Move red_knot_python_semantic::PythonVersion to the ruff_python_ast crate (#16147)

## Summary

This PR moves the `PythonVersion` struct from the
`red_knot_python_semantic` crate to the `ruff_python_ast` crate so that
it can be used more easily in the syntax error detection work. Compared
to that [prototype](https://github.com/astral-sh/ruff/pull/16090/) these
changes reduce us from 2 `PythonVersion` structs to 1.

This does not unify any of the `PythonVersion` *enums*, but I hope to
make some progress on that in a follow-up.

## Test Plan

Existing tests, this should not change any external behavior.

---------

Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>

Cargo.lock

@@ -2414,6 +2414,7 @@ dependencies = [
  "red_knot_server",
  "regex",
  "ruff_db",
+ "ruff_python_ast",
  "ruff_python_trivia",
  "salsa",
  "tempfile",
@@ -2563,9 +2564,9 @@ dependencies = [
  "js-sys",
  "log",
  "red_knot_project",
- "red_knot_python_semantic",
  "ruff_db",
  "ruff_notebook",
+ "ruff_python_ast",
  "wasm-bindgen",
  "wasm-bindgen-test",
 ]
@@ -2726,7 +2727,6 @@ dependencies = [
  "mimalloc",
  "rayon",
  "red_knot_project",
- "red_knot_python_semantic",
  "ruff_db",
  "ruff_linter",
  "ruff_python_ast",

crates/red_knot/Cargo.toml

@@ -16,6 +16,7 @@ red_knot_python_semantic = { workspace = true }
 red_knot_project = { workspace = true, features = ["zstd"] }
 red_knot_server = { workspace = true }
 ruff_db = { workspace = true, features = ["os", "cache"] }
+ruff_python_ast = { workspace = true }
 
 anyhow = { workspace = true }
 chrono = { workspace = true }

crates/red_knot/src/python_version.rs

@@ -40,7 +40,7 @@ impl std::fmt::Display for PythonVersion {
     }
 }
 
-impl From<PythonVersion> for red_knot_python_semantic::PythonVersion {
+impl From<PythonVersion> for ruff_python_ast::python_version::PythonVersion {
     fn from(value: PythonVersion) -> Self {
         match value {
             PythonVersion::Py37 => Self::PY37,
@@ -61,8 +61,8 @@ mod tests {
     #[test]
     fn same_default_as_python_version() {
         assert_eq!(
-            red_knot_python_semantic::PythonVersion::from(PythonVersion::default()),
-            red_knot_python_semantic::PythonVersion::default()
+            ruff_python_ast::python_version::PythonVersion::from(PythonVersion::default()),
+            ruff_python_ast::python_version::PythonVersion::default()
         );
     }
 }

crates/red_knot/tests/file_watching.rs

@@ -9,13 +9,14 @@ use red_knot_project::metadata::pyproject::{PyProject, Tool};
 use red_knot_project::metadata::value::{RangedValue, RelativePathBuf};
 use red_knot_project::watch::{directory_watcher, ChangeEvent, ProjectWatcher};
 use red_knot_project::{Db, ProjectDatabase, ProjectMetadata};
-use red_knot_python_semantic::{resolve_module, ModuleName, PythonPlatform, PythonVersion};
+use red_knot_python_semantic::{resolve_module, ModuleName, PythonPlatform};
 use ruff_db::files::{system_path_to_file, File, FileError};
 use ruff_db::source::source_text;
 use ruff_db::system::{
     OsSystem, System, SystemPath, SystemPathBuf, UserConfigDirectoryOverrideGuard,
 };
 use ruff_db::Upcast;
+use ruff_python_ast::python_version::PythonVersion;
 
 struct TestCase {
     db: ProjectDatabase,

crates/red_knot_project/src/combine.rs

@@ -1,7 +1,8 @@
 use std::{collections::HashMap, hash::BuildHasher};
 
