[css-houdini-drafts] The IDL for StylePropertyMap is not valid

bzbarsky has just created a new issue for https://github.com/w3c/css-houdini-drafts:

== The IDL for StylePropertyMap is not valid ==
https://heycam.github.io/webidl/#idl-maplike clearly says:

> The inherited interfaces of a maplike interface must not also have a maplike declaration. 

but that's precisely what StylePropertyMap is doing: inheriting from another interface with a maplike declaration.

The reason for this restriction is that a maplike declaration induces the existence of a  [[BackingMap]] internal slot on instances.  When there are multiple maplike declarations it's undefined whether there are multiple internal slots or whether they interact with the same internal slot or something else.

Please view or discuss this issue at https://github.com/w3c/css-houdini-drafts/issues/649 using your GitHub account

Received on Thursday, 15 February 2018 17:40:50 UTC