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. The standard MVC architecture of such frameworks makes execution order hard to understand, a problem colloquially called callback hell. 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 presentation that, like a spreadsheet, provides a fully WYSIWYG programming experience.
Discussion at alarmingdevelopment.org/?p=911