Chore: Create generic pattern-match object

[jeswr]

Issue type:

• ➕ Feature request

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Description:

To structure capture the logic we have for keeping track of combined lazy/incremental reasoning. It should adhere to the following interface:

interface Patterns {
  // Adds a pattern
  add(quad: RDF.BaseQuad, done?: Promise<void>): boolean;
  // Invalidate all patterns matching {quad}
  invalidate(quad: RDF.BaseQuad): boolean;
  // Check if there is a pattern matching {quad}. For instance if (?s, a, Person) has already been
  // `add`ed then, has((?s, a, Person) and has((Jesse, a, Person)) should be true, while has((?s, a, Agent)) should be false.
  // {resolved} Whether or not the pattern matching must be resolved. Default is false
  has(quad: RDF.BaseQuad, resolved?: boolean): boolean;
  // Resolves when any pattern matching {quad} is resolved
  awaitPattern(quad: RDF.BaseQuad): Promise<void>; 
}

I think this will also be useful in the core of Comunica @rubensworks. Rather than caching AsyncIterators for remotely retrieved data, it can instead be cached inside an N3Store; and retrieved patterns are stored in the data structure adhering to the above interface.

[github-actions]

Thanks for the suggestion!

[rubensworks]

Important to keep memory in mind here. The implementation of this could require some kind of lru-cache.