The document discusses domain-specific languages (DSLs) and model-driven development using the Meta Programming System (MPS). It provides examples of DSL concepts like abstract syntax trees, language modularization, projectional editing, and static semantics. It also outlines features for defining a language in MPS, including structure, editor, code generation, and integration with Java. MPS allows focusing languages on specific domains and processes models instead of text.

1. MPS
Are you talking my language?
Václav Pech

2. Future

4. Code orchestra

5. mbeddr

6. YouTrack

7. Karel

8. High thoughts must have high language.
Aristophanes

9. DSL
A DSL is a focussed, processable language for describing a
specific concern when building a system in a specific domain.
The abstractions and notations used are natural/suitable for the
stakeholders who specify that particular concern.
Markus Voelter

10. Cypher for Neo4j
START john=node:node_auto_index(name = 'John')
MATCH john-[:friend]->()-[:friend]->fof
RETURN john, fof
http://docs.neo4j.org/chunked/milestone/cypher-query-lang.html

11. Grails
Customer.findAllByNameAndAgeBetween('Joe', 20, 40)
class Phone {
....
static belongsTo = [owner : Person]
}

12. Spock (Groovy)
class DataDriven extends Specification {
def "maximum of two numbers"() {
expect:
Math.max(a, b) == c
where:
a|b|c
7|3|7
4|5|5
9|9|9
}}
http://code.google.com/p/spock/

13. JMock
context.checking(new Expectations() {{
oneOf (clock).time(); will(returnValue(loadTime));
oneOf (clock).time(); will(returnValue(fetchTime));
allowing (reloadPolicy).shouldReload(loadTime,
fetchTime); will(returnValue(false));
}});
http://www.jmock.org/expectations.html

14. DSLs with the benefits of General Purpose Langs

15. Abstract Syntax Tree

16. Abstract Syntax Tree

17. Programs are trees
R
Models composed of nodes
A
B
C
E
D
F
G

18. Programs are trees
R
A
IfStatement
condition
Expr
E
body
StmtList
F
G

19. References cross the tree
R
A
B
C
E
D
F
G

20. Languages are sets of concepts
C1
L
Cn
C2
C3

21. Programs and Languages
C1
Cn
R
L
A
C2
Meta-models consist of concepts
B
C
E
C3
D
F
Models consist of nodes
G

22. Programs and Languages
WhileLoop
MethodDef
R
L
A
IfStatement
Meta-models consist of concepts
B
C
E
MethodCall
D
F
Models consist of nodes
G

23. Concept inheritance
C1
C2
L1
C3
C4
L2
C5

24. Domain Hierarchy
D2.1.1 D2.1.2
...
D2.2.1 D2.2.2
D1.1
D1.2
D0
More specialized domains
More specialized languages
...

25. Language modularization
Categorization proposed by Markus Voelter, http://http://voelter.de/

26. Projectional editor
The coding experience is different (better :)
Cooperate with the existing text tool-chain

27. Non-parseable notations

28. Multiple projections

29. Language combinations

30. Language combinations

31. Making Java in MPS better

32. Collections
cities.where({~it => it.startsWith("P"); })
.select({~it => it.toUpperCase(); })
cities.any({~it => it.size() > populationLimit; })

33. Closures
{int => long} fact = {int n =>
if (n == 1) {
return 1L;
} else {
return n * invoke(n - 1);
}
};

34. Date/Time
datetime start = now in (Europe/Berlin);
......
period processingTime = now in (Europe/Berlin) – start;
datetime meeting = now in (GMT) + 2 days
with (hours = 11)
with (minutes = 0)
with (seconds = 0)

35. And a lot more
Tuples
Regular expressions
Builders
XML processing
Unit testing
Custom operators
And others ...

36. Java-MPS interoperability
Java into MPS
Integrate Java sources
Import Java sources
Import a library
Paste Java code snippets

37. Java-MPS interoperability
MPS into Java
Generate into a Java project
IDE plugin

38. Java IDE integration
Design DSLs in MPS
Use them in
–
–
–
–
IntelliJ IDEA
Standalone IDE (on IntelliJ platform)
Web
Eclipse

39. Aspects of language definition
●
Abstract syntax
●
Concrete syntax (editor)
●
Static semantics
●
Constraints
●
Type-system
●
Dataflow
●
Execution semantics / Generator
●
IDE support

40. Aspects of language definition
●
Abstract syntax
●
Concrete syntax (editor)
●
Static semantics
●
Constraints
●
Type-system
●
Dataflow
●
Execution semantics / Generator
●
IDE support

41. Example: Range Iterator

42. Structure
Statement

43. Integration points
Statement

44. Integration points
Expression
numberOfIterations

45. Integration points
Expression
numberOfIterations
StatementList
body

46. Integration points
Expression
numberOfIterations
StatementList
body

47. Structure
Define the abstract syntax
new concepts for nodes to use in the AST

48. Structure
Define the abstract syntax
new concepts for nodes to use in the AST

49. Aspects of language definition
●
Abstract syntax
●
Concrete syntax (editor)
●
Static semantics
●
Constraints
●
Type-system
●
Dataflow
●
Execution semantics / Generator
●
IDE support

50. Editor
Define the concrete syntax
the projection on the screen

51. Styling the editor

52. Aspects of language definition
●
Abstract syntax
●
Concrete syntax (editor)
●
Static semantics
●
Constraints
●
Type-system
●
Dataflow
●
Execution semantics / Generator
●
IDE support

53. Code generation
Java source

54. Code generation
MPS BaseLang
Text generation
Java source

55. Code generation
Closures
Date/Time
Model to model transformation
MPS BaseLang
Text generation
Java source

56. Code generation
Custom 2
Custom 1
Model to model transformation
Closures
Date/Time
Model to model transformation
MPS BaseLang
Text generation
Java source

57. Generator
Transform the new concept into BaseLanguage

59. mbeddr.com

60. What to expect?
Graphical notations
Web-base editor
Eclipse integration
… and a lot more

61. Grasp the subject, the words will follow.
Cato the Elder

62. Questions
Want more?
http://www.jetbrains.com/mps
http://jetbrains.dzone.com
vaclav@jetbrains.com

63. 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/