a commit before the forst query

I think the main functionalities are already there, but the lack of
querying capabilities makes this not very useful at the moment.

This commit is right before an attempt to add this missing piece.

1 files changed, 9 insertions, 0 deletions

diff --git a/chain/src/item/default/mod.rs b/chain/src/item/default/mod.rs
index 01e463e..f532805 100644
--- a/chain/src/item/default/mod.rs
+++ b/chain/src/item/default/mod.rs
@@ -127,6 +127,11 @@ impl<T: GraphLabel> LabelGraph<T> for DefaultForest<T> {
     where
         Self: 'a;
 
+    type TupleIter<'a> = std::iter::Empty<(T, usize)>
+    where
+        Self: 'a,
+        T: 'a;
+
     type LabelIter<'a> = std::iter::Empty<(&'a T, <Self as LabelGraph<T>>::Iter<'a>)>
     where
         Self: 'a,
@@ -163,6 +168,10 @@ impl<T: GraphLabel> LabelGraph<T> for DefaultForest<T> {
         unimplemented!("edges have no labels")
     }
 
+    fn tuples_of(&self, _node_id: usize) -> Result<Self::TupleIter<'_>, GError> {
+        unimplemented!("edges have no labels")
+    }
+
     fn labels_of(&self, _node_id: usize) -> Result<Self::LabelIter<'_>, GError> {
         unimplemented!("edges have no labels")
     }