Transient Typechecks are (Almost) Free [Artifact]

Transient gradual typing imposes run-time type tests that typically cause a linear slowdown in programs' performance. This performance impact discourages the use of type annotations because adding types to a program makes the program slower. A virtual machine can employ standard just-in-time optimizations to reduce the overhead of transient checks to near zero. These optimizations can give gradually-typed languages performance comparable to state-of-the-art dynamic languages, so programmers can add types to their code without affecting their programs' performance.

This artifact includes our implementation as part of Moth, an implementation of the Grace language on top of the Truffle/Graal platform. The artifact contains all elements of our empirical evaluation. It aims to enable other researchers to repeat our experiments, verify our results, and possibly extend our research.