Thanks, Dan.

Can't detect any significant improvement in speed over use of ($ $ ,).
But I'm only using small examples (but representative of intended
usage).


On Sun, May 29, 2011 at 1:17 PM, Dan Bron <[email protected]> wrote:
> You could speed up the latter by using the hook formulation, which is 
> supported by special code.  To wit:
>
> reshape=:$ ,
> memcopy=:$ reshape ]
>
> That said, I haven't checked whether this has copy-by-reference or -value 
> semantics for mmapped nouns.
>
> -Dan
>
>
> Please excuse typos; composed on a handheld device.
>
> -----Original Message-----
> From: Ian Clark <[email protected]>
> Sender: [email protected]
> Date: Sat, 28 May 2011 22:38:00
> To: Programming forum<[email protected]>
> Reply-To: Programming forum <[email protected]>
> Subject: Re: [Jprogramming] decoupling assignments to mapped files
>
> Thanks, Dan.
>
> Works nicely, and is slightly faster than: $ $ ,
>
> Ian
>
>
> On Sat, May 28, 2011 at 12:52 AM, Dan Bron <[email protected]> wrote:
>> Ian asked:
>>>  Can you think of a low-overhead verb which
>>>  will force J to allocate sav its own separate
>>>  space in memory?
>>
>> Try a:&{
>>
>>           load'jmf'
>>           createjmf_jmf_ 400;~fn=.jpath'~temp\F.jmf'
>>           map_jmf_ 'F';fn
>>
>>           F=:'hello there'
>>
>>           G=:a:{F
>>           G=:'goodbye here'
>>
>>           F
>>        hello there
>>
>> Roger will make no guarantees about this behavior or any way to force a
>> memcopy.
>>
>> -Dan
>>
>>
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