Module:Ordered pairs

local p = {}

local function __genOrderedIndex(t) local orderedIndex = {} for key in pairs(t) do       table.insert(orderedIndex, key) end table.sort(orderedIndex) return orderedIndex end

local function orderedNext(t, state) -- Equivalent of the next function, but returns the keys in the alphabetic -- order. We use a temporary ordered key table that is stored in the -- table being iterated.

local key = nil if state == nil then -- the first time, generate the index t.__orderedIndex = __genOrderedIndex(t) key = t.__orderedIndex[1] else -- fetch the next value for i = 1, #(t.__orderedIndex) do           if t.__orderedIndex[i] == state then key = t.__orderedIndex[i + 1] end end end

if key then return key, t[key] end

-- no more value to return, cleanup t.__orderedIndex = nil return end

function p.orderedPairs(t) -- Equivalent of the pairs function on tables. Allows to iterate in order. return orderedNext, t, nil end

return p