keynote extreme modelling 2014

Putting Engineering into MDE

Components and contracts for models and transformations

Steffen Zschaler

29 September, 2014With (lots of) help by

Francisco Duran, Jeffrey Terrell, Jendrik Johannes, Dimitris Kolovos, and many others

All errors my own!

(c) Steffen Zschaler

Motivation

• MDE is beginning to see some use– Automotive– Telecommunications– Enterprise systems (especially for quality prediction)

• Need for systematic engineering– To deal with scale of models– To deal with complexity of domains– To ensure correctness so MDE techniques can be

relied on

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Motivation (2)

• Elements of systematic MDE engineering– Requirements– Architectures– (Reusable) Components– Patterns and Architecture Styles– Methods and Guidelines

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A framework for discussing composition

Uwe Aßmann: Invasive Software Composition.29/09/2014 4



Component Model

(incl. contracts)




Composition Model(composition

technique)

Component Model

(incl. contracts)




Composition Language


technique)

Component Model

(incl. contracts)




Composition System

Composition Language


technique)

Component Model

(incl. contracts)



Outline

1. Motivation

2. Models

3. Transformations

4. Challenges

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Outline

1. Motivation

2. Models

3. Transformations

4. Challenges

1. Composition techniques2. Contracts

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Model components

• Variety of approaches– Model/Package Import– AOM

• Package Merge• Language-specific merges

– E.g., for sequence diagrams– RAM, MATA, ...

• Generic merges– E.g., GeKo, Reuseware, ...

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Model componentsExample 1

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(c) Steffen Zschaler29/09/2014 8

Model componentsExample 2


Model componentsContracts?

• Only syntactical, if any– Meta-classes of elements expected– Naming and signatures of operations

• Key exception: Rely-Guarantee Specifications– For temporal logic and state machines

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Syntactic Contracts

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Outline

1. Motivation

2. Models

3. Transformations

4. Challenges

1. Composition techniques2. Contracts

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Transformation Composition

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InternalExternal

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InternalExternal

Sequential

T1

M

1

M

2

M

3

T2

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InternalExternal

Sequential Rule Superimposition(aka import with replacement)

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InternalExternal

Sequential Rule Superimposition(aka import with replacement)

M

2

M

1

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InternalExternal

Sequential Parallel Rule Superimposition(aka import with replacement)

T1

M

1

M

2

M

3

T2

M

4

M

5

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InternalExternal


Rule Weaving(aka full aspect orientation)

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InternalExternal


Rule Weaving(aka full aspect orientation)

M

2

M

1

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Transformation CompositionSequential

OO to Relational

Class Model

Table Model

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Table Model

NormalisedTable Model

Normalisation

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OO to Relational

Class Model

Table Model


Normalisation

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Parallel

Based on Jendrik Johannes, Steffen Zschaler, Miguel A. Fernández, Antonio Castillo, Dimitrios S. Kolovos, Richard F. Paige: Abstracting Complex Languages through Transformation and Composition. MODELS 2009, LNCS 5795, pp 546–550.

:Table

<<hook>>:Column

*


Parallel


:Table

<<hook>>:Column

*:Class


Parallel


:Table

<<hook>>:Column

*:Class

:Attribute


Parallel


<<anchor>>:Column

:Table

<<hook>>:Column

*:Class

:Attribute


Parallel


<<anchor>>:Column

:Table

<<hook>>:Column

*:Class

:Attribute

:Classsuper

sub


Parallel

<<anchor>><<slot>>:Table

<<hook>>:Column

*


<<anchor>>:Column

:Class

:Attribute

:Classsuper

sub


Parallel


<<hook>>:Column

*


<<anchor>>:Column


<<hook>>:Column

*

:Class

:Attribute

:Classsuper

sub


Parallel


<<hook>>:Column

*


<<anchor>>:Column


<<hook>>:Column

*

:Class

:Attribute

:Classsuper

sub

Weaving

Weaving



Superimposition

Based on Lawley, M., Duddy, K., Gerber, A., Raymond, K. Language Features for Re-Use and Maintainability of MDA Transformations. OOPSLA & GPCE Workshop, 2004

and: Jouault, F. and Kurtev, I. Transforming models with ATL. In: Satellite Events at the MoDELS 2005 Conference, Oct 2005, Montego Bay, Jamaica. pp. 128-138, LNCS 3844 (long version from http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.99.6117&rep=rep1&type=pdf )

module Class2Relational;create OUT : Relational from IN : Class;

rule Class2Table { from c : Class!Class to out : Relational!Table ( name <- c.name, col <- Sequence {key} ->union(c.attr)), key : Relational!Column ( name <- 'objectId', type <- objectIdType)}

rule Attribute2Column { from a : Class!Attribute to out : Relational!Column ( name <- a.name, type <- a.type)}

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http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.99.6117&rep=rep1&type=pdf



Superimposition






module Class2RelationalInheritance;create OUT : Relational from IN : Class;

rule Class2Table { from c : Class!Class ( c.parent.oclIsUndefined()) to out : Relational!Table ( name <- c.name, col <- Sequence {key} ->union(c.flattenedFeatures)), key : Relational!Column ( name <- 'objectId', type <- objectIdType)}

-- flattenedFeatures helper not shown.-- It collects all features of a class-- and all its sub-classes

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Superimposition







rule Class2Table { from c : Class!Class ( c.parent.oclIsUndefined()) to out : Relational!Table ( name <- c.name, col <- Sequence {key} ->union(c.flattenedFeatures)), key : Relational!Column ( name <- 'objectId', type <- objectIdType)}


-- flattenedFeatures helper-- not shown...

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(c) Steffen Zschaler29/09/2014


Weaving

16


Contracts

• Need both syntactical and semantic contracts

• Goal:– Be precise enough to enable reasoning and

give assurances– Be lenient enough to maximise reusability

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Contracts (2)

Will look at two types of contracts:– Syntactic contracts for sequential composition

(aka model typing)– Semantic contracts for rule weaving

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Contracts for sequential composition

• Contracts specify the kinds of models read and written by a transformation

• Options:1. Meta-models

2. Effective meta-models

3. Model types / Concepts

OO to Relational

Class Model

Table Model


Normalisation

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Model typing problems

mmo NewSM (s : Simple) { s += new StateMachine ()}

S. Zschaler: Towards Constraint-Based Model Types: A Generalised Formal Foundation for Model Genericity.In VAO’14



StateMachineState

name: String

Transitionevent: String

initialState0..1

containedState *

src 1

tgt1

incoming*

*outgoing




StateMachineState

name: String


initialState0..1

containedState *

src 1

tgt1

incoming*

*outgoing

Difference between Simple and Mandatory-startMandatory-start <:Steel Simple




StateMachineState

name: String


initialState0..1

containedState *

src 1

tgt1

incoming*

*outgoing

Difference between Simple and Mandatory-start

Error: Allows passing in Mandatory-start instance, but breaks it.

Mandatory-start <:Steel Simple


mmo NewSM (s : Simple) { sm := new StateMachine () ; sm.initialState += new State () ; s += sm}


StateMachineState

name: String


initialState0..1

containedState *

src 1

tgt1

incoming*

*outgoing

Difference between Simple and Mandatory-startMandatory-start <:Guy Simple


mmo NewSM (s : Simple) { sm := new StateMachine () ; sm.initialState += new State () ; s += sm}


StateMachineState

name: String


initialState0..1

containedState *

src 1

tgt1

incoming*

*outgoing

Difference between Simple and Mandatory-start

Over-restriction: Would work with Mandatory-start instance, but cannot specify.

Mandatory-start <:Guy Simple



Syntactic contracts:Research challenges

• Type theory of transformations– Including intrinsic and extrinsic contracts

• Static analysis of transformations– Data flow analysis

• Tool support for managing and checking transformation contracts

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Contracts for rule weaving

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Contracts for rule weaving

• Morphisms over transformation systems– Both for parameter and bindings

• Define Properties of morphisms to ensure semantics of weaving– Behaviour reflection and preservation

Semantic contracts

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• Other semantic properties– Allow some change of behaviour– Express behaviour of base parametrised over

transformations to be woven

Semantic contracts:Research challenges

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τM1 M2

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τM1 M2

ζ

sem1 sem2

Γ1 Γ229/09/2014 24





τ(τ1, .. , τn)

f(ζ1, .. , ζn)

M1 M2

ζ

sem1 sem2

Γ1 Γ229/09/2014 24


Outline

1. Motivation

2. Models

3. Transformations

4. Challenges

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Research Agenda

• Need a calculus of transformation components– What do they look like?– What composition operations are there?– What are contracts?– What properties can we derive for composite transformations?

• Some work exists:– See talk– Megamodelling (e.g., MINNT for typing)

• But are still missing fundamental theory

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(c) Steffen Zschalerhttp://xkcd.com/1343/

29/09/2014