httpbis-sfbis notes

Hi!

Just wanted to share I updated my Javascript implementation to the 
latest Structured Fields draft:

https://www.npmjs.com/package/structured-headers
(released with an alpha tag until the RFC is published).

Bit annoying I called it 'structured headers', but I'm kind of stuck 
with that now. I've shared these in the past, but there's 2 slight 
incompatibilities with the spec that might be interesting for the authors.

 1. Javascript can't differentiate between |1.0| and |1|. As a result
    we're skipping the tests that require a serialiation output of |1.0|.
 2. Javascript rounds slightly different from the spec. The tests
    suggest that |0.0025| should round to the nearest event number
    (|0.002|), but Javascript rounds to |0.003|.

Just wanted to share this as a data point. It would be possible to wrap 
every number in a class that labels it as decimal or int, but this would 
reduce the ergonomics of the standard use-case quite a bit.

The library has quite a bit of downloads (400K / week), which surprised 
me. So if people will be reaching to this when they want to 
serialize/parse Structured headers I would like to be a good citizen, so 
I'm open for any feedback.

The one thing I will change before a 2.0 release is that I intend to 
ship a `Dictionary` wrapper. v1 returns a deep structure with simple 
arrays and Maps, and I think it's a bit frustrating to work with for 
simple use-cases.

Evert