Re: [RFC] Scope functions

On Thu, May 7, 2026, at 5:52 AM, Rowan Tommins [IMSoP] wrote: > For something like "run this in a transaction", the closure is really > acting like a poor man's "continuation": it creates two new stack > frames (transaction wrapper, callback) when what you really want is to > *interleave* the boilerplate and the case-specific code. > > In that sense, hygienic macros are probably the "ideal" solution - > everything is expanded inline into a single scope, and there's no > Closure object which can be misused. > > Context Managers could in fact be implemented as such a macro, and as I > understand it, the implementation is basically doing that internally by > manipulating ASTs. Correct. Absent a macro system like Rust, it's just a one-off compiler "macro" that turns into try-catch-finally. > I wonder if there's any "minimal" macro system which would allow this > kind of inline boilerplate expansion, without needing to design an > entire meta-language? The PFA implementation does generate new opcodes at runtime and cache them. So such things are possible. Wise to generalize or not is an entirely separate question, though. :-) --Larry Garfield