A short adventure into the depths of optional and/or keyword functions in Racket.

Several old questions from the Typed Racket mailing list have new and simple answers under a “transient” Typed Racket.

What type-directed optimizations does Typed Racket perform and do any require full types?

The transient approach to migratory typing (circa 2014) is similar to type erasure in Java (circa 2004) in a few interesting ways.