On 2010-11-29, at 1:18 PM, Abram Hindle wrote:

Mildly unrelated but at the same time relevant.

http://matt.might.net/articles/red-black-delete/

The author describes the functional red-black tree and then how to write
a delete function for that tree.

What's also interesting about the article is the demonstration of
racket's pattern matching. This kind of syntax would be worthwhile in
any LISP.

abram

Thanks, Abram. I checked that link - looks interesting.

I did a bit more reading on this, and see that I have some more general things to learn, e.g. unification. As I usually do, I am procrastinating about learning either cl-match or cl-unification, since I can drop over into racket for ordinary pattern matching when I need to. I am becoming a bit more adept at Haskell and OCaml too, but more slowly than I should, I confess.

Paul's mention of Prolog tipped me off that I should go back and read Chapter 24 of Graham's On Lisp, in which a CL prolog implementation is discussed. I shall probably have time to get to grips with this stuff during xmas break, after exams are over for the term.

Give us an update on what you have been up to - on the list or off, if you prefer.

- Dave -