Or tacitly

   foldr=: (~/)(@|.)

   - foldr i.5
_10

   foldr
(~/)(@|.)

   -foldr
-~/@|.

The initial accumulator is superflous in J,
which knows the identity elements of verbs.

--- Devon McCormick <[EMAIL PROTECTED]> wrote:

> Maybe along these lines?
> 
>    -/i.5 NB. Right fold
> 2
>    (((0-1)-2)-3)-4 NB. Left fold
> _10
>    (-~)/|.i.5
> _10
> 
>    ((((0-1)-2)-3)-4)-5
> _15
>    (-~)/|.i.6
> _15
> 
>    %/>:i.5 NB. Right fold
> 1.875
>    (%~)/|.>:i.5 NB. Left fold
> 0.0083333333
>    (((1%2)%3)%4)%5
> 0.0083333333
> 
> 
> 
> On 11/16/07, metaperl.j <[EMAIL PROTECTED]> wrote:
> >
> >
> > Folding and unfolding are staples of functional programming. Insert
> > approximates fold-left, but what approximates fold-right?
> >
> > --
> > View this message in context:
> > http://www.nabble.com/Where-is-right-fold-in-J--tf4824111s24193.html#a13802283
> > Sent from the J General mailing list archive at Nabble.com.
> >
> > ----------------------------------------------------------------------
> > For information about J forums see http://www.jsoftware.com/forums.htm
> >
> 
> 
> 
> -- 
> Devon McCormick, CFA
> ^me^ at acm.
> org is my
> preferred e-mail
> ----------------------------------------------------------------------
> For information about J forums see http://www.jsoftware.com/forums.htm
> 



      
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