slow runtime

[Jonathan M Davis]

On Thursday 09 September 2010 19:40:47 Dr. Smith wrote:
> The class code below runs terribly slow.  Conversely, when converted into a
> function (albeit returning only one value), it runs fast.  Any insights
> into this or suggestions to get a function to return multiple types at
> once?
> 
> ...library code...
> 
> module testlib;
> import std.stdio, std.string;
> 
> class classtest {
> 
>   int i, j;
> 
>   double[][] hit() {
> 
>     double[][] hi = new double[][](1000, 40);
> 
>     for(i = 1; i < 1000; i++) {
>       for(j = 1; j < 40; j++) {
>         hi[i][j] = (i);
>       }
>     }
>     return hi;
>   }
> 
>   double[][] hot() {
> 
>     double[][] ho = new double[][](1000, 40);
> 
>     for(i = 1; i < 1000; i++) {
>       for(j = 1; j < 40; j++) {
>         ho[i][j] = (j);
>       }
>     }
>     return ho;
>   }
> 
>   string stest () {
>     string hello = "yo!";
>     return hello;
>   }
> }
> 
> ... calling code ...
> 
> import std.stdio, std.string;
> import testlib;
> 
> void main() {
> 
>   classtest obj = new classtest;
>   int i, j;
> 
>   for(i = 1; i < obj.hit.length; i++) {
>     for(j = 1; j < obj.hit[i].length; j++) {
>       writefln("%s\t%f\t%f", obj.stest, obj.hit[i][j], obj.hot[i][j]);
>     }
>   }
> }

By the way, it looks like what you're trying to do could be shrunk down to

import std.stdio;

void main()
{
    for(float i = 1; i < 1000; ++i)
    {
        for(float j = 1; j < 40; ++j)
            writefln("yo!\t%f\t%f", i, j);
    }
}


and that runs _way_ faster. I don't understand why you're doing anything with 
arrays in the first place given what you're printing. But maybe you're just 
trying to show a simplified test case.

- Jonathan M Davis