[WIP] Reduce HTML output in rustdoc

[GuillaumeGomez]

 > du -sh normal/std/index.html
 60K	normal/std/index.html
 > du -sh build/x86_64-apple-darwin/doc/std/index.html
 36K	build/x86_64-apple-darwin/doc/std/index.html

r? @rust-lang/docs

[frewsxcv]

For reference https://github.com/GuillaumeGomez/minifier-rs

[killercup]

@GuillaumeGomez I'm pretty surprised to see your minifier drop so many closing tags. Especially the rules around omitting </li> seem to be error-prone to me (but I haven't dealt with stuff like that in quite a while). Two more things:

1. Compare the gzip'd sizes as basically all HTTP traffic is compressed (as are blobs stored in a git repo IIRC)
2. Have I linked to http://stackoverflow.com/a/1732454/1254484 recently? :)

[GuillaumeGomez]

I'm pretty surprised to see your minifier drop so many closing tags. Especially the rules around omitting seem to be error-prone to me (but I haven't dealt with stuff like that in quite a while).

li, tr, td and equivalent can be unclosed considering they can't be directly in each others.

Compare the gzip'd sizes as basically all HTTP traffic is compressed (as are blobs stored in a git repo IIRC)

Hum, good point.

Have I linked to http://stackoverflow.com/a/1732454/1254484 recently? :)

The compression isn't "hardcore" so it leaves place for improvements. Using html5ever for this could be worth it, to be tested. This PR is a work in progress after all and isn't to be merged right now.

[alexcrichton]

Note that a tool like this seems like it has a high chance of accidentally introducing regressions, it'd be great if we could add some regression testing as well to this.

[GuillaumeGomez]

@alexcrichton: it's not close at all to get merged. For now it was mostly to get some feedbacks. Do you have an idea by any chance on how I could test regressions in here?

[alexcrichton]

To start this could use an html parser like html5ever and enusre the document structure doesn't change for standard Rust properties like:

• The book
• Standard library docs
• Popular crates on docs.rs

[sophiajt]

I'm not currently on rustdoc, so assigning to alex

r? @alexcrichton

[clarfonthey]

It'd be nice if we could do this to rustdoc's CSS as well.

[GuillaumeGomez]

@clarcharr: It's scheduled (at least I intend to do it).

[frewsxcv]

In my opinion, minimizing HTML and CSS is something that would be cool to do for all pages generated by rustdoc, but it seems the underlying tool has some incubation to so. I have some concerns about some of the strategies it does and the lack of testing. I don't know if this PR is the most effective way to get feedback though

[GuillaumeGomez]

Well, at least it opens the debate. I still have a lot to do on the minimizer tool.

[TimNN]

@GuillaumeGomez: What's the current status of this PR?

[GuillaumeGomez]

Quite busy, I still need to rewrite the HTML minifier (using html5ever). I'll try to get to it in the next weeks or so.

[bors]

☔ The latest upstream changes (presumably #41843) made this pull request unmergeable. Please resolve the merge conflicts.

[alexcrichton]

Ok I'm going to close this for now to help keep the queue clear, but please of course feel free to resubmit!