RdfGraph class final

Represents an immutable RDF graph with triple pattern matching capabilities

An RDF graph is formally defined as a set of RDF triples. This class provides functionality for working with such graphs, including:

• Creating graphs from sets of triples
• Adding or removing triples (creating new graph instances)
• Merging graphs
• Querying triples based on patterns
• Optional lazy indexing for improved query performance

The class is designed to be immutable for thread safety and to prevent accidental modification. All operations that would modify the graph return a new instance.

Indexing Behavior: When indexing is enabled (default), an internal index is created lazily on the first query operation that can benefit from it. This means there is no immediate memory cost for enabling indexing - the memory is only used when and if queries are performed.

Example:

// Create a graph with some initial triples
final graph = RdfGraph(triples: [
  Triple(john, name, johnSmith),
  Triple(john, knows, jane)
]);

// Create a new graph with an additional triple
final updatedGraph = graph.withTriple(Triple(jane, name, janeSmith));