An array-oriented (APL) wish list

Abstract

The fundamental, data structure in APL is the array. Arrays are, in most APL dialects, the only data structure, from scalars as arrays with no dimensions to the complex structures of nested arrays. But there are other ways in which array concepts could be applied, yet so far they have not. These are the top items on my "Array-Oriented Wish List".Less fundamental---but far easier to implement---should be certain operators and functions I propose, which I think would enhance the power of existing array operations. Some of these already exist in one or more dialects of APL, and I think all would benefit if they were universally adopted.In this suite of proposals, some are general, others more specific, and some could interact with each other in positive synergy, but none of them requires any of the others to be useful. In some cases, I suggest potential variants, each reasonable in its own right.The purpose of this paper is to present the concepts. In most cases, I don't attempt to go into details of implementation. That would require a much more extensive treatment of each concept. I hope that others---especially implementers---might take up the challenge.