I assume only the agenda trick can do it tacitly:
firstT =: (`(i.`1:))(@.(<0 1 2)) There is an upto 10% performance improvement (sometimes in J6. Not J7) in the tacit version but both are very fast. ----- Original Message ----- From: Pascal Jasmin <[email protected]> To: "[email protected]" <[email protected]> Cc: Sent: Saturday, November 2, 2013 2:06:56 PM Subject: [Jprogramming] making a 'first' adverb tacit I'm pleased that this is as elegant as it is already, but can the 2 adverbs be defined tacitly? first =: 1 : 'u i. 1:' retitem =: 1 : '] {~ u' (4<])first i.7 5 4< first i.7 5 Its nice that the adverb doesn't require a duplicate dyadic definition. 4< first >:i.7 4 4< first retitem >:i.7 5 ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
