ERRATA: ...Boolean and a scalar. (erase "and a scalar".)
Paul Gauthier APL Software Developer - Senior [EMAIL PROTECTED] Phone: 312-739-3467 Fax: 312-739-3496 CheckFree. The Company that Powers Payment on the WebSM. http://www.checkfree.com/paybillsonline Paul Gauthier/NJ/CheckFree 03/14/2007 03:23 PM To General forum <[email protected]> cc Subject Re: [Jgeneral] definition of a: the reason I used 42=$0 is twofold: 1) It highlights that the argument of weather to use $0 or 0$0 was a no man's land debate. 2) It refers to the movie "hitchhiker's guide to the galaxy" where as everyone knows, the meaning of life is 42. As a footnote, I remember early discussions of "jot" being the enclose of the empty vector as in: <i.0 As I see now, the only difference is that a: is actually Boolean and a scalar. I was thinking that Roger could explain the evolution from "jot" to the actual a: and make comments if required. But I suppose I was ignored and misinterpreted (as is usually the case). My only excuse is to be from a different cultural background... Paul Gauthier APL Software Developer - Senior [EMAIL PROTECTED] Phone: 312-739-3467 Fax: 312-739-3496 CheckFree. The Company that Powers Payment on the WebSM. http://www.checkfree.com/paybillsonline Dan Bron <[EMAIL PROTECTED]> Sent by: [EMAIL PROTECTED] 03/14/2007 03:01 PM Please respond to General forum <[email protected]> To General forum <[email protected]> cc Subject Re: [Jgeneral] definition of a: Why is everyone quoting 3!:3 all of a sudden? What is 3!:3]42=$0 supposed to demonstrate? What about 3!:3]'Q'=$0 ? The only interesting byte I see in either result is 2nd row, 2nd column, which indicates the result type is boolean, which is what you would expect from a logical comparison like = . By the way, in the context of the current discussion, it would be more useful to quote 3!:0 which gives the datatype of the argument. All the rest of the output of 3!:3 is just noise to that signal. >The result's domain as a side effect of a loose type language seems to be >at the center of the argument... What is the argument? That empty arrays of type A should not match empty arrays of type B when A isn't B? To me, the crux of THAT argument lies in 1 = *./'' . For the details of my thoughts on this, see: http://www.jsoftware.com/pipermail/general/2005-November/025629.html If the argument is whether a: should be documented as <$0 or <0$0 , then: datatype $0 integer datatype 0$0 boolean datatype >a: boolean But, since ($0)-:0$0 (and even ($0) -:&{. 0$0), REGARDLESS of the reasons, then <$0 is not wrong; so what matters it? -Dan ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
