@jahed/sparql-engine/dist/engine/stages/path-stage-builder.d.ts

SPARQL query engine for servers and web browsers.

import type { PropertyPath } from "sparqljs";
import { Bindings } from "../../rdf/bindings.ts";
import Graph from "../../rdf/graph.ts";
import type { EngineIRI, EngineObject, EnginePathTriple, EngineSubject, EngineTriple } from "../../types.ts";
import ExecutionContext from "../context/execution-context.ts";
import type { PipelineStage } from "../pipeline/pipeline-engine.ts";
import StageBuilder from "./stage-builder.ts";
/**
 * The base class to implements to evaluate Property Paths.
 * A subclass of this class only has to implement the `_executePropertyPath` method to provide an execution logic for property paths.
 * @abstract
 */
export default abstract class PathStageBuilder extends StageBuilder {
    /**
     * Return the RDF Graph to be used for BGP evaluation.
     * * If `iris` is empty, returns the default graph
     * * If `iris` has a single entry, returns the corresponding named graph
     * * Otherwise, returns an UnionGraph based on the provided iris
     * @param  iris - List of Graph's iris
     * @return An RDF Graph
     */
    _getGraph(iris: EngineIRI[]): Promise<Graph>;
    /**
     * Get a {@link PipelineStage} for evaluating a succession of property paths, connected by joins.
     * @param source - Input {@link PipelineStage}
     * @param  triples - Triple patterns
     * @param  context - Execution context
     * @return A {@link PipelineStage} which yield set of bindings from the pipeline of joins
     */
    execute(source: PipelineStage<Bindings>, triples: EnginePathTriple[], context: ExecutionContext): Promise<PipelineStage<Bindings>>;
    /**
     * Get a {@link PipelineStage} for evaluating the property path.
     * @param  subject - Path subject
     * @param  path  - Property path
     * @param  obj   - Path object
     * @param  context - Execution context
     * @return A {@link PipelineStage} which yield set of bindings
     */
    _buildIterator(subject: EngineSubject, path: PropertyPath, obj: EngineObject, context: ExecutionContext): Promise<PipelineStage<Bindings>>;
    /**
     * Execute a property path against a RDF Graph.
     * @param  subject - Path subject
     * @param  path  - Property path
     * @param  obj   - Path object
     * @param  graph - RDF graph
     * @param  context - Execution context
     * @return A {@link PipelineStage} which yield RDF triples matching the property path
     */
    abstract _executePropertyPath(subject: EngineSubject, path: PropertyPath, obj: EngineObject, graph: Graph, context: ExecutionContext): PipelineStage<EngineTriple>;
}