Long String Generation

Maurice Lombardi Maurice.Lombardi at ujf-grenoble.fr
Mon Feb 15 20:01:35 CET 2010


Kevan Hashemi a écrit :
> Dear GPC Users,
> 
> I use long strings to pass numerical data into and out of a shared 
> library I compile from Pascal. Right now, I generate a long string of 
> numbers like this.
> 
> program string_demo;
> 
> var
>   long_string:string(100000);
>   i:integer;
> 
> begin
>   long_string:='';
>   for i:=1 to 10000 do
>     writestr(long_string,long_string,i:1,' ');
> end.
> 
> Clearly, this is inefficient. It takes 200 ms on my machine. If I use an 
> array of characters instead of a string, and append each new entry to 
> the array, execution time drops to 10 ms.
> 
> I can't see a way of using GPC's writestr, concat, or trim functions to 
> accelerate my string generation. I can't alter the long_string.length 
> field directly. 

SetLength(long_string, 999999).

If I could fill up the string with spaces first, I could
> use the string as an array, then trim the spaces off the end. But 
> filling up the string with spaces requires multiple calls to writestr, 
> so I'm back where I started.
> 
> It seems to me that I'm missing an obvious solution to my problem, and I 
> thought you might point it out to me.

  Maurice

-- 
        Maurice Lombardi
Laboratoire de  Spectrometrie Physique,
Universite Joseph Fourier de Grenoble, BP87
38402 Saint Martin d'Heres Cedex     FRANCE
Tel: 33 (0)4 76 51 47 51
Fax: 33 (0)4 76 63 54 95
mailto:Maurice.Lombardi at ujf-grenoble.fr





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