How to remove all characters from a string, except the integers?

H. S. Teoh hsteoh at quickfur.ath.cx
Fri Mar 4 20:33:08 UTC 2022


On Fri, Mar 04, 2022 at 07:51:44PM +0000, matheus via Digitalmars-d-learn wrote:
[...]
>     for(j=0;j<1_000_000;++j){
>         s="";
>     	s = str.filter!(ch => ch.isDigit).to!string;

This line allocates a new string for every single loop iteration.  This
is generally not something you want to do in an inner loop. :-)


>     }

[...]
> Unless I did something wrong (If anything please tell). By the way on
> DMD was worse, it was like 5x slower in your version.
[...]

I don't pay any attention to DMD when I'm doing anything remotely
performance-related. Its optimizer is known to be suboptimal. :-P


T

-- 
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