Clojure for Lisp Programmers Part 1 - Rich Hickey

Context: this is not only a very good introduction to Clojure and the design decisions made by Rich Hickey it also is a video that isn't very widely known. The video was uploaded to Youtube after the migration from Blip.tv but somehow got broken ( ▶ this video ) and lived in a parallel universe in Youtube. I remember I found the video a few years ago but was unable to watch it. Last year someone re-uploaded the video to Youtube and it seems to works now. Transcript: link

Hy may have changed since I last looked at it, but when I had looked at it, Hy was more of an s-expression syntax bolted onto python. Some random thoughts on why this matters: Clojure is very much not a thin s-expression layer for java; that would have been terrible (Python is more like lisp than java which is why Hy is tenable whatsoever). In particular, CL style macros with out some first-class concept of symbols are a footgun[1], but I'm sure I could find other issues. Another item that can't be ignored is that Hy selected the clojure syntax, which is going to be a turn-off for anyone coming from Lisp or Scheme. Finally, there are hundreds of thin s-expression layers on top of existing languages, and most of them are terrible; Hy has done nothing to stand out from this crowd, so most lispers will not look closely at it. 1: See ▶ this video for Rich's discussion of how he managed this issue in Clojure.

> Pity he hadn't heard of Armed Bear Common Lisp ( link ), which runs on the JVM. He was certainly aware of SBCL. He had a number of reasons for not wanting to use it. [1] > I don't mind mutable state, since the real world is not functional: I hear this argument often, but the "real world" is not linked lists or hash maps or mutable or 0s and 1s either, but they are all useful representations. > real programs are all about side effects Clojure has plenty of facilities for side effects, and without having to resort to monads (though you could if you wanted). [1]: ▶ this video