• Tofu Ninja (10/10) Sep 22 2015 Trying to implement a bi directional range and it is slightly
• John Colvin (10/21) Sep 22 2015 The last one. E.g. for arrays (except narrow strings... ugh)
• Tofu Ninja (3/27) Sep 24 2015 Ok cool, that's what I ended up doing.

Tofu Ninja <emmons0 purdue.edu> writes:

Trying to implement a bi directional range and it is slightly 
unclear what the semantics are supposed to be and just wanted 
some clarification.

Are bidirectional ranges supposed to be able to support switching 
direction mid iteration? Like if I do popFront popFront popBack 
should that be equal to just a single popFront? Or once you start 
on a direction should switching be considered an error? Or is 
popFront and popBack supposed to consume from both ends of the 
range and the range is empty when they meet?

-tofu

John Colvin <john.loughran.colvin gmail.com> writes:

On Wednesday, 23 September 2015 at 02:10:22 UTC, Tofu Ninja wrote:
 Trying to implement a bi directional range and it is slightly 
 unclear what the semantics are supposed to be and just wanted 
 some clarification.

 Are bidirectional ranges supposed to be able to support 
 switching direction mid iteration? Like if I do popFront 
 popFront popBack should that be equal to just a single 
 popFront? Or once you start on a direction should switching be 
 considered an error? Or is popFront and popBack supposed to 
 consume from both ends of the range and the range is empty when 
 they meet?

 -tofu

The last one. E.g. for arrays (except narrow strings... ugh)

auto popFront(T)(ref T[] a)
{
     a = a[1 .. $];
}

auto popBack(T)(ref T[] a)
{
     a = a[0 .. $-1];
}

Tofu Ninja <emmons0 purdue.edu> writes:

On Wednesday, 23 September 2015 at 03:26:29 UTC, John Colvin 
wrote:
 On Wednesday, 23 September 2015 at 02:10:22 UTC, Tofu Ninja 
 wrote:
 Trying to implement a bi directional range and it is slightly 
 unclear what the semantics are supposed to be and just wanted 
 some clarification.

 Are bidirectional ranges supposed to be able to support 
 switching direction mid iteration? Like if I do popFront 
 popFront popBack should that be equal to just a single 
 popFront? Or once you start on a direction should switching be 
 considered an error? Or is popFront and popBack supposed to 
 consume from both ends of the range and the range is empty 
 when they meet?

 -tofu

 The last one. E.g. for arrays (except narrow strings... ugh)

 auto popFront(T)(ref T[] a)
 {
     a = a[1 .. $];
 }

 auto popBack(T)(ref T[] a)
 {
     a = a[0 .. $-1];
 }

Ok cool, that's what I ended up doing.