Action Language for EMF

ALE is a language to make Ecore metamodels executable. Concretely, ALE allows to “re-open” the EClasses from Ecore metamodels to implement existing EOperations and weave new features or new operations. The main advantage is to split abstract syntax and semantics concerns by weaving new features and implementations on EClasses. The original Ecore files remain unmodified but thanks to the ALE interpreter new elements can be used in the execution of the implemented operations.

Main features of ALE include:

• Executable metamodeling: Re-open existing EClasses to insert new methods with their implementations
• Metamodel extension: The very same mechanism can be used to extend existing Ecore metamodels and insert new features (eg. attributes) in a non-intrusive way
• Interpreted: No need to deploy Eclipse plugins, just run the behavior on a model directly in your modeling environment
• Extensible: If ALE doesn’t fit your needs, register Java classes as services and invoke them inside your implementations of EOperations.

Breathe life into your metamodels!

ALE makes it easy to address a wide range of activities related to model elements manipulation. This includes activities such as:

• weaving operational semantics in metamodel definitions,
• defining model checkers,
• defining model-to-model transformations,
• defining model-to-text transformations.

Open-class mechanism

behavior fsm.dummy.implementation;

open class FSM {

    State currentState;
    String currentEvent;

    override void execute(EList<String> events) {
        'Start'.log();
        self.currentState := self.initialState;
        for(event in events) {
            self.currentState.execute();
            self.currentState :=
                self.currentState.transitions
                    ->select(t | t.event = self.currentEvent)
                    ->first();
        }
        'End'.log();
    }

}