Re: [Feature Request?] __key

[Coda Highland <chighland@...>]

On Mon, Jul 11, 2016 at 3:54 PM, Soni L. <fakedme@gmail.com> wrote:
> After LuaConf 2016, more specifically the Lua stored procedures talk, I kept
> thinking about something... They had to modify the Lua VM just so they can
> decay userdata into keys when indexing, everything else could be done with a
> substitution layer on top of Lua.
>
> So, can we get a __key metamethod *for userdata only* that takes an
> userdatum and returns a value to be used for table indexing?
>
> For t[k] and t[k] = v this is pretty simple to understand, but Lua isn't
> that simple:
>
> - How should rawget() and rawset() work?
> - Should there be a way to invoke __index and __newindex without invoking
> __key? (rawkeyset() and rawkeyget()?)
> - Should there be a way to invoke __key without indexing? (getkey()?) (for
> use with rawset/rawget)
> - Or is this the wrong way to go about it?

Just to verify: Are we effectively discussing something equivalent to
Python's __hash__?

/s/ Adam