History

Vincent Ambo f88d248f48 feat(tvix/eval): implement runtime closure construction (OpClosure) Implements the final bit of logic remaining for wiring up closures, which is the runtime construction of closure objects. When encountering an OpClosure, the VM walks through the bytecode collecting all the upvalue location operands (see commit introducing the OpCode::Data* variants for details) and stores the runtime values in the new closures upvalue vector. After that, the handling of the closure itself becomes functionally identical to that of lambdas. With this initial implementation of closures there are several large optimisation potentials available, the two most notable ones are: - Distinguish the runtime representation of lambdas and closures explicitly. - Detect and handle multiple-arity functions directly in the compiler. However, for both of these we should wait until we have appropriate benchmarking infrastructure in place. This is because our test implementations have shown that the complexity of either of these changes is quite significant, and we do not yet know if they really pay off. Change-Id: I077e977810fd5cb2b1ecd7f1a119e728025dd786 Reviewed-on: https://cl.tvl.fyi/c/depot/+/6295 Tested-by: BuildkiteCI Reviewed-by: grfn <grfn@gws.fyi>		2022-09-03 21:55:04 +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	feat(tvix/eval): implement runtime closure construction (OpClosure)	2022-09-03 21:55:04 +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

README.md

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.