diff --git a/src/diff/graph.rs b/src/diff/graph.rs
index 2facbad921..5192e613e1 100644
--- a/src/diff/graph.rs
+++ b/src/diff/graph.rs
@@ -548,8 +548,8 @@ pub(crate) fn set_neighbours<'s, 'b>(
         {
             // The list delimiters are equal, but children may not be.
             if lhs_open_content == rhs_open_content && lhs_close_content == rhs_close_content {
-                let lhs_next = lhs_children.get(0).copied();
-                let rhs_next = rhs_children.get(0).copied();
+                let lhs_next = lhs_children.first().copied();
+                let rhs_next = rhs_children.first().copied();
 
                 // TODO: be consistent between parents_next and next_parents.
                 let parents_next = push_both_delimiters(&v.parents, lhs_syntax, rhs_syntax);
@@ -672,7 +672,7 @@ pub(crate) fn set_neighbours<'s, 'b>(
             }
             // Step into this partially/fully novel list.
             Syntax::List { children, .. } => {
-                let lhs_next = children.get(0).copied();
+                let lhs_next = children.first().copied();
 
                 let parents_next = push_lhs_delimiter(&v.parents, lhs_syntax);
 
@@ -737,7 +737,7 @@ pub(crate) fn set_neighbours<'s, 'b>(
             }
             // Step into this partially/fully novel list.
             Syntax::List { children, .. } => {
-                let rhs_next = children.get(0).copied();
+                let rhs_next = children.first().copied();
                 let parents_next = push_rhs_delimiter(&v.parents, rhs_syntax);
 
                 let (lhs_syntax, rhs_syntax, lhs_parent_id, rhs_parent_id, parents) =
diff --git a/src/files.rs b/src/files.rs
index 0fa3cc25a3..7501647bca 100644
--- a/src/files.rs
+++ b/src/files.rs
@@ -229,7 +229,6 @@ pub(crate) fn guess_content(bytes: &[u8]) -> ProbableFileKind {
 /// All the files in `dir`, including subdirectories.
 fn relative_file_paths_in_dir(dir: &Path) -> Vec<PathBuf> {
     Walk::new(dir)
-        .into_iter()
         .filter_map(Result::ok)
         .map(|entry| Path::new(entry.path()).to_owned())
         .filter(|path| !path.is_dir())
diff --git a/src/main.rs b/src/main.rs
index 9cb0f48e21..4ab0c3b545 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -585,8 +585,8 @@ fn diff_file_content(
                                 init_next_prev(&rhs_section_nodes);
 
                                 match mark_syntax(
-                                    lhs_section_nodes.get(0).copied(),
-                                    rhs_section_nodes.get(0).copied(),
+                                    lhs_section_nodes.first().copied(),
+                                    rhs_section_nodes.first().copied(),
                                     &mut change_map,
                                     diff_options.graph_limit,
                                 ) {