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JavaScript Class System with Multiple Inheritance


How does Ring.js makes multiple inheritance?

Most inheritance systems in JavaScript (like John Resig’s one) use prototype inheritance. They create a chain of prototypes and the JavaScript virtual machine will recursively search that chain to find the methods to call.

Unfortunately this behavior makes it impossible to use multiple inheritance. So Ring.js uses a different system.

When a new class is created, Ring.js creates a completely new prototype by using the methods defined in its whole set of base classes. To solve problems created by the diamond inheritances Ring.js linearize the classes graph using the C3 algorithm as defined in the Python standard.

What browsers are supported?

node.js is also supported.

Is Ring.js fast?

Yes. When compared to similar libraries Ring.js has good performances.

When comparing classes libraries, it is necessary to explain the differences between them. Basically, if the syntax is nice and easy to type it will be slower. To make it faster you have to remove features and makes the syntax more and more ugly.

For Ring.js I tried to use a syntax as nice as possible while still keeping very good performances. This was quite successful since, when compared to libraries providing similar features (mainly this.$super that gives access to the super method), Ring.js has excellent performances. It can be much faster than some well-known libraries, notably John Resig’s inheritance. Additionally, none of these other class systems provide multiple inheritance. See the test result:


See this link to the test.

Some class systems can still have better performances. None of these have this.$super and require to use longer syntax instead. But this type of performance difference should not be overestimated because it’s only the measurement of pure performances when calling a method. Real programs do a lot of other things rather that calling methods that performs no operations.

Anyway, I think it’s better to favor shorter and nicer syntax to improve the productivity of the programmers rather than trying to gain some milliseconds every x millions calls, that’s why I chose to use this.$super in Ring.js rather than an uglier system.

How to contribute?

Go on the Github page.

Report bugs, propose improvements, improve the documentation. Any help will be welcomed!