diff -r 2afaa0145584 -r 9b0e1f64656f rust/rhg/src/utils/path_utils.rs
--- a/rust/rhg/src/utils/path_utils.rs	Fri Dec 10 16:31:16 2021 +0100
+++ b/rust/rhg/src/utils/path_utils.rs	Fri Dec 10 16:57:39 2021 +0100
@@ -3,8 +3,6 @@
 // This software may be used and distributed according to the terms of the
 // GNU General Public License version 2 or any later version.
 
-use crate::error::CommandError;
-use crate::ui::UiError;
 use hg::errors::HgError;
 use hg::repo::Repo;
 use hg::utils::current_dir;
@@ -13,37 +11,45 @@
 use hg::utils::hg_path::HgPathBuf;
 use std::borrow::Cow;
 
-pub fn relativize_paths(
-    repo: &Repo,
-    paths: impl IntoIterator<Item = Result<impl AsRef<HgPath>, HgError>>,
-    mut callback: impl FnMut(Cow<[u8]>) -> Result<(), UiError>,
-) -> Result<(), CommandError> {
-    let cwd = current_dir()?;
-    let repo_root = repo.working_directory_path();
-    let repo_root = cwd.join(repo_root); // Make it absolute
-    let repo_root_hgpath =
-        HgPathBuf::from(get_bytes_from_path(repo_root.to_owned()));
-    let outside_repo: bool;
-    let cwd_hgpath: HgPathBuf;
+pub struct RelativizePaths {
+    repo_root: HgPathBuf,
+    cwd: HgPathBuf,
+    outside_repo: bool,
+}
+
+impl RelativizePaths {
+    pub fn new(repo: &Repo) -> Result<Self, HgError> {
+        let cwd = current_dir()?;
+        let repo_root = repo.working_directory_path();
+        let repo_root = cwd.join(repo_root); // Make it absolute
+        let repo_root_hgpath =
+            HgPathBuf::from(get_bytes_from_path(repo_root.to_owned()));
 
-    if let Ok(cwd_relative_to_repo) = cwd.strip_prefix(&repo_root) {
-        // The current directory is inside the repo, so we can work with
-        // relative paths
-        outside_repo = false;
-        cwd_hgpath =
-            HgPathBuf::from(get_bytes_from_path(cwd_relative_to_repo));
-    } else {
-        outside_repo = true;
-        cwd_hgpath = HgPathBuf::from(get_bytes_from_path(cwd));
+        if let Ok(cwd_relative_to_repo) = cwd.strip_prefix(&repo_root) {
+            // The current directory is inside the repo, so we can work with
+            // relative paths
+            Ok(Self {
+                repo_root: repo_root_hgpath,
+                cwd: HgPathBuf::from(get_bytes_from_path(
+                    cwd_relative_to_repo,
+                )),
+                outside_repo: false,
+            })
+        } else {
+            Ok(Self {
+                repo_root: repo_root_hgpath,
+                cwd: HgPathBuf::from(get_bytes_from_path(cwd)),
+                outside_repo: true,
+            })
+        }
     }
 
-    for file in paths {
-        if outside_repo {
-            let file = repo_root_hgpath.join(file?.as_ref());
-            callback(relativize_path(&file, &cwd_hgpath))?;
+    pub fn relativize<'a>(&self, path: &'a HgPath) -> Cow<'a, [u8]> {
+        if self.outside_repo {
+            let joined = self.repo_root.join(path);
+            Cow::Owned(relativize_path(&joined, &self.cwd).into_owned())
         } else {
-            callback(relativize_path(file?.as_ref(), &cwd_hgpath))?;
+            relativize_path(path, &self.cwd)
         }
     }
-    Ok(())
 }