11 parts
First day of the v0.5 rewrite. I tore out the `<-` send operator and the spawn-lambda form, and spent the rest of the day deciding what the actor and machine surface should look like before a single line of it lowers to a binary.
Today the value layer stops being vague. I gave integers real widths and platform-sized isize/usize, wired records all the way through with auto-derived markers, and made arithmetic that overflows trap instead of silently lying.
The day the pipeline became Rust top to bottom — over fifteen hundred C++/MLIR files deleted, and generics finally grew a spine through the IR ladder.
Actors stopped being syntax today. I wired actor method calls down to spawn/send/ask, made init and the on(start)/on(stop) hooks fire at the right moments, and threaded an execution context through the whole thing so the reply channel has somewhere to live.
Machine declarations used to type-check and then stop — no runtime behaviour. Now they lower all the way through to native code. Plus pipe-form closures, a canonical pointer spelling, and a TCP-as-Stream bridge.
Generic enum values now make it all the way to LLVM, so I get to delete the not-yet-supported guard that's been standing in for them. Match over payload-bearing variants works, and for and while loops lower to real control flow for the first time.
Two dense days grouped together — generator lowering finally has a state record and cross-yield liveness, the SWIM detector goes phi-accrual, and I delete the 2498-line hand-built wire format in favour of a CBOR envelope with a CDDL schema.
Two days of making the compiler refuse to lie — fail-closed gates that reject unsupported shapes at compile time, a memory-safety sweep through the runtime, and a `hew check` that finally runs the real pipeline.
Two days on the substrate under generic data structures — what a layout descriptor actually carries, why the closure checker now infers move vs borrow, and the moment I noticed three different pieces of the compiler each had their own opinion about how a method call lowers.
Two days on ownership — retiring the old HashMap/HashSet dual-dispatch, turning `string` into a copy-on-write refcounted value, and adding `&T` borrow markers that fail closed when you try to clone the wrong way.
Generics that lower without a concrete type yet, an actor receive path that takes a non-owning borrow of the message, and the smaller control-flow pieces — const globals, bare loop, break/continue — I'd been putting off.