[awj]

How hard would it be to get usable type signatures out of the compiler as well? It seems like diffing two sets of type signatures would capture everything but purely semantic api incompatibility. Also seems like "here's a machine-readable version of all the types in this package" is a useful thing for a compiler toolchain to produce.

Because, of course, Mozilla is paying you to sit around on your hands.

[steveklabnik]

It shouldn't be that bad, given the need for the compiler to export an AST.