feat(scan): model Rust impl scopes and call forms

docs/architecture/language-support.md

@@ -14,7 +14,7 @@ contracts and fixtures reach the same standard.
 | Language | Useful current coverage | Important gaps | Tier |
 | --- | --- | --- | --- |
 | Dart | Classes, mixins, enums, extensions, methods, named constructors, accessors, import/export/part directives, `extends`/`with`/`implements`/`on`, and ordinary calls | operators, generic relationship targets, conditional directives, and multiline declarations | first-class target |
-| Rust | Structs, enums, traits, ordinary/async/const/unsafe/extern functions, simple `use`, calls, and raw-string masking | impl/module ownership, unions/type aliases, macros, turbofish calls, and braced/glob imports | first-class target |
+| Rust | Structs, enums, traits, ordinary/async/const/unsafe/extern functions, simple inherent/trait impl ownership, ordinary/turbofish/macro calls, braced `use` resolution, and raw-string masking | module ownership, unions/type aliases, nested generic impl headers, glob imports, and macro definitions | first-class target |
 | C | Files, basic includes, structs, and narrow function forms through the shared C/C++ profile | distinct C identity, enums/typedefs/function pointers, multiline declarations, macros, and declaration masking | first-class target |
 | C++ | Basic classes/structs, narrow function forms, calls, and local include resolution | templates, constructors/destructors/operators, multiple inheritance, namespaces, overloads, lambdas, qualifiers, and multiline declarations | first-class target |
 | JavaScript | Named functions, simple classes/extends, ES imports, and call-shaped expressions | methods, arrows/function expressions, CommonJS, dynamic imports, re-exports, decorators, and template literals | first-class target |

src/scan.rs

@@ -279,6 +279,23 @@ impl ScanState {
                 }
             }
 
+            if let Some(pattern) = patterns.enclosing_scope.as_ref()
+                && let Some(name) = pattern
+                    .captures(line)
+                    .and_then(|captures| captures.name("name"))
+                && let Some(id) = self
+                    .symbols_by_name
+                    .get(&(language.into(), name.as_str().into()))
+                    .and_then(|ids| (ids.len() == 1).then(|| ids[0].clone()))
+                && self.node_kind(&id) == Some(NodeKind::Class)
+            {
+                scopes.push(Scope {
+                    id,
+                    indent,
+                    brace_depth: brace_depth + 1,
+                });
+            }
+
             if let Some(captures) = patterns.class.captures(line)
                 && let Some(name) = captures.name("name")
             {
@@ -365,7 +382,7 @@ impl ScanState {
                 if let Some(target) = captures.name("name").or_else(|| captures.name("name2")) {
                     self.pending.push(PendingRelationship {
                         source: file_id.into(),
-                        target_name: clean_target(target.as_str()),
+                        target_name: clean_import_target(target.as_str(), language),
                         kind: EdgeKind::Imports,
                         language: language.into(),
                         member_call: false,
@@ -376,7 +393,11 @@ impl ScanState {
                 }
             }
 
-            for captures in patterns.call.captures_iter(&call_line) {
+            for captures in patterns
+                .call
+                .iter()
+                .flat_map(|pattern| pattern.captures_iter(&call_line))
+            {
                 let Some(target_match) = captures.name("name") else {
                     continue;
                 };
@@ -602,8 +623,9 @@ struct Patterns {
     class: Regex,
     function: Vec<Regex>,
     import: Regex,
-    call: Regex,
+    call: Vec<Regex>,
     relationships: Option<Regex>,
+    enclosing_scope: Option<Regex>,
 }
 
