Elm-format as prettier plugin?

[kachkaev]

TL;DR: The plugin is here https://github.com/gicentre/prettier-plugin-elm

Hi everyone 👋

I became interested in formatting ```elm code blocks inside markdown files and my first approach to this was to tweak atom-beautify: Glavin001/atom-beautify#1990. The PR is still waiting to be merged, but I'm generally happy with the solution locally even despite two issues described in #65 (comment).

Unfortunately, the tool I've got is Atom-specific and only works when Remark is chosen as a beautifier for markdown (which is not so by default). Of course, the situation is far from a zero-config command-line heaven or from supporting other editors like VSCode 😅

I recently noticed that Prettier (a fast-growing opinionated code formatter) added plugin support. Potentially, that's great news for the Elm community, because it seems like it is now possible to access elm-format via unified Prettier API from anywhere. In addition to that, the docs mention something called embed, which possibly means that elm-format can be applied to markdown code blocks that start with ```elm 🎉

I'm opening this issue because I have not yet found an npm package called prettier-plugin-elm and would like to help with putting it together. Sorry that it's not as relevant to elm-format as other issues, but perhaps this repo is still the best place to start a discussion. There is a chance that I might find some time on implementing a prototype in the next several weeks, but I'd be keen to see a bit of support from experienced members of the Elm community.

Who would like to join? What do you think of this idea in general?

[ohanhi]

From what I can tell, Prettier plugins need to be JavaScript. elm-format is written in Haskell. I don't know if you can somehow write a middle layer that could make the elm-format binary to work as a Prettier plugin parser, but surely it would not be easy. I'm not saying it's not a good idea, just that it might not be as straightforward as one might think.

[kachkaev]

Thanks for your comment @ohanhi, you're right!

I just discovered https://discourse.elm-lang.org/ and am tending to move this discussion there. Will share a link once I'm done.

[kachkaev]

➡️ https://discourse.elm-lang.org/t/elm-format-as-prettier-plugin/683

[avh4]

FYI, I am interested in making elm-format available as a javascript package, likely using ghcjs like what https://ellie-app.com has done for elm-compiler. If anyone is interested in working on that, please coordinate with me.

[Glavin001]

@kachkaev : I am developing Unibeautify (complete rewrite of Atom-Beautify) with the intention of becoming a universal code beautifier. This sounds like what you're looking for.

Unfortunately, the tool I've got is Atom-specific and only works when Remark is chosen as a beautifier for markdown (which is not so by default). Of course, the situation is far from a zero-config command-line heaven or from supporting other editors like VSCode 😅

I recently noticed that Prettier (a fast-growing opinionated code formatter) added plugin support.

Unibeautify will eventually have both Atom (rewrite of Atom-Beautify ) and VSCode (New extension: https://github.com/Unibeautify/vscode ) support. And potentially others, too, like Sublime Text ( https://github.com/Unibeautify/unibeautify-sublime ).

Unibeautify's beautifiers are similar to Atom-Beautify's design. Take a look at https://github.com/Unibeautify/beautifier-prettier and https://github.com/Unibeautify/beautifier-prettydiff and others at https://github.com/Unibeautify for example. If you are interested in adding ELM Format support to Unibeautify please let us know! /cc @szeck87

[kachkaev]

If anyone is interested in an integration of elm-format into Prettier, see
https://github.com/gicentre/prettier-plugin-elm 🎉

Feedback is welcome!

[kachkaev]

Follow-up PR: #574