refactor(semver): change ConstraintInterface to a closed enum

Replace the dyn ConstraintInterface trait objects with an AnyConstraint
enum closing over its four implementors (Simple, Multi, MatchAll,
MatchNone), mirroring the earlier Rule enum conversion. Rename
constraint.rs to simple_constraint.rs to match the renamed Constraint
type.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

1 files changed, 16 insertions, 9 deletions

diff --git a/crates/shirabe/src/package/version/version_parser.rs b/crates/shirabe/src/package/version/version_parser.rs
index 46a2356..1b588bc 100644
--- a/crates/shirabe/src/package/version/version_parser.rs
+++ b/crates/shirabe/src/package/version/version_parser.rs
@@ -1,16 +1,16 @@
 //! ref: composer/src/Composer/Package/Version/VersionParser.php
 
 use indexmap::IndexMap;
-use std::sync::{Arc, LazyLock, Mutex};
+use std::sync::{LazyLock, Mutex};
 
 use shirabe_external_packages::composer::pcre::Preg;
-use shirabe_semver::constraint::ConstraintInterface;
+use shirabe_semver::constraint::AnyConstraint;
 use shirabe_semver::semver::Semver;
 use shirabe_semver::version_parser::VersionParser as SemverVersionParser;
 
 use crate::repository::PlatformRepository;
 
-static CONSTRAINTS: LazyLock<Mutex<IndexMap<String, Arc<dyn ConstraintInterface + Send + Sync>>>> =
+static CONSTRAINTS: LazyLock<Mutex<IndexMap<String, AnyConstraint>>> =
     LazyLock::new(|| Mutex::new(IndexMap::new()));
 
 #[derive(Debug, Clone)]
@@ -21,12 +21,19 @@ pub struct VersionParser {
 impl VersionParser {
     pub const DEFAULT_BRANCH_ALIAS: &'static str = "9999999-dev";
 
-    pub fn parse_constraints(
-        &self,
-        constraints: &str,
-    ) -> anyhow::Result<Box<dyn ConstraintInterface>> {
-        // TODO(phase-b): re-introduce a memoization cache once trait objects are Send+Sync.
-        self.inner.parse_constraints(constraints)
+    pub fn parse_constraints(&self, constraints: &str) -> anyhow::Result<AnyConstraint> {
+        {
+            let cache = CONSTRAINTS.lock().unwrap();
+            if let Some(cached) = cache.get(constraints) {
+                return Ok(cached.clone());
+            }
+        }
+        let parsed = self.inner.parse_constraints(constraints)?;
+        CONSTRAINTS
+            .lock()
+            .unwrap()
+            .insert(constraints.to_string(), parsed.clone());
+        Ok(parsed)
     }
 
     pub fn parse_name_version_pairs(