diff --git a/lua/jjannotate.lua b/lua/jjannotate.lua
index 60858aa..e3889c2 100644
--- a/lua/jjannotate.lua
+++ b/lua/jjannotate.lua
@@ -115,11 +115,7 @@ function M.is_open(path, revset)
     return w and w:is_open() or false
   end
 
-  for _, w in pairs(cache.wins) do
-    if w and w:is_open() then return true end
-  end
-
-  return false
+  return vim.iter(cache.wins):any(function(_, w) return w and w:is_open() end)
 end
 
 --- Close annotate window
diff --git a/lua/jjannotate/window.lua b/lua/jjannotate/window.lua
index 1e55eef..a3b4950 100644
--- a/lua/jjannotate/window.lua
+++ b/lua/jjannotate/window.lua
@@ -142,17 +142,20 @@ end
 local function find_file(tab, revision)
   local uri = util.revision_uri("file", revision)
   local wins = vim.api.nvim_tabpage_list_wins(tab)
-  for _, win in ipairs(wins) do
-    local buf = vim.api.nvim_win_get_buf(win)
-    local name = vim.api.nvim_buf_get_name(buf)
+  return vim
+    .iter(wins)
+    :map(function(win)
+      local buf = vim.api.nvim_win_get_buf(win)
+      local name = vim.api.nvim_buf_get_name(buf)
 
-    if name == uri then return { buf = buf, win = win } end
+      if name == uri then return { buf = buf, win = win } end
 
-    local info = util.buf_repo_info(buf)
-    if info and info.repo == revision.repo and info.path == revision.path then
-      return { buf = buf, win = win }
-    end
-  end
+      local info = util.buf_repo_info(buf)
+      if info and info.repo == revision.repo and info.path == revision.path then
+        return { buf = buf, win = win }
+      end
+    end)
+    :find(function(x) return x ~= nil end)
 end
 
 ---@param revision jjannotate.Revision
@@ -630,14 +633,12 @@ end
 ---@param dir "prev" | "next"
 function Window:_move_change(dir)
   local row = cursor_row(self.annotate.win) - 1
+  local lines = self.result.lines
   local target --[[@type jjannotate.Line?]]
-  for _, line in ipairs(self.result.lines) do
-    if dir == "next" and line.range.start > row then
-      target = line
-      break
-    elseif dir == "prev" and line.range._end < row then
-      target = line
-    end
+  if dir == "next" then
+    target = vim.iter(lines):find(function(line) return line.range.start > row end)
+  else
+    target = vim.iter(lines):filter(function(line) return line.range._end < row end):last()
   end
   if target then
     local line = target.range.start + 1