chore: Add a extension trait for Tags type

Signed-off-by: Awiteb <a@4rs.nl>

src/nostr_utils/traits.rs

@@ -0,0 +1,36 @@
+// n34 - A CLI to interact with NIP-34 and other stuff related to codes in nostr
+// Copyright (C) 2025 Awiteb <a@4rs.nl>
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program. If not, see <https://gnu.org/licenses/gpl-3.0.html>.
+
+use nostr::event::{TagKind, TagStandard, Tags};
+
+
+/// A trait to add helper instance function to [`Tags`] type
+#[easy_ext::ext(TagsExt)]
+impl Tags {
+    /// Search for the given tag and map it value to a function
+    pub fn map_tag<T>(&self, kind: TagKind, f: impl FnOnce(&TagStandard) -> T) -> Option<T> {
+        self.find_standardized(kind).map(f)
+    }
+
+    /// Search for the given tag and map it value to a function. If the tag not
+    /// found return the default `T`
+    pub fn dmap_tag<T>(&self, kind: TagKind, f: impl FnOnce(&TagStandard) -> T) -> T
+    where
+        T: Default,
+    {
+        self.map_tag(kind, f).unwrap_or_default()
+    }
+}