Function compact_node_reference 

pub fn compact_node_reference<N>(
    vocabulary: &N,
    id: &Id<N::Iri, N::BlankId>,
    index: Option<&str>,
    active_context: &Context<N::Iri, N::BlankId>,
    active_property: Option<&str>,
    options: Options,
) -> Result<Value, IriConfusedWithPrefix>
where
    N: Vocabulary,
    N::Iri: Clone + Hash + Eq,
    N::BlankId: Clone + Hash + Eq,

Compacts a node reference, a node object whose only entry is @id, against an active context in which the active property’s scoped context is already in force.

Follows step 7 of the value compaction algorithm: under a term whose type mapping is @id the reference becomes the @id compacted as an IRI reference (vocab set to false), under a term whose type mapping is @vocab it becomes the @id compacted with vocab set to true, and in either case index is dropped. Otherwise the result is an object holding the @id, compacted with vocab set to false, under the active context’s alias of @id, plus index under the alias of @index unless the active property’s container mapping includes @index.

active_property is the compacted term the reference is written under, or None at the top level. When that term defines a scoped @context, active_context must be the result of processing it on top of the context the term was selected in; a node reference does not revert a term-scoped context to the previous context, and type-scoped contexts do not apply because a reference has no @type. This is synchronous and needs no loader.

Errors

Returns IriConfusedWithPrefix when the @id can only be written out in full and would then be read back as a compact IRI.