Implementing a Bidirectional Model Transformation Language as an Internal DSL in Scala

Size: px

Start display at page:

Download "Implementing a Bidirectional Model Transformation Language as an Internal DSL in Scala"

Lindsey Baker
8 years ago
Views:

Transformations @EDBT/ICDT 14, Athens, Greece Arif Wider

1 Implementing a Bidirectional Model Transformation Language as an Internal DSL in Scala BX 14: 3rd International Workshop on Bidirectional 14, Athens, Greece Arif Wider Humboldt-University of Berlin, Germany Beuth University of Applied Sciences, Berlin, Germany

2 Motivation Impression: Often, plain Java is used for implementing model transformations, both uni- and bidirectional. 2

3 Motivation Impression: Often, plain Java is used for implementing model transformations, both uni- and bidirectional. Possible reasons: Weak (or outdated) tool-support No seamless integration with existing technologies Limited means of a special language 3

4 Motivation Impression: Often, plain Java is used for implementing model transformations, both uni- and bidirectional. Possible reasons: Weak (or outdated) tool-support No seamless integration with existing technologies How can we make special transformation languages more usable in practice? Limited means of a special language 4

5 External vs. Internal DSLs External DSL (own parser etc.) Tailored tool support: code completion, error checking & highlighting Developing tool support is costly and tools need to be maintained 5

6 External vs. Internal DSLs External DSL (own parser etc.) Tailored tool support: code completion, error checking & highlighting Developing tool support is costly and tools need to be maintained Internal DSL (library) Flexibility: mix with host language or other DSL Reuse of existing tools of the host language tool support and its maintenance for free 6

7 Tool-support using regular Scala tooling Code completion Compile-time error checking & highlighting Full debugging with EMF integration 7

8 Statically Typed Tree Lenses in Scala Ambitious goal: 8

9 Statically Typed Lenses in Scala Main challenge for complete static type checking: Lenses can produce intermediate output structures with no corresponding type in the source- or the target-metamodel structural types needed (Terms) Common type systems provide either generic tuples with fixed arity (e.g., Tuple3[A,B,C]) or collections with homogeneous collection type (List[A]) 9

10 Statically Typed Tree Lenses in Scala Solution: heterogeneously typed lists HList<A, HList<B, HList<C>>> 10

11 Statically Typed Tree Lenses in Scala Solution: heterogeneously typed lists HList<A, HList<B, HList<C>>> and implicit conversions 11

12 What else is in the paper Handling non-containment references A BX Languages as an Internal DSLs in Scala Arif Wider 12

13 What else is in the paper A bidirectional version of Families2Persons 13

14 Problem: Error Messages 14

15 Conclusion Scala s type system allows for extensive static verification of composed lenses. Implicit conversions and type inference can make their usage & composition comfortable. No special tooling is needed & lenses written in Scala can directly transform Java-based models. State-based tree lenses can be adapted for transformations of EMF models, i.e., graphs with a spanning containment tree. 15

16 Conclusion Scala s type system allows for extensive static verification of composed lenses. Implicit conversions and type inference can make their usage & composition comfortable. No special tooling is needed & lenses written in Scala can directly transform Java-based models. State-based tree lenses can be adapted for transformations Thank you of for EMF the models, attention! i.e., graphs with a spanning containment tree. 16

Textual Modeling Languages

Textual Modeling Languages Slides 4-31 and 38-40 of this lecture are reused from the Model Engineering course at TU Vienna with the kind permission of Prof. Gerti Kappel (head of the Business Informatics