Support fast_html as an optional html parser

[rinpatch]

Feature goal

fast_html is a C-Node binding for lexborisov's myhtml, it's from 1.2 to 2 times faster than html5ever (benchmark link) and requires only a c complier and gmake.

I can open a PR if you have no objection to adding it.

Dependencies

{:fast_html, "~> 0.99"}

:)

[chengyin]

mochiweb's lack of proper whitespace handling is a deal breaker for us.

html5ever's great on the correctness, and we are not that concerned with its performance. The problem is the elixir package, which is not maintained.

html5ever_rustler requires a rustler version update for each major Erlang/OTP release, otherwise build simply fails for the whole application. But the PR for upgrading hasn't received any feedback since August.

I've been searching for replacements and I'm excited for fast_html.

@rinpatch do you have any comments on the maintainance plan for fast_html going forward?

[philss]

@rinpatch I think this may be a great addition to the lib! Is it possible to do it by adding the fast_html dependency as optional?

[rinpatch]

@rinpatch do you have any comments on the maintainance plan for fast_html going forward?

First of all, it's a pretty small library, so it doesn't take much effort to maintain. Second, it's used in Pleroma, which is an application deployed on 500 servers and fast_html parses thousands of html fragments there daily, so I am sure it's going to be maintained.

[rinpatch]

@rinpatch I think this may be a great addition to the lib! Is it possible to do it by adding the fast_html dependency as optional?

I believe so, will try adding it on the weekend then.