1 files changed, 76 insertions, 0 deletions
diff --git a/intl/l10n/rust/l10nregistry-rs/src/solver/serial.rs b/intl/l10n/rust/l10nregistry-rs/src/solver/serial.rs
new file mode 100644
index 0000000000..9368c12c9e
--- /dev/null
+++ b/intl/l10n/rust/l10nregistry-rs/src/solver/serial.rs
@@ -0,0 +1,76 @@
+use super::ProblemSolver;
+use std::ops::{Deref, DerefMut};
+
+pub trait SyncTester {
+    fn test_sync(&self, res_idx: usize, source_idx: usize) -> bool;
+}
+
+pub struct SerialProblemSolver(ProblemSolver);
+
+impl Deref for SerialProblemSolver {
+    type Target = ProblemSolver;
+
+    fn deref(&self) -> &Self::Target {
+        &self.0
+    }
+}
+
+impl DerefMut for SerialProblemSolver {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        &mut self.0
+    }
+}
+
+impl SerialProblemSolver {
+    pub fn new(width: usize, depth: usize) -> Self {
+        Self(ProblemSolver::new(width, depth))
+    }
+}
+
+impl SerialProblemSolver {
+    fn test_current_cell<T>(&mut self, tester: &T) -> bool
+    where
+        T: SyncTester,
+    {
+        let res_idx = self.idx;
+        let source_idx = self.solution[res_idx];
+        let cell = &mut self.cache[res_idx][source_idx];
+        *cell.get_or_insert_with(|| tester.test_sync(res_idx, source_idx))
+    }
+
+    pub fn try_next<T>(&mut self, tester: &T, prefetch: bool) -> Result<Option<&[usize]>, usize>
+    where
+        T: SyncTester,
+    {
+        if self.width == 0 || self.depth == 0 {
+            return Ok(None);
+        }
+        if self.dirty {
+            if !self.bail() {
+                return Ok(None);
+            }
+            self.dirty = false;
+        }
+        loop {
+            if !self.test_current_cell(tester) {
+                if !self.bail() {
+                    if let Some(res_idx) = self.has_missing_cell() {
+                        return Err(res_idx);
+                    } else {
+                        return Ok(None);
+                    }
+                }
+                continue;
+            }
+            if self.is_complete() {
+                if !prefetch {
+                    self.dirty = true;
+                }
+                return Ok(Some(&self.solution));
+            }
+            if !self.try_advance_resource() {
+                return Ok(None);
+            }
+        }
+    }
+}