Abstract
Throughout history, every time a new idea has come along there have been many people quick to criticize it. As often as not, such criticism has come from detractors of the idea, and has been motivated by its threat to older, more established beliefs. The Biblical prophets, Socrates, Jesus, Copernicus, Galileo, Pasteur, Marx, Darwin, Stravinsky, and countless others, all experienced resistance to their ideas for essentially emotional rather than intellectual reasons.
From its early days as “Iverson Notation” through its more recent development, APL has been the target of heated discussion. This paper is a criticism of APL, but I believe, different from others. I am not a detractor of APL; in fact, I have been a supporter, developer, and promoter of the language for quite some time. Therefore, the intention of this review is not to suggest that since APL has faults it is worthless. To the contrary, I hope that these comments will lead to further improvements of APL and perhaps suggest some of the directions to consider in the development of its successors.
This paper could not have been written much earlier. It is because APL has come of age, both in the theoretical domain and in the commercial world, that it is possible to look at it publicly with a critical eye.
The discussion that follows is written for the APL community, present and future. My wish is that APL “believers” will accept this analysis in the constructive spirit in which it is offered, and that those who still do not appreciate the beauty, elegance, and practical power of APL will not take these comments out of the context in which they are presented.