-use red_knot_python_semantic::{PythonPlatform, PythonVersion, SitePackages};
+use red_knot_python_semantic::{PythonPlatform, SitePackages};
 use ruff_db::system::SystemPathBuf;
+use ruff_python_ast::python_version::PythonVersion;
 
 /// Combine two values, preferring the values in `self`.
 ///

crates/red_knot_project/src/metadata.rs

@@ -309,8 +309,8 @@ mod tests {
 
     use anyhow::{anyhow, Context};
     use insta::assert_ron_snapshot;
-    use red_knot_python_semantic::PythonVersion;
     use ruff_db::system::{SystemPathBuf, TestSystem};
+    use ruff_python_ast::python_version::PythonVersion;
 
     use crate::{ProjectDiscoveryError, ProjectMetadata};
 

crates/red_knot_project/src/metadata/options.rs

@@ -1,13 +1,12 @@
 use crate::metadata::value::{RangedValue, RelativePathBuf, ValueSource, ValueSourceGuard};
 use crate::Db;
 use red_knot_python_semantic::lint::{GetLintError, Level, LintSource, RuleSelection};
-use red_knot_python_semantic::{
-    ProgramSettings, PythonPlatform, PythonVersion, SearchPathSettings, SitePackages,
-};
+use red_knot_python_semantic::{ProgramSettings, PythonPlatform, SearchPathSettings, SitePackages};
 use ruff_db::diagnostic::{Diagnostic, DiagnosticId, Severity, Span};
 use ruff_db::files::system_path_to_file;
 use ruff_db::system::{System, SystemPath};
 use ruff_macros::Combine;
+use ruff_python_ast::python_version::PythonVersion;
 use rustc_hash::FxHashMap;
 use serde::{Deserialize, Serialize};
 use std::borrow::Cow;

crates/red_knot_project/src/metadata/pyproject.rs

@@ -1,7 +1,7 @@
 use crate::metadata::options::Options;
 use crate::metadata::value::{RangedValue, ValueSource, ValueSourceGuard};
 use pep440_rs::{release_specifiers_to_ranges, Version, VersionSpecifiers};
-use red_knot_python_semantic::PythonVersion;
+use ruff_python_ast::python_version::PythonVersion;
 use serde::{Deserialize, Deserializer, Serialize};
 use std::collections::Bound;
 use std::ops::Deref;

crates/red_knot_python_semantic/src/db.rs

@@ -19,7 +19,6 @@ pub(crate) mod tests {
     use std::sync::Arc;
 
     use crate::program::{Program, SearchPathSettings};
-    use crate::python_version::PythonVersion;
     use crate::{default_lint_registry, ProgramSettings, PythonPlatform};
 
     use super::Db;
@@ -29,6 +28,7 @@ pub(crate) mod tests {
     use ruff_db::system::{DbWithTestSystem, System, SystemPathBuf, TestSystem};
     use ruff_db::vendored::VendoredFileSystem;
     use ruff_db::{Db as SourceDb, Upcast};
+    use ruff_python_ast::python_version::PythonVersion;
 
     #[salsa::db]
     #[derive(Clone)]

crates/red_knot_python_semantic/src/lib.rs

@@ -9,7 +9,6 @@ pub use module_name::ModuleName;
 pub use module_resolver::{resolve_module, system_module_search_paths, KnownModule, Module};
 pub use program::{Program, ProgramSettings, SearchPathSettings, SitePackages};
 pub use python_platform::PythonPlatform;
-pub use python_version::PythonVersion;
 pub use semantic_model::{HasType, SemanticModel};
 
 pub mod ast_node_ref;
@@ -20,7 +19,6 @@ mod module_resolver;
 mod node_key;
 mod program;
 mod python_platform;
-mod python_version;
 pub mod semantic_index;
 mod semantic_model;
 pub(crate) mod site_packages;

