On 7/17/17 9:23 AM, Petar Kirov [ZombineDev] wrote:
On Monday, 17 July 2017 at 12:38:27 UTC, Steven Schveighoffer wrote:
On 7/16/17 1:04 PM, Andrei Alexandrescu wrote:
On 7/16/17 9:10 AM, Mike Parker wrote:
Congratulations to Timon Gehr. Not only was his "Static foreach" DIP
accepted, it picked up a good deal of praise from Walter & Andrei.
Indeed. Kudos to Timon (and thanks Mike for driving the process).
This is a well done DIP that many others could draw inspiration from.
-- Andrei
What is the resolution of how break statements affect static
foreach/foreach?
i.e. this section:
"As some consider this to be potentially confusing, it has been
suggested that break and continue directly inside static foreach
should instead be compiler errors and require explicit labels. This
DIP leaves this decision to the language authors, but recommends the
above semantics."
I think the only reliable way is to not use jumps (goto, break,
continue) at all.
E.g. if you want to unroll the following loop:
foreach (x; someRange)
{
if (x.isSpecial)
break;
x.writeln();
}
You would need to guard every statement/declaration:
static foreach (x; someRange)
static if (!x.isSpecial)
x.writeln();
My concern is that the proposal asked for break to apply to the runtime
construct that surrounds the loop. So for instance, break would apply to
the switch statement outside the static foreach.
This differs from current static looping (i.e. foreach over a tuple),
where break applies to the foreach.
I'm not concerned with breaking out of the loop. I agree that the
proposed behavior is the best choice. However, it's confusing given
existing behavior that doesn't do that.
-Steve
