-- LibStub is a simple versioning stub meant for use in Libraries.  http://www.wowace.com/wiki/LibStub for more info
-- LibStub is hereby placed in the Public Domain Credits: Kaelten, Cladhaire, ckknight, Mikk, Ammo, Nevcairiel, joshborke
local LIBSTUB_MAJOR, LIBSTUB_MINOR = 'LibStub', 2 -- NEVER MAKE THIS AN SVN REVISION! IT NEEDS TO BE USABLE IN ALL REPOS!
local LibStub = _G[LIBSTUB_MAJOR]

if not LibStub or LibStub.minor < LIBSTUB_MINOR then
  LibStub = LibStub or { libs = {}, minors = {} }
  _G[LIBSTUB_MAJOR] = LibStub
  LibStub.minor = LIBSTUB_MINOR

  function LibStub:NewLibrary(major, minor)
    assert(type(major) == 'string', "Bad argument #2 to `NewLibrary' (string expected)")
    minor = assert(
      tonumber(strmatch(minor, '%d+')),
      'Minor version must either be a number or contain a number.'
    )

    local oldminor = self.minors[major]
    if oldminor and oldminor >= minor then
      return nil
    end
    self.minors[major], self.libs[major] = minor, self.libs[major] or {}
    return self.libs[major], oldminor
  end

  function LibStub:GetLibrary(major, silent)
    if not self.libs[major] and not silent then
      error(('Cannot find a library instance of %q.'):format(tostring(major)), 2)
    end
    return self.libs[major], self.minors[major]
  end

  function LibStub:IterateLibraries()
    return pairs(self.libs)
  end
  setmetatable(LibStub, { __call = LibStub.GetLibrary })
end
