Question

I’m trying to learn APL (Kona), and I’m looking for example projects so I can get an understanding of how an experienced APL’er would organize his/her code.

Any open source projects would be helpful but, non-financial or anything lacking heavy math would be awesome.

Answer 1

I’ve been looking too, and haven’t found any yet. APL is a very old language; it completely predates the whole open-source movement. Unlike equally-old Lisp (whose history includes much AI lab research and a spirit of open collaboration), APL’s culture has been historically associated with IBM, commercial timesharing systems, and finance. Kevin and I are trying to change this with Kona, though.

There is a fair bit of k code at no stinking loops. Some of it was written for a different version of k than what Kona targets, though. Hakan Kjellerstrand also has an excellent K page.

There are also several great APL/J/K/Q books. I particularly recommend Kenneth Iverson’s A Programming Language, Henry Rich’s J for C Programmers, Jeffry Borror’s Q for Mortals (Q is the newest version of Kx’s K), and Gilman & Rose’s APL: An Interactive Approach. All but the last are readily available online.

Keep in mind is that many people are using APLs as mathematical tools (like R, mathematica, gnuplot, etc.) rather than for programming, per se. (IMHO, J is best for that.) K is designed to be a more general-purpose programming language, and feels like a synthesis of APL, Lisp, and C. It is an outlier in the language family, though.