1. Building Modular and Efficient DSML in Eclipse
Breathe life into your metamodels
Building Modular and Efficient DSML in Eclipse
The KERMETA Experience (v2!)
O. Barais, B. Baudry, J. Bourcier, A. Blouin, B. Combemale, J.-M. Jézéquel,
N. Plouzeau, D. Vojtisek
EclipseCon Europe, Ludwigsburg, Oct 2013

2. Triskell research group

3. Triskell Permanent staff 20 PhD students 4 engineers, 2 postdoc
Olivier Barais (MCF UR1)
Benoit Baudry (CR INRIA)
Arnaud Blouin (MCF INSA)
Johann Bourcier (MCF UR1)
Benoit Combemale (MCF UR1)
Jean-Marc Jézéquel (PR UR1)
Noël Plouzeau (MCF UR1)
Gerson Sunyé (on sabatycal)
Didier Vojtisek (IR INRIA)
20 PhD students
4 engineers, 2 postdoc

4. The Kermeta Workbench: Goals
Offer a generic solution covering most model manipulation needs
Focus of this talk:
Design of DSML
modular and safe
Implementation of DSML
scalable, interoperable and runtime
a workbench dedicated to metamodeling activities
Help building a set of tools for a given domain (metamodel)
Those tools must interoperate with third party tools
Ex: modelers, other transformations,…
Generalize generative and transformation techniques
Use mechanisms that allow to scale up if necessary
Simplify use of design patterns that have proved to be useful for metamodeling activities
Help to detect errors as soon as possible
Building modular and efficient DSL tools with Kermeta
November 18, 2018

5. What our users want to build
Designing a DSML
Editors
(textuals, graphicals, …)
Checkers
(static & dynamics)
Documentation generators
Compilers
What our users want to build
Test generators
Translators
Simulators
Code generators
Analyzers
Etc.
Refactoring
Building modular and efficient DSL tools with Kermeta
November 18, 2018

6. xText, EMFText, GMF, Topcased, Antlr…
Designing a DSML
MOF/Ecore + OCL
Abstract
Syntax
(+ static semantics) * *
Concrete
syntax
Focus on the integration of various concerns and tooling
Kermeta workbench makes it possible to mashup these meta-languages
Dynamic
Semantics
xText, EMFText, GMF, Topcased, Antlr…
QVT*,
Kermeta AL, Java EMF…
Building modular and efficient DSL tools with Kermeta
November 18, 2018

7. What our users want to build
Designing a DSML
Building DSML tools involves several DSMLs at the meta level
Mashup of metalanguages!
We apply AOM at the metamodeling level
Aspect Oriented MetaModeling (AOMM)
Editors
(textuals, graphicals, …)
Checkers
(static & dynamics)
Documentation generators
What our users want to build
Compilers
Test generators
Translators
Simulators
Code generators
Same as building an eclipse tool with the specificity of reusing modeling technology for speeding up the developments.
Organized around a (set of) metamodel(s) representing the domain
Analyzers
Etc.
Refactoring
Building modular and efficient DSL tools with Kermeta
November 18, 2018

8. Designing a DSML Separation of Concerns
A DSML involves several concerns (syntax, semantics…), for many purposes (edition, simulation, generation, interoperability…)
Use appropriate language for each use
Compose them as necessary
Solution in the Kermeta Workbench: Static Introduction
Ecore: abstract syntax (metamodel) is the core language
OCL: constraints (inv., pre-, post-)
Kermeta Action Language: side effects = model manipulation
Additional extension mechanisms : add classes, operations, attributes, property opposite, inheritance …
Composition mechanism :
Model element composition: keyword aspect
Model composition: keyword import AL
Abstract syntax = Ecore or MOF
Static semantic = OCL
Dynamic semantic = Kermeta action language, QVT, java, scala
Kermeta action language : Basically an OO extention to MOF/ecore
+ other Model oriented features
Concrete syntax = GMF/Topcased, xText, EMFtext, antlr,
Merge/aspect directive for combining them
Implementation of the merge to produce the runtime
Compiler
Not to be confused with AspectJ aspects !
Building modular and efficient DSL tools with Kermeta
November 18, 2018

9. Principle of the mashup
context FSM
inv: ownedState->forAll(s1,s2|
s1.name=s2.name implies s1=s2)
aspect class FSM{
reference currentState : State
operation run() : Void is do …
end }
aspect class Transition {
operation fire() : EString is do
source.owningFSM.currentState := target
result := output AL
import "FSM.ecore"
import "FSM.ocl"
import "FSMbehavior.kmt
inv: ownedState->forAll(s1,s2|
s1.name=s2.name implies s1=s2)
Technically speaking, the principle used here is not new anymore (some other tools also do it) but we generalize it
Model of the resulting composition
Building modular and efficient DSL tools with Kermeta
November 18, 2018

