--[[
Copyright (c) 2012-2013 Kaarle Ritvanen
See LICENSE file for license details
--]]

module(..., package.seeall)

function setdefault(t, k, v)
   if t[k] == nil then t[k] = v end
   return t[k]
end

function update(dst, src, preserve)
   for k, v in pairs(src) do
      if not preserve or dst[k] == nil then dst[k] = v end
   end
   return dst
end

function setdefaults(dst, src) return update(dst, src, true) end

function copy(var)
   return type(var) == 'table' and setdefaults({}, var) or var
end

function map(func, tbl)
   local res = {}
   for k, v in pairs(tbl) do res[k] = func(copy(v)) end
   return res
end