tvl-depot/tvix/eval
Vincent Ambo 776120de05 fix(tvix/eval): instantiate *new* closures from blueprints each time
The previous closure refactoring introduced a bug in which the same
closure object would get mutated constantly for each instance of a
closure, which is incorrect behaviour.

This commit instead introduces an explicit new Value variant for the
internal "blueprint" that the compiler generates (essentially just the
lambda) and uses this variant to construct the closure at runtime.

If the blueprint ever leaks out to a user somehow that is a critical
bug and tvix-eval will panic.

As a ~treat~ test for this, the fibonacci function is being used as it
is a self-recursive closure (i.e. different instantiations of the same
"blueprint") getting called with different values and it's good to
have it around.

Change-Id: I485de675e9bb0c599ed7d5dc0f001eb34ab4c15f
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6323
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
2022-09-06 07:45:43 +00:00
..
benches test(tvix/eval): Add attr merge benchmarks 2022-09-03 06:56:02 +00:00
docs docs(tvix/eval): start a document on known optimisation potential 2022-09-06 07:29:25 +00:00
src fix(tvix/eval): instantiate *new* closures from blueprints each time 2022-09-06 07:45:43 +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 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): 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.