redefine pairs for all tables

tabletest.lua

local original_next = next
local original_pairs = pairs

local function sorted_next(t, k)
    local keys = {}
    for key in original_pairs(t) do
        table.insert(keys, key)
    end
    table.sort(keys)

    local current_index = 1
    if k ~= nil then
        for i, key in ipairs(keys) do
            if key == k then
                current_index = i + 1
                break
            end
        end
    end

    local next_key = keys[current_index]
    if next_key then
        return next_key, t[next_key]
    else
        return nil
    end
end

_G.next = sorted_next

function _G.pairs(t)
    return sorted_next, t, nil
end

local t = {
    dog = "woof",
    cat = "meow",
    bird = "tweet",
    fish = "blub"
}

print("pairs test:")
for k, v in pairs(t) do
    print(k, v)
end

print("next test:")
local k, v = next(t)
while k do
    print(k, v)
    k, v = next(t, k)
end