Tribal Ownership Nicholas Cameron James Noble Tobias Wrigstad Victoria University of Wellington Uppsala University

Tribe c1:Canvas world s1:Shape s2:Shape r1:Rectangle c2:Canvas s3:Shape s4:Shape r2:Rectangle c3:InCanvas...

Ownership c1:Canvas world s1:Shape s2:Shape r1:Rectangle c2:Canvas s3:Shape s4:Shape r2:Rectangle c3:InCanvas...

Tribal Ownership c1:Canvas world s1:Shape s2:Shape r1:Rectangle c2:Canvas s3:Shape s4:Shape r2:Rectangle c3:InCanvas...

? Questions

Virtual Classes Nested Classes Family Polymorphism Class Families Nested Inheritance...

Virtual Classes Scala Newspeak GBeta...

Tribe class Canvas { class Shape {... } class Circle extends Shape {... } class Rectangle extends Shape {... }... } class ICanvas extends Canvas { class Shape { void onClick() {... } }

Tribe class Canvas { class Shape {... } class Circle extends Shape {... } class Rectangle extends Shape {... }... } class InCanvas extends Canvas { class Shape { void onClick() {... } }

10 Tribe Canvas Shape Circle Rectangle

Tribe Canvas Shape Circle Rectangle InCanvas Shape Circle Rectangle onClick()

Canvas Shape Circle Rectangle InCanvas Shape Circle Rectangle onClick()

Tribe c1:Canvas world s1:Shape s2:Shape r1:Rectangle c2:Canvas s3:Shape s4:Shape r2:Rectangle c3:InCanvas...

c1.Shape c2.Shape Tribe Types

class Canvas { this.Shape f1; world.Canvas f2; class Shape { this.out.out.Canvas f3; this.out.Circle f4; } class Circle extends Shape {... } } Tribe Types

Tribe Types class Canvas { this.Shape f1; world.Canvas f2; class Shape {... } } :Canvas f1:Shape world f2:Canvasf4:Canvas f3:Circle :Shape

Tribe Types :Canvas f1:Shape world f2:Canvasf4:Canvas f3:Circle :Shape class Canvas {... class Shape { this.out.Circle f3; this.out.out.Canvas f4; }

Ownership Types

class List { ListNode first;... } class ListNode { ListNode next; Object datum;... } new List (); Ownership Types

? What if...

c1:Canvas world s1:Shape r1:Rectangle c2:Canvas s3:Shape r2:Rectangle

c1.Shape Tribal Ownership

class Canvas { this.Shape f1; world.Canvas f2; class Shape { this.out.Circle f3; this.out.out.Canvas f4; } class Circle extends Shape {... } } Tribe

class Canvas { this.Shape f1; world.Canvas f2; class Shape { this.out.Circle f3; this.out.out.Canvas f4; } class Circle extends Shape {... } } Tribal Ownership

class List { ListNode first;... } class ListNode { ListNode next; Object datum;... } new List (); What about List?

class List { this.ListNode first; class ListNode { this.out.ListNode next; X datum;... }... } new this.List (); What about List? - Generics

class List { this.ListNode first; class ListNode { this.out.ListNode next; X datum;... }... } new this.List (); What about List? - Generics

class List { this.ListNode first; class ListNode { this.out.ListNode next; X datum;... }... } new this.List (); What about List?

module Collections { class List {... } class Foo imports world.Collections { this.List f; } What about List? – Module classes

Encapsulation

Owners-as-Dominators Owners-as-Modifiers Encapsulation

Descriptive Ownership

O-as-D

Owners-as-Local-Dominators Encapsulation

O-as-LD

O-as-LD private public Only public classes can be named externally

Virtual classes in Tribe give ownership – No syntactic overhead Generics Module classes – Cross family inheritance Owners-as-Local-Dominators Summary

Thank you!

? Questions