Using PowerShell as DSL in .Net applications

Joy George K

Jr.Architect, Orion India Systems

www.joymononline.in , joymon@gmail.com

PowerShell as DSL in .Net– What is DSL?

A computer language that's targeted to A particular kind of problem, rather than A general purpose language that's aimed at any kind of software problem. Domain specific languages have been talked about, and used for almost as long as computing has been done.

Martin fowler

PowerShell as DSL in .Net – What can be DSL

• Excel macros• SQL• CSS• RegEx• .Bat files

PowerShell as DSL in .Net – Why its needed?

• Make the users as programmers.• Tackle ever changing requirements• Easy maintainability• Extensibility ?• …

PowerShell as DSL in .Net– Internal & External

• Internal• Uses existing special language constructs to achieve• Fluid API

• eg : Linq (entries.Where(e => e.Approved) .OrderBy(e => e.Rating)

.FirstOrDefault())• External

• Uses different language• Special parsers

PowerShell as DSL in .Net – Arch

DSL EngineCore app

Files

Objects and DSL script

Return objectsAlter objects, prepare result

DSL

PowerShell as DSL in .Net – Selecting my DSL

• Internal v/s external• If External

• Creating custom parser, compilers• Leverage existing scripting languages

PowerShell as DSL in .Net - Demo

• External DSL• PowerShell as DSL scripting language

• Inbuilt in Windows vista onwards• Pipeling support which helps to write less

PowerShell as DSL in .Net – Pros and Cons

• Pros• Easy customization / extensibility.• Relief from frequent requirement changes.

• Cons• Performance• Maintenance overhead, if its external own DSL• No auto completion

PowerShell as DSL in .Net – Referenceshttp://martinfowler.com/books/dsl.htmlhttp:// joymonscode.blogspot.in/2013/01/what-is-domain-specific-language-dsl-in.html

http:// joymonscode.blogspot.in/2013/01/dsl-demo-first-c-application-which-uses.html

DSLs in Action by Debasish Ghosh

Are you ready to try DSL in your project ?

PowerShell as DSL in .Net – Q & A

Thank YouJoy George K

Jr.Architect, Orion India Systems

www.joymononline.injoymon@gmail.com