Описание тега groovydsl
GroovyDSL is an IntelliJ framework to define the behaviour of end-user DSLs as script files which are executed by the IDE.
GroovyDSL is a framework with a domain-specific language designed to define the behaviour of end-user DSLs as script files which are executed by the IDE on the fly, bringing new reference resolution and code completion logic into the scope of a project. GroovyDSL relies on the Program Structure Interface (PSI), a set of internal classes and interfaces of IntelliJ IDEA, which allow all programming languages to be described in a uniform way.
Taken from the project page.