metatable-powered aliasing

["Soni \"They/Them\" L." <fakedme@...>]

in lua, everything is tables, so I can do this:

mt = {}

mt.__index = function(t, k)
  if k == "colour" then
    return t.color
  end
  -- optionally do other stuff
  return nil
end
mt.__newindex = function(t, k, v)
  if k == "colour" then
    t.color = v
  end
  rawset(t, k, v)
end

and everything works! and this just isn't possible in (most) other 
languages. (side note: would be nice if the return value of __newindex 
could be used instead of calling rawset. so e.g. if you return true, it 
rawsets, otherwise it doesn't. anyway...)

... well almost everything: a proper solution would have to scan the 
table before setting the metatable, to handle the case where the table 
was created with "colour" instead of "color". however, I think this is a 
pretty good start for a potential "accessibility module" for Lua.

thoughts? :3

(motivation: real ppl, working on real projects, found it extremely 
frustrating to deal with an API using both spellings of "color". this 
would solve that problem by allowing them to pick one and stick with it, 
regardless of whatever mess upstream modules are using. well, upstream 
modules would have to explicitly support it, but they could use the 
spellings however they want internally, and still expose a consistent 
API. and it's the public API that matters.)
_______________________________________________
lua-l mailing list -- lua-l@lists.lua.org
To unsubscribe send an email to lua-l-leave@lists.lua.org