I'm trying to understand APL, J, K, and it's slightly frustrating since:
Most books seen to be about APL, but few APL implementations, and I don't have weird keyboards.
K appears to have been replaced by Q
J doesn't seem to have
I almost feel like I'm staring at Common Lisp, Guile, Gambit, Chicken, SBCL -- when I really want is is to see two pages of a scheme evaluator.
Thus, my question: is there a short (say ~50 page) document that discusses the core of APL/J/K, i.e things like:
its evaluation model
its parsing model (since left/right precedence seems to be important)
its syntax
Thanks!
I think you trailed off on "J doesn't seem to have...", so I don't know if you've already found all of the things that I'm going to link to and were dismissing them above.
My background is as a fan of a very broad set of language paradigms, and of the APL/J/Q/K set, I've chosen to spend most of my time using J. That said, given that J was developed by the same Ken Iverson of APL fame, it turns out that much of the same thinking went in to it. I even find that old papers that were written about APL seem to apply to J after a very simple transliteration effort is applied.
Low level references
The very best low level J reference (at the level of parsing, evaluation, syntax, and even its internal data structure primitives) is a set of HTML files that come with the open source distribution of J.
You can browse it online: here.
Higher level intro stuff
This blog post is actually a really good crash course on the way J thinks about things.
In addition to that, I've found that there are 2 books in particular on jsoftware.com that provide good introductions to programming in J: