Added the functionality of split or clone.

I need more than the ability to clone nodes: I also need to split the
nodes.  Now this seems to be correctly added.

1 files changed, 9 insertions, 0 deletions

diff --git a/grammar/src/lib.rs b/grammar/src/lib.rs
index a8e0fd7..ab0f693 100644
--- a/grammar/src/lib.rs
+++ b/grammar/src/lib.rs
@@ -538,6 +538,15 @@ impl Grammar {
         Ok(self.reduction_map.get(&(pos1, pos2)).map(AsRef::as_ref))
     }
 
+    /// Set the reduction information.
+    ///
+    /// This is used to set the reduction information for the virtual
+    /// nodes that are added after the left closure has been computed.
+    #[inline]
+    pub fn set_reduction(&mut self, pos1: usize, pos2: usize, info: Vec<usize>) {
+        self.reduction_map.insert((pos1, pos2), info);
+    }
+
     // REVIEW: Do we have a better way to record expansion and
     // reduction information than to compute the transitive closure?