Function make_result 

pub fn make_result(
    out: &mut CodeValue,
    class_name: &'static CStr,
    fill: impl FnOnce(&mut CodeValue),
)

Build a { _class = <class_name>, value = <fill's result> } particle into out — the shape emit ... to <alias> get x expects a handler’s result to have. Mirrors runtime.c’s own code_make_result, which a C module reaches via #include "runtime.c" but isn’t exported for a separately-linked module to call directly, so this is a small reimplementation rather than an FFI binding.