January 09
On Wed, Jan 10, 2018 at 12:18:46AM +0100, Timon Gehr via Digitalmars-d-learn wrote:
> On 09.01.2018 22:04, H. S. Teoh wrote:
> > 	if (0 == 3) {}
> > 	// all subsequent iterations deleted
> > 
> > because the static break is unconditionally compiled (it has nothing to do with the runtime branch).  You'd have to use static if to make it conditionally-compiled and thus not instantly aborting the loop.
> > 
> > Such semantics would be logically consistent, but unfortunately rather counterintuitive at first glance.
> 
> I think "if (0 == 3) { static break; }" should be a compile-time error.

That's also a possible solution, perhaps a better solution than what I described.  Make it so that static break/continue cannot be nested inside runtime conditionals.  That should exclude all of the pathological cases, hopefully.


T

-- 
The diminished 7th chord is the most flexible and fear-instilling chord. Use it often, use it unsparingly, to subdue your listeners into submission!
January 10
On Tuesday, 9 January 2018 at 23:27:42 UTC, H. S. Teoh wrote:
> On Wed, Jan 10, 2018 at 12:18:46AM +0100, Timon Gehr via Digitalmars-d-learn wrote:
>> On 09.01.2018 22:04, H. S. Teoh wrote:
>> > [...]
>> 
>> I think "if (0 == 3) { static break; }" should be a compile-time error.
>
> That's also a possible solution, perhaps a better solution than what I described.  Make it so that static break/continue cannot be nested inside runtime conditionals.  That should exclude all of the pathological cases, hopefully.
>
>
> T

FWIW I recently bumped into a problem where `static break` would be _really_ useful:

https://github.com/dlang/dmd/pull/7577#discussion_r159175229
January 12
On Sunday, 7 January 2018 at 02:17:02 UTC, Stefan Koch wrote:
> On Sunday, 7 January 2018 at 01:08:44 UTC, H. S. Teoh wrote:
>> On Sun, Jan 07, 2018 at 12:55:27AM +0000, Stefan Koch via Digitalmars-d-learn wrote:
>>> On Saturday, 6 January 2018 at 23:25:58 UTC, Ali Çehreli wrote:
>>> > Is 'static foreach' sufficient for all needs or is there any value for regular foreach over compile-time sequences?
>> [...]
>>> No it's not.
>>> When you can use the old style do so. Since it puts less stress on the
>>> compiler in the general case.
>>
>> Really? Based on a recent post by Jonathan Davis, the new static foreach actually runs faster in certain use cases.
>>
>>
>> T
>
> That might be true.
> If you are hitting some constant factor, however the big-o for static foreach is worse then for tuple foreach.


FWIW there isn't any measurable performance penalty / difference.
We moved to use static foreach on Phobos recently: https://github.com/dlang/phobos/pull/5989
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