move ExternalPointer to nip73 and write nip27.Parse() that gets all the parts of the text including URLs, Nostr URIs and just raw text.

nip73/pointer.go

@@ -0,0 +1,23 @@
+package nip73
+
+import "github.com/nbd-wtf/go-nostr"
+
+var _ nostr.Pointer = (*ExternalPointer)(nil)
+
+// ExternalPointer represents a pointer to a URL or something else.
+type ExternalPointer struct {
+	Thing string
+}
+
+// ExternalPointerFromTag creates a ExternalPointer from an "i" tag
+func ExternalPointerFromTag(refTag nostr.Tag) (ExternalPointer, error) {
+	return ExternalPointer{refTag[1]}, nil
+}
+
+func (ep ExternalPointer) MatchesEvent(_ nostr.Event) bool { return false }
+func (ep ExternalPointer) AsTagReference() string          { return ep.Thing }
+func (ep ExternalPointer) AsFilter() nostr.Filter          { return nostr.Filter{} }
+
+func (ep ExternalPointer) AsTag() nostr.Tag {
+	return nostr.Tag{"i", ep.Thing}
+}