BALISP (Bay Area Lisp and Scheme Users Group)

Hello, hacker ladies and gentlemen!

This month, we'll return to Hacker Dojo in Mountain View, this time at 3pm-6pm. We'll meet on Saturday, January 21st. We'll have two long-form talks, then lightning talks (five minutes speaking, five minutes of Q&A) and socializing.

Scott Burson will start us off with a talk about his FSet collections library for Common Lisp:

Modern Common Lisp with FSet
All programming involves collections: objects that contain or reference some number of other objects. Lisp's lists are a familiar example. Also, in programming, a distinction we must be aware of, though it's rarely discussed, is that between data types with "functional" semantics and those with "stateful" semantics. There has been a tendency, in our programming languages, for collections to be stateful (though there have been some interesting exceptions). In recent years, there has been a movement toward functional collections, the most notable example being Rich Hickey's Clojure. Code written using functional collections is seen to be more reliable and maintainable.

FSet is a library that brings the benefits of functional collections to Common Lisp. In this talk I will explain exactly what a functional collection is (and why I don't like to call them "immutable"), and discuss their advantages. I will give a brief summary of the FSet API and how it is implemented, then go into more depth about some of the design decisions I made and the pressures that motivated them, emphasizing those applicable to any language. I will list some functional collections libraries for other languages, and critique them from the FSet perspective. So even if you never expect to use Common Lisp, this talk will show you what's possible; maybe some of these features will be things you'd like to see implemented in your preferred language.

Scott Burson learned Lisp at MIT in 1978, initially from Bernie Greenberg, then Gerry Sussman, then by screwing around on the Lisp Machines at the AI Lab. He went on to write Zeta-C, the first C compiler for Lisp Machines, released in 1984. He went on to work in Common Lisp for Reasoning Systems, a for-profit spinoff of Cordell Green's Kestrel Institute. Scott has also worked on a leading application security static analysis product, and on the compiler team of an AI hardware startup.

Mark Friedman will give a two-part talk on his work in Scheme:

The Story of Scheme in MIT App Inventor
Deep in the heart of MIT App Inventor, a popular visual programming environment for mobile app development, there is a core of Scheme. This talk goes into how that came about, describes some of the details of the use of Scheme in App Inventor and some of the implications of its use, both positive and negative. It's a story full of surprises!

Scheme-JS: A Vibe Coded, R7RS-Small Scheme Implementation with Transparent JavaScript Interoperability
This talk describes a new Scheme implementation, my motivations for creating it, and my experiences vibe coding it.

Mark was previously a member of the MIT Scheme development team and was a co-creator and leader of the MIT App Inventor team at Google. He is currently a member of the Board of Directors of the App Inventor Foundation and a Research Affiliate at the MIT Computer Science and Artificial Intelligence Laboratory (CSAIL).

If you'd like to give a lightning talk, please let me know at the beginning of the meeting. We'd love to hear about your projects and interests.

Please join us in person. (I'll do my best to record the talks, but I won't live-stream them.) Good things come from meeting in person.

#balisp #hacker-dojo