cob: Refactor `Thread` methods

radicle-cli/src/commands/comment.rs

@@ -97,9 +97,10 @@ fn comment(
         store::Error::NotFound(_, _) => anyhow::anyhow!("Could not find issue {}", options.id),
         _ => e.into(),
     })?;
-    let (comment_id, _) = issue.root().expect("root comment always exists");
+    let (comment_id, _) = issue.comments().next().expect("root comment always exists");
 
     issue.comment(message, *comment_id, &signer)?;
+
     Ok(())
 }
 

radicle/src/cob/patch.rs

@@ -353,7 +353,7 @@ impl Revision {
     }
 
     pub fn description(&self) -> Option<&str> {
-        let (_, comment) = self.discussion.root()?;
+        let (_, comment) = self.discussion.first()?;
         Some(comment.body())
     }
 }

radicle/src/cob/thread.rs

@@ -203,11 +203,12 @@ impl Thread {
         }
     }
 
-    pub fn root(&self) -> Option<(&CommentId, &Comment)> {
-        self.comments
-            .iter()
-            .filter_map(|(id, r)| r.get().map(|comment| (id, comment)))
-            .next()
+    pub fn first(&self) -> Option<(&CommentId, &Comment)> {
+        self.comments().next()
+    }
+
+    pub fn last(&self) -> Option<(&CommentId, &Comment)> {
+        self.comments().next_back()
     }
 
     pub fn replies<'a>(
@@ -235,14 +236,10 @@ impl Thread {
             .map(|(a, r)| (a, r))
     }
 
-    pub fn comments(&self) -> impl Iterator<Item = (&CommentId, &Comment)> + '_ {
-        self.comments.iter().filter_map(|(id, comment)| {
-            if let Redactable::Present(c) = comment {
-                Some((id, c))
-            } else {
-                None
-            }
-        })
+    pub fn comments(&self) -> impl DoubleEndedIterator<Item = (&CommentId, &Comment)> + '_ {
+        self.comments
+            .iter()
+            .filter_map(|(id, comment)| comment.get().map(|comment| (id, comment)))
     }
 }