Adding upstream version 0.0~git20250501.71edba4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

extractors.go

@@ -0,0 +1,60 @@
+package activitypub
+
+func PreferredNameOf(it Item) string {
+	var cont string
+	if IsObject(it) {
+		_ = OnActor(it, func(act *Actor) error {
+			if act.PreferredUsername != nil {
+				cont = act.PreferredUsername.First().String()
+			}
+			return nil
+		})
+	}
+	return cont
+}
+
+func ContentOf(it Item) string {
+	var cont string
+	if IsObject(it) {
+		_ = OnObject(it, func(ob *Object) error {
+			if ob.Content != nil {
+				cont = ob.Content.First().String()
+			}
+			return nil
+		})
+	}
+	return cont
+}
+
+func SummaryOf(it Item) string {
+	var cont string
+	if IsObject(it) {
+		_ = OnObject(it, func(ob *Object) error {
+			if ob.Summary != nil {
+				cont = ob.Summary.First().String()
+			}
+			return nil
+		})
+	}
+	return cont
+}
+
+func NameOf(it Item) string {
+	var name string
+	if IsLink(it) {
+		_ = OnLink(it, func(lnk *Link) error {
+			if lnk.Name != nil {
+				name = lnk.Name.First().String()
+			}
+			return nil
+		})
+	} else {
+		_ = OnObject(it, func(ob *Object) error {
+			if ob.Name != nil {
+				name = ob.Name.First().String()
+			}
+			return nil
+		})
+	}
+	return name
+}