lua 递归遍历table所有元素

TableHeapStr=""
CurrentTableName=""
function prt(x)
    local rst=""

    if type(x)=='number' or type(x)=='string' or type(x)=='function' or type(x)=='nil' then 
         rst=rst..tostring(x) ..' '
    end

    if type(x)=='table' and string.find(TableHeapStr,tostring(x))==nil then
        TableHeapStr=TableHeapStr..tostring(x)
        rst=rst..'\n'..CurrentTableName ..'{'
        for i,k in pairs(x) do
            if type(i)=='number' then
             rst=rst..prt(k) ..'  '
            else
             rst=rst..i..'= '..prt(k) ..'  '
             end
         CurrentTableName=i
        end
        rst=rst..'}\n'
    end
    return rst
end

testList={1,2,{33,44,55,{66,77,88} ,},prt}
b=prt(_G)
print( b )