d504b440c2
Previously, Output deserialization would silence validation errors and provide `None` for `hash_with_mode` as soon as a validation error would happen inside of the `NixHashWithMode` deserialization, e.g. invalid hash length would not provide an validation error but a silent `None` value. This is problematic, we workaround a serde limitation here by writing our own Deserializer. As you can see, we write some boilerplate code unfortunately, as, for example: - `#[serde(fail_if_unparsed_as="Option::is_none")]` is not a thing, otherwise, we could have been able to just bubble up errors in case of "not fully parsed" (and not missing) values. - `From<&serde_json::Value> for serde:🇩🇪:Unexpected` is not a thing, otherwise, we could just map invalid type errors and reuse the existing types instead of doing extremely bizarre things with `serde:🇩🇪:Unexpected::Other`, note: this is a not problem for expected, we know what we expect, we don't know what we received in practice. I decided to write a `NixHashWithMode::from_map` which will eat a map deserialized via `serde_json`, so our serde magic is not totally "data model" agnostic. I wanted to go for data model agnosticity and enable maximal performance, e.g. building the structure as the map values are streamed in the Visitor, this is needlessly painful because `Output` and `NixHashWithMode` are in different files and this really makes sense only if we write the full implementation in one file, indeed, otherwise, you end up duplicating the work or having strange coupling. So, for now, we will allocate a full map of the fields inside the `Output`, i.e. if any "unknown field" is in that map, we will deserialize it for no reason. Doing it properly, as I repeat it in the code and to flokli at C3Camp 2023, requires to patch serde upstream IMHO. Change-Id: I46fe6ccb8c390c48d6934fd3e3f02a0dfe59557b Reviewed-on: https://cl.tvl.fyi/c/depot/+/9107 Tested-by: BuildkiteCI Reviewed-by: flokli <flokli@flokli.de> |
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|---|---|---|
| .. | ||
| .vscode | ||
| cli | ||
| docs | ||
| eval | ||
| nix-compat | ||
| nix_cli | ||
| proto | ||
| serde | ||
| store | ||
| verify-lang-tests | ||
| website | ||
| .gitignore | ||
| Cargo.lock | ||
| Cargo.nix | ||
| Cargo.toml | ||
| crate-hashes.json | ||
| default.nix | ||
| LICENSE | ||
| OWNERS | ||
| README.md | ||
Tvix is a new implementation of the Nix language and package manager. See the announcement post for information about the background of this project.
Tvix is developed by TVL in our monorepo, the depot, at
//tvix. Code reviews take place on Gerrit, bugs are
filed in our issue tracker.
For more information about Tvix, feel free to reach out. We are interested in people who would like to help us review designs, brainstorm and describe requirements that we may not yet have considered.
Most of the discussion around development happens on our IRC channel, which you can join in several ways documented on tvl.fyi, or on our mailing list.
Contributions to Tvix follow the TVL review flow and contribution guidelines.
WARNING: Tvix is not ready for use in production. None of our current APIs should be considered stable in any way.
WARNING: Any other instances of this project or repository are
josh-mirrors. We do not accept code contributions or issues outside of
the tooling and communication methods outlined above.
Components
This folder contains the following components:
//tvix/eval- an implementation of the Nix programming language//tvix/nix-compat- library functions for compatibility with C++ Nix//tvix/cli- preliminary REPL & CLI implementation for Tvix//tvix/serde- Rust library for using the Nix language for app configuration//tvix/store- implementation of a file store for Tvix
Some additional folders with auxiliary things exist and can be explored at your leisure.
Building the CLI
The CLI can also be built with standard Rust tooling (i.e. cargo build),
as long as you are in a shell with the right dependencies.
- If you cloned the full monorepo, it can be provided by
mg shell //tvix:shell. - If you cloned the
tvixworkspace only (git clone https://code.tvl.fyi/depot.git:workspace=views/tvix.git),nix-shellprovides it.
If you're in the TVL monorepo, you can also run mg build //tvix/cli
(or mg build from inside that folder) for a more incremental build.
Please follow the depot-wide instructions on how to get mg and use the depot
tooling.
Compatibility
Important note: We only use and test Nix builds of our software against Nix 2.3. There are a variety of bugs and subtle problems in newer Nix versions which we do not have the bandwidth to address, builds in newer Nix versions may or may not work.
Rust projects, crate2nix
Some parts of Tvix are written in Rust. To simplify the dependency
management on the Nix side of these builds, we use crate2nix in a
single Rust workspace in //tvix to maintain the Nix build
configuration.
When making changes to Cargo dependency configuration in any of the
Rust projects under //tvix, be sure to run
mg run //tvix:crate2nixGenerate -- in //tvix itself and commit the changes
to the generated Cargo.nix file. This only applies to the full TVL checkout.
License structure
All code implemented for Tvix is licensed under the GPL-3.0, with the exception of the protocol buffer definitions used for communication between services which are available under a more permissive license (MIT).
The idea behind this structure is that any direct usage of our code (e.g. linking to it, embedding the evaluator, etc.) will fall under the terms of the GPL3, but users are free to implement their own components speaking these protocols under the terms of the MIT license.