There is one minor syntactical convenience available to make the message example slightly more concise: switch msg := msg.(type) would make msg a message of the

There is one minor syntactical convenience available to make the message example slightly more concise: switch msg := msg.(type) would make msg a message of the specific type inside each case. (So msg would be a DrawLine between 'case DrawLine:' and the next case.) Author might have just wanted different names in the different cases, which is a perfectly defensible reason for doing it the way he did instead. He says "Go seems to advocate runtime over compile time checking." I think it's less that folks prefer run-time checks on principle than that they simply don't yet have in hand great ways to strengthen compile-time safety while meeting their other goals (meeting backcompat promises, not complicating spec/impl too much, other work like shorter GC pauses or new platform support). As an example of a team member not being a fan of all the runtime checks, bradfitz complains about the occasional gross interface{} here: http://talks.golang.org/2014/gocon-tokyo.slide#50 http://talks.golang.org/2014/gocon-tokyo.slide#50 . And there is active work from the team and community on static checking, though most of that right now is in the form of heuristic checks in external tools, e.g., go vet and errcheck. All in I love this--I tire a bit of posts that are like "I wrote a toy program [or not even that]; here's Why Everyone Else Is Wrong" (because anyone could give an opinion that informed given a day or two, and hot takes are getting old). But it's cool to see someone who, by virtue of working on Rust (and seeing it evolve) has unusual perspective on tradeoffs and seems to have written, you know, pretty thoughtfully and maturely about them.