Paper of the Week: On Understanding Data Abstraction, Revisited

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

This week’s paper is On Understanding Data Abstraction, Revisited by William Cook, an Associate Professor of Computer Science at The University of Texas at Austin. It was originally presented at OOPSLA ‘09. Among his many accomplishments, Cook was one of the original designers of AppleScript. He wrote a history of the language, which you can find on his website. He’s also currently fighting cancer, so if you enjoy his paper and have a bit of money to spare, you can donate to his treatment.

This week, I decided to submit a paper myself. Alan O'Donnell, one of our facilitators, told me about this paper last year and it has had a profound effect on how I think about programming. The paper compares two forms of data abstraction, objects – the kind you find in Smalltalk, Java, Ruby, etc. – and abstract data types (ADTs), which include C’s built-in primitive types and the algebraic data types that are common to the ML family of languages. Cook’s thesis is that while people often conflate the two, objects and ADTs are two distinct forms of data abstraction, which have different properties and use-cases.

Reading this paper felt like lifting a mental fog. Every programming problem that I approached suddenly had two possible solutions instead of one: I could solve the problem with objects, or I could solve it with ADTs. I mostly program in Ruby and JavaScript, which makes it more likely that I’ll solve my problems with objects (both languages have stronger support for objects than ADTs), but even the knowledge that there’s another option has been a useful tool for me in my everyday programming.

Read Along

Read Along is a way for you to participate in Paper of the Week. If you want to take part, all you have to do is read the paper, make something small in response (code or prose), email us a link of what you make by noon Eastern Time next Monday, and we’ll link to it from our blog.

Hacker School facilitator Tom Ballinger is back with another Read Along submission. In it, he works through parts of last week’s paper in Python while reflecting on his own reading and learning styles.

Happy reading!