypes' worth of plugins/syntax highlighting right now. It also gives other devs on your team more leeway in what tools they use, especially if you're working on a project with large component files.

That said, single-file components are pretty great, and I think it's worth the effort to make them work smoothly in this plugin. I'll see what I can do to optimize this plugin a bit more and hopefully get a pull request in sometime soon. In the meantime, hopefully the workaround I described can help some people out :)

[tetreault]

thx for the feedback @rjmill appreciate it! for now, disabling the preprocessors in my vimrc file has resulted in a sufficient enough speed up :)

[adriaanzon]

I suppose we can add an option for only including the languages that are actually found in the file. And if you then add a section you run :e to get syntax highlighting for that section too.

[adriaanzon]

Can you check out the performance-enhancement branch and see if it makes any difference?

[pearofducks]

@adriaanzon - just tested, performance-enhancement is tangibly faster for me

[maple-leaf]

I reinstall the plugin by using branch performance-enhancement. But I don't get the performance gains. It still take > 20% CPU more cost than without this plugin.

CPU cost	file type	with the plugin
<8%	vue(behavior like plain text without syntax highlight)	no
6-12%	html	no
30%-45%	vue	yes