[Jprogramming] Selfdescribing Sequence

[Roger Hui]

There can be substantial savings in space (and a slight
saving in time) if you use  x +/@:< y  instead of  +/x<y .
The former exploits special code.

   ts=: 6!:2 , 7!:2@]

   ts '+/ golo < 1e9'
0.0933345 2.09843e6
   ts 'golo +/@:< 1e9'
0.0818995 1408



----- Original Message ----- 
From: "Miller, Raul D" <rdmiller at usatoday.com>
To: "Programming forum" <programming at jsoftware.com>
Sent: Monday, January 09, 2006 2:55 PM
Subject: RE: [Jprogramming] Selfdescribing Sequence

Jose Mario Quintana wrote:
> But, of course, by definition the compact form of the series
> is the series itself.  There you go!

I suppose I buried my treatment of this issue in too
much chatter, and left out part of the punchline.

   self=: # >:@i.@#
   unpack=: +/\^:_1
   golo=: self&.unpack(^:7) 1 3
   sg=:3 :'>: +/ golo < y.'"0

   sg 1e9
438744