Replace function ComponentType by more comprehensive ComponentInfo

CHANGELOG.md

@@ -15,8 +15,8 @@ This change was necessary to get the same performance as before, despite the mor
 
 ### Features
 
-* Adds functions `ComponentType(*World, ID) reflect.Type` and `ResourceType(*World, ID) reflect.Type` (#315)
-* Adds methods `World.Ids(Entity) []ID` and `Query.Ids() []ID` (#315)
+* Adds functions `ComponentInfo(*World, ID)` and `ResourceType(*World, ResID)` (#315, #318)
+* Adds methods `World.Ids(Entity)` and `Query.Ids()` (#315)
 
 ### Other
 

ecs/types.go

@@ -25,3 +25,11 @@ type componentType struct {
 	ID
 	Type reflect.Type
 }
+
+// CompInfo provides information about a registered component.
+// Returned by [ComponentInfo].
+type CompInfo struct {
+	ID         ID
+	Type       reflect.Type
+	IsRelation bool
+}

ecs/world.go

@@ -25,9 +25,18 @@ func TypeID(w *World, tp reflect.Type) ID {
 	return w.componentID(tp)
 }
 
-// ComponentType returns the reflect.Type for a component [ID], and whether the ID is assigned.
-func ComponentType(w *World, id ID) (reflect.Type, bool) {
-	return w.registry.ComponentType(id)
+// ComponentInfo returns the [CompInfo] for a component [ID], and whether the ID is assigned.
+func ComponentInfo(w *World, id ID) (CompInfo, bool) {
+	tp, ok := w.registry.ComponentType(id)
+	if !ok {
+		return CompInfo{}, false
+	}
+
+	return CompInfo{
+		ID:         id,
+		Type:       tp,
+		IsRelation: w.registry.IsRelation.Get(id),
+	}, true
 }
 
 // ResourceID returns the [ResID] for a resource type via generics.

ecs/world_test.go

@@ -182,22 +182,22 @@ func TestWorldComponents(t *testing.T) {
 	assert.Panics(t, func() { w.Get(newEntityGen(1, 0), posID) })
 }
 
-func TestWorldTypes(t *testing.T) {
+func TestWorldComponentInfo(t *testing.T) {
 	w := NewWorld()
 	_ = ComponentID[Velocity](&w)
 	posID := ComponentID[Position](&w)
 
-	tp, ok := ComponentType(&w, posID)
+	info, ok := ComponentInfo(&w, posID)
 	assert.True(t, ok)
-	assert.Equal(t, tp, reflect.TypeOf(Position{}))
+	assert.Equal(t, info.Type, reflect.TypeOf(Position{}))
 
-	tp, ok = ComponentType(&w, 3)
+	info, ok = ComponentInfo(&w, 3)
 	assert.False(t, ok)
-	assert.Equal(t, tp, nil)
+	assert.Equal(t, info, CompInfo{})
 
 	resID := ResourceID[Velocity](&w)
 
-	tp, ok = ResourceType(&w, resID)
+	tp, ok := ResourceType(&w, resID)
 	assert.True(t, ok)
 	assert.Equal(t, tp, reflect.TypeOf(Velocity{}))