History

sterni 067f2b16f6 feat(tvix/eval): implement Value::coerce_to_path() This function is necessary for all builtins that expect some form of path as an argument. It is merely a wrapper around coerce_to_string that can shortcut if we already have a path. The absolute path check is done in the same way as in C++ Nix for compatibility, although it should probably be revised in the long term (think about Windows, for example). Since coercing to a path is not an operation possible in the language directly, this function can live in the builtins module as the only place it is required. Change-Id: I69ed5455c00d193fea88b8fa83e28907a761cab5 Reviewed-on: https://cl.tvl.fyi/c/depot/+/6574 Autosubmit: sterni <sternenseemann@systemli.org> Reviewed-by: tazjin <tazjin@tvl.su> Tested-by: BuildkiteCI		2022-09-15 20:58:00 +00:00
..
benches	test(tvix/eval): Add attr merge benchmarks	2022-09-03 06:56:02 +00:00
docs	docs(tvix/eval): propose builtin "inlining" optimisation	2022-09-11 20:02:46 +00:00
src	feat(tvix/eval): implement Value::coerce_to_path()	2022-09-15 20:58:00 +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	chore(tvix/eval): add dependency on codemap-diagnostic	2022-09-13 10:54:14 +00:00
Cargo.toml	chore(tvix/eval): add dependency on codemap-diagnostic	2022-09-13 10:54:14 +00:00
default.nix	fix(tvix/eval): don't rebuild drv upon changes in cargo target dir	2022-09-04 21:02:50 +00:00
README.md	docs(tvix/eval): remove the note on the private repo	2022-09-11 19:58:44 +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.