Interestingly, J appears in http://en.wikipedia.org/wiki/FP_programming_language http://en.wikipedia.org/wiki/Functional_programming which have many definitions and examples of functional forms, but the J article itself on Wikipedia does not list any functional forms in J, albeit indirectly; so to those unfamiliar with J syntax it may not be clear how it is functional.
--- Roger Hui <[EMAIL PROTECTED]> wrote: > > Backus had a reciprocal relationship with APL. > > He admired it but didn't think it had gone far > > enough. In his FP he described an "insert" > > function which was later adopted by APL, as a > > better way to describe what was then called > > "reduction" in APL. > > I don't think this description of how "insert" > got into APL is accurate. APL had slash and > slash-bar many years prior to Backus' August 1978 > paper. Iverson in his "Operators and Function" > (1978-04-26) described a innerproduct/ example, and > innerproduct slashbar was interpreted exactly the > same as how innerproduct/ is interpreted in J today. > It _is_ better to call / "insert" rather than > "reduction" because for an arbitrary function f, > f/ may not reduce anything. In older APLs f/ was > restricted to scalar functions, and in such cases > f/ does reduce an axis. > > Backus discussed APL in section 8 of his 1978 paper. > He erroneously described APL as having "exactly > three functional forms, called inner product, > outer product, and reduction". As of 1978, there > were two others: bracket axis (APL\360 circa 1966) > and scan (APLSV circa 1972). > > > > ----- Original Message ----- > From: Eugene McDonnell <[EMAIL PROTECTED]> > Date: Monday, March 19, 2007 8:13 pm > Subject: Re: [Jgeneral] John Backus Died > > > > > On Mar 19, 2007, at 7:53 PM, June Kim wrote: > > > > > http://www.nytimes.com/2007/03/19/obituaries/20cnd-backus.html? > > > _r=1&oref=slogin > > > ----------------------------------------------------------------- > > ----- > > > For information about J forums see > > http://www.jsoftware.com/forums.htm > > Backus had a reciprocal relationship with APL. He admired it but > > didn't think it had gone far enough. In his FP he described an > > "insert" function which was later adopted by APL, as a better way > > to > > describe what was then called "reduction" in APL. > > > > It was some of his cohorts who,without meaning it, benefitted APL; > > > > they were in charge of a computer, but chose not to give all 8 > > bits > > of a byte. Since this was required by the APL group, they had to > > go > > their own way, successfully. > > > > My first manager at IBM was Andy Kinslow, who was another one of > > the > > group that included Backus. With Andy, I helped create the first > > IBM > > time-sharing system. > > > > Eugene > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ____________________________________________________________________________________ Finding fabulous fares is fun. Let Yahoo! FareChase search your favorite travel sites to find flight and hotel bargains. http://farechase.yahoo.com/promo-generic-14795097 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
