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Bluetooth support for the Web.
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[[BackingMap]] manipulation is underdefined #351

Open bzbarsky opened 7 years ago

bzbarsky commented 7 years ago

The spec has things like:

Add a mapping from code to new DataView(bytes) in event.manufacturerData.[[BackingMap]].

What does that mean? Is it doing event.manufacturerData.[[BackingMap]].set(code, new DataView(bytes) using whatever the current value of %MapPrototype%.set is? Or is it using the default value of %MapPrototype%.set? Or something else?

jyasskin commented 7 years ago

Thanks for pushing. I'd like to be able to call out to https://infra.spec.whatwg.org/#map-set in order to manipulate the map entries. Does anything need to change in WebIDL to allow that?

@tobie

tobie commented 7 years ago

As far as I'm concerned, you can tap into the infra standard for concepts and slots all you want.

jyasskin commented 7 years ago

@tobie I'm worried that an Infra map is not the same thing as an ES Map, and WebIDL says that [[BackingMap]] is an ES Map.

Infra is careful to say that its lists are the same as ES's List type, and Infra's sets are specified as a particular kind of list, but Infra's maps are not specified as a kind of list. If they were, we could manipulate [[BackingMap]].[[MapData]] with the Infra algorithms. Is that the Right Thing to do? @annevk too, I guess.

tobie commented 7 years ago

Oh, sorry. I didn't think that's what you were doing.

Manipulating ES types using infra terms sounds like a terrible idea.

bzbarsky commented 7 years ago

Probably we should fix https://github.com/heycam/webidl/issues/254 and in the process have IDL expose some things other specs can use to do the guts of what IDL's generated set does...