Alan Dipert - Old School FP: A Common Lisp Experience Report

Abstract: Common Lisp (CL), standardized in 1994 and alive today in the form of several free and commercial implementations, is the closest modern language to that presented in John McCarthy's landmark 1960 paper [1] introducing the idea that the lambda calculus could be a practical basis for computer programming.

I was introduced to CL through Peter Norvig's PAIP [2] about 5 years ago and have been experimenting with it on and off since then. Through the study of one open source implementation, Steel Bank Common Lisp (SBCL) I have learned a lot about language design and implementation.

I would like to share some of what I've learned, including:

• The CL REPL-driven workflow: ideate, implement, try, repeat
• CL's memory model and type system and how they enable high-performance numerical computing (relative to many other dynamic languages)
• Oddities and inconveniences I've encountered, and their mitigations
• Resources for learning more

1. https://aiplaybook.a16z.com/reference-material/mccarthy-1960.pdf
2. https://github.com/norvig/paip-lisp
3. http://www.sbcl.org/