Alphabetical Sort Test

function pairsByKeys (t, f)
      local a = {}
      for n in pairs(t) do table.insert(a, n) end
      table.sort(a, f)
      local i = 0      -- iterator variable
      local iter = function ()   -- iterator function
        i = i + 1
        if a[i] == nil then return nil
        else return a[i], t[a[i]]
        end
      end
      return iter
    end

lines = {
      apple = 3,
      banana = 2,
      carrot = 1}

for name, line in pairsByKeys(lines) do
  print(name, line)
end