Breathe life into your metamodels

Weaving behavior into Metamodels with Kermeta

Didier VojtisekTriskell Project-Team

http://www.irisa.fr/triskell

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Outline

Rationale

What is Kermeta?

Kermeta In Action

What For? (task oriented view)

How To? (metamodel oriented view)

Conclusion

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Rationale

● Metamodel technology is well adapted to build tool and to capture DS(M)L concepts (ie. Its abtstract syntax)

● Model, meta-model, meta-metamodel, DSLs, …– Meta-bla-bla too complex for the normal engineer– Designing DSML and associated tool chain is usually done by

software engineer● On the other hand, engineers are familiars with

– OO programming languages (Java,C#,C++,..)– UML (at least class diagram)– May have heard of Design-by-Contract

● Kermeta leverages this familiarity to make Meta-modeling easy for the masses

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Breathing life into Meta-Models

// MyKermetaProgram.kmt// An E-MOF metamodel is an OO program that does nothing

require "StateMachine.ecore" // to import it in Kermeta

// Kermeta lets you weave in aspects// Contracts (OCL WFR)require “StaticSemantics.ocl”// Method bodies (Dynamic semantics)require “DynamicSemantics.kmt”// Transformations

run()

reset()

FSM

name: EString

step()

State input: EString

output: EString

fire()

Transition

initialState

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owningFSM 1 ownedState*currentState

0..1

source

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outgoingTransition

*target

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incomingTransition

0..1

Context FSM inv: ownedState->forAll(s1,s2|s1.name=s2.name implies s1=s2)

aspect class FSM { operation reset() : Void {

currentState := initialState}}class Minimizer {

operation minimize (source: FSM):FSM {…}}

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Outline

Rationale

What is Kermeta?

Kermeta In Action

What For? (task oriented view)

How To? (metamodel oriented view)

Conclusion

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Kermeta, a Kernel to Meta

Actions

Transformations

Constraints

Metadata

Kermeta

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Kermeta:a Kernel metamodeling

language● Strict EMOF extension● 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– Arbitrary complex aspect weaving as a framework

● Still “kernel” language– Seamless import of Java classes in Kermeta for GUI/IO etc.

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Operational semantic

● Operational semantic of MM is expressed into Kermeta which in turn is formalized into F. Fleurey's Phd Thesis– For example : OCL behavior is translated

in Kermeta before evaluation● This operational semantics acts as a

reference implementation

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Outline

Rationale

What is Kermeta?

Kermeta In Action

What For? (task oriented view)

How To? (metamodel oriented view)

Conclusion

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Example

run()

reset()

FSM

name: EString

step()

State input: EString

output: EString

fire()

Transition

initialState

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owningFSM 1 ownedState*currentState

0..1

source

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outgoingTransition

*target

1

incomingTransition

0..1

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class FSM{attribute ownedState : State[0..*]#owningFSMreference initialState : State[1..1]reference currentState : Stateoperation run() : kermeta::standard::~Void is doendoperation reset() : kermeta::standard::~Void is doend}

class State{ reference owningFSM : FSM[1..1]#ownedState attribute name : String attribute outgoingTransition : Transition[0..*]#source reference incomingTransition : Transition#target operation step(c : String) : kermeta::standard::~Void is do end}class Transition{ reference source : State[1..1]#outgoingTransition reference target : State[1..1]#incomingTransition attribute input : String attribute output : String operation fire() : String is do end}

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Example

run()

reset()

FSM

name: EString

step()

State input: EString

output: EString

fire()

Transition

initialState

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owningFSM 1 ownedState*currentState

0..1

source

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outgoingTransition

*target

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incomingTransition

0..1

operation fire() : String

source.owningFSM.currentState := target result := output

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run()

reset()

FSM

name: EString

step()

State input: EString

output: EString

fire()

Transition

initialState

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owningFSM 1 ownedState*currentState

0..1

source

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outgoingTransition

*target

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incomingTransition

0..1

// Get the valid transitions var validTransitions : Collection<Transition> validTransitions :=outgoingTransition.select { t |

t.input.equals(c) } // Check if there is one and only one valid transition if validTransitions.empty then raise NoTransition.new end if validTransitions.size > 1 then raise NonDeterminism.new end // fire the transition result := validTransitions.one.fire

operation step(c : String) : String

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run()

reset()

FSM

name: EString

step()

State input: EString

output: EString

fire()

Transition

initialState

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owningFSM 1 ownedState*currentState

0..1

source

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outgoingTransition

*target

1

incomingTransition

0..1

from var str : String until str == "exit" loop stdio.writeln("current state is " + currentState.name) str := stdio.read("Enter an input string or 'exit'

to exit simulation : ") stdio.writeln(str) if str != "exit" then do stdio.writeln("Output string : " + currentState.step(str)) rescue (ex : FSMException) stdio.writeln("ERROR : " + ex.toString) end end end stdio.writeln("* END OF SIMULATION *")

operation run() : Void

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S1 S3S2

a/b x/y

b/a

y/x

/** * Load a sample FSM from a xmi2 file */operation loadFSM() : FSM is do var repository : EMFRepository init EMFRepository.new var resource : EMFResource resource ?= repository.createResource("../models/fsm_sample1.xmi", "../metamodels/fsm.ecore") resource.load

// Load the fsm (we get the main instance) result ?= resource.instances.oneend

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Improve MM design using Kermeta weaving

● For example to separate abstract syntax from semantic domain

require "FSM.ecore"

aspect class FSM

{

reference currentState : State

operation run() : Void is do

…

end

operation reset() : Void is do

…

end

}

…

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Kermeta workbench● Metamodel engineering environment

– Editors (textual and graphical) (syntax highlighting, autocompletion, …)

– Interpreter, (compiler is under development)– Workflow manager (user customizable

transformation automation)– Various views

● Compatibility with existing MM developed in Eclipse EMF

● Connexion to team and third-party tools to build DSL/DSML– Concrete syntax examples : GMF/Topcased,

Sintaks, …

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Kermeta workbench snapshotK

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Outline

Rationale

What is Kermeta

Kermeta in Action

What For? (task oriented view)

How To? (metamodel oriented view)

Conclusion

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Kermeta: What For?

