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This implements an initial fancy display for warnings emitted by the tvix compiler, using the codemap_diagnostic crate. Each warning variant has an associated message, and optionally an associated annotation for the span displayed to the user. In theory we could get a lot more fancy with the display for specific variants if needed (e.g. re-parse the AST and actually add multiple semantic spans based on context), but this is already a good start. Example: tvix-repl> let toString = https://tvl.fyi; in let inherit toString; in ({}: 42) rec {} warning[W004]: declared variable 'toString' shadows a built-in global! --> [tvix-repl]:1:5 | 1 | let toString = https://tvl.fyi; in let inherit toString; in ({}: 42) rec {} | ^^^^^^^^ variable declared here warning[W001]: URL literal syntax is deprecated, use a quoted string instead --> [tvix-repl]:1:16 | 1 | let toString = https://tvl.fyi; in let inherit toString; in ({}: 42) rec {} | ^^^^^^^^^^^^^^^ warning[W002]: inherited variable already exists with the same value --> [tvix-repl]:1:40 | 1 | let toString = https://tvl.fyi; in let inherit toString; in ({}: 42) rec {} | ^^^^^^^^^^^^^^^^^ warning[W999]: feature not yet implemented in tvix: recursive attribute sets --> [tvix-repl]:1:70 | 1 | let toString = https://tvl.fyi; in let inherit toString; in ({}: 42) rec {} | ^^^^^^ warning[W999]: feature not yet implemented in tvix: closed formals --> [tvix-repl]:1:62 | 1 | let toString = https://tvl.fyi; in let inherit toString; in ({}: 42) rec {} | ^^ warning[W003]: variable 'toString' is declared, but never used: --> [tvix-repl]:1:5 | 1 | let toString = https://tvl.fyi; in let inherit toString; in ({}: 42) rec {} | ^^^^^^^^ variable declared here => 42 :: int These are coloured when output to a terminal. Change-Id: If315648a07e333895db4ae1d0915ee2013806585 Reviewed-on: https://cl.tvl.fyi/c/depot/+/6532 Autosubmit: tazjin <tazjin@tvl.su> Reviewed-by: grfn <grfn@gws.fyi> Tested-by: BuildkiteCI |
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| .. | ||
| benches | ||
| docs | ||
| src | ||
| .gitignore | ||
| .skip-subtree | ||
| Cargo.lock | ||
| Cargo.toml | ||
| default.nix | ||
| 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.