Category: General

I’ll be demoing my latest work at the Future Programming Workshop at both Strange Loop and SPLASH. My talk is called “Two-way Dataflow”. Here is the abstract:

Subtext is an experiment to radically simplify application programming. The goal is to combine the power of frameworks like Rails and iOS with the simplicity of a spreadsheet. Mutable state is a notorious source of complexity in application programming and indeed has long been a major dilemma in programming language design. I propose a new approach called two-way dataflow, which breaks the program into cyclic output and input phases. Output is handled with traditional one-way dataflow, which is realized here as a form of pure lazy functional programming. Input is governed by a new semantics called one-way action which is a highly restricted form of event-driven imperative programming. These restrictions statically order event execution to avoid callback hell. Two-way dataflow has been designed not only to simplify the semantics of application programming but also to support a representation that, like a spreadsheet, provides a fully WYSIWYG programming experience.

This work is still very experimental and preliminary but I hope it is complete enough to convey several key new ideas that are relevant to the current trends of “reactive” and “live” programming.

Richard Gabriel and I are planning a workshop at SPLASH focused on screencast demos: The Future Programming Workshop. This will be a workshop in the sense of a writer’s workshop: the participants will present their talks/demos and the group will critique them. After the workshop people will revise their screencasts to be published on our website. Please signup at the website if you are interested.

Increasingly, new programming ideas show up first as video talks and screencast demos, long before any papers get written. A good example is Bret Victor’s videos. My own screencasts have led to far more interaction than my papers. Frankly, writing papers is really hard, especially for raw new ideas. Non-academics often struggle to write papers, effectively excluding them from the conversation. The point of this workshop is to foster the exchange of radical new programming ideas in their formative stage, via the medium of screencasts. We hope to build a community of explorers at the frontier of programming. Please join us.

Interesting new work: Lamdu [Hacker News discussion] from Eyal Lotem and Yair Chuchem. They aren’t showing a lot of results yet, but I really like the espoused principles of the project. This is worth keeping an eye on.

They are building an advanced IDE for a variant of Haskell with keyword arguments and structural record types (Subtext makes the same choices). They have moved type inference from the compiler into the IDE, where it can be exploited for assisting programming. I like that they are thinking beyond just live execution to the bigger issues of code refactoring and intensional versioning. They also appreciate the benefits of normalizing code formatting: “co-macros” re-sugar into normal forms (ditto Subtext).

It will be most interesting to see in what ways Lamdu alters the experience of Haskell. I’ve long said that functional languages are a better fit for advanced IDEs. Haskell is the state of the art in functional programming, so it is a useful experiment to enliven and illuminate it, and perhaps even make it more friendly. If they can pull this off it will be a really big win because they can leverage the large capital investment in Haskell implementation and libraries.

I wish Lamdu the best of luck and look forward to learning more about it.