● Prototype operational semantics of MM– Get an instant interpreter for it– Generative environment for DSMLs

● Complemented with Sintaks & TopcaseD editor generators● Static checking of models & transformations

– Beyond WFR, model type conformance● Does T(MM1 m1) work for a model m2 conforming to MM2?

● Alternative to QVT style Model Transformation● Model level aspect weaving

– The AOSD-Europe Model Aspect Weaver

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Kermeta as a model transformation language

● One of the possible use case of Kermeta– Should allow to express all kind of

transformations● However, the language itself aims to stay

minimal (a kernel for metamodeling)– Specific features (such as rules, …) can be

implemented as a framework or within a MDK● With Kermeta the transformation is

simply an object-oriented program that manipulates model elements

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Transformations directly with Kermeta

Source model

Source Metamodel Target MetamodelTransformation model

MOF + actions ==Transformation Metamodel ==Kermeta metamodel

Target modelTransformation execution

A

B C

:A :C

:C

:H :C

F

D E

H

B C

:F :E

MOF MOF

+ eventual behavior if the source or target

metamodels are expressed with Kermeta

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Model level aspect weaving

● At model level, Aspect Weaving boild down to:– Pattern matching (aka join point detection)

● May be non trivial, with wildcards or semantic based– Model composition

● Respecting WFRs● Kermeta approach

– Arbitrary complex algorithms encapsulated into frameworks for model weaving

– Simple syntax for simple cases● The implementation vector of

AOSD-Europe approaches

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Using aspect weaving to build Kermeta

ExecutableEMOF

M3

M2EMOF

ActionMeta-model

Composition

Primarymeta-model

Promotion

ActionMeta-model

Aspect meta-model

UML

EMOF

EMOF

ExecutableEMOF

ExecutableEMOF

M3

M2EMOF

ActionMeta-model

Composition

Primarymeta-model

Promotion

ActionMeta-model

Aspect meta-model

UML

EMOF

EMOF

ExecutableEMOF

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See PA Muller et al. ,« Weaving executability into meta-models » in Proc. MODELS 2005 for details

See PA Muller et al. ,« Weaving executability into meta-models » in Proc. MODELS 2005 for details

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Outline

Rationale

What is Kermeta?

Kermeta In Action

What For? (task oriented view)

How To? (metamodel oriented view)

Conclusion

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Kermeta Model Development Kits

● How to organize tasks in a consistent fashion around metamodels?

● MDK (Model Development Kit) = an OO/AO framework for a given Metamodel– Implementation of the operations of the

metamodel– Constraints such as WFR– Library of useful transformations for this

metamodel● Ex: interpreter and/or compiler in the case of a

language, …– Provide support for concrete syntax

● tree, graphical and textual editors using Kermeta generators (Sintaks) or thirdparty tools (from TopCaseD)

How

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Examples of MDKs

● Production (operational use intended)– Ecore/Kermeta– Sintaks (concrete syntax <-> model)– RDL (Requirement Description Language)– UML2.1

● Profiles such as SysML, SPEEDS, MARTE– Java5 (complete metamodel based on Spoon)– And also Tracability, CWM, DocBook…

● Research– Pattern matching, advanced model composition,

model testing, …● Demos/Tutorials

– FSM, Logo…

How

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Application example : Logo turtle robot

Static constraints in OCL

Simulator in Kermeta

Result of a simulation interpreted with Kermeta

Input scenario

Embedded source code inside the robot

Result of a real execution

Transformation written in Kermeta

Interaction between the current simulation (Kermeta) and the GUI (Java)

Logo Semantic in Kermeta

AS VMSemantic mapping

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Used in RT projects

● Artist2, the European network of excellence on real-time embedded systems

● UsineLogicielle, a System@tic project where Kermeta based operational semantic is associated to functional requirement for test synthesis purposes.

● Speeds, a European FP6 project for aspect-oriented metamodeling of avionics and automotive systems, including operational semantics aspects

● OpenEmbedd, A French project building a MDE platform for realtime system.

● Mopcom, a French project applying MDE to hardware for generating SOC and introduce dynamic reconfigurability to them.

● Topcased, a consortium that aims to build modelers for avionics and system engineering

How

-to?

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Outline

Rationale

What is Kermeta?

Kermeta In Action

What For? (task oriented view)

How To? (metamodel oriented view)

Conclusion

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Conclusion

● Kermeta is for the normal Software Engineer– Not just for PhDs

● It’s just OO, plus a bit of Aspects and design by contract if needed

● Lets you develop bunches of useful things around metamodels and encapsulate them into MDK– With static type checking through model types

● Kermeta is a no risk approach– Your metamodels stay standard E-MOF MM

● Can use whatever other tools are needed

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Smoothly interoperates Smoothly interoperates with Eclipse/EMFwith Eclipse/EMF

Open Source, available Open Source, available on the INRIA Forgeon the INRIA Forge►Download it Download it now!now! Breathe life into your metamodels

Con

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● Home page– http://www.kermeta.org

● Development page – http://kermeta.gforge.inria.fr/