abstract data types

I was just lucky enough to see Peter Hawkins present a particularly compelling synthesis language: data structure synthesis:

This post is triggered by Jules asking, essentially, how could FRP support imperative structures?

Part of the answer is about interface -- a command becomes an input stream of commands, which is a common pattern in systems like Max/MSP, and most FRP systems also provide mutable reactive cells (... a worthwhile topic for another day).

More interesting is when we want a particular imperative implementation that the automatic incrementalizer wouldn't have picked, such as a hand-tuned one in a lower-level language.

Functional Pearl: Implicit Configurations —or, Type Classes Reflect the Values of Types, by Oleg Kiselyov and Chung-chieh Shan:

The configurations problem is to propagate run-time preferences throughout a program, allowing multiple concurrent configuration sets to coexist safely under statically guaranteed separation.

This problem is common in all software systems, but particularly acute in Haskell, where currently the most popular solution relies on unsafe operations and compiler pragmas.

One of the themes of Barbara Liskov's Turing Award lectue ("CS History 101") was that nobody has invented a better programming concept than abstract data types.

William Cook wrote a paper for OOPSLA '09 that looks at how well PLT'ers understand their own vocabulary, in particular abstract data types and concepts that on the syntactical surface blend to all seem like ADTs.

The paper is On Understanding Data Abstractions, Revisited.

News flash: Barbara Liskov Wins Turing Award.

The full citation:

Barbara Liskov has led important developments in computing by creating and implementing programming languages, operating systems, and innovative systems designs that have advanced the state of the art of data abstraction, modularity, fault tolerance, persistence, and distributed computing systems.