Good point and definitely an annoying limitation. The work around is to use an interface as the expected type as I do in the lexing example. I should have incl

Good point and definitely an annoying limitation. The work around is to use an interface as the expected type as I do in the lexing example. I should have included a section on the limitations of embedding. This is what happens when I don't stew on the writing for a day or two before putting it out there! I will have to make a pass through the article and clear up the terminology. Thanks for the feedback!