Lua gist

deep_compare.lua

-- deeply compare two objects like 'pl.tablex.deepcompare()'
local function deep_equals(t1, t2, ignore_mt)
    -- different type
    if t1Type ~= t2Type then return false end
    -- compare simple values directly
    if t1Type ~= 'table' then return t1 == t2 end

    -- both table type; try metatable method
    if not ignore_mt then
        local mt1 = getmetatable(t1)
        if mt1 and mt1.__eq then
            --compare using built in method
            return t1 == t2
        end
    end

    -- without metatable method or ignore metatable
    -- iterate over t1
    for key1, value1 in pairs(t1) do
        local value2 = t2[key1]
        if value2 == nil or deep_equals(value1, value2, ignore_mt) == false then
            return false
        end
    end

    -- check keys in t2 but missing from t1
    for key2, _ in pairs(t2) do
        if t1[key2] == nil then return false end
    end
    return true
end


-- example
local t1 = { { 1 }, { 2 }, { 3 } }; local t2 = { { 3 }, { 2 }, { 1 } }

if deep_equals(t1, t2, true) then
   print("yes")
else
   print("no")
end