On Thursday, March 23, 2023 7:22 PM, Felipe Contreras wrote: >On Sat, Feb 18, 2023 at 5:12 AM Phillip Wood <phillip.wood123@xxxxxxxxx> wrote: >> >> On 18/02/2023 01:59, demerphq wrote: >> > On Sat, 18 Feb 2023 at 00:24, Junio C Hamano <gitster@xxxxxxxxx> wrote: >> >> >> >> Emily Shaffer <nasamuffin@xxxxxxxxxx> writes: >> >> >> >>> Basically, if this effort turns out not to be fruitful as a whole, >> >>> I'd like for us to still have left a positive impact on the codebase. >> >>> ... >> >>> So what's next? Naturally, I'm looking forward to a spirited >> >>> discussion about this topic - I'd like to know which concerns >> >>> haven't been addressed and figure out whether we can find a way >> >>> around them, and generally build awareness of this effort with the community. >> >> >> >> On of the gravest concerns is that the devil is in the details. >> >> >> >> For example, "die() is inconvenient to callers, let's propagate >> >> errors up the callchain" is an easy thing to say, but it would take >> >> much more than "let's propagate errors up" to libify something like >> >> check_connected() to do the same thing without spawning a separate >> >> process that is expected to exit with failure. >> > >> > >> > What does "propagate errors up the callchain" mean? One >> > interpretation I can think of seems quite horrible, but another >> > seems quite doable and reasonable and likely not even very invasive >> > of the existing code: >> > >> > You can use setjmp/longjmp to implement a form of "try", so that >> > errors dont have to be *explicitly* returned *in* the call chain. >> > And you could probably do so without changing very much of the >> > existing code at all, and maintain a high level of conceptual >> > alignment with the current code strategy. >> >> Using setjmp/longjmp is an interesting suggestion, I think lua does >> something similar to what you describe for perl. However I think both >> of those use a allocator with garbage collection. I worry that using >> longjmp in git would be more invasive (or result in more memory leaks) >> as we'd need to to guard each allocation with some code to clean it up >> and then propagate the error. That means we're back to manually >> propagating errors up the call chain in many cases. > >We could just use talloc [1]. talloc is not portable. This would break various platforms. --Randall
