Talks to Watch

Practical Common Lisp

98K views · Oct 9, 2007 · 1:12:10 · 3 HN recommenders · 5 mentions · discussed 2011–2025

Peter Seibel's 2006 Google TechTalk on Practical Common Lisp, framed by the Sapir-Whorf hypothesis and Paul Graham's Blub paradox. It shows Lisp features such as condition restarts and its generic-function object system.

Why Hacker News points people here: HN remembers it as the memorable explanation of restarts and multiple dispatch, referenced whenever those features come up.

“I will forever think of this talk by Peter Siebel”HN comment, 2025

What Hacker News said 5

RecommendstdrgabiMay 2011

“Restarts are really nice, I first heard about them in”

Introduces Lisp restarts.

Full comment

I agree that my macros explanation was stretched. I simplified it too much. Restarts are really nice, I first heard about them in "Practical Common Lisp" google talk: this video

in “The German School of Lisp ("Fluchtpunkt Lisps")” · view on HN
Recommendsjlg23Jul 2015

“explains that pretty well”

Explains Common Lisp's generic-method object system versus C++/Java.

Full comment

The author provides a good example of legitimate use of change-class with his compiler example. About violating "some earlier architectural plan" in the case of libraries: Being able to do this allows CL programmers to freely mix libraries with different "architectural plans" without resorting to some half-baked fusion architecture that has to account for the different styles used by the libraries. Last but not least, change-class is not a hack - it's behavior is well defined and documented. And when you consider that CL's "object orientation" is more generic that c++'s or java's, based on generic methods alone, inferring from c++- or java-paradigms to good CL style just does not work. Peter Seibel's talk "Practical Common Lisp" at google explains that pretty well: this video

in “Use Cases for Change-Class in Common Lisp” · view on HN
Recommendsjlg23Apr 2016

“covers that from a different angle, also comparing multiple dispatch with the visitor pattern”

Compares multiple dispatch with the visitor pattern.

Full comment

Peter Seibel's talk "Practical Common Lisp"[1] covers that from a different angle, also comparing multiple dispatch with the visitor pattern. [1] this video

in “A polyglot's guide to multiple dispatch” · view on HN
RecommendsethagnawlJun 2025

“I will forever think of this talk by Peter Siebel”

Memorable talk associated with multiple dispatch.

Full comment

I will forever think of this talk by Peter Siebel (author of Practical Common Lisp) whenever I hear about multiple dispatch: this video

in “Ovld – Efficient and featureful multiple dispatch for Python” · view on HN
Cites itbjoliNov 2019

“Peter Seibel talks about it in Practical Common Lisp”

Seibel discusses Lisp error handling in his Google talk.

Full comment

Peter Seibel talks about it in Practical Common Lisp and in the talk he had at Google about the book: this video The book is available online I think.

in “Overview of Rust error handling libraries” · view on HN