Struct OverlayGraph 

pub struct OverlayGraph<'a, G: GraphRead + ?Sized, S: GraphRead + ?Sized> { /* private fields */ }

Add a separate named shapes graph without cloning or modifying the base. Shapes are projected from their union; their original contexts do not leak into the base dataset. The reserved graph exists even when shapes are empty.

Implementations

impl<'a, G: GraphRead + ?Sized, S: GraphRead + ?Sized> OverlayGraph<'a, G, S>

pub fn new( source: &'a G, shapes: &'a S, graph: NamedOrBlankNode, ) -> Result<Self>

Reserve a fresh named graph; collisions, including empty graphs, fail.

Trait Implementations

impl<'source, G: GraphRead + ?Sized, S: GraphRead + ?Sized> GraphRead for OverlayGraph<'source, G, S>

fn matching_quads<'a>( &'a self, subject: Option<NamedOrBlankNodeRef<'_>>, predicate: Option<NamedNodeRef<'_>>, object: Option<TermRef<'_>>, graph: Option<GraphNameRef<'_>>, ) -> impl Iterator<Item = Result<Quad>> + use<'a, 'source, G, S>

Stream matching quads. Read failures must remain errors, never omissions. Retain the source borrow, not the caller’s temporary pattern references.

fn named_graphs(&self) -> impl Iterator<Item = Result<NamedOrBlankNode>> + '_

Stream each named graph exactly once, including empty backend graphs. Iteration must not materialize the set of graph names.

fn contains_named_graph(&self, graph: &NamedOrBlankNode) -> Result<bool>

Test graph existence, including empty graphs in capable storage backends.