Simplifying the parsing

[pintariching]

I think the original compiler goes in a big roundabout way when parsing. Couldn't we simplify it?
I think we can start by splitting the .svelte file into three parts. Extract the script and style and the remainder is svelte flavored HTML, where all the parts between curly braces get thrown through the swc parser.

[qwertydelle]

I think this what the svelte compiler already does but instead of swc it uses acorn. The tag.ts file basically has special cases for style tags and script and every other tag us treated as an html tag. We could use nom to simplifying parsing but at this point we are too far ahead.

[pintariching]

I don't think we're too far ahead, I plan to rewrite the parsing anyway when I figure out how it works. How could we use nom?

[qwertydelle]

Nom is a parser combinator framework basically it breaks your parser components into small chunks. It is also declarative so much easier to work on in the future. But what I think once we finish the current parser it would much easier to implement it in nom in the future.

[qwertydelle]

Also for the current parser all we really need to implement so far is the mustache and tag functions.

[mystique09]

What about pest.rs for parsing?

[pintariching]

I made a branch rustify-parsing where I followed the awesome video from Tan Li Hau called Build your own Svelte. He goes into detail on how it works and I think I now get it how it works. He also released a followup on implementing more features.

[qwertydelle]

Oh wait so is parsing complete?

[pintariching]

Not really complete, just some of it works. Check the integration tests, I have an example. A lot of functionality is still missing but it can parse a simple file now!

[qwertydelle]

Nice project going good

[pintariching]

I commented out a lot of the code we've written so far for now. I'm going to try and follow the video to get a simple compiler going. Currently I'm stuck at the analyze stage where in the video he uses a library 'periscopic' to traverse the AST and split the code into scopes. I think SWC has this functionality but the documentation is a bit vague.