Cross-reference resolution involves several mechanisms. In this section, we introduce the main concepts behind these mechanisms and describe how they interact. We will also write tests to get familiar with cross-reference resolution.
Xtext relies on EMF for the in-memory representation of a parsed program, thus, it is necessary to understand how cross-references are represented in EMF.
In EMF, when a feature is not a datatype (string, integer, and so on), it is a reference, that is, an instance of EReference. A containment reference
defines a stronger type of association. The association is stronger regarding the lifecycle. The referenced object is contained in the referring object, called the container. In particular, an object can have only one container. If you delete the container, all its contents are also automatically deleted. For non-containment references, the referenced object is stored somewhere else, for example...
