[Doxin]

Signedness depends on your interpreter. In practice it hardly matters since there's no print function anyways, so if you want 2s complement you'll end up implementing it yourself anyways.

[+] should always overflow to 0 at some point, which is entirely doable for 8 bit, but less so for 32bit. as for choosing between [-] and [+] you'll just have to guesstimate if 0 or intmax is on average closer to your value.