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](#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 <[email protected]>

Author: ntBre

Cargo.lock

@@ -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/Cargo.toml

@@ -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/src/python_version.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/tests/file_watching.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/combine.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.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/options.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_project/src/metadata/pyproject.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/db.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;