On Mon, Aug 07, 2000 at 02:23:08PM -0400, Chaim Frenkel wrote:
> >>>>> "DS" == Dan Sugalski <[EMAIL PROTECTED]> writes:
>
> DS> At 06:37 AM 8/7/00 -0400, Chaim Frenkel wrote:
> >> Are there any (p5p) pragmas that have a runtime effect?
>
> DS> strict, for one. Warnings for another.
>
> Please explain how these are runtime? I see them as compile time.
These set flags in the op that are checked at runtime.
> >> Would requiring/limiting pragmas to have a strictly compile time effect
> >> have a win for internals (performance, development, whatever)?
>
> DS> Probably, but perl's dynamic enough that I don't think it's feasable.
>
> How about a trial-balloon so that we can have some performance wins.
>
> DS> I've been thinking we could have a "state change" op that would
> DS> selectively and lexically alter the appropriate state variable
> DS> (warnings, stricture, shell, taint checking, whatever) on the
> DS> fly. Each op would check the current state if the situation
> DS> warranted, rather than sprinkling "check this assumption" ops
> DS> througout the code.
>
> A different op would be a better performance win. Even those sections
> that didn't want the check has to pay for it.
That may not be completly true. You would in effect be increasing the
size of code for perl itself. Whether or not it would be a win would
depend on how many times the extra code caused a cache miss and a fetch
from main memory.
As Chip says, human intuition is a very bad benchmark.
Graham.