crates/red_knot_python_semantic/src/module_resolver/path.rs

@@ -631,10 +631,10 @@ impl PartialEq<SearchPath> for VendoredPathBuf {
 #[cfg(test)]
 mod tests {
     use ruff_db::Db;
+    use ruff_python_ast::python_version::PythonVersion;
 
     use crate::db::tests::TestDb;
     use crate::module_resolver::testing::{FileSpec, MockedTypeshed, TestCase, TestCaseBuilder};
-    use crate::python_version::PythonVersion;
 
     use super::*;
 

crates/red_knot_python_semantic/src/module_resolver/resolver.rs

@@ -6,12 +6,13 @@ use rustc_hash::{FxBuildHasher, FxHashSet};
 use ruff_db::files::{File, FilePath, FileRootKind};
 use ruff_db::system::{DirectoryEntry, System, SystemPath, SystemPathBuf};
 use ruff_db::vendored::{VendoredFileSystem, VendoredPath};
+use ruff_python_ast::python_version::PythonVersion;
 
 use crate::db::Db;
 use crate::module_name::ModuleName;
 use crate::module_resolver::typeshed::{vendored_typeshed_versions, TypeshedVersions};
 use crate::site_packages::VirtualEnvironment;
-use crate::{Program, PythonVersion, SearchPathSettings, SitePackages};
+use crate::{Program, SearchPathSettings, SitePackages};
 
 use super::module::{Module, ModuleKind};
 use super::path::{ModulePath, SearchPath, SearchPathValidationError};
@@ -724,12 +725,12 @@ mod tests {
         assert_const_function_query_was_not_run, assert_function_query_was_not_run,
     };
     use ruff_db::Db;
+    use ruff_python_ast::python_version::PythonVersion;
 
     use crate::db::tests::TestDb;
     use crate::module_name::ModuleName;
     use crate::module_resolver::module::ModuleKind;
     use crate::module_resolver::testing::{FileSpec, MockedTypeshed, TestCase, TestCaseBuilder};
-    use crate::PythonVersion;
     use crate::{ProgramSettings, PythonPlatform};
 
     use super::*;

crates/red_knot_python_semantic/src/module_resolver/testing.rs

@@ -1,9 +1,9 @@
 use ruff_db::system::{DbWithTestSystem, SystemPath, SystemPathBuf};
 use ruff_db::vendored::VendoredPathBuf;
+use ruff_python_ast::python_version::PythonVersion;
 
 use crate::db::tests::TestDb;
 use crate::program::{Program, SearchPathSettings};
-use crate::python_version::PythonVersion;
 use crate::{ProgramSettings, PythonPlatform, SitePackages};
 
 /// A test case for the module resolver.

crates/red_knot_python_semantic/src/module_resolver/typeshed.rs

@@ -4,11 +4,12 @@ use std::num::{NonZeroU16, NonZeroUsize};
 use std::ops::{RangeFrom, RangeInclusive};
 use std::str::FromStr;
 
+use ruff_python_ast::python_version::PythonVersion;
 use rustc_hash::FxHashMap;
 
 use crate::db::Db;
 use crate::module_name::ModuleName;
-use crate::{Program, PythonVersion};
+use crate::Program;
 
 pub(in crate::module_resolver) fn vendored_typeshed_versions(db: &dyn Db) -> TypeshedVersions {
     TypeshedVersions::from_str(
@@ -278,12 +279,12 @@ impl FromStr for PyVersionRange {
         let mut parts = s.split('-').map(str::trim);
         match (parts.next(), parts.next(), parts.next()) {
             (Some(lower), Some(""), None) => {
-                let lower = PythonVersion::from_versions_file_string(lower)?;
+                let lower = python_version_from_versions_file_string(lower)?;
                 Ok(Self::AvailableFrom(lower..))
             }
             (Some(lower), Some(upper), None) => {
-                let lower = PythonVersion::from_versions_file_string(lower)?;
-                let upper = PythonVersion::from_versions_file_string(upper)?;
+                let lower = python_version_from_versions_file_string(lower)?;
+                let upper = python_version_from_versions_file_string(upper)?;
                 Ok(Self::AvailableWithin(lower..=upper))
             }
             _ => Err(TypeshedVersionsParseErrorKind::UnexpectedNumberOfHyphens),
@@ -302,21 +303,21 @@ impl fmt::Display for PyVersionRange {
     }
 }
 