 impl Patterns {
@@ -651,6 +673,13 @@ impl Patterns {
                 None,
             ),
         };
+        let mut calls = vec![r"(?P<name>[A-Za-z_]\w*(?:::\w+)*)\s*\("];
+        if language == "rust" {
+            calls.extend([
+                r"(?P<name>[A-Za-z_]\w*(?:::\w+)*)\s*::\s*<[^>]+>\s*\(",
+                r"(?P<name>[A-Za-z_]\w*(?:::\w+)*)!\s*\(",
+            ]);
+        }
         Self {
             class: Regex::new(class).expect("class regex is static"),
             function: functions
@@ -658,10 +687,18 @@ impl Patterns {
                 .map(|pattern| Regex::new(pattern).expect("function regex is static"))
                 .collect(),
             import: Regex::new(import).expect("import regex is static"),
-            call: Regex::new(r"(?P<name>[A-Za-z_]\w*(?:::\w+)*)\s*\(")
-                .expect("call regex is static"),
+            call: calls
+                .into_iter()
+                .map(|pattern| Regex::new(pattern).expect("call regex is static"))
+                .collect(),
             relationships: relationships
                 .map(|pattern| Regex::new(pattern).expect("relationship regex is static")),
+            enclosing_scope: (language == "rust").then(|| {
+                Regex::new(
+                    r"^\s*impl(?:<[^>]*>)?\s+(?:(?:[A-Za-z_]\w*(?:::\w+)*)\s+for\s+)?(?P<name>[A-Za-z_]\w*)",
+                )
+                .expect("scope regex is static")
+            }),
         }
     }
 }
@@ -748,6 +785,15 @@ fn clean_target(value: &str) -> String {
         .into()
 }
 
+fn clean_import_target(value: &str, language: &str) -> String {
+    let target = clean_target(value);
+    if language == "rust" {
+        target.trim_end_matches("::").into()
+    } else {
+        target
+    }
+}
+
 fn import_keys(name: &str, language: &str) -> Vec<String> {
     let mut keys = vec![name.to_owned()];
     match language {

tests/fixtures/languages/rust/basic.rs

@@ -1,12 +1,18 @@
-use crate::support::Dependency;
+mod support;
+
+use crate::support::{helper, Dependency};
 
 pub struct Worker;
 
-pub fn start() {
-    helper();
+impl Worker {
+    pub fn start() {
+        helper();
+        generic::<usize>();
+        trace!();
+    }
 }
 
-fn helper() {}
+fn generic<T>() {}
 
 pub const fn constant() -> usize {
     1

tests/fixtures/languages/rust/support.rs

@@ -0,0 +1,3 @@
+pub struct Dependency;
+
+pub fn helper() {}

tests/language_parity.rs

@@ -27,11 +27,18 @@ fn first_class_language_fixtures_have_stable_baseline_evidence() {
         FixtureCase {
             directory: "rust",
             language: "rust",
-            classes: &["Worker"],
-            functions: &["constant", "ffi_entry", "helper", "start", "unsafe_op"],
+            classes: &["Dependency", "Worker"],
+            functions: &[
+                "constant",
+                "ffi_entry",
+                "generic",
+                "helper",
+                "start",
+                "unsafe_op",
+            ],
             imports: 1,
             inherits: 0,
-            calls: 1,
+            calls: 3,
         },
         FixtureCase {
             directory: "c",
@@ -76,10 +83,37 @@ fn first_class_language_fixtures_have_stable_baseline_evidence() {
     }
 }
 
+#[test]
+fn rust_fixture_models_impl_ownership_and_local_imports() {
+    let root = fixture_root("rust");
+    let building = scan(&root).unwrap();
+    let worker = building
+        .nodes
+        .iter()
+        .find(|node| node.kind == NodeKind::Class && node.name == "Worker")
+        .unwrap();
+    let start = building
+        .nodes
+        .iter()
+        .find(|node| node.kind == NodeKind::Function && node.name == "start")
+        .unwrap();
+    let support = building
+        .nodes
+        .iter()
+        .find(|node| node.kind == NodeKind::File && node.path.as_deref() == Some("support.rs"))
+        .unwrap();
+
+    assert_eq!(start.parent.as_deref(), Some(worker.id.as_str()));
+    assert!(
+        building
+            .edges
+            .iter()
+            .any(|edge| { edge.kind == EdgeKind::Imports && edge.target == support.id })
+    );
+}
+
 fn assert_fixture(case: FixtureCase) {
-    let root = PathBuf::from(env!("CARGO_MANIFEST_DIR"))
-        .join("tests/fixtures/languages")
-        .join(case.directory);
+    let root = fixture_root(case.directory);
     let building = scan(&root).unwrap();
     let mut classes: Vec<_> = building
         .nodes
@@ -126,6 +160,12 @@ fn assert_fixture(case: FixtureCase) {
     );
 }
 
+fn fixture_root(directory: &str) -> PathBuf {
+    PathBuf::from(env!("CARGO_MANIFEST_DIR"))
+        .join("tests/fixtures/languages")
+        .join(directory)
+}
+
 fn edge_count(building: &brick::Building, kind: EdgeKind) -> usize {
     building
         .edges