undocumented features

["Wim Couwenberg" <w.couwenberg@...>]

Hi,

marcus.cf:
> I also found some undocumented functions in lualib (some
> peole may already know them).

[... snip snip ...]

There are more undocumented and interesting features (found while doing some
Lua 5.0 experiments):

* __metatable field:  If the metatable of some object contains a
"__metatable" field then the metatable is considered "protected."  This
means that a) you cannot change the metatable of that object (through
setmetatable) and b) a getmetatable call returns the __metatable value.  The
__metatable field does not need to contain a table!

* __globals field:  If the globals table of a function contains a
"__globals" field then the globals table is considered "protected".  This
means that a) you cannot change the globals table of that function (through
setglobals) and b) a getglobals call returns the __globals value.  The
__globals field does not need to contain a table!

Again, maybe these features were left undocumented because they are likely
to change??

Which reminds me: what is the status of the Lua Web Encyclopedia that was
proposed on this list recently?  It would be an excellent place to collect
and document Lua's features.

Bye,
Wim