head/tail

[dahtah]

Not a major problem, but head and tail behave in a counter-intuitive manner, I think. I'd expect:

create_ring(10) %>% activate(nodes) %>% head

to return information on the first 10 nodes

create_ring(10) %>% activate(edges) %>% head

to return information on the first 10 edges, and finally

create_ring(10) %>% head

to maybe say that a graph doesn't have a head. tidygraph reverts to igraph's default in all cases. I thought I'd add a head.tbl_graph function myself, but noticed that a tbl_graph doesn't seem to have an unactivated state - it's nodes by default. Wouldn't it make sense to have such a state?

On an unrelated note (sorry), the initial table for nodes created by create_ * is empty - perhaps it'd make sense to initialise it with a single index column?

[thomasp85]

Don't think there's much sense in an unactivated state - you're either working with nodes or edges...

As for head/tail, I've been very deliberate in not masking any functionality from graph, so that it is almost certain that a tbl_graph will behave as an graph object if passed into a function that expects an graph object... if you want to glimpse the top of either nodes or edges just do %>% as_tibble