On Mon, 1 Dec 2014, Boris Zbarsky wrote:
On 12/1/14, 1:49 PM, Travis Leithead wrote:
I believe so; this will give many specs a baseline WebIDL document to point
to in their references at the very least. Many specs don't rely on the more
advanced feature set being defined in WebIDL Second Edition.
Here's the problem.
As of today, v2 is not just v1 plus some more features. They actually have
some disagreements on how identical IDL syntactic constructs are handled.
For example, sequence behavior is different: in v1 a sequence has magic for
platform array objects and the gets the "length" property and goes from 0 to
length, while in v2 a sequence is an iterable and uses the ES6 iterator
protocol.
Pretty much like refactoring XHR using Fetch or not. Most implementations
will most probably move to the latest version, but the external interface
will be the same. In the case of Sequence, the ES binding says in the two
versions "IDL sequence<T> values are represented by ECMAScript Array
values."
The option 2 you outline seems best here, the syntax is considered as
stable (well, can be expanded, things can be declared obsolete, but there
won't be breaking changes), but implementations (as in the es binding
algorithms) may change to match the evolution of the underlying language.
Or another example: in v1 having an indexed getter implies nothing about
being iterable, but in v2 it implies ES6 iterability.
This is an example of v1 plus one feature.
More generally, v1 is pretty much defined in ES5 terms, while v2 is aiming
for closer convergence with ES6.
What happens when a spec uses a sequence argument and references v1? Are UAs
supposed to implement the v1 behavior or v2 behavior?
However, let's not hijack this thread; I'd love to hear what the next steps
are for moving this v1 forward.
I think that actually depends on how we want to handle the problem I describe
above.
Some obvious options are:
1) Backport all behavior changes from v2 to v1 so they agree on the set of
syntactic constructs supported by v1. This makes v1 depend on ES6, which I
understood to be a non-goal (or perhaps even anti-goal, given ES6 is not
finalized yet? But it's close).
2) Treat v1 as a syntax spec (with v2 a superset of the syntax) and
explicitly say somewhere in v1 that v2 can redefine the behavior. Not sure
how happy people referencing v1 will be with that.
Other options?
Another option would be to define only the syntax and leave the bindings
to v2 only, but it wouldn't help much for testing.
--
Baroula que barouleras, au tiéu toujou t'entourneras.
~~Yves
