History

Griffin Smith 2592113435 fix(tvix/eval): Thunk `if` expr Since the body of an `if` expr can refer to deferred upvalues, it needs to be thunked so when we actually compile those deferred upvalues we have something for the finalize op to point at. Without this all sorts of weird things can happen due to the finalize op being run in the wrong lambda context, up to and including a panic. Change-Id: I040d5e1a7232fd841cfa4953539898fa49cbbb83 Reviewed-on: https://cl.tvl.fyi/c/depot/+/6929 Reviewed-by: sterni <sternenseemann@systemli.org> Reviewed-by: tazjin <tazjin@tvl.su> Autosubmit: grfn <grfn@gws.fyi> Tested-by: BuildkiteCI		2022-10-10 20:35:11 +00:00
..
benches	refactor(tvix/eval): use Clap for arg+env parsing	2022-09-18 22:08:43 +00:00
docs	docs(tvix/eval): start doc about problematic/weird lang behavior	2022-10-01 12:30:17 +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	fix(tvix/eval): Thunk `if` expr	2022-10-10 20:35:11 +00:00
tests	feat(tvix/eval): Allow adding strings to paths	2022-10-10 20:23:41 +00:00
.envrc	chore(tvix/eval): add simple .envrc / shell.nix	2022-09-17 17:31:08 +00:00
.gitignore	feat(tvix/eval): check in generated project skeleton	2022-08-12 12:34:29 +00:00
.skip-subtree	feat(tvix/tests): check in Nix' language test suite	2022-08-24 21:25:41 +00:00
Cargo.lock	fix(tvix/eval): support string identifiers in inherits	2022-09-22 23:07:14 +00:00
Cargo.toml	fix(tvix/eval): support string identifiers in inherits	2022-09-22 23:07:14 +00:00
default.nix	feat(tvix/eval): Add passthru build for benchmark binaries	2022-10-02 22:43:34 +00:00
README.md	docs(tvix/eval): remove the note on the private repo	2022-09-11 19:58:44 +00:00
shell.nix	chore(tvix/eval): add rustfmt to the shell	2022-09-18 23:19:54 +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).

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.