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2024-10-18libexpr: move parser semantics into separate filepiegames
Another preparation for forking off and versioning the parser Change-Id: I7b1225a44a3b81486414c1d37bd3e76a3ab307f9
2024-10-18libexpr: rename grammar to grammar::v1piegames
Let's make some space in the namespace for a v2 https://wiki.lix.systems/books/lix-contributors/page/nix-lang-v2 Change-Id: If56e6dbf680d931233aa822ef91c8832464471e4
2024-08-21libexpr: Soft-deprecate ancient let syntaxpiegames
Change-Id: I6802b26f038578870ea1fa1ed298f0c4b1f29c4a
2024-08-21libexpr: Soft-deprecate __overridespiegames
Change-Id: I787e69e1dad6edc5ccdb747b74a9ccd6e8e13bb3
2024-08-17libexpr: Deprecate URL literalspiegames
Closes #437. Change-Id: I9f67fc965bb4a7e7fd849e5067ac1cb3bab064cd
2024-08-17libexpr: Introduce Deprecated featurespiegames
They are like experimental features, but opt-in instead of opt-out. They will allow us to gracefully remove language features. See #437 Change-Id: I9ca04cc48e6926750c4d622c2b229b25cc142c42
2024-08-08libexpr: Add experimental pipe operatorpiegames
The |> operator is a reverse function operator with low binding strength to replace lib.pipe. Implements RFC 148, see the RFC text for more details. Closes #438. Change-Id: I21df66e8014e0d4dd9753dd038560a2b0b7fd805
2024-08-07libexpr/parser: Test experimental featurespiegames
Currently, the parser relies on the global experimental feature flags. In order to properly test conditional language features, we instead need to pass it around in the parser::State. This means that the parser cannot cache the result of isEnabled anymore, which wouldn't necessarily hurt performance if the function didn't perform a linear search on the list of enabled features on every single call. While we could simply evaluate once at the start of parsing and cache the result in the parser state, the more sustainable solution would be to fix `isEnabled` such that all callers may profit from the performance improvement. Change-Id: Ic9b9c5d882b6270e1114988b63e6064d36c25cf2
2024-08-04tree-wide: fix various lint warningsJade Lovelace
Change-Id: I0fc80718eb7e02d84cc4b5d5deec4c0f41116134
2024-07-22libexpr: fix -Wunused-const-variable warningeldritch horrors
Change-Id: Ib986ece0ab2eff83e7abd7f1f915cd8f761827ad
2024-07-04give ExprInheritFrom a handle to what its standing in forQyriad
Change-Id: I12088e0b618407e5432523bbc97be63c8d6fce62
2024-06-25libexpr: rewrite the parser with pegtl instead of flex/bisoneldritch horrors
this gives about 20% performance improvements on pure parsing. obviously it will be less on full eval, but depending on how much parsing is to be done (e.g. including hackage-packages.nix or not) it's more like 4%-10%. this has been tested (with thousands of core hours of fuzzing) to ensure that the ASTs produced by the new parser are exactly the same as the old one would have produced. error messages will change (sometimes by a lot) and are not yet perfect, but we would rather leave this as is for later. test results for running only the parser (excluding the variable binding code) in a tight loop with inputs and parameters as given are promising: - 40% faster on lix's package.nix at 10000 iterations - 1.3% faster on nixpkgs all-packages.nix at 1000 iterations - equivalent on all of nixpkgs concatenated at 100 iterations (excluding invalid files, each file surrounded with parens) more realistic benchmarks are somewhere in between the extremes, parsing once again getting the largest uplift. other realistic workloads improve by a few percentage points as well, notably system builds are 4% faster. Benchmarks summary (from ./bench/summarize.jq bench/bench-*.json) old/bin/nix --extra-experimental-features 'nix-command flakes' eval -f bench/nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix mean: 0.408s ± 0.025s user: 0.355s | system: 0.033s median: 0.389s range: 0.388s ... 0.442s relative: 1 new/bin/nix --extra-experimental-features 'nix-command flakes' eval -f bench/nixpkgs/pkgs/development/haskell-modules/hackage-packages.nix mean: 0.332s ± 0.024s user: 0.279s | system: 0.033s median: 0.314s range: 0.313s ... 0.361s relative: 0.814 --- old/bin/nix --extra-experimental-features 'nix-command flakes' eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' mean: 6.133s ± 0.022s user: 5.395s | system: 0.437s median: 6.128s range: 6.099s ... 6.183s relative: 1 new/bin/nix --extra-experimental-features 'nix-command flakes' eval --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' mean: 5.925s ± 0.025s user: 5.176s | system: 0.456s median: 5.934s range: 5.861s ... 5.943s relative: 0.966 --- GC_INITIAL_HEAP_SIZE=10g old/bin/nix eval --extra-experimental-features 'nix-command flakes' --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' mean: 4.503s ± 0.027s user: 3.731s | system: 0.547s median: 4.499s range: 4.478s ... 4.541s relative: 1 GC_INITIAL_HEAP_SIZE=10g new/bin/nix eval --extra-experimental-features 'nix-command flakes' --raw --impure --expr 'with import <nixpkgs/nixos> {}; system' mean: 4.285s ± 0.031s user: 3.504s | system: 0.571s median: 4.281s range: 4.221s ... 4.328s relative: 0.951 --- old/bin/nix --extra-experimental-features 'nix-command flakes' search --no-eval-cache github:nixos/nixpkgs/e1fa12d4f6c6fe19ccb59cac54b5b3f25e160870 hello mean: 16.475s ± 0.07s user: 14.088s | system: 1.572s median: 16.495s range: 16.351s ... 16.536s relative: 1 new/bin/nix --extra-experimental-features 'nix-command flakes' search --no-eval-cache github:nixos/nixpkgs/e1fa12d4f6c6fe19ccb59cac54b5b3f25e160870 hello mean: 15.973s ± 0.013s user: 13.558s | system: 1.615s median: 15.973s range: 15.946s ... 15.99s relative: 0.97 --- Change-Id: Ie66ec2d045dec964632c6541e25f8f0797319ee2