Make l20n work in Servo

[zbraniecki]

Servo is very close to have everything needed to support l20n.js in its current form. Let's track what's missing.

[zbraniecki]

Depends on #1980 and #2974

[zbraniecki]

CC @stasm

[zbraniecki]

Depends on #4282

[jdm]

These dependencies seem to belie the original assertion of "very close" :)

[zbraniecki]

We didn't use Promise at the time when I tested and dataset was about to land. Now we have MutationObserver and Promise missing - it's a bit further, but both depend on the same issue (microtasks) which is progressing.

[zbraniecki]

Also, pending #4283

[zbraniecki]

As of today, l20n is only blocked by #1980

[fabricedesre]

@zbraniecki Now that #20740 has landed I think we are in a much better shape. Do you have a test suite we can run on Servo?

[zbraniecki]

www.projectfluent.org uses Fluent (which is the new incarnation of L20n). If it doesn't work, I'll have to dig deeper to find what breaks.
You can also try a simple example - https://github.com/projectfluent/fluent.js/blob/master/fluent-web/examples/simple.html

[zbraniecki]

Ok, the website seems to work! The exampl doesn't because servo uses old SpiderMonkey(?) - async functions don't work, const in for loops etc. I think once we get an update of SM we should be good! :)

[zbraniecki]

I believe that means we're only blocked by #20585 now.

[fabricedesre]

Right now we can run in "compat" mode, but yes we need #20585 to get all the goodies.

[atouchet]

#20585 has now been done.

[zbraniecki]

Yay! Confirmed that latest servo works with FluentDOM and FluentWeb! It properly displays https://www.projectfluent.org as well :)