This is an impressive effort, but one major problem is that the Python runtime lacks efficient support for tail calls. I see that there is an annotation for sel

This is an impressive effort, but one major problem is that the Python runtime lacks efficient support for tail calls. I see that there is an annotation for self-recursion, but this is only a special case. Scala has a similar problem with the JVM. Still, it does permit a nice functional syntax above perhaps lower-level imperative code.