Re: Using environment for OO

["Martin C. Martin" <martin@...>]

I want that to be transparent to the function definer, so my class 
object looks like this:

MyClass = {
  __newindex = function (table, key, value)
    if type(value) == "function" then
      setfenv(value, table)
    end
    rawset(table, key, value)
  end
}

My "new" function takes a table to use for the object, so it goes 
through it an calls setfenv() on each function, like this:

function MyClass.new(obj)
   obj = obj or {}
   for k, v in pairs(obj) do
     if type(v) == "function" then
       print ("Setting environment for ", k)
       setfenv(v, obj)
     end
   end
   setmetatable(obj, MyClass)
   MyClass.__index = MyClass
   return obj
end

For a class with no base class, I need to do this:

setmetatable(MyClass, {__index = _G})

Best,
Martin

David Given wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
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> Martin C. Martin wrote:
> [...]
> > For an OO style while accessing fields is more common than globals, the
> > environment option seems cleaner than the standard : option.  Are there
> > any down sides that I'm missing?
>
> Correct me if I'm wrong, but won't the same function (with one
> environment) need to be shared among several different objects? Won't
> you have to explicitly call setfenv() at the top of each method,
> preventing them from being called reentrantly?
>
> - --
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