Wouldn't this limit the number of copies to a maximum of 9? And if you suppressed copying and a character before and after (0e1j1) would only insert one fill instead of two.
On Sun, Mar 14, 2010 at 7:45 AM, Dan Bron <[email protected]> wrote: > Roger wrote: > > b. What happens if fills are wanted before _and_ after > > the copied items? > > I responded: > > b. Quaternions :) > > While we're waiting for quaternions, here is a notation that approximates > how we'd use them with # . Of course this is just a start and will have > multiple issues, but I hope it gets the idea across: > > decompose =: (,~ (( (-~#) ,~ 10 #. {.)~ > 1+i:&1@:~:&0)@:(10&#.^:_1) )~/@+. > mask =: <@(-@:(1&{) |. {. , 0 #~ +/@:}.)@decompose > expand =: ( ((+ =&0)@:] # (#^:_1!.'.'~ *)) ;@:mask ) ~ > > > '..a.......bbb..........cccc......' -: 1e2j3 3e4j5 4e5j6 expand > 'abc' > > Here, the notation is NeBjA where N is the number of copies, B is the > number of fills before the copies, and A is the number of fills after the > copies. I wanted to use p or e in order to keep the numbers smaller (and > therefore retain more precision) but the constant hierarchy isn't right for > that purpose. > > By the way, why must the left argument to #^:_1 be boolean? Why can't I > say, e.g. 0 0 4 0 0 #!.'x'^:_1 '!' to get 'xx!!!!xx' ? Another > enhancement request for # . > > -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
