You say "cover all the cases" like it is trivial. The RFCs only define about 60% of the behavior, with the rest left up to the implementer. As a recursive you h

You say "cover all the cases" like it is trivial. The RFCs only define about 60% of the behavior, with the rest left up to the implementer. As a recursive you have to deal with every difference of opinion of authoritative implementers and the bugs they might have introduced.