keying by function and index

[Lucas Ackerman <ackerman7@...>]

Hi, I need to be able to use functions as keys in a table but also need 
to associate different indexed values for each function.  I could go 
with keying first by function then via the index in sub-tables, but for 
my particular use it would be better to have all of the references in a 
single table.  Would it be good then to key by a string with the index 
appended?  Something analagous to this:

local function f() end
local index = 3
local value = "foo"
local t = {}
t[tostring(f) .. "_" .. index] = value


Using tostring() on a function gives strings like "function: 0x80652c0", 
so I could strip out the "function: 0x" part to save space, or for that 
matter turn the rest into a number and tack my index on the end.

I just want to be reasonably sure that a function's tostring() is usable 
in such a manner without any hidden gotcha's, since I haven't seen 
anything like this mentioned on lua-l before.  Other suggestions are 
welcome.  Thanks,

-Lucas