Just a few simple slides for a presentation at Kraków's Scala User Group. The rest of the session is live coding where we reimplement a tiny subset of Rogue, Foursquares MongoDB DSL.

1. Scala DSLs
Dissecting Rogue
Konrad Malawski / @ktosopl
GDG / PJUG / KSUG / SCKRK
ScalaCamp 23.01.2012
Wednesday, December 26, 12

2. Wednesday, December 26, 12

3. Querying Mongo
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4. Querying Mongo
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5. Querying Mongo
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6. Querying Mongo
QL = Plain JSON
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7. Querying Mongo
QL = Plain JSON
JavaScript Console
Wednesday, December 26, 12

8. Querying Mongo
QL = Plain JSON
JavaScript Console
Java Driver
Wednesday, December 26, 12

9. Querying Mongo
QL = Plain JSON
JavaScript Console
Java Driver
Casbah = Scala Driver
Wednesday, December 26, 12

10. Querying Mongo
QL = Plain JSON
JavaScript Console
Java Driver
Casbah = Scala Driver
... used by Rogue
Wednesday, December 26, 12

11. Querying Mongo: JS
Console API
Wednesday, December 26, 12

12. Querying Mongo: JS
db.inventory.find( {} )
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13. Querying Mongo: JS
db.inventory.find( {} )
“find all”
Wednesday, December 26, 12

14. Querying Mongo: JS
db.inventory.find(
{
qty: { $gt: 20 }
}
)
Wednesday, December 26, 12

15. Querying Mongo: JS
db.inventory.find(
{
qty: { $gt: 20 }
}
)
gt means >=
Wednesday, December 26, 12

16. Querying Mongo: JS
db.pople.find(
{
age: { $gte: 20 },
$or: [
{ name: “Ken” },
{ name: “Kenshiro” },
{ city: “Tokyo” },
...
]
}
)
Wednesday, December 26, 12

17. Querying Mongo: JS
db.pople.find(
{
age: { $gte: 20 },
$or: [
{ name: “Ken” }, $or may contain any clause
{ name: “Kenshiro” },
{ city: “Tokyo” },
...
]
}
)
Wednesday, December 26, 12

18. Querying Mongo: Java
Java API
(Morhpia)
Wednesday, December 26, 12

19. Querying Mongo: Java
ds.find(Employee.class).field("manager").equal(null).get();
Wednesday, December 26, 12

20. Querying Mongo: Java
ds.find(Employee.class).field("manager").equal(null).get();
You call this typesafe!?
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21. Mongo with Rogue
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22. Rogue in Action
import com.foursquare.rogue.Rogue._
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23. Rogue in Action
Person where(_.age gte 18) limit(100) fetch()
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24. Rogue in Action
Code Completion
Code Completion
Person where(_.age gte 18) limit(100) fetch()
Code Completion
Code Completion
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25. Rogue in Action
Person where(_.age gte “Bazinga”) limit(100) fetch()
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26. Rogue in Action
Person where(_.age gte “Bazinga”) limit(100) fetch()
Won’t compile - age is IntField
Wednesday, December 26, 12

27. Rogue in Action
Person where(_.age gte 18) limit(100) fetch()
Wednesday, December 26, 12

28. Rogue in Action
Person where(_.age gte 18) limit(100) fetch()
Limit
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29. Rogue in Action
Person where(_.age gte 18) limit(100) foreach { p =>
println(”Name: ” + p.firstName)
}
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30. Rogue in Action
gte means >=
Person where(_.age gte 18) limit(100) foreach { p =>
println(”Name: ” + p.firstName)
}
Wednesday, December 26, 12

31. Rogue in Action
Person or(
_.where(_.name eqs "Ken"),
_.where(_.name eqs "ken")
_.whereOpt(Option("Kenshiro")(_.name eqs _))
) get()
Wednesday, December 26, 12

32. Rogue in Action
eqs means Equals
Person or(
_.where(_.name eqs "Ken"),
_.where(_.name eqs "ken")
_.whereOpt(Option("Kenshiro")(_.name eqs _))
) get()
Wednesday, December 26, 12

33. Rogue in Action
eqs means Equals
Person or(
_.where(_.name eqs "Ken"),
_.where(_.name eqs "ken")
_.whereOpt(Option("Kenshiro")(_.name eqs _))
) get()
Get me one Person.
Wednesday, December 26, 12

34. Rogue in Action
eqs means Equals
Person or(
_.where(_.name eqs "Ken"),
_.where(_.name eqs "ken")
_.whereOpt(Option("Kenshiro")(_.name eqs _))
) get()
Issue #69: fix in my pull req
Get me one Person.
Wednesday, December 26, 12

35. Live Hacking
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36. Live Hacking
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37. Live Hacking
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38. Live Hacking
Advanced Stuff.
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39. Live Hacking
Advanced Stuff.
Fast.
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40. Live Hacking
Advanced Stuff.
Fast.
Ask Questions!
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41. Wednesday, December 26, 12

42. def links =
• Scala Lang http://www.scala-lang.org/
• Scala Koans http://www.scalakoans.org
• Blog.Project13.pl - http://www.blog.project13.pl
•MongoDB ref - docs.mongodb.org/manual/reference/operators/
• Foursquare Rogue - https://github.com/foursquare/rogue
• Java Morphia - http://code.google.com/p/morphia/
• Kraków Scala UG - http://krakowscala.pl / http://scalacamp.pl
Wednesday, December 26, 12

43. def links =
• Scala Lang http://www.scala-lang.org/
• Scala Koans http://www.scalakoans.org
• Blog.Project13.pl - http://www.blog.project13.pl
•MongoDB ref - docs.mongodb.org/manual/reference/operators/
• Foursquare Rogue - https://github.com/foursquare/rogue
• Java Morphia - http://code.google.com/p/morphia/
• Kraków Scala UG - http://krakowscala.pl / http://scalacamp.pl
Mailing lists rock!
Wednesday, December 26, 12

44. Thanks!
Dziękuję!
ありがとう！
Konrad Malawski / @ktosopl
GDG / PJUG / KSUG / SCKRK
ScalaCamp 23.01.2012
Wednesday, December 26, 12

45. Thanks!
Dziękuję!
ありがとう！
I love feedback! <3 Konrad Malawski / @ktosopl
GDG / PJUG / KSUG / SCKRK
ScalaCamp 23.01.2012
Wednesday, December 26, 12