Way to get all "supertables" (opposite of metatables)?

Comments

• Jmv38 Mod

  March 2015 Posts: 3,297

  http://codea.io/talk/discussion/275/faq-please-read#latest
• time4coding

  March 2015 Posts: 12

  @Jmv38 Thanks, that helped a lot! I was able to make my question much clearer.
• Ignatz Mod

  March 2015 Posts: 5,396

  @time4coding - try this, it's a bit of a kludge because it loops through every object in memory to get the list - but it is fast. The variable _G is worth exploring, it is a table holding absolutely everything.

  function setup()
      mt={}
      t=setmetatable({},mt)
      t2=setmetatable({},mt)
      list=GetTableList(mt)
      print(t==list[1],t2==list[2]) --check it worked
  end
  
  function GetTableList(m)
      local list={}
      for n,v in pairs(_G) do --look at everything
          if type(v)=="table" then
              local mt=getmetatable(v)
              if mt==m then table.insert(list,v) end
          end
      end
      return list
  end
  
• Jmv38 Mod

  March 2015 edited March 2015 Posts: 3,297

  Precision: _G holds everything that is *top level* : it doesnt see local variables, or objects recorded inside tables only. (@Ignatz: i know you know).
• Jmv38 Mod

  March 2015 edited March 2015 Posts: 3,297

  You probably want to access only some special metatables, corresponding to some class you've created? If so you can simply record each object when it is created:

  
  --# example
  example = class()
  example.list = {}
  function example:init(name)
      self.name = name
      table.insert(example.list,self)
  end
  
  
  
  --# Main
  -- class list
  function setup()
      ex1 = example("name 1")
      ex2 = example("name 2")
      for k,v in pairs(example.list) do
          print(v.name)
      end
  end
  

  here example variable is the metatable of every object you create with example("xx"), so it looks pretty much like what you wanted (a list of all objects with this metatable).
• time4coding

  March 2015 Posts: 12

  Both of these methods work great! Thanks for introducing me to _G too.
• Ignatz Mod

  March 2015 Posts: 5,396

  @time4coding - welcome to the forum, by the way. :-h
• stevon8ter

  March 2015 Posts: 547

  @Jmv38 thanks for that, I was able to use it for resetting all my buttons when a popup occured

  @time4coding welcome to the forum indeed