Fix the bug of incorrectly setting the end of forest nodes

Previously when generating a fragment of the forest corresponding to
the expansion of a non-terminal by a terminal, we incorrectly set the
end of every node within it to be one plus the start, if the expansion
happens due to a reduction.

Now this mistake is fixed and the ending positions are correctly set.

1 files changed, 3 insertions, 8 deletions

diff --git a/chain/src/item/genins.rs b/chain/src/item/genins.rs
index 07dbdfb..1996545 100644
--- a/chain/src/item/genins.rs
+++ b/chain/src/item/genins.rs
@@ -335,7 +335,7 @@ impl DefaultForest<ForestLabel<GrammarLabel>> {
                             if let Some(frag) = virtual_frag {
                                 let mut frag = (*frag.get(0).unwrap()).clone();
 
-                                frag.set_pos(node_label.label().start(), false)?;
+                                frag.set_pos(atom, node_label.label().start(), false)?;
 
                                 let frag_nodes_len = frag.nodes_len();
 
@@ -720,15 +720,10 @@ impl DefaultForest<ForestLabel<GrammarLabel>> {
                 //     return Err(Error::CannotClose(nt, t, node, node_label_start));
                 // }
 
-                // FIXME: It is not correct to set the end of all
-                // nodes unconditionally here.
-                //
-                // We need to figure out the correct way to set the
-                // ending positions.
-
                 for frag in reduction_fragment.into_iter().flatten() {
                     let mut frag = frag.clone();
-                    frag.set_pos(node_label_start, true)?;
+
+                    frag.set_pos(atom, node_label_start, true)?;
 
                     node = self.plant_at_start(node, frag)?;
                 }