Various Eclipse Modeling technologies are trying to empower domain experts in the creation of specific tools. Using EcoreTools and Sirius a domain expert can define languages, graphical modelers and editors without writing a single line of Java code or launching a new Eclipse runtime. However, when come the time to add behaviors to the language structure (e.g., to implement interpreters, compilers, static analysis, refactoring, or generators), the domain expert has to face all the complexity of Eclipse Plugin development, OSGi, Java and much more.
This is a no-go in some contexts and as such there was a sweet spot for a new technology in Eclipse Modeling that support a seamless mechanism to weave behaviors across (Ecore-based) language structure.
This talk will present an integrated approach for weaving behavior of domain specific languages right from the EcoreTools modeler, that can be automatically applied to conforming models while having the following novel characteristics:
Domain experts are able to weave the behaviors across the language structure, seamlessly supporting the definition of a visitors for any kind of purposes.
No need for code generation, any change is instantly reflected and can be tested right away, even on Dynamic Instances
Strong optional validation, fast evaluation
"on demand" extension through Java services
behavior definition which is non-intrusive to the Ecore model
complemented by a first prototype of a dual compiler that seamlessly complement the EMF generation results.
The talk will demo the creation of a DSL and its behavior through the use of these plugins which are extending EcoreTools. The design of the language will also be discussed as it is embeds the Eclipse "aql" query language, leverage union types and type inference and can itself be integrated in other contexts. The audience will leave with a clear understanding of how they could define the behavior of their DSL using this technology, how it compares to approaches like Xcore/Xbase and when it could be part of the Eclipse release.
The technology is currently considered as good enough for experimenting and is being contributed to Eclipse Modeling through the EcoreTool project.
3. 3
ALE : Action Language for EMF
Complement an Ecore metamodel
➢ with Runtime Data
➢ by implementing EOperation
4. 4
What is ALE ?
Ale is a type of beer brewed using a warm fermentation method, resulting in
a sweet, full-bodied and fruity taste.
– Wikipedia
5. 5
What is ALE ?
Integrated to EcoreTools
Define behavior
over metamodel
➢ Interpreted Language
➢ Static typing, type inference
➢ Open class support
open class FSM {
def void foo() {
State currentState := … ;
if (currentState.oclIsKindOf(Initial)) {
Initial state := currentState; //valid statement
}
}
}
Action Language for EMF
8. 8
Write implementation
is not that easy
➢ Modify generated code
➢ Configure the code generation
➢ Use delegation mechanism
➢ Use the generated Switch
➢ Use other tools
Generate code and then:
9. 9
Write implementation
is not that easy
➢ Modify generated code
➢ Configure the code generation
➢ Use delegation mechanism
➢ Use the generated Switch
➢ Use other tools
You have to master the compilation chain
Generate code and then:
18. 18
ALE is two things:
➢ Open Class
➢ Action Language
19. 19
AQL
● EMF Language in Eclipse Acceleo
– Navigate & Query model
– Lightning speed evaluation, strong validation
● Expression
● Lambda
● Easy extension through services mechanism
● Interpreted
– No code generation needed
(x.tokens > 0) or ( x.tokens = -1)
myCollection.select(elem | elem.tokens = -1)
obj.myNewService()
Acceleo Query Language
20. 20
ALE extends AQL
AQL is an expression
language
➢ No side effects
➢ Assignements
➢ More control flow
➢ Multi-inheritance
➢ Runtime data
➢ Type inference
ALE provides :
22. 22
Summary
➢ Made an Executable FSM from scratch
Beyound this presentation
➢ Website
http://gemoc.org/ale-lang/
➢ Animated execution & Debugger
https://www.eclipse.org/sirius/lab.html
Perspectives
➢ Maturate to industrial grade
Contribution to EcoreTools
➢ Compiler: Open class to Java code
