Re: Assign idiom

["Alexander Gladysh" <agladysh@...>]

> >> local    sp = self.spBackGround = CreateSprite()
> >> sp:setSize( 10, 10 )

What about something like this? (All code right from my head, without
syntax check.)

 -- Meaning a member function defined somewhere
 self.InitBGSprite = function(self)
   self.spBackGround = CreateSprite()
   return self.spBackGround
 end

 local sp = self.InitBGSprite()

Or even this (looks like overkill though, I like previous one more):

 -- Meaning a member function defined somewhere
 self.InitVar = function(self, name, ctorfn, ...)
   local v = ctorfn(...)
   self[name] = v
   return v
 end

 local sp = self.InitVar("spBackGround", CreateSprite)

 -- If your CreateSprite() accepts some extra arguments, say, size,
 -- you can do this instead:
 local sp2 = self.InitVar("spBackGround", CreateSprite, 800, 600)

If you're going to use this idiom very often, you can use combined approach:

 -- A global function constructor
 MakeInitializer = function(name, ctorfn)
   return function(self, ...)
     local v = ctorfn(...)
     self[name] = v
     return v
   end
 end

 -- Meaning a member function defined somewhere
 self.InitBGSprite = MakeInitializer("spBackGround", CreateSprite)

 local sp = self.InitBGSprite()
 -- or --
 local sp1 = self.InitBGSprite(800, 600)

HTH,
Alexander.