Gene McDonnell
Eugene Edward McDonnell (October 18, 1926 – August 17, 2010) was an APL implementer and designer, and popularizer of APL and J. He edited the APL Quote-Quad column "Recreational APL" and wrote the "At Play with J" series of articles for Vector journal, and received the Iverson Award in 1987.
McDonnell, a programmer since 1954, joined IBM and first learned about Iverson notation in 1961, and joined Ken Iverson's group at IBM in 1968.[1] He left IBM for I.P. Sharp Associates in 1978, where he worked under Eric Iverson.[2]
Contributions to APL and J
McDonnell suggested the symbol × for Signum and designed the Circle function (○) as a way to unify trigonometric and hyperbolic functions[3]. He designed APL's complex Floor[4] and suggested the extension of Or (∨) and And (∧) to GCD and LCM[5]. He was also involved in the introduction of complex numbers to SHARP APL[6]. His suggestion that zero divided by zero should be zero rather than one[7] was later adopted by J.
In 1988, McDonnell and Ken Iverson developed function train notation, one of the major innovations that spurred the creation of J.
External links
- Eugene McDonnell
- JSoftware paper collection (includes links to Recreational APL and At Play with J articles)
- "At Play With J", updated by the J community
- Eugene McDonnell Quotations and Anecdotes assembled by Roger Hui
References
- ↑ Anon. Candidates for STAPL Offices (excerpt). APL Quote-Quad, Volume 7, Number 4, Winter 1977.
- ↑ Hui, Roger. "Eugene McDonnell Quotations and Anecdotes".
- ↑ McDonnell, Eugene. "The Story of ○".
- ↑ McDonnell, Eugene. "Complex Floor".
- ↑ McDonnell, Eugene. "A Notation for the GCD and LCM Functions".
- ↑ McDonnell, Eugene. SATN-40: Complex Numbers.
- ↑ McDonnell, Eugene. "Zero Divided by Zero".