Practical Models in Practice
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Lukas Renggli is a software engineer at Google who specializes in meta-models. He discusses several meta-models he has worked with including Protocol Buffers for serialization, Magritte for generic services, Google Web Toolkit for model-driven web development, and Helvetia for programming languages. He explains how each meta-model provides practical benefits like extensibility, language independence, and enabling the creation of specialized tools and applications.
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![#( #[1 0 9 0 25 0 13 0 34 0 17 0 40 0 21 0 41]
#[1 0 9 0 25 0 13 0 34 0 93 0 76 0 157 0 112]
#[1 2 38 0 21 2 38 0 25 2 38 0 26 0 13 0 34]
#[0 1 154 0 16 0 21 0 25 0 26 0 34 0 40 0 41]
#[0 1 210 0 76 0 81]
#[0 1 214 0 76 0 81]
#[1 0 173 0 76 0 177 0 81]
#[0 1 134 0 16 0 21 0 25 0 26 0 34 0 40 0 41]
#[1 1 46 0 21 1 46 0 25 1 46 0 26 1 69]
#[1 1 54 0 21 1 54 0 25 1 54 0 26 1 54 0 34]
#[0 2 102 0 21 0 25 0 26 0 34 0 40 0 41 0 76]
#[0 2 50 0 21 0 25 0 26 0 76 0 79]
#[1 1 13 0 76 2 85 0 124 1 21 0 125]
#[1 2 89 0 17 2 30 0 21 2 30 0 82]
#[1 2 93 0 21 2 97 0 82] )](https://image.slidesharecdn.com/choose-forum-lukasrenggli-130213062508-phpapp01/85/Practical-Models-in-Practice-43-320.jpg)
Practical Models in Practice
- 1. Practical Models in Practice www.lukas-renggli.ch
- 2. Practical Models of Models in Practice www.lukas-renggli.ch
- 3. Practical Meta- Models in Practice www.lukas-renggli.ch
- 4. Lukas Renggli ‣ Software Engineer at Google YouTube Video Analytics ‣ SCG Alumni Bachelor, Master and PhD ‣ Open-Source Communities Seaside, Magritte and Pier Helvetia, PetitParser
- 5. Roadmap 1. Protocol Buffers Meta-data model for serialization 2. Magritte Meta-model for generic services 3. Google Web Toolkit Model-driven web architecture 4. Helvetia Meta-model for programming languages
- 6. Protocol Buffers Meta-data model for serialization
- 7. Protocol Buffers ‣ Encode structured data ‣ Language-neutral ‣ Platform-neutral ‣ Extensible ‣ Efficient
- 8. Protocol Buffer IDL message Person { required int32 id = 1; required string name = 2; optional string email = 3; }
- 9. message Person { required int32 id = 1; required string name = 2; optional string email = 3; } protoc C++
- 10. Serialize in C++ Person person; person.set_name("John Doe"); person.set_id(1234); person.set_email("[email protected]"); fstream output("myfile", ios::out | ios::binary); person.SerializeToOstream(&output);
- 11. Deserialize in Python file = open("myfile", "rb") person = Person() person.ParseFromString(file.read()) file.close print "Name: ", person.name print "E-mail: ", person.email
- 12. Demo
- 13. Why not XML/JSON? ‣ Protocol Buffers are – 3—10 times smaller – 20—100 times faster – consistent code generators – less ambiguous – evolvable
- 14. message Person { message Person { required int32 id = 1; required int32 id = 1; required string name = 2; required string name = 2; optional string email = 3; repeated string email = 3; } repeated Phone phone = 4; } :Person :Person :Person
- 15. ‣ Describe your data once, and use it across platforms and languages ‣ Evolution supported by design ‣ Used at Google for almost all – data storage (file formats, database) – remote procedure protocols (RPC)
- 16. Magritte Meta-model for generic services
- 17. Address Object :Address street = 'Schützenmattstrasse' plz = 3012 place = 'Bern' canton = 'Bern'
- 18. Address Class :Address Address street = 'Schützenmattstrasse' class street: String plz = 3012 plz: Integer place = 'Bern' place: String canton = 'Bern' canton: String
- 19. Address Description Magritte :StringDescription label = 'Street' :NumberDescription label = 'PLZ' required = true :Address range = 1000..9999 street = 'Schützenmattstrasse' description :StringDescription :Container plz = 3012 label = 'Place' label = 'Address' place = 'Bern' required = true canton = 'Bern' :SingleOptionDescription label = 'Canton' required = true sorted = true options = #( 'Bern' 'Zurich' ... )
