Cursor Function of the ART

[bprovot]

I don't really understand the goal of the Cursor function in this case. I understand how the cursor is built but I can't understand what it should do in this case. Is the goal to iterate on the tree here to return the cursor associated with a key ?

[jeehoonkang]

• A cursor is meant to point to a point (which is either the node or on an edge) in the tree.
• What do you mean by the "cursor function"? Please refer to the lines of code in GitHub.

[Shynar88]

I guess it's line 110 from art.rs.

fn cursor<'a, I>(&'a mut self, key: &mut Peekable<I>) -> Cursor<'a, V>
    where
        I: 'a + Iterator<Item = u8>,
    {
        unimplemented!()
    }

[jeehoonkang]

• You can point to the code like this: https://github.com/kaist-cp/cs492-concur/blob/afc09d9e0c532ded69d1c6d2a2420f74ebc38f79/art/src/art.rs#L110-L115

• It's meant to return the cursor corresponding to the given key.

[bprovot]

Ok then I'm not sure to understand what a cursor pointing to an edge is. Could you please illustrate ?

[Shynar88]

Maybe #394 can help? As far as I understood, the purple line is the cursor pointing to the edge

[bprovot]

OK this helped. Thanks a lot