MPS

Domain Specific Languageswith pleasure

Václav Pech

JetBrains MPS

High thoughts must have high language.

Aristophanes

Your vocabulary reflects the way you thinkSeth Godin

[Embedded Software]mbeddr

[Data analysis]MetaR

[Business Application]Insurance Configuration Tool

[Business Application]Insurance Configuration Tool

<no variables> <no parent>

<no libraries>

<no business objects>

<no parent>

[Business Application]Insurance Configuration Tool

Notations for DSLs

● Text● Diagrams● Tables● Forms● Mixtures of all● …

The number and the type of the basic colour words of a language determine how one sees the rain bow

Programs are trees

R

A B

C D

G

R

E F

Programs are trees

R

A B

C D

G

R

E F

Children have roles

R

A IfStatement

Expr StmtList

G

R

E F

condition body

References cross the tree

R

Routine def B

Call D

G

R

E F

Languages are sets of concepts

C1

C2C3

Cn

L1

L2

Programs and Languages

R

A B

C D

G

R

E F

C1

C2C3

Cn

L

Models consist of nodes

Meta-models consist of concepts

IntelliJ IDEA inspections

Groovy AST transformations

Groovy AST transformations

There's no life without trees

● Extending IDEs● External DSLs● Internal DSLs in modern languages

● Groovy AST transformations● Scala macros● Lisp, Clojure macros● Lombok

Notations for DSLs

● Text● Diagrams● Tables● Forms● Mixtures of all● …

Parsing is the bottleneck

… of language expressiveness

Editing text

Parsing

Programs are trees

R

A B

C D

G

R

E F

WhileLoop

MethodDef

MethodCall

L IfStatement

Models consist of nodes

Meta-models consist of concepts

Editing trees directly

Projecting

by Jens Nerche @jensnerche

Rich syntaxes

Combine languages

Multiple notations

Parsing is the bottleneck

… of language expressiveness

● Limits the possible syntaxes● Allows only one editable code visualization● Complicates combining languages

Aspects of language definition

● Abstract syntax● Concrete syntax (editor)● Static semantics

● Constraints● Type-system● Dataflow

● Execution semantics / Generator● IDE support

Books

● http://books.campagnelab.org

● http://dslbook.org

https://www.jetbrains.com/mps/publications

Books

● http://books.campagnelab.org

● http://dslbook.org

← He is a Biologist!

https://www.jetbrains.com/mps/publications

The limits of language are the limits of one's worldLudwig Wittgenstein

Questions

Want more?

http://www.jetbrains.com/mps

@vaclav_pech

Image credits

http://www.flickr.com/photos/horiavarlan/4329908160/sizes/m/in/photostream/

http://www.flickr.com/photos/pink_floyd/2409134519/sizes/m/in/photostream/

http://www.flickr.com/photos/atache/4124732863/sizes/m/in/photostream/

http://www.flickr.com/photos/a_ninjamonkey/3294014627/sizes/m/in/photostream/

http://www.flickr.com/photos/carlc/1968636137/

http://www.flickr.com/photos/tasuki/3503304405/sizes/m/in/photostream/

http://www.flickr.com/photos/bmwccgb/5069454884/sizes/m/in/photostream/

http://www.flickr.com/photos/rpmarks/3932013183/sizes/m/in/photostream/

http://www.flickr.com/photos/orqwith/4325166853/

https://www.flickr.com/photos/charlestilford/732688216