The goal of this thesis is to write a per-function, ahead-of-time compiler for a subset of TypeScript. The compiler will decide, separately for each function, whether it is possible to compile it (given the restricted language support in the compiler). It will then generate machine code for the selected subset of input functions in such a way that the remainder of the code can be interpreted using an existing JavaScript interpreter and seamlessly call compiled versions of functions if available. The motivation for this approach is to reduce the overhead associated with using JavaScript in restricted environments (especially on microcontrollers), where it is likely that the performance-sensitive parts of the input program will be sufficiently simple to compile ahead of time.