- 20. User Interfaces result := anAddress asMorph addButtons; addWindow; callInWorld
- 21. Web Interfaces result := self call: (anAddress asComponent addValidatedForm; yourself) * * *
- 22. Other Services Reports Viewers Filtering Editors Validation Serialization Initialization Indexing Copying Initialization Extension Customization Adaptation
- 23. Meta- Metamodel <described-by> Metamodel Developer <described-by> Domain Model End User
- 24. Meta- Metamodel <described-by> Metamodel Magritte Developer <described-by> Domain Model Magritte End User
- 25. Run- t im e Adaptive Object Model
- 27. Demo
- 28. Magritte ‣ Very powerful and flexible ‣ Runtime adaptive code ‣ End-user programmable code ‣ Can cause meta meta-confusion ‣ Can be slower than hardcoding
- 29. Google Web Toolkit Model-driven web architecture
- 30. Is this really a model? public class Main implements EntryPoint { public void onModuleLoad() { Label label = new Label(“Hello World”); RootPanel.add(label); } }
- 31. Is this really a model? public class Main implements EntryPoint { public void onModuleLoad() { Label label = new Label(“Hello World”); RootPanel.add(label); } } High-level Widgets
- 32. Is this really a model? public class Main implements EntryPoint { public void onModuleLoad() { Label label = new Label(“Hello World”); RootPanel.add(label); } } High-level Description Widgets Language
- 33. public class Main implements EntryPoint { public void onModuleLoad() { platform Label label = new Label(“Hello World”); RootPanel.add(label); independent } } model model transformation
- 34. Transformation Mozilla Chrome Safari IE ... English French German ...
- 35. GWT ‣ Write JavaScript using a high-level widget library in a well defined (statically typed) language ‣ Translate and optimize code towards specific browsers ‣ Debugging actually works nowadays
- 36. He vetia Helvetia Meta-model for programming languages
- 40. Programming Language Model
- 41. ID ::= letter { letter | digit } ; a..z a..z 0..9
- 42. scanIdentifier self step. ((currentCharacter between: $A and: $Z) or: [ currentCharacter between: $a and: $z ]) ifTrue: [ [ self recordMatch: #IDENTIFIER. self step. (currentCharacter between: $0 and: $9) or: [ (currentCharacter between: $A and: $Z) or: [ currentCharacter between: $a and: $z ] ] ] whileTrue. ^ self reportLastMatch ]
- 43. #( #[1 0 9 0 25 0 13 0 34 0 17 0 40 0 21 0 41] #[1 0 9 0 25 0 13 0 34 0 93 0 76 0 157 0 112] #[1 2 38 0 21 2 38 0 25 2 38 0 26 0 13 0 34] #[0 1 154 0 16 0 21 0 25 0 26 0 34 0 40 0 41] #[0 1 210 0 76 0 81] #[0 1 214 0 76 0 81] #[1 0 173 0 76 0 177 0 81] #[0 1 134 0 16 0 21 0 25 0 26 0 34 0 40 0 41] #[1 1 46 0 21 1 46 0 25 1 46 0 26 1 69] #[1 1 54 0 21 1 54 0 25 1 54 0 26 1 54 0 34] #[0 2 102 0 21 0 25 0 26 0 34 0 40 0 41 0 76] #[0 2 50 0 21 0 25 0 26 0 76 0 79] #[1 1 13 0 76 2 85 0 124 1 21 0 125] #[1 2 89 0 17 2 30 0 21 2 30 0 82] #[1 2 93 0 21 2 97 0 82] )
- 44. ID ::= letter { letter | digit } ; a..z a..z 0..9 44
- 45. ID ::= letter { letter | digit } ; sequence letter many choice letter digit 45
- 46. Extensible sequence letter many Composable choice Transformable letter digit Customizable 46
- 47. Editors Code Highlighting Contextual He vetia Menus Custom sequence Inspector Navigation letter many Search Code choice Error Folding Correction letter digit Code Expansion Debuggers Refactorings 47
- 48. Demo
- 49. He vetia ‣ Grammar is the meta-model ‣ Composable programming languages ‣ Extensible programming languages ‣ Tooling is built around the grammar
- 50. Structural Behavioral Model Model Run-time Static Run-time Adaptive He vetia
- 51. “Meta-models are the enablers of practical software development.” He vetia www.lukas-renggli.ch