We present a new solution to the problem of (strongly) typing compiler passes when the source and destination language share multiple node kinds. We are interested in approaches that limit the amount of boilerplate that needs to be (re)written for each language, while still maintaining a very strict typing discipline.

Our solution uses well-known tools, but combines them in a novel way: - the idea of nanopasses, in which each pass encodes a very limited transformation - the traversal of the AST using recursion schemes

We present our implementation of this approach in the context of the Ada frontend for the Infer analyzer.