Elm is small, purely functional language for web-programming designed by Evan Czaplicki. It is based on the model-view-update render loop, providing an immediate mode UI programming model, similar to game engine render loops. One of the main benefits is that it leads to straight-line code, without call-back hell or the dependency glitches often observed in reactive programming systems. I’ve ported this programming model to Rascal as an embedded DSL/library, called Salix. I will discuss some trade-offs and challenges in the design and demonstrate its abilities and limitations.

Tijs van der Storm is senior researcher in the Software Analysis and Transformation (SWAT) group at Centrum Wiskunde & Informatica (CWI) in Amsterdam, and full professor in Software Engineering at the University of Groningen in Groningen. His research focuses on improving programmer experience through new and better software languages and developing the tools and techniques to engineer them in a modular and interactive fashion.