Cleanup

src/model/TreeNodeEx.swift

@@ -17,11 +17,7 @@ extension TreeNode {
     }
 
     var workspace: Workspace {
-        if let workspace = self as? Workspace {
-            return workspace
-        } else {
-            return parent.workspace
-        }
+        self as? Workspace ?? parent.workspace
     }
 
     var anyChildWindowRecursive: MacWindow? {

src/util/Maybe.swift

@@ -16,10 +16,6 @@ extension Maybe {
     }
 
     static func from(_ value: T?) -> Maybe<T> {
-        if let value {
-            return Maybe.Just(value)
-        } else {
-            return Maybe.Nothing
-        }
+        value.flatMap { Maybe.Just($0) } ?? Maybe.Nothing
     }
 }

src/util/OptionalEx.swift

@@ -1,9 +1,5 @@
 extension Optional {
     func filterIsInstance<R>(of: R.Type) -> Optional<R> {
-        if let value = self as? R {
-            return value
-        } else {
-            return nil
-        }
+        self as? R ?? nil
     }
 }