It makes a significant difference if you "put the data back",
i.e. do the operation in place:
10 ts 'ii reverse`[`]}xx'
0.0131137 4.1968e6
10 ts '(ii reverse xx) ii}xx'
0.0127947 4.19597e6
10 ts 'xx=: (ii reverse xx) ii}xx'
1.00851e_5 1792
The last benchmark would be the goal for the prospective special
code for the following:
10 ts 'xx=: ii reverse`[`]}xx'
0.0136649 4.19686e6
But perhaps the special code is not needed? There isn't
much difference between the two:
xx=: (ii reverse xx) ii}xx
xx=: ii reverse`[`]}xx
Not enough to justify a lot of work and more specialness.
----- Original Message -----
From: greg heil <[EMAIL PROTECTED]>
Date: Wednesday, July 12, 2006 2:09 pm
Subject: Re: [Jprogramming] special coding for stack operations
> On 7/12/06, R&S HUI <[EMAIL PROTECTED]> wrote:
> > The prospects for more efficient computation improves if you say
> name=: x u@:{`[`]} name NB. (0)
> name=: x u`[`]} name NB. (1)
> instead of
> name=: x reverse amend name NB. (2)
> name=: x |.@:{ amend name NB. (3)
> It is easier and more productive for the prospective special code to
> handle (0) and (1) than (2) or (3).
>
> i do gather that special code does not like "cover functions". But
> currently the flexibility/generality offered by the namings does not
> seem to make a significant difference:
>
> ii=:(1 2; 2 0)
> xx=:i. 999 999
> 10 Ts 'ii reverse`[`]} xx'
> 0.0163818 4.1968e6
> 10 Ts 'ii ([:|.{)`[`]} xx'
> 0.0192198 4.19686e6
> 10 Ts 'ii reverse amend xx'
> 0.0194623 4.19674e6
> 10 Ts 'ii swapG xx'
> 0.0159129 4.19578e6
>
> i had been hoping there might be a more efficient way of doing
> what i
> was doing...
>
> Is there some prospect for special coding for this more generic swap
> functionality? i would certainly forgo the perspicuity and generality
> if there were such a prospect - though i dislike such hard coding
> which is hard to maintain and read. It is a significant time sink in
> my app.
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