-impl PythonVersion {
-    fn from_versions_file_string(s: &str) -> Result<Self, TypeshedVersionsParseErrorKind> {
-        let mut parts = s.split('.').map(str::trim);
-        let (Some(major), Some(minor), None) = (parts.next(), parts.next(), parts.next()) else {
-            return Err(TypeshedVersionsParseErrorKind::UnexpectedNumberOfPeriods(
-                s.to_string(),
-            ));
-        };
-        PythonVersion::try_from((major, minor)).map_err(|int_parse_error| {
-            TypeshedVersionsParseErrorKind::IntegerParsingFailure {
-                version: s.to_string(),
-                err: int_parse_error,
-            }
-        })
-    }
+fn python_version_from_versions_file_string(
+    s: &str,
+) -> Result<PythonVersion, TypeshedVersionsParseErrorKind> {
+    let mut parts = s.split('.').map(str::trim);
+    let (Some(major), Some(minor), None) = (parts.next(), parts.next(), parts.next()) else {
+        return Err(TypeshedVersionsParseErrorKind::UnexpectedNumberOfPeriods(
+            s.to_string(),
+        ));
+    };
+    PythonVersion::try_from((major, minor)).map_err(|int_parse_error| {
+        TypeshedVersionsParseErrorKind::IntegerParsingFailure {
+            version: s.to_string(),
+            err: int_parse_error,
+        }
+    })
 }
 
 #[cfg(test)]

crates/red_knot_python_semantic/src/program.rs

@@ -1,10 +1,10 @@
 use crate::module_resolver::SearchPaths;
 use crate::python_platform::PythonPlatform;
-use crate::python_version::PythonVersion;
 use crate::Db;
 
 use anyhow::Context;
 use ruff_db::system::{SystemPath, SystemPathBuf};
+use ruff_python_ast::python_version::PythonVersion;
 use salsa::Durability;
 use salsa::Setter;
 

crates/red_knot_python_semantic/src/site_packages.rs

@@ -14,8 +14,7 @@ use std::num::NonZeroUsize;
 use std::ops::Deref;
 
 use ruff_db::system::{System, SystemPath, SystemPathBuf};
-
-use crate::PythonVersion;
+use ruff_python_ast::python_version::PythonVersion;
 
 type SitePackagesDiscoveryResult<T> = Result<T, SitePackagesDiscoveryError>;
 

crates/red_knot_python_semantic/src/types.rs

@@ -8,6 +8,7 @@ use itertools::Itertools;
 use ruff_db::diagnostic::Severity;
 use ruff_db::files::File;
 use ruff_python_ast as ast;
+use ruff_python_ast::python_version::PythonVersion;
 use type_ordering::union_elements_ordering;
 
 pub(crate) use self::builder::{IntersectionBuilder, UnionBuilder};
@@ -43,7 +44,7 @@ use crate::types::diagnostic::INVALID_TYPE_FORM;
 use crate::types::infer::infer_unpack_types;
 use crate::types::mro::{Mro, MroError, MroIterator};
 use crate::types::narrow::narrowing_constraint;
-use crate::{Db, FxOrderSet, Module, Program, PythonVersion};
+use crate::{Db, FxOrderSet, Module, Program};
 
 mod builder;
 mod call;
@@ -4949,12 +4950,12 @@ pub(crate) mod tests {
     use super::*;
     use crate::db::tests::{setup_db, TestDbBuilder};
     use crate::stdlib::typing_symbol;
-    use crate::PythonVersion;
     use ruff_db::files::system_path_to_file;
     use ruff_db::parsed::parsed_module;
     use ruff_db::system::DbWithTestSystem;
     use ruff_db::testing::assert_function_query_was_not_run;
     use ruff_python_ast as ast;
+    use ruff_python_ast::python_version::PythonVersion;
     use test_case::test_case;
 
