Is the Didache One Document or Three?

I have been discussing the interesting and important early Christian document called the Didache.  Yesterday I gave a translation of its first part, the “two ways” or the “two paths” section.  After that the topic and tone of the book changes, as it starts to talk about how Christian baptism and eucharist should be celebrated.  It ends on a completely different note, with a one-chapter description of the coming apocalypse.  Scholars have asked whether the book as we now have it was actually c...