recursion - Lua : recursive multiple numbers GCD Euclide calculation -- everlasting loop -

i try calculate recusively gcd of several numbers.

here try. more numbers 2 erverlasting loop. i'm not sure pgcd( unpack(arg)) part, have no idea of else.

edit in fact, seems arg.n >2 not efficient...

function pgcd ( ... )     local arg = table.pack(...)     if arg.n >2             local tmp = table.remove(arg,1)          return pgcd (tmp, pgcd( unpack(arg) ))     else         a,b = unpack(arg)         repeat         , b = b , % b         until % b == 0         return b     end end   print (pgcd(18,12))  -- works fine   print (pgcd(18,12,9)) -- everlasting loop 

in fact endding test testing once far.

function pgcd ( ... )     local arg = table.pack(...)     if arg.n > 2             local tmp = table.remove(arg,1)         return pgcd (tmp, pgcd( unpack(arg) ) )     else         a,b = unpack(arg)         repeat         , b = b , math.fmod(a,b)         until b == 0 -- test once far         return     end end   print (pgcd(18,12))  -- works fine  print (pgcd(18,12,6)) -- works fine