     /// Explicitly test for Python version <3.13 and >=3.13, to ensure that

crates/red_knot_test/src/config.rs

@@ -9,7 +9,8 @@
 //! ```
 
 use anyhow::Context;
-use red_knot_python_semantic::{PythonPlatform, PythonVersion};
+use red_knot_python_semantic::PythonPlatform;
+use ruff_python_ast::python_version::PythonVersion;
 use serde::Deserialize;
 
 #[derive(Deserialize, Debug, Default, Clone)]

crates/red_knot_test/src/db.rs

@@ -3,12 +3,13 @@ use std::sync::Arc;
 use red_knot_python_semantic::lint::{LintRegistry, RuleSelection};
 use red_knot_python_semantic::{
     default_lint_registry, Db as SemanticDb, Program, ProgramSettings, PythonPlatform,
-    PythonVersion, SearchPathSettings,
+    SearchPathSettings,
 };
 use ruff_db::files::{File, Files};
 use ruff_db::system::{DbWithTestSystem, System, SystemPath, SystemPathBuf, TestSystem};
 use ruff_db::vendored::VendoredFileSystem;
 use ruff_db::{Db as SourceDb, Upcast};
+use ruff_python_ast::python_version::PythonVersion;
 
 #[salsa::db]
 #[derive(Clone)]

crates/red_knot_wasm/Cargo.toml

@@ -19,10 +19,10 @@ doctest = false
 default = ["console_error_panic_hook"]
 
 [dependencies]
-red_knot_python_semantic = { workspace = true }
 red_knot_project = { workspace = true, default-features = false, features = ["deflate"] }
 
 ruff_db = { workspace = true, default-features = false, features = [] }
+ruff_python_ast = { workspace = true }
 ruff_notebook = { workspace = true }
 
 console_error_panic_hook = { workspace = true, optional = true }

crates/red_knot_wasm/src/lib.rs

@@ -198,7 +198,7 @@ pub enum PythonVersion {
     Py313,
 }
 
-impl From<PythonVersion> for red_knot_python_semantic::PythonVersion {
+impl From<PythonVersion> for ruff_python_ast::python_version::PythonVersion {
     fn from(value: PythonVersion) -> Self {
         match value {
             PythonVersion::Py37 => Self::PY37,
@@ -308,8 +308,8 @@ mod tests {
     #[test]
     fn same_default_as_python_version() {
         assert_eq!(
-            red_knot_python_semantic::PythonVersion::from(PythonVersion::default()),
-            red_knot_python_semantic::PythonVersion::default()
+            ruff_python_ast::python_version::PythonVersion::from(PythonVersion::default()),
+            ruff_python_ast::python_version::PythonVersion::default()
         );
     }
 }

crates/ruff_benchmark/Cargo.toml

@@ -49,7 +49,6 @@ ruff_python_ast = { workspace = true }
 ruff_python_formatter = { workspace = true }
 ruff_python_parser = { workspace = true }
 ruff_python_trivia = { workspace = true }
-red_knot_python_semantic = { workspace = true }
 red_knot_project = { workspace = true }
 
