Paper of the Week: The Power of Interoperability: Why Objects Are Inevitable

David albert circle David Albert

This is part of our “Paper of the Week” series. For more info, check out our introductory blog post.

This week’s paper is The Power of Interoperability: Why Objects Are Inevitable by Jonathan Aldrich an Associate Professor at Carnegie Mellon University. It was published in Onward! Essays, 2013

I submitted this paper because it’s a good companion to last week’s. Aldrich argues that the essential thing about objects is that they can provide services that operate at a higher level than just data abstraction. I don’t think this paper invalidates last week’s. It’s perspective is different and complimentary.

This paper also draws on The Early History Of Smalltalk by Alan Kay, which could easily be called The Early History of Object-Oriented Programming. Aldrich’s perspective on objects seems much closer to Kay’s original ideas than Cook’s does.

When I found Aldrich’s paper on the front page of Hacker News last week, I had just finished reading Kay’s. If you have time, Kay’s paper is a nice companion to this one.

At the suggestion of Hacker Schooler Leah Hanson, we’re going to be posting the abstract from each paper to whet your appetite. Here’s this week’s:

Three years ago in this venue, Cook argued that in their essence, objects are what Reynolds called procedural data structures. His observation raises a natural question: if procedural data structures are the essence of objects, has this contributed to the empirical success of objects, and if so, how?

This essay attempts to answer that question. After reviewing Cook’s definition, I propose the term service abstractions to capture the essential nature of objects. This terminology emphasizes, following Kay, that objects are not primarily about representing and manipulating data, but are more about providing services in support of higher-level goals. Using examples taken from object-oriented frameworks, I illustrate the unique design leverage that service abstractions provide: the ability to define abstractions that can be extended, and whose extensions are interoperable in a first-class way. The essay argues that the form of interoperable extension supported by service abstractions is essential to modern software: many modern frameworks and ecosystems could not have been built without service abstractions. In this sense, the success of objects was not a coincidence: it was an inevitable consequence of their service abstraction nature.

Read Along

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Happy reading!