memoize.lua

memoize.lua

--[[
 memoize.lua

 http://lua-users.org/wiki/FuncTables
 http://www.lua.org/pil/17.1.html

 Code is public domain.
 D.Manura.
--]]

local M = {}
function M.memoize(f)
  local mt = {}
  local t = setmetatable({}, mt)
  function mt:__index(k)
    local v = f(k); t[k] = v
    return v
  end
  return t
end
return M