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On 11/07/16 11:52 PM, Soni L. wrote:


On 11/07/16 11:38 PM, Sean Conner wrote:
It was thus said that the Great Soni L. once stated:
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?
   Previous discussions on __key:

http://lua-users.org/cgi-bin/namazu.cgi?query=__key&idxname=lua-l&max=20&result=normal&sort=date%3Aearly

Interesting. Such a shame previous threads didn't go very far. However, the use-case I proposed is different, as it's about compatibility/interoperability with Lua types (number, string, boolean, etc).


   And just because ... __hash:

http://lua-users.org/cgi-bin/namazu.cgi?query=__hash&idxname=lua-l&max=20&result=normal&sort=date%3Aearly

   -spc (Wow ... that __hash one goes way back to 2003 I see ... )



(Empty reply so someone sees this. The table vs array threads kill all other threads :/)

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