Chapter 9. Type Checking

In this chapter we will develop a small object-oriented DSL, which can be seen as a smaller version of Java that we call SmallJava. We will use this DSL to show some type checking techniques that deal with object-oriented features such as inheritance and subtyping (type conformance). This will also allow us to learn other features of Xtext grammars and to see some good practices in Xtext DSL implementations.


The language we develop in this chapter is a simplified version of Java, called SmallJava. This language does not aim at being useful in practice and cannot be used to write real programs such as Java. However, SmallJava contains enough language features that will allow us to explore advanced type checking ...

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