10. Action language feature highlightAL
Statically Typed
Generics, Function types (for OCL-like iterators)
Object-Oriented
Multiple inheritance / dynamic binding / reflection
Model-Oriented
Model are first class citizens, notion of model type
Design by contract
Aspect-Oriented
Simple syntax for static introduction
Still “kernel” language
Use JVM/Scala bytecode compatibility for GUI/IO etc.
Building modular and efficient DSL tools with Kermeta
November 18, 2018

11. Separation of concerns using OO Visitor versus AO Visitor
<<Abstract>>
Visitor
visit(e : VisitableElement)
<<Abstract>>Visitable
Element
accept(v : Visitor)
"Visiting " + e.name + "!!"
v.visit(self)
MyCompiler
main()
root 1
MyCompiler
main()
root 1
Concrete
Visitor
visit(e : VisitableElement)
"Compiling " + e.name
"Compiling " + e.name
Concrete
Element
compile()
Ecore-to- EcoreVisitable
Concrete
Element
Illustrates how the aspect weavig mechanism allows simple an elegant design for an equivalent result.
Last but not least, simplified like this, the code is more efficient because its call stack can be shallower.
metamodel.ecore
metamodel.ecore
<<require>>
metamode_ visitable .ecore
Simu1 .kmt
<<require>>
compiler1.java
compiler1.kmt
<<require>>
compiler2.kmt
compiler2.java
Simu1 .java
Building modular and efficient DSL tools with Kermeta
November 18, 2018

12. Implementing a DSML: Mashup of the concerns into bytecode
Probably, the most important slide for the talk at EclipseCon France:
It explain teh integration of the generated code in the Eclipse platform taking into account legacy code. Legacy is :
- Other EMF tools
- EMF bytecode provided by the user (might be customised)
Standard EMF tooling
<<use>> …
Building modular and efficient DSL tools with Kermeta
November 18, 2018

13. Internal workflow + modular Architecture
Kmt parser
Checker
Km loader
Ecore 2 km
Merger
Resolver
KM 2 scala
Scala 2 bytecode
UML profile 2 km
QVT 2 km
KP Project
Orchestration
OCL 2 km
Clean FrontEnd-BackEnd structure
Front end: allows integration of various metalanguages (or language use at the meta level)
Back end: various back end are possible depending on performance and compatibility required
fUML 2 km
Integration
Ket 2 km
Allow integration of new "meta" languages
Customisable with other steps (optimization, slicing,…)
ALF 2 km
Building modular and efficient DSL tools with Kermeta
November 18, 2018

14. Implementing a DSML: Consequence
Runtime is more efficient
Ex Hashtable : no search, ask directly the object
Ex visitor: No more "ping pong" overhead between accept and visit methods
Validation: Java-based vs. Kermeta-based implementation of fUML
fUML samples published by the
Java-based reference implementation
Building modular and efficient DSL tools with Kermeta
November 18, 2018
- 14

15. Conclusion: Kermeta Workbench
Modular design of DSMLs
One meta-language per language concern (import)
Ecore, OCL, Kermeta Action Language
But also: QVTo, fUML, Alf, Ket, Xsd…
Specific architecture supporting this
Static introduction mechanism
Efficient implementation of DSMLs
Mashup of the meta-languages to efficient bytecode
Integrated with third-party tools (EMF compliant)
Building modular and efficient DSL tools with Kermeta
November 18, 2018

16. Conclusion: Kermeta Action Language
Provides a model oriented action language
to implement (E)Operation’s bodies
allows common model manipulation tasks
Imperative, statically typed, object-oriented, aspect-oriented (aspect, context), model-oriented, DbC, Unit testing
Java and Scala compliant
EMF based
Run as Eclipse plugin or as standard Java application
Building modular and efficient DSL tools with Kermeta
November 18, 2018

17. Ongoing work: Extend and compile Model Type
reusable
transformation
A metamodel is used to:
Build a model
Type a model (aka model type)
A metamodel is substitutable to another through a matching relation (extended from the one introduced in OO between “type groups” [Bruce et al.])
Provide the typing facilities in software language engineering
from abstraction, reuse and safety
to impact analyses and auto-completion)
4 matching relations according to two orthogonal criteria:
total vs partial
(subgraph) iso vs non-iso
Model
TypeC
reusable
transformation
<<matches>>
Model
TypeA
Meta
ModelA
Model
TypeB
<<matches>>
<<conformsTo>>
<<typedBy>>
<<typedBy>>
ModelA
ModelB
Building modular and efficient DSL tools with Kermeta
November 18, 2018

18. Breathe life into your metamodels
Conclusion Kermeta
Smoothly interoperates
with Eclipse/EMF
Open Source, available on the Inria Forge
V2.1.0
Breathe life into your metamodels
Home page
Development page
18 novembre 2018-

19. Questions ?