[Fwd: Fail-fast on non-existing [[Get]]]
brendan at mozilla.org
Wed Oct 17 11:55:18 PDT 2012
Tom Van Cutsem wrote:
> 2012/10/16 Herby Vojčík <herby at mailbox.sk <mailto:herby at mailbox.sk>>
> I see two solutions:
> - add something to the freeze, seal, preventExtensions family which
> would set an object to the fail-fast [[Get]] state.
> - use a Proxy in the proto chain to trap the unknown [[Get]] and
> throw early
> Do you think this needs a solution at all? If yes, which option would
> you favour?
> The second option is easy to accomplish but pretty invasive since it
> requires you to inherit from a particular object. If you have an
> abstraction that already inherits from something else, you're hosed.
> Personally, I'm not convinced this is a big enough problem to warrant
This has come up in TC39, and on this list. Waldemar would like a way
(not the default) to seal a class so typo'ed member names throw:
However, since then, I recall hearing Waldemar say that the private
at-name syntax in classes (for him) made the case that maximally minimal
classes hang together in ES6, without any "const class" or sealed class
I agree it's not a big enough problem to add a "mode" or anything like
that. Opt-in by class could be helpful. TypeScript has its optional
member syntax (?:) and can give warnings. It seems to me this kind of
tool-time help might be enough.
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