| 10 Dec 2025 |
 Qyriad | * or whenever someone pays us for it | 17:35:36 |
 piegames | I think browser engines have sufficient control over their baseline caching pipelines and what data changes when that they can probably just track what changes easily, but I'm guessing here | 17:36:08 |
 KFears (they/them) | In reply to @piegames:flausch.social
no, parsing is super fast, mostly thanks to horrors, it's just that Nixpkgs is 3.6MLOC over 40k files and every single NixOS eval loads a good chunk of that, realistically multiple times. The main issue is that caching was never a thought in the architecture and adding it afterwards is really tricky I don't know how many of those lines are going to be actually parsed (now I wish I could somehow learn that into), but assuming 20% utilization (that doesn't sound too unreasonable, considering that my desktop has 2k packages, but there's a lot of re-evals due to module system, splicing, package variations etc.), that doesn't sound too terrible? Like, other interpreters and compilers probably deal with 700k LOC codebases. How do they deal with that? | 17:36:40 |
| piegames | I'm dreaming of tackling it for 2.96 really | 17:36:58 |
| piegames | I already have a half-working prototype from a year ago, horrors had one too, and we should soon have all the parts together for doing it | 17:37:37 |
| piegames | main question is whether to do it in C++ or to block it on RPC and do it in Rust | 17:37:53 |
 helle (just a stray cat girl) | please don't do it in C++ | 17:38:13 |
| helle (just a stray cat girl) | we don't want to have to migrate that later on | 17:38:26 |
| Qyriad | we would either block it on RPC, or bind it to existing libexpr over C bindings. the refactoring necessary for libexpr to use a bytecode interpreter over C ABI would be like half the battle for the decoupling we need to do anyway | 17:40:46 |
 Sergei Zimmerman (xokdvium) | FWIW v8 uses the source code hash as the cache key https://github.com/v8/v8/blob/427f7cce6d69a2d6ce113200e8dcc1151765058c/src/snapshot/code-serializer.cc#L820-L834 | 17:41:09 |
| Sergei Zimmerman (xokdvium) | So the closest thing would be to hash .nix files -> cached bytecode -> cached optimizer -> .... -> profit? | 17:42:32 |
| piegames | that's the goal yes | 17:44:02 |
| piegames | unclear about profit though | 17:44:06 |
 Rutile (rootile) | Do we understand the overall parsergoal correctly as "use the fastest parser available, errors be damned and if it fails reparse with a good error handling one performance be damned"? | 17:44:16 |
