DSL Tools in Visual Studio Stuart Kent Senior

DSL* Tools in Visual Studio Stuart Kent Senior Program Manager Visual Studio Team System – DSL Tools http: //blogs. msdn. com/stuart_kent http: //lab. msdn. microsoft. com/vs 2005/teamsystem/workshop/dsltools/ * DSL = Domain Specific Language

What is a domain? Business Systems Real-Time Systems Requirements Specification Aircraft control systems Airline Baggage Handling Systems Insurance Management Systems Implementation Deployment

What is a language? ¶C(x) h 2 ¶ 2 C(x) ih = – ¶t 2 m ¶ x 2 a>b && c==d Declarative jo biscuits 24 green pat cakes 32 pink <Call. Record> <caller><number>07713248</number> Textual Employee name address promote 0. . * Job description pay assign Pictorial Call Record base rate: £/s class Magnox : Nuclear. Power. Station { public void drop. Rods () call length call Procedural store

Domain Specific Languages (DSLs) make problems “Small Scale” Small scale = Not much design beyond existing platform easy to understand agile small team early prototypes easy maintenance changes inexpensive

Finding prime numbers is Small Scale … If we have a system that can: do multiplication and division do things repeatedly _*_ _/_ while (…) {…} platform: Von Neumann computer with conventional CPU _%_ language: C, Pascal, Fortran, …

Finding parts lists is Small Scale … If we have a system that can: keep large lists of parts & scan them quickly combine and filter the lists efficiently JOIN … … WHERE … platform: Relational Database CREATE … SELECT … language: SQL

Developing a GUI is Small Scale … If we have a system that can: display combinations of windows and widgets show things and interact with user in them platform: Interactive app platform language: Visual programming languages

Phone billing systems are Small Scale … if we have a language of phone billing Call Record base rate: £/s Telephone Billing Scheme call length store call friend discount rate: £/s calendar month other calls - friends call length store billing period Phone Billing Engine and a platform to run it on

Using a domain specific language 7 prospect initiated prospective sale prospect cancels 1 week delay overflow accumulator 4 Sat weeklyempty £ 30 £ 20 £ 31 salesperson’s account monthly pay customer bank a/c animator generator tweak hack prototype for review phone bill system tablet PC customer -facing developer

Other things you can do… 7 prospect initiated prospective sale prospect cancels 1 week delay overflow accumulator Sat generator list of parts generator business plan 4 weeklyempty £ 30 £ 20 £ 31 salesperson’s account monthly pay bank a/c animator prototype for review C#, Java C# C# generator phone bill system XML SQL mixed code and config files

Other inputs to generation functional model 7 prospect initiated prospective sale prospect 1 week delaycancels overflow accumulator 4 Sat empty weekly £ 30 £ 20 £ 31 salesperson’s account monthly pay bank a/c refine animator functional model refined/augmented for performance data model generator existing api model tweak etc hack prototype for review phone bill system

“Mind The Gap” – DSLs & Code Generation Model Generated Code Application Generated Code Framework Domain Specific Framework Pattern Framework Language Platform Platform Frameworks (a) (c) Model Generated Application Code Generated Application. Code Generated Code Platform Platform Frameworks (b) (d)

What are (could) DSLs (be) used for? To write models that drive code generators Configuring code frameworks, configuring deployment DSL unifies points of variability scattered amongst artefacts Delivers software product lines To write interpreted configuration files Often expressed in XML To provide a domain-specific abstractions for the purposes of… Simulation/animation Monitoring system execution What-if analysis Metric taking Generating business plans and reports … As part of a software factory Combines all of the above

How are DSLs implemented now? XML Syntax very raw, no graphics Validation weak Multiple cross-referencing docs are difficult to manage N. B. Required for large models in a team environment UML profiles (UML + stereotypes / tagged values) XML persistence ugly & hard to handle Stereotypes / tagged values not very powerful UML profiles can bear little semantic resemblance to mainstream UML Game of square peg in round hole Packaging in UML is not so conducive to working with large models in a team environment

How are DSLs implemented now? MOF/EMF Deals with conceptual aspects of language Rest of designer/editor is hand-coded In meta-environments Releases a meta-monster that can be hard to tame Often doesn’t scale to large models in a team environment Tools not integrated into familiar IDEs

DSL Tools in Visual Studio – V 1 To make it cost-effective to develop DSLspecific, visual designers hosted in Visual Studio For SI’s & large enterprises (at least) For a particular class of DSLs In a way that makes the model data easily accessible by automation tools, that are easy to author using XML and/or. Net technology In a way that enables working with large models in a team environment To make it cost-effective to author DSL-driven code/artefact generators

Mainline scenario

Demo We’ll build a designer from scratch Here’s a screenshot of the target designer…

DSL Tools in Visual Studio Stuart Kent Senior Program Manager Visual Studio Team System – DSL Tools http: //blogs. msdn. com/stuart_kent http: //lab. msdn. microsoft. com/vs 2005/teamsystem/workshop/dsltools/