Re: Let's talk about __call

[Phil Leblanc <philanc@...>]

On Fri, Jul 22, 2016 at 3:48 AM, Dirk Laurie <dirk.laurie@gmail.com> wrote:
> I use a minimal object-oriented paradigm in which the method
> table is also the __index and the constructor.

Same here:

 class = {
   __call = function(c, t)
      local obj = setmetatable(t or {}, c)
      if c == class then obj.__index = obj end
      return obj
   end
 }
setmetatable(class, class)

-- Let's use 'class' to define new classes:
 list = class()

-- Let's define some list methods
 list.append = function(t, elem) t[#t+1] = elem ; return t end
 list.remove = table.remove

-- Now, for a second use of __call(), let's define a list iterator:

 local inext = ipairs{}
 list.__call = function(l, x, i) return inext(l, i or 0)  end

-- ... and use it:
 mylist = list{11, 22, 33}
 for idx, value in mylist do print(idx, value) end