case *ast.ReturnStmt:
		f.walk(n.Results, ctxExpr, visit)
	case *ast.BranchStmt:
	case *ast.BlockStmt:
		f.walk(n.List, context, visit)
	case *ast.IfStmt:
		f.walk(n.Init, ctxStmt, visit)
		f.walk(&n.Cond, ctxExpr, visit)
		f.walk(n.Body, ctxStmt, visit)
		f.walk(n.Else, ctxStmt, visit)
	case *ast.CaseClause:
		if context == ctxTypeSwitch {
			context = ctxType
		} else {
			context = ctxExpr
		}