History

Vincent Ambo d101151fc5 feat(tvix/eval): begin introducing new public API A step towards something more like how I imagine the future public API for tvix-eval. Please note that this is definitely not the final version yet, but it's better than the previous API that either exposed a side-effecting blackbox, or a very low-level "interface". The basic idea is that an evaluation of some Nix code is requested by a caller with various parameters, but not all callers are interested in all of these parameters. There are also some bits of information that are returned from an evaluation that are not necessarily relevant to all callers. To support this somewhat ergonomically, the API is built around an `Evaluation` struct that is configured by the caller with the various parameters and then "executed". Change-Id: I71826f3897126898adc2873d31c44d3eaf5c2be0 Reviewed-on: https://cl.tvl.fyi/c/depot/+/7542 Reviewed-by: grfn <grfn@gws.fyi> Autosubmit: tazjin <tazjin@tvl.su> Tested-by: BuildkiteCI		2022-12-21 13:09:27 +00:00
..
benches	refactor(tvix/eval): use Clap for arg+env parsing	2022-09-18 22:08:43 +00:00
builtin-macros	refactor(tvix): share a Cargo.lock file between Rust projects	2022-12-15 17:26:45 +00:00
docs	docs(tvix/eval): document abandoned thread-local vm	2022-11-08 08:41:04 +00:00
proptest-regressions/value	test(tvix/eval): Add tests for the Eq laws of Value	2022-09-18 17:57:09 +00:00
src	feat(tvix/eval): begin introducing new public API	2022-12-21 13:09:27 +00:00
tests	feat(tvix/eval): Allow adding strings to paths	2022-10-10 20:23:41 +00:00
.skip-subtree	feat(tvix/tests): check in Nix' language test suite	2022-08-24 21:25:41 +00:00
build.rs	feat(tvix/eval): implement builtins.currentSystem	2022-10-24 12:20:01 +00:00
Cargo.toml	refactor(tvix): share a Cargo.lock file between Rust projects	2022-12-15 17:26:45 +00:00
default.nix	refactor(tvix): build Rust projects using crate2nix	2022-12-15 17:26:45 +00:00
README.md	docs(tvix/eval): explain where to find the site-specific `mg` tool	2022-10-13 18:41:02 +00:00

README.md

Tvix Evaluator

This project implements an interpreter for the Nix programming language. You can experiment with an online version of the evaluator: tvixbolt.

The interpreter aims to be compatible with nixpkgs, on the foundation of Nix 2.3.

Important note: The evaluator is not yet feature-complete, and while the core mechanisms (compiler, runtime, ...) have stabilised somewhat, a lot of components are still changing rapidly.

Please contact TVL with any questions you might have.

Building the evaluator

If you are in a full checkout of the TVL depot, you can simply run mg build in this directory (or mg build //tvix/eval from anywhere in the repo). The mg command is found in /tools/magrathea.

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.

The evaluator can also be built with standard Rust tooling (i.e. cargo build).

If you would like to clone only the evaluator and build it directly with Rust tooling, you can do:

git clone https://code.tvl.fyi/depot.git:/tvix/eval.git tvix-eval

cd tvix-eval && cargo build

Nix test suite

C++ Nix implements a language test suite in the form of Nix source code files, and their expected output. The coverage of this test suite is not complete, but we intend to be compatible with it.

We have ported the test suite to Tvix, but do not run it by default as we are not yet compatible with it.

You can run the test suite by enabling the nix_tests feature in Cargo:

cargo test --features nix_tests

rnix-parser

Tvix is written in memory of jD91mZM2, the author of rnix-parser who sadly passed away.

Tvix makes heavy use of rnix-parser in its bytecode compiler. The parser is now maintained by Nix community members.