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Xactium

xDSLs Run Models Not Code

Tony Clarktony.clark@xactium.com

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Overview

Developments in Modelling Technology

xDSLs – A Modelling Methodology

Xactium.

xDSL Technology.

Details of an Application: The Xactium BMS Product.

Conclusion

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Modelling Technology Development

Assembler

HLLs

Symbolic OO

Scripting

StructuredDesign

OOD FormalExecutable

UML

MDA

DSLAgile

xDSL

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Generate Code From Models

CompilerCompiler

Platform

SourceCode

SourceCode

bin

System Model

System Model

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Run the Model

SystemModel

SystemModel

Platform

xDSL EngineCompilerCompiler

SourceCode

SourceCode

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Code Generation

Pros– Stand-alone.– Arbitrary extension.– No-proprietary platform.– Efficiency.

Cons– Complexity.– Platform Dependence.– Two Representations.– No Domain Specific Semantics.– Difficult to provide tool support.– Difficult to dynamically update.

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xDSLsPros:

Complete Model of application.Mix of graphical and textual syntax.Can be used for simulation, analysis, real app or code gen.High fidelity.Single representation.Dynamic updates.Reduced time and increased agility.Technology agnostic.

Cons: Careful about proprietary engines.Careful about efficiency.Careful about expertise.More effort up front.

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Xactium

Provide model-based solutions.

Eclipse based applications.

Started in 2003.

Developed an xDSL engine – XMF.

New product for 2007: Business Motivation Solution (BMS)

Require model based technology to be agile and flexible.

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Xactium -Applications

Applications:

Aerospace Integrated Modular Avionics – configuration checking.

Testing – run the test case models against application.

Application Simulations – e.g. satellite payload.

Business Management Information – match goals and information system to progress.

Service Oriented Architecture – executable design of component interfaces.

Interactive Applications – agile system development through incremental process definition.

Transformation: XMI transformation against a proprietary API.

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An xDSL ExampleXactium-BMS answers questions WHAT and WHY in business planning.

Applications include: – Mergers and Acquisitions.– Verification of Standards.– Business Plan Analysis.– Impact Analysis.– Planning and Monitoring Business Change.

BMS based on emerging BMM OMG standard that includes many business concepts.

BMS-Solutions rely on technology for flexible and complex analysis of the concepts.

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BMS Concepts: Goals

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BMS Concepts: Sub-Goals

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BMS Concepts: Tactics

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BMS Concepts: Units

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BMS Solution Rules

A business goal g is OK when:– It has at least one supporting tactic t; and– The tactic is established by an organization unit.

A business goal g is OK when all its child goals are OK.

An organization unit uses a single unit of resource for each tactic it establishes.

An organization unit cannot use more resource than it owns.

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Demo

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BMS as an xDSL Application

BMS has DSL syntax: the diagrams.

Code generation not appropriate – want to interact with the models.

Interaction and analysis involves an engine that processes BMM data.

Example is just one of many different ways of analysing BMM information.

Require technology that supports flexible dynamic processing of BMM models.

xDSL Technology

xDSL can be implemented in any technology. Some are better than others. Xactium uses the following components:

An xDSL architecture consisting of:

Eclipse as a tool platform for standards and inter-operability.

EMF as a basic data format and to generate data editors.

GMF as a means of generating GEF-based diagram editors.

XMF as an xDSL engine.

Graphical Editor(GMF)

Graphical Editor(GMF)

Technology

RepositoryRepository

TextualxDSL Information

TextualxDSL Information

Model DataModel Editors

(EMF)

Model DataModel Editors

(EMF)

xDSLxDSL

EclipseEclipse

Model Execution Engine(XMF)

OutputOutputGraphical xDSLFunctionality

EMF/GMF/XMF Connectivity

EMFModel

GMFModel

MenusPlugin

MenuHandlers XMF

xDSLDef

BMS Tool with xDSL

BMM Model

BMS Results Model

XMF Features

Meta-programming engine.Object-oriented.Extensive high-level programming features.Rich model processing facilities.Language extension facilities.Open architecture.Seamless Java integration.Dynamic.Written in itself.Can be embedded

BMM Class Definitions in XMF

context Root

@Class Goal metaclass JavaClass extends BMM_Element

EMF_Descriptor("BMM.impl.GoalImpl")

@Operation pprintString(model) "Goal " + self.getName() + " is supported by: " + self.getSupported_by().asSeq() ->collect(t | t.getName()) ->separateWith(", ") end

@Operation toString() "Goal(" + self.getName() + ")" end

end

Language Fragments

Selection from a collection:

@Select x:T from Collection when Guard do Bodyelse Alternativeend

Produce a result:

@Result (Goal,Tactic,Unit) Bodyend

Language FragmentsCheck each element in a collection:

@ForAll x in Collection do Bodyend

Use a unit of resource:

@Use(unit)end

Guarded expressions:

@Unless Condition do Bodyend

xDSL Engine@Operation ok(goal,resources,results,succ,fail) @Select tactic:Tactic from goal.getSupported_by() do @Select unit:Organization_Unit from self.getElements() when unit.establishes(tactic) and resources.lookup(unit.getName()) > 0 do @Result(goal,tactic,unit) @Use(unit) end end end else @Unless goal.getComposed_of().isEmpty() do @ForAll child in goal.getComposed_of() do self.ok(child.getName(),resources,results,succ,fail) end end end end end

xDSL Language EngineeringOK manages a table of resources.Use, increments a usage count for a resource.

@Use(Unit) Bodyend

is shorthand for...

let name = Unit.getName() then usage = resources.lookup(name) then resources = resources.bind(name,usage – 1)in Bodyend

Syntax Class

Syntax classes extend the XMF engine:

@Class Use extends Sugar

@Attribute unit : Performable end

@Attribute body : Performable end

@Constructor(unit,body) ! end

end

Grammars

Define a grammar for the syntax class:

context Use

@Grammar extends OCL.grammar

Use ::= '(' u = Exp ')' b = Exp 'end' {

Use(u,b)

}.

end

Desugar the Syntax

Translate Use to the basic language:

context Use @Operation desugar() [| let name = <unit>.getName() then usage = resources.lookup(name) then resources = resources.bind(name,usage - 1) in <body> end |] end

Review

xDSLs is an approach to system development.

xDSLs provide advantages over code gen.

xDSLs can be built using any technology, but…

… some technologies make it easier than others…

…XMF has been designed to support xDSLs

Integrated with EMF/GMF

Xactium planning XMF Open Source edition in 2007.

BMS is an xDSL application based on XMF available in 2007.