@comunica/mediator-combine-pipeline

Comunica Mediator Sequential

A comunica mediator that goes over all actors in sequence and forwards I/O. This requires the action input and the actor output to be of the same type.

This module is part of the Comunica framework, and should only be used by developers that want to build their own query engine.

Click here if you just want to query with Comunica.

Install

$ yarn add @comunica/mediator-sequential

Configure

After installing, this mediator can be instantiated as follows:

{
  "@context": [
    ...
    "https://linkedsoftwaredependencies.org/bundles/npm/@comunica/mediator-combine-pipeline/^4.0.0/components/context.jsonld"
  ],
  "actors": [
    ...
    {
      "@type": "SomeActor",
      "someMediator": {
        "@id": "#mediatorOptimizeQueryOperation",
        "@type": "MediatorCombinePipeline",
        "bus": { "@id": "ActorOptimizeQueryOperation:_default_bus" }
      }
    }
  ]
}

Config Parameters

• bus: Identifier of the bus to mediate over.
• filterErrors: Optional flag to indicate if actors that throw test errors should be filtered out of the pipeline, defaults to false.
• field: Optional field to use for ordering (if the ordering strategy is chosen). Leave undefined if the test output is a number rather than an object.
• order: Optional strategy of ordering the pipeline (increasing or decreasing).
  • For choosing to leave the order of the pipeline unchanged, leave this undefined.
  • For choosing to order by increasing values: 'increasing'.
  • For choosing to order by decreasing values: 'decreasing'.

Changelog

v4.0.2 - 2024-10-16

Changed

• Document that algebra inputs should not contain blank nodes, Closes #1234

Fixed

• Fix some zero-or-more path queries producing empty results, Closes #1449

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