tvl-depot/tvix/eval
Vincent Ambo 3a2fcc8bc2 refactor(tvix/eval): avoid cloning in NixAttrs::update if possible
Refactors the update function to take the attribute sets by value
instead.

To facilitate this, we use an equivalent of the currently unstable
`Rc::clone_or_unwrap` in the VM when encountering attribute sets, so
that in cases where the only references to the attrs being updated are
the ones on the stack those clones are avoided completely.

This does make update() a little bit more tricky internally, as some
optimised branches can directly return the moved value, and others
need to destructure with ownership. For this reason there are now two
different match statements handling the different ownership cases.

Change-Id: Ia77d3ba5c86afb75b9f1f51758bda61729ba5aab
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6279
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-03 13:19:48 +00:00
..
benches test(tvix/eval): Add attr merge benchmarks 2022-09-03 06:56:02 +00:00
docs docs(tvix/eval): add an overview of all builtins in Nix 2022-09-02 12:59:23 +00:00
src refactor(tvix/eval): avoid cloning in NixAttrs::update if possible 2022-09-03 13:19:48 +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 test(tvix/eval): Add attr merge benchmarks 2022-09-03 06:56:02 +00:00
Cargo.toml test(tvix/eval): Add attr merge benchmarks 2022-09-03 06:56:02 +00:00
default.nix chore(tvix/eval): Build with --all-targets 2022-09-02 19:10:45 +00:00
README.md docs(tvix/eval): add a note on how to run Nix tests 2022-09-03 00:47:58 +00:00

Tvix Evaluator

This project implements an interpreter for the Nix programming language.

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

Work on this project is extremely in-progress, and the state of the project in the public repository may not necessarily reflect the state of the private codebase, as we are slowly working on publishing it.

We expect this to have caught up in a handful of weeks (as of 2022-08-12).

Please contact TVL with any questions you might have.

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.