std.regex performance

[Timon Gehr]

On 02/08/2012 11:46 PM, bearophile wrote:
> David Nadlinger:
>
>> Could it be that you are rebuilding the regex engine on every iteration
>> here?
>
> This isn't the first time I see this problem.
> CPython caches the RE engines to avoid this problem, so after the first time you use it, it doesn't create the same engine again and again.
>
> Another solution is to change the API, and use a long and ugly function name like buildREengine() that makes it clear to the user that it's better to pull it out of loops :-)
>
> Bye,
> bearophile

The compiler should do loop invariant code motion for pure functions.