On Tue, Oct 26, 2010 at 11:31 AM, Ian Clark <[email protected]> wrote: > I'd got to here, and was puzzling about sample 3 vs sample 2, when > your reminder arrived of how J parses "trains" (have I got the right > term?) -- in order to implement hooks and forks I guess. ...
I do not know if you were asking for help, or if you wanted help, but if I understand the issue you were expressing here: sample 2? > a=: 5 > a ; a ; (3 :'a=: 10')0 NB. J needs to read last 4 tokens at once > +--+-+--+ > |10|5|10| > +--+-+--+ sample 3? > a=: 5 > a ; a ; (a=:10) NB. but here it doesn't > +--+--+--+ > |10|10|10| > +--+--+--+ ... the following are all distinct "tokens": a ; ( 3 : 'a=: 10' ) 0 =: 10 That said, note also that the contents of a parenthesis are evaluated before J inspects any tokens left of the left parenthesis. Consider also: a;a;3 :'a=: 10'a=:5 a;a;(3 :'a=: 10'0)[a=:5 a;a;(3 :'a=: 10'a=:5) -- Raul ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
