An Ecore model basically consists of an EPackage containing EClasses, EDataTypes and EEnums (see the section on EMF for more details) and describes the structure of the instantiated objects.
Such object-graphs are instances of EMF Ecore models. Xtext parsers create in-memory object graphs while consuming text.
An Xtext grammar can declare another existing grammar to be reused. The second aspect that can be deduced from the first line of the grammar is its relationship to other languages. xtext file has to reside in a Java source folder to be valid. Domainmodel.xtext and must be placed in a package on your project’s class path. The grammar file name needs to correspond to the language name and have the file extension. This means that the name can be any valid Java qualifier. Xtext leverages Java’s class path mechanism. The first line declares the name of the language. Language DeclarationĮach Xtext grammar starts with a header that defines some properties of the grammar. In the following the different concepts and syntactical constructs of the grammar language are explained. Of course the Xtext grammar language itself is implemented with Xtext, so you will find parts of its syntax described with its own means in this documentation.Īn example grammar is shown in the 15 Minutes Tutorial. This model will be created by the parser on-the-fly when it consumes an input file. The main idea is to describe the concrete syntax and how it is mapped to an in-memory representation – the semantic model. It is a domain-specific language, carefully designed for the description of textual languages. The grammar language is the corner stone of Xtext.
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