[anaumann]

> But I keep wondering if they could integrate at a lower-level than the source code.

For my version (aptly named "Goto" [1]), I forked the go compiler with the intent of keeping it up to date. All changes I made only apply to .goto files, .go files compile exactly as is and are interoperable both ways with goto.

I paused the project due to hitting type-checking bugs when trying to add non-nillable pointers. Everything before was just desugared directly when converting to AST, but for those I needed to touch the typechecker which was too time-consuming for a hobby project back then (pre-coding agents). I might give it another go sometime as I did like the full interoperability aspect.

[1] https://github.com/goto-lang/goto