From 8832da028c3a8dbdf3d33e221fed1a7a942a7fb9 Mon Sep 17 00:00:00 2001
From: adamnemecek <adamnemecek@gmail.com>
Date: Sun, 26 Oct 2025 12:39:23 -0700
Subject: [PATCH] refactored counting functions to use `std::iter::successors`

---
 src/diff/dijkstra.rs        | 33 ++++++++++-----------------------
 src/diff/stack.rs           |  8 +-------
 src/parse/guess_language.rs |  2 +-
 3 files changed, 12 insertions(+), 31 deletions(-)

diff --git a/src/diff/dijkstra.rs b/src/diff/dijkstra.rs
index 8fe86748c..627e7280d 100644
--- a/src/diff/dijkstra.rs
+++ b/src/diff/dijkstra.rs
@@ -156,33 +156,20 @@ fn edge_between<'s, 'v>(before: &Vertex<'s, 'v>, after: &Vertex<'s, 'v>) -> Edge
 
 /// What is the total number of AST nodes?
 fn node_count(root: Option<&Syntax>) -> u32 {
-    let mut node = root;
-    let mut count = 0;
-    while let Some(current_node) = node {
-        let current_count = match current_node {
-            Syntax::List {
-                num_descendants, ..
-            } => *num_descendants,
-            Syntax::Atom { .. } => 1,
-        };
-        count += current_count;
-
-        node = current_node.next_sibling();
-    }
-
-    count
+    let iter = std::iter::successors(root, |node| node.next_sibling());
+
+    iter.map(|node| match node {
+        Syntax::List {
+            num_descendants, ..
+        } => *num_descendants,
+        Syntax::Atom { .. } => 1,
+    })
+    .sum::<u32>()
 }
 
 /// How many top-level AST nodes do we have?
 fn tree_count(root: Option<&Syntax>) -> u32 {
-    let mut node = root;
-    let mut count = 0;
-    while let Some(current_node) = node {
-        count += 1;
-        node = current_node.next_sibling();
-    }
-
-    count
+    std::iter::successors(root, |node| node.next_sibling()).count() as _
 }
 
 pub(crate) fn mark_syntax<'a>(
diff --git a/src/diff/stack.rs b/src/diff/stack.rs
index 6ca1d379f..1e845c223 100644
--- a/src/diff/stack.rs
+++ b/src/diff/stack.rs
@@ -39,13 +39,7 @@ impl<'b, T> Stack<'b, T> {
 
     // O(n)
     pub(crate) fn size(&self) -> usize {
-        let mut count = 0;
-        let mut node = &self.head;
-        while let Some(next) = node {
-            count += 1;
-            node = &next.next;
-        }
-        count
+        std::iter::successors(self.head, |&n| n.next).count()
     }
 
     pub(crate) fn is_empty(&self) -> bool {
diff --git a/src/parse/guess_language.rs b/src/parse/guess_language.rs
index 565b4dee1..d2c96dd08 100644
--- a/src/parse/guess_language.rs
+++ b/src/parse/guess_language.rs
@@ -569,7 +569,7 @@ fn from_emacs_mode_header(src: &str) -> Option<Language> {
             "yaml" => Yaml,
             "zig" => Zig,
             _ => continue,
-        })
+        });
     }
 
     None