A new portable interpreter for the J notation of the APL language, J, has been developed by Roger Hui, a lecturer at the US Association for Computing Machinery, who works for Morgan Stanley & Co in New York. J was written by Kenneth Iverson, the original author of APL, to eradicate the various anomalies inherent in the old language. It was released in 1990, and is written in C. Secretary of the British APL Association, Anthony Camacho, claims that J is less complicated as it uses fewer symbols than APL – its syntax analyser takes up only one page of C, while other versions take up enormous amounts. J is also said to be more powerful because it can list arrays. Hui says that because the source code is written under the assumption that the user knows both J and C, someone that knows APL and C will find J much easier to use than someone who knows only C. Another advantage is that J can run on a range of boxes, including the RS/6000, Digital Equipment Corp VAX, Apple Computer Inc’s Macintosh and iAPX-86 personal computers. It provides access to host or native files, can be used for functional programming, and can call functions that use the C calling convention. Because J uses standard ASCII symbols, it does not require special keyboards, displays, printers or editors as previous APLs did. It is available now and costs UKP16 for a starter kit, including a manual and Hui’s interpreter. Programs are free, but each customer will need to buy a manual, costing UKP12.
