The Evolution of APL

27 Jan 2016 | , ,
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The evolution of APL is a fascinating story for programmers who appreciate array processing languages. In this article, which originally appeared in the ACM SIGPLAN notices in 1978, Ken Iverson and Adin Falkoff go back to the beginning of APL. Following the article is an interesting transcribed presentation, discussion, and Q&A session.

The original concepts of APL began to take form in the late 50’s, then a rich period of innovation followed in the 60’s. Iverson and Falkoff write:

“The development of the language was first begun by Iverson as a tool for describing and analyzing various topics in data processing, for use in teaching classes, and in writing a book, Automatic Data Processing, undertaken together with Frederick P. Brooks, Jr., then a graduate student at Harvard. Because the work began as incidental to other work, it is difficult to pinpoint the beginning, but it was probably early 1956; the first explicit use of the language to provide communication between the designers and programmers of a complex system occurred during a leave from Harvard spent with the management consulting firm of McKinsey and Company in 1957.”


Kdb+ Utilities: Essential utility for identifying performance problems

28 Feb 2018 | ,

If you are a kdb+/q developer, you will find the utilities created by Kx Managing Director and Senior Solution Architect Leslie Goldsmith to be a valuable resource. The “Kdb+ Utilities” series of blog posts gives a quick introduction to the utilities, available at Leslie Goldsmith’s GitHub. In this third part of the series we look at Leslie’s qprof, which allows a programmer to drill down into q functions or applications to inspect performance and CPU usage in a fine-grained fashion.