[Jprogramming] Newbie question about {.&>

[Roger Hui]

> It does save a pair of '()' but that seems to be not a good 
> practice as it
> doesn't use the 'primary' functionality of '>' which is to unbox

Who's to say what the "primary functionality" of 
something is?  I have on occasion used the monad
":&.> to produced formatted numbers individually boxed:

   ":&.> 0 1 1 2 3 5 8 13
+-+-+-+-+-+-+-+--+
|0|1|1|2|3|5|8|13|
+-+-+-+-+-+-+-+--+

where > is used to effect box (rather than unbox),
among other effects.  Other examples:

   ; i.&.> 4 5 2
0 1 2 3 0 1 2 3 4 0 1
   ; 4 5 2 {.&.> 1
1 0 0 0 1 0 0 0 0 1 0



----- Original Message -----
From: gary ng <garyng2000 at gmail.com>
Date: Wednesday, May 13, 2009 19:11
Subject: Re: [Jprogramming] Newbie question about {.&>
To: Programming forum <programming at jsoftware.com>

> On Wed, May 13, 2009 at 6:53 PM, bill lam 
> <bbill.lam at gmail.com> wrote:
> 
> > On Wed, 13 May 2009, gary ng wrote:
> > > Are there any hidden 'gem' or reason to say '{.&>' rather 
> than '({."0)'
> > as
> > > to me the only reason for the &> is to modify the rank of {. ?
> >
> > If the argument is un-boxed, why would you use {.&> ?  
> What effect did
> > you expect from that > ?
> >
> 
> That is what puzzled me. This is the original code I came across :
> 
> (,|.@}:)(,.|.@}:"1)({.&>~#{.i:@#)(65}.a.)(>:@i.{.[)'E'
> 
> from http://www.craigmurphy.com/blog/?p=1417#comment-66863
> 
> It does save a pair of '()' but that seems to be not a good 
> practice as it
> doesn't use the 'primary' functionality of '>' which is to unbox