From 6f00c565b298c78b758a5a076622e98dbee2e054 Mon Sep 17 00:00:00 2001
From: Yuya Nishihara <yuya@tcha.org>
Date: Sun, 22 Dec 2024 10:28:14 +0900
Subject: [PATCH] graph: inline ReverseGraphIterator to callers

---
 cli/src/commands/log.rs  |  4 ++--
 lib/src/graph.rs         | 28 +---------------------------
 lib/tests/test_revset.rs |  9 +++------
 3 files changed, 6 insertions(+), 35 deletions(-)

diff --git a/cli/src/commands/log.rs b/cli/src/commands/log.rs
index 3ef67cf565..8492e4fa9a 100644
--- a/cli/src/commands/log.rs
+++ b/cli/src/commands/log.rs
@@ -17,8 +17,8 @@ use clap_complete::ArgValueCompleter;
 use jj_lib::backend::CommitId;
 use jj_lib::config::ConfigGetError;
 use jj_lib::config::ConfigGetResultExt as _;
+use jj_lib::graph::reverse_graph;
 use jj_lib::graph::GraphEdgeType;
-use jj_lib::graph::ReverseGraphIterator;
 use jj_lib::graph::TopoGroupedGraphIterator;
 use jj_lib::repo::Repo;
 use jj_lib::revset::RevsetEvaluationError;
@@ -208,7 +208,7 @@ pub(crate) fn cmd_log(
                     }
                 }
                 if args.reversed {
-                    Box::new(ReverseGraphIterator::new(forward_iter)?)
+                    Box::new(reverse_graph(forward_iter)?.into_iter().map(Ok))
                 } else {
                     Box::new(forward_iter)
                 }
diff --git a/lib/src/graph.rs b/lib/src/graph.rs
index 4e2282a8c7..26d2041fea 100644
--- a/lib/src/graph.rs
+++ b/lib/src/graph.rs
@@ -19,8 +19,6 @@ use std::collections::HashSet;
 use std::collections::VecDeque;
 use std::hash::Hash;
 
-use crate::revset::RevsetEvaluationError;
-
 /// Node and edges pair of type `N`.
 pub type GraphNode<N> = (N, Vec<GraphEdge<N>>);
 
@@ -74,32 +72,8 @@ fn reachable_targets<N>(edges: &[GraphEdge<N>]) -> impl DoubleEndedIterator<Item
         .map(|edge| &edge.target)
 }
 
-pub struct ReverseGraphIterator<N> {
-    items: std::vec::IntoIter<GraphNode<N>>,
-}
-
-impl<N> ReverseGraphIterator<N>
-where
-    N: Hash + Eq + Clone,
-{
-    pub fn new(
-        input: impl Iterator<Item = Result<GraphNode<N>, RevsetEvaluationError>>,
-    ) -> Result<Self, RevsetEvaluationError> {
-        let items = reverse_graph(input)?.into_iter();
-        Ok(Self { items })
-    }
-}
-
-impl<N> Iterator for ReverseGraphIterator<N> {
-    type Item = Result<GraphNode<N>, RevsetEvaluationError>;
-
-    fn next(&mut self) -> Option<Self::Item> {
-        self.items.next().map(Ok)
-    }
-}
-
 /// Creates new graph in which nodes and edges are reversed.
-fn reverse_graph<N: Clone + Eq + Hash, E>(
+pub fn reverse_graph<N: Clone + Eq + Hash, E>(
     input: impl Iterator<Item = Result<GraphNode<N>, E>>,
 ) -> Result<Vec<GraphNode<N>>, E> {
     let mut entries = vec![];
diff --git a/lib/tests/test_revset.rs b/lib/tests/test_revset.rs
index 51ee358de4..3063abea3c 100644
--- a/lib/tests/test_revset.rs
+++ b/lib/tests/test_revset.rs
@@ -26,8 +26,8 @@ use jj_lib::commit::Commit;
 use jj_lib::fileset::FilesetExpression;
 use jj_lib::git;
 use jj_lib::git_backend::GitBackend;
+use jj_lib::graph::reverse_graph;
 use jj_lib::graph::GraphEdge;
-use jj_lib::graph::ReverseGraphIterator;
 use jj_lib::id_prefix::IdPrefixContext;
 use jj_lib::object_id::ObjectId;
 use jj_lib::op_store::RefTarget;
@@ -3942,7 +3942,7 @@ fn test_evaluate_expression_conflict() {
 }
 
 #[test]
-fn test_reverse_graph_iterator() {
+fn test_reverse_graph() {
     let settings = testutils::user_settings();
     let test_repo = TestRepo::init();
     let repo = &test_repo.repo;
@@ -3977,10 +3977,7 @@ fn test_reverse_graph_iterator() {
         repo.as_ref(),
         &[&commit_a, &commit_c, &commit_d, &commit_e, &commit_f],
     );
-    let commits: Vec<_> = ReverseGraphIterator::new(revset.iter_graph())
-        .unwrap()
-        .try_collect()
-        .unwrap();
+    let commits = reverse_graph(revset.iter_graph()).unwrap();
     assert_eq!(commits.len(), 5);
     assert_eq!(commits[0].0, *commit_a.id());
     assert_eq!(commits[1].0, *commit_c.id());