Metamodel pattern matching example: Ecore Queries

Overview

Have you ever tried to query a meta-model, i.e. a model consisting of EClasses, EAttributes, and EReferences, against a meta-model pattern? For an example, look here. In this case, we want to look for a certain sub-configuration in an Ecore metamodel, where two EClasses (each having an EAttribute of type EString) are connected by a 0-* EReference.

Use-cases of this technique include meta-transformation, meta-model analysis, higher-order transformations where transformation rules are generated/parameterized by metamodel analysis etc.

We would like to sincerely thank Christian Schweda for the inspiration for this example.

Obtaining the example

Make sure you run the latest IncQuery tooling and runtime by downloading and installing from the nightly update site.

Check out the source project from GitHub:

• https://github.com/csurgotamas/EMF-IncQuery-Example/

Running the example

1. Import the ecorequery project into your workspace.
2. There is a file in src/hu.bme.mit.incquery.ecorequeries.example directory: queries.eiq, right click on this, select EMF-IncQuery queries | Register patterns in Query Explorer.
3. There is a useful, pre-prepared .ecore file in the models/sample directory: My.ecore. Open it, after that click on Load model in Query Explorer View (if you could not see this view then go to Window->Show View->Other->EMF-IncQuery->Query Explorer) .
4. You should see the match of the pattern according to the specification found in hu.bme.mit.ecorequery/spec/example.pdf in Query Explorer view.