Add completion for expressions

Author: vinistock

rust/rubydex/src/model/declaration.rs

@@ -479,6 +479,11 @@ impl Namespace {
     pub fn set_singleton_class_id(&mut self, declaration_id: DeclarationId) {
         all_namespaces!(self, it => it.set_singleton_class_id(declaration_id));
     }
+
+    #[must_use]
+    pub fn owner_id(&self) -> &DeclarationId {
+        all_namespaces!(self, it => &it.owner_id)
+    }
 }
 
 namespace_declaration!(Class, ClassDeclaration);

rust/rubydex/src/model/graph.rs

@@ -320,6 +320,27 @@ impl Graph {
         name_id
     }
 
+    /// Searches for the initial attached object for an arbitrarily nested singleton class
+    ///
+    /// # Panics
+    ///
+    /// Only panics if we attached a singleton class to something that isn't a namespace
+    #[must_use]
+    pub fn attached_object<'a>(&'a self, maybe_singleton: &'a Namespace) -> &'a Namespace {
+        let mut attached_object = maybe_singleton;
+
+        while matches!(attached_object, Namespace::SingletonClass(_)) {
+            attached_object = self
+                .declarations
+                .get(attached_object.owner_id())
+                .unwrap()
+                .as_namespace()
+                .unwrap();
+        }
+
+        attached_object
+    }
+
     #[must_use]
     pub fn get(&self, name: &str) -> Option<Vec<&Definition>> {
         let declaration_id = DeclarationId::from(name);

rust/rubydex/src/model/name.rs

@@ -157,6 +157,11 @@ impl ResolvedName {
     pub fn declaration_id(&self) -> &DeclarationId {
         &self.declaration_id
     }
+
+    #[must_use]
+    pub fn nesting(&self) -> &Option<NameId> {
+        self.name.nesting()
+    }
 }
 
 /// A usage of a constant name. This could be a constant reference or a definition like a class or module