• "ixid" <nuaccount gmail.com> May 09 2012
• Timon Gehr <timon.gehr gmx.ch> May 09 2012
• Timon Gehr <timon.gehr gmx.ch> May 09 2012
• mta`chrono <chrono mta-international.net> May 11 2012
• "ixid" <nuaccount gmail.com> May 09 2012
• "H. S. Teoh" <hsteoh quickfur.ath.cx> May 09 2012
• "bearophile" <bearophileHUGS lycos.com> May 09 2012
• "Steven Schveighoffer" <schveiguy yahoo.com> May 11 2012

"ixid" <nuaccount gmail.com> writes:

With this code foreach works but foreach_reverse does not:

void main()
{   int[] ints = [2,2,2,5,5,5,4,4,4];
     auto temp = group(ints);
     foreach_reverse(i;temp)
         i[1].writeln;
}

Is this a known issue? Is there a sensible reason for this?

Timon Gehr <timon.gehr gmx.ch> writes:

On 05/09/2012 10:50 PM, ixid wrote:
 With this code foreach works but foreach_reverse does not:

 void main()
 { int[] ints = [2,2,2,5,5,5,4,4,4];
   auto temp = group(ints);
   foreach_reverse(i;temp)
   i[1].writeln;
 }

 Is this a known issue? Is there a sensible reason for this?


group returns a lazy forward range. use foreach(i; group(retro(ints)))

Timon Gehr <timon.gehr gmx.ch> writes:

On 05/09/2012 11:33 PM, ixid wrote:
 Thanks, sorry to have not understand such a basic point, it's rather
 hard to get to grips with everything like this in D.


No worries.

mta`chrono <chrono mta-international.net> writes:

 group returns a lazy forward range. use foreach(i; group(retro(ints)))


 Yet another reason foreach_reverse needs to go.
 
 
 T
 


No please don't! There are hundred and ten very usefull cases.

"ixid" <nuaccount gmail.com> writes:

Thanks, sorry to have not understand such a basic point, it's 
rather hard to get to grips with everything like this in D.

"H. S. Teoh" <hsteoh quickfur.ath.cx> writes:

On Wed, May 09, 2012 at 11:09:15PM +0200, Timon Gehr wrote:
 On 05/09/2012 10:50 PM, ixid wrote:
With this code foreach works but foreach_reverse does not:

void main()
{ int[] ints = [2,2,2,5,5,5,4,4,4];
  auto temp = group(ints);
  foreach_reverse(i;temp)
  i[1].writeln;
}

Is this a known issue? Is there a sensible reason for this?


 group returns a lazy forward range. use foreach(i; group(retro(ints)))


Yet another reason foreach_reverse needs to go.


T

-- 
It only takes one twig to burn down a forest.

"bearophile" <bearophