2018-07-29 HPR Actors and Agents, Sprites and Fractals

In which I sit down with Christopher Lemmer Webber and try to keep it short, but end up with an hour of Actor Models, Flow-Based Programming, Object Capabilities, ActivityPub and more

Plugs:

• Chris works on Object Capabilities for Linked Data (OCAP-LD) and other things for a living, at https://digitalbazaar.com/ .

• clacke works at https://fractalide.com/ making better tools for future programmers.

• We’re both fortunate enough to have the chance to get paid for creating all Free Software.

• Christopher Lemmer Webber and Morgan Lemmer Webber will be speaking at RacketCon 2018 on the topic Racket for Everyone (Else), how non-programmers can do "programmable publishing" using Scribble when writing humanities papers, and how Racket could better target not just beginner programmers and hard-core language theorists, but also the huge space in between.

More information on the topics covered:

• For my last show with Chris, see hpr2198 :: How awesome is Guix and why will it take over the world

• His Actors library for Guile Scheme is 8sync. A video of him playing in front of an audience with the Multi-User Dungeon (MUD) on top of 8sync is available on the front page.

• Spritely, the media sharing platform that may or may not be the next MediaGoblin, is currently vaporware, but the underlying Goblins Actors library for Racket is real and works.

• Wikipedia has more on the Actor Model, Flow-Based Programming and Object Capabilities (OCap).

• We also mentioned in passing Communicating Sequential Processes.

• I knew that OCap grew up in the context of E, but I didn’t know that E itself actually grew out of the needs of a form of MUD, built by Electric Communities (EC). I’m guessing this is the graphical MMORPG Habitat that EC built for Lucasfilm.

• Language-oriented programming (LOP) is an old LISP methodology: Understand the problem, write a language for describing and solving the problem, write the solution in that language. Racket (itself a LISP) is heavily focused on this, and comes with a whole slew of languages out of the box. The Racket slogan on http://racket-lang.org/ is "solve problems — make languages".

• A recent ACM article describes in depth what the challenges of good LOP are, and how Racket helps the programmer work with it.

• https://mint.com is an example of a service that would benefit from fine-grained capabilities when accessing your financial services.