Module:Herança

Documentation for this module may be created at Module:Herança/doc

local i = {}

local Class = {}
Class.__index = Class;

setmetatable(Class, {
  __call = function (cls, ...)
    local self = setmetatable({}, cls);
    self:init(...);
    return self;
  end,
});

function Class:init()
end

function Class:isa(aClass)
  local crrClass = self;
  while nil ~= crrClass do
    if crrClass == aClass then
      return true;
    end
    crrClass = crrClass:super();
  end
  return false
end

function Class:super()
  return nil;
end

i.Class = Class;

---

function i.extend(baseClass)
  -- limit inheritance to module class tree
  assert(baseClass ~= nil
    and baseClass["isa"] ~= nil
    and baseClass:isa(Class));

  local thisClass = {}
  thisClass.__index = thisClass;
  
  setmetatable(thisClass, {
    __index = baseClass,
    __call = function (cls, ...)
      local self = setmetatable({}, cls)
      self:init(...);
      return self;
    end,
  });
  
  function thisClass:super()
    return baseClass;
  end
  
  return thisClass;
end

return i;