Compiler Lab

Edit a Hoopoe module and inspect each stage of the real compiler. The Macro Expansion panel shows the formatted runtime module after compile-time expansion reaches its fixed point, with const-only declarations and macro markers removed. It clears when expansion fails. Everything runs locally in your browser through WebAssembly; source code is never uploaded.

The Diagnostics panel uses the same visual renderer as the command-line compiler, including source excerpts, carets, secondary labels, notes, help, and macro expansion traces. The browser also retains the structured diagnostic fields used for source selection and other tooling behavior.