Implement `std::iter::Extend` for provided `Graph`/`Dataset` implementations

[damooo]

std::iter::Extend allows to extend collections with iterators / streams that produce same type of items.

Though there are CollectableGraph and CollectableDataset, they won't work with methods provided by futures::stream::TryStreamExt etc to consume from non blocking streams.

Currently DatasetAsGraph, UnionGraph, FastGraph etc implementations are painful to construct from async streams. while HashSet/Vec are trivial as they implement extend.

[pchampin]

std::iter::Extend allows to extend collections with iterators / streams that produce same type of items.

There is an insert_all method in MutableGraph and MutableDataset that plays a similar role.

Some implementations of Graph and Dataset already implement Extend (namely those based on Vec and HashMap). It would be possible to make other implementations (e.g. inmem::FastGraph) implement Extend, but generally, insert_all is more flexible (it works with any impl of Triple).

Do you have a use-case where using Extend::extend would be superior to using Graph::insert_all?

Though there are CollectableGraph and CollectableDataset, they won't work with methods provided by futures::stream::TryStreamExt etc to consume from non blocking streams.

As discussed in #134, Sophia is currently focused on "sync" Rust. I suggest we continue discussing this on #134.

Currently DatasetAsGraph, UnionGraph, FastGraph etc implementations are painful to construct from async streams. while HashSet/Vec are trivial as they implement extend.

I don't get the link between async streams and the Extend trait (which is about sync iterators!).

Note that you should not have to create DatasetAsGraphs nor UnionGraphs "manually":

• DatasetAsGraphs are constructed via the Dataset::graph and Dataset::graph_mut methods
• UnionGraphs are constructed via the Dataset::union_graph and Dataset::into_union_graph method

[damooo]

Do you have a use-case where using Extend::extend would be superior to using Graph::insert_all?

I don't get the link between async streams and the Extend trait (which is about sync iterators!).

TryStreamExt::try_collect

StreamExt::collect

[damooo]

DatasetAsGraphs are constructed via the Dataset::graph and Dataset::graph_mut methods

Yes, i tried them first. But the method signature require bounds of T: for<'x> Term<BorrowTerm<'x> = DTerm<'x, Self>> + 'static, for T in GraphName, which was not possible in my case with few generic interactions.

It gets sometimes complicated due to GATs and lack of functionality to constrain a GAT value, as in this post, and this rfc

[damooo]

Sorry for spamming this issue, it would also be great to have DatasetGraph to implement SetGraph when underlying Dataset implements SetDataset.

[pchampin]

Sorry for spamming this issue, it would also be great to have DatasetGraph to implement SetGraph when underlying Dataset implements SetDataset.

Very good point. Could you please open a dedicated issue for this? And/or even better, a PR ? :wink:

[pchampin]

DatasetAsGraphs are constructed via the Dataset::graph and Dataset::graph_mut methods

Yes, i tried them first. But the method signature require bounds of T: for<'x> Term<BorrowTerm<'x> = DTerm<'x, Self>> + 'static, for T in GraphName, which was not possible in my case with few generic interactions.

If you need a graph with a different type of Terms than the underlying dataset, then you need to copy the corresponding data in a separate graph (e.g. a Vec<[Term; 3]> or a FastGraph), you should not try using DatasetAsGraph for this.

But granted, this is not clear from the documentation of DatasetAsGraph, which should be improved in that line.

[pchampin]

Are you ok to close this issue (opening new ones for the most specific questions above, if needed)?

[damooo]

Sorry for late response. I am closing the issue.

And my laptop is of 4GB ram, and developing rust projects is not practical. I have to use free credits from github codespaces. Currently i am using them for Manas Soid Server. Hence cannot send a PR.