perf: hoist C# type-declaration Set to static readonly and use childForFieldName in Go receiver lookup

src/metricsAnalyzer/languages/csharpAnalyzer.ts

@@ -77,6 +77,15 @@ interface CSharpFunctionMetrics {
  * ```
  */
 export class CSharpMetricsAnalyzer {
+  /** Node types that represent type declarations (class, struct, interface, record, enum). */
+  private static readonly TYPE_DECLARATION_TYPES: ReadonlySet<string> = new Set([
+    "class_declaration",
+    "struct_declaration",
+    "interface_declaration",
+    "record_declaration",
+    "enum_declaration",
+  ]);
+
   /** Current nesting level during analysis */
   private nesting = 0;
   /** Current complexity score during analysis */
@@ -221,16 +230,9 @@ export class CSharpMetricsAnalyzer {
    * @returns The enclosing type name, or null if none found
    */
   private getEnclosingTypeName(node: Parser.SyntaxNode): string | null {
-    const typeDeclarations = new Set([
-      "class_declaration",
-      "struct_declaration",
-      "interface_declaration",
-      "record_declaration",
-      "enum_declaration",
-    ]);
     let parent = node.parent;
     while (parent) {
-      if (typeDeclarations.has(parent.type)) {
+      if (CSharpMetricsAnalyzer.TYPE_DECLARATION_TYPES.has(parent.type)) {
         const nameNode = parent.childForFieldName("name");
         if (nameNode) {
           return this.sourceText.substring(nameNode.startIndex, nameNode.endIndex);

src/metricsAnalyzer/languages/goAnalyzer.ts

@@ -268,7 +268,9 @@ export class GoMetricsAnalyzer {
   }
 
   /**
-   * Finds the type identifier within a parameter list (used for method receivers).
+   * Finds the type node within a parameter list (used for method receivers).
+   * Returns the full type node via the tree-sitter "type" field, which correctly
+   * handles any type form the grammar may produce (pointer, qualified, slice, etc.).
    *
    * @param parameterList - The parameter list node to search
    * @returns The type node or null if not found
@@ -278,13 +280,9 @@ export class GoMetricsAnalyzer {
   ): Parser.SyntaxNode | null {
     for (const child of parameterList.children) {
       if (child.type === "parameter_declaration") {
-        // Look for type_identifier or pointer_type
-        const typeNode = child.children.find(
-          (c) =>
-            c.type === "type_identifier" ||
-            c.type === "pointer_type" ||
-            c.type === "qualified_type"
-        );
+        // Use childForFieldName for O(1) field access rather than a linear
+        // scan over the parameter's children.
+        const typeNode = child.childForFieldName("type");
         if (typeNode) {
           return typeNode;
         }