Add World.getScope and .setScope functions

src/entity.zig

@@ -142,8 +142,8 @@ pub fn Entity(comptime ctx: anytype) type {
 
             // Set the scope to create the entity under (its parent).
             // This avoids using up an id for a `ChildOf` relationship.
-            const previous = if (scope) |s| c.ecs_set_scope(world.raw, s) else null;
+            const previous = if (scope) |s| world.setScope(s) else null;
-            defer _ = if (previous) |s| c.ecs_set_scope(world.raw, s);
+            defer _ = if (previous) |s| world.setScope(s);
 
             // TODO: Use an allocator that's well-fitted for super short-lived allocations.
             const nameZ = if (name) |n| try flecs.allocator.dupeZ(u8, n) else null;

src/world.zig

@@ -145,5 +145,25 @@ pub fn World(comptime ctx: anytype) type {
                 context.func(iter);
             }
         };
+
+        /// Gets the current scope of this `World`. See also: `setScope()`.
+        pub fn getScope(self: *Self) ?Entity(ctx) {
+            const result = c.ecs_get_scope(self.raw);
+            return if (result != 0) Entity(ctx).fromRaw(self, result) else null;
+        }
+
+        /// Sets the current scope of this `World` to the specified entity.
+        ///
+        /// Setting a scope causes certain operations to be made in relation
+        /// to the scope entity, rather than the world root. Passing `null`
+        /// causes the scope to be set to the world root.
+        ///
+        /// Returns the previously set scope, if any. It's recommended to set
+        /// the scope back to the previous value after you're done operating
+        /// in the desired scope.
+        pub fn setScope(self: *Self, value: anytype) ?Entity(ctx) {
+            const result = c.ecs_set_scope(self.raw, util.anyToEntity(ctx, value));
+            return if (result != 0) Entity(ctx).fromRaw(self, result) else null;
+        }
     };
 }