All I can say is that you are chasing ghosts.
----- Original Message ----- From: Dan Bron <[EMAIL PROTECTED]> Date: Thursday, December 20, 2007 13:34 Subject: Re: [Jprogramming] Programming Digest, Vol 27, Issue 39 To: [email protected] > > The Dictionary says : > > The conjunction !: applies to > integer scalar > > left and right arguments ... > > I wrote: > > This phrase checks from 0!:0 to 255!:255 > > Noticing that the DoJ doesn't say the integers can't be > negative, I took > this a bit further, and obstained some interesting > results. > > I looked at all pairs of integers from _1024 to 1024 (i.e. > {;~i:2^10 ) . > I found 34 foriegns whose nameclass wasn't verb. In fact, > it turned out > they were all adverbs: > > 0 600 > 1 480 > 2 360 > 3 240 > 4 120 > 5 0 > 5 993 > 5 994 > 6 _120 > 6 873 > 6 874 > 7 _240 > 7 753 > 7 754 > 8 _360 > 8 633 > 8 634 > 9 _480 > 9 513 > 9 514 > 10 393 > 10 394 > 12 153 > 12 154 > 13 33 > 13 34 > 14 _87 > 14 _86 > 15 _207 > 15 _206 > 16 _327 > 16 _326 > 17 _447 > 17 _446 > > I thought at first that the arguments to !: might > have to be single bytes, > and the negative numbers might just represent "wraparound" (i.e. > they'reidentical into their complementary positive bytes) but > that's clearly not > the case. > > Some of these foreigns represent deprecated familes, and I > suspect they're > throwbacks*. Others, however, seem to come come in > pairs. This pattern is > also evident in the documented foreigns, where m!:(2*n) > means query and > m!:(1+2*n) means set. However, I don't know if this > paradigm is applicable > to adverbs (though we do have the example of 5!:0 > and 5!:1 ). > > Then you have thought provoking little gems like > 0!:600 . Given the known > uses of 0!: apply to scripts, I tried passing one > to 0!:600 : > > '+' > 0!:600 + > > plus=.+ > > 'plus' 0!:600 > + > > > minus =. ]&.plus > > 'minus' 0!:600 > ]&.plus > > (<'+') 0!:600 > + > > (5!:1{.;:'toJ') 0!:600 > ((10{a.) I.@(e.&(13{a.))@]} ])@:(#~ -.@((13 10{a.)&E.@,)) > > > I'm not sure what to make of this, yet. > > And I wonder what other foreigns are hiding under the covers. > There's no > good way to distinguish between a m!:n that doesn't > exist and one that's a > valid verb which you're supplying with inappropriate arguments > (or even the > wrong number of arguments (viz valence) ). > > -Dan > > *: I can't think of a reason to "hide" an undocumented > foreign in a > deprecated family, when it can be hidden just as effectively > within its > "natural" (functionally related) family. ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