 [lints]

crates/ruff_benchmark/benches/red_knot.rs

@@ -8,13 +8,13 @@ use red_knot_project::metadata::options::{EnvironmentOptions, Options};
 use red_knot_project::metadata::value::RangedValue;
 use red_knot_project::watch::{ChangeEvent, ChangedKind};
 use red_knot_project::{Db, ProjectDatabase, ProjectMetadata};
-use red_knot_python_semantic::PythonVersion;
 use ruff_benchmark::criterion::{criterion_group, criterion_main, BatchSize, Criterion};
 use ruff_benchmark::TestFile;
 use ruff_db::diagnostic::{Diagnostic, DiagnosticId, Severity};
 use ruff_db::files::{system_path_to_file, File};
 use ruff_db::source::source_text;
 use ruff_db::system::{MemoryFileSystem, SystemPath, SystemPathBuf, TestSystem};
+use ruff_python_ast::python_version::PythonVersion;
 use rustc_hash::FxHashSet;
 
 struct Case {

crates/ruff_graph/src/db.rs

@@ -4,13 +4,13 @@ use zip::CompressionMethod;
 
 use red_knot_python_semantic::lint::{LintRegistry, RuleSelection};
 use red_knot_python_semantic::{
-    default_lint_registry, Db, Program, ProgramSettings, PythonPlatform, PythonVersion,
-    SearchPathSettings,
+    default_lint_registry, Db, Program, ProgramSettings, PythonPlatform, SearchPathSettings,
 };
 use ruff_db::files::{File, Files};
 use ruff_db::system::{OsSystem, System, SystemPathBuf};
 use ruff_db::vendored::{VendoredFileSystem, VendoredFileSystemBuilder};
 use ruff_db::{Db as SourceDb, Upcast};
+use ruff_python_ast::python_version::PythonVersion;
 
 static EMPTY_VENDORED: std::sync::LazyLock<VendoredFileSystem> = std::sync::LazyLock::new(|| {
     let mut builder = VendoredFileSystemBuilder::new(CompressionMethod::Stored);

crates/ruff_python_ast/src/lib.rs

@@ -19,6 +19,7 @@ mod node;
 mod nodes;
 pub mod operator_precedence;
 pub mod parenthesize;
+pub mod python_version;
 pub mod relocate;
 pub mod script;
 pub mod statement_visitor;

crates/ruff_python_ast/src/python_version.rs

@@ -2,8 +2,7 @@ use std::fmt;
 
 /// Representation of a Python version.
 ///
-/// Unlike the `TargetVersion` enums in the CLI crates,
-/// this does not necessarily represent a Python version that we actually support.
+/// N.B. This does not necessarily represent a Python version that we actually support.
 #[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
 pub struct PythonVersion {
     pub major: u8,
@@ -41,8 +40,7 @@ impl PythonVersion {
             PythonVersion::PY312,
             PythonVersion::PY313,
         ]
-        .iter()
-        .copied()
+        .into_iter()
     }
 
     pub fn free_threaded_build_available(self) -> bool {
@@ -84,7 +82,7 @@ impl fmt::Display for PythonVersion {
 
 #[cfg(feature = "serde")]
 mod serde {
-    use crate::PythonVersion;
+    use super::PythonVersion;
 
     impl<'de> serde::Deserialize<'de> for PythonVersion {
         fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>

fuzz/fuzz_targets/red_knot_check_invalid_syntax.rs

@@ -11,12 +11,13 @@ use red_knot_python_semantic::lint::LintRegistry;
 use red_knot_python_semantic::types::check_types;
 use red_knot_python_semantic::{
     default_lint_registry, lint::RuleSelection, Db as SemanticDb, Program, ProgramSettings,
-    PythonPlatform, PythonVersion, SearchPathSettings,
+    PythonPlatform, SearchPathSettings,
 };
 use ruff_db::files::{system_path_to_file, File, Files};
 use ruff_db::system::{DbWithTestSystem, System, SystemPathBuf, TestSystem};
 use ruff_db::vendored::VendoredFileSystem;
 use ruff_db::{Db as SourceDb, Upcast};
+use ruff_python_ast::python_version::PythonVersion;
 use ruff_python_parser::{parse_unchecked, Mode};
 
 /// Database that can be used for testing.