Re: Functions with individual metatables
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- Subject: Re: Functions with individual metatables
- From: Richard Hundt <richardhundt@...>
- Date: 2009年5月19日 10:12:59 +0200
Richard Hundt wrote:
__newindex = function(func, key, val)
local meta = func_meta[func]
if meta and meta.__newindex then
if type(meta.__newindex) == "function" then
return meta:__newindex(key, val)
else
meta.__newindex[key] = val -- HERE
end
end
end;
-- the rest of the meta table events here...
})
Aplogies, I had some dain brammage in my code in my previous post.
To optimise for lookup, we could "flatten" out the meta events, keeping
each in a separate table, so we don't need to test if we have a function
"__index" handler or a table:
local func_meta = { }
setmetatable(func_meta, { __mode = "k" })
local func_meta__index = { }
setmetatable(func_meta__index, { __mode = "k" })
local func_meta__newindex = { }
setmetatable(func_meta__newindex, { __mode = "k" })
debug.setmetatable(function() end, {
__index = function(func, key)
local meta = func_meta__index[func]
if meta then
return meta[key]
end
end;
__newindex = function(func, key, val)
local meta = func_meta__newindex[func]
if meta then
meta[key] = val
end
end
})
function setfmeta(func, meta)
func_meta[func] = meta
func_meta__index[func] = meta.__index
func_meta__newindex[func] = meta.__newindex
return func
end
function getfmeta(func)
return func_meta[func]
end
Cheers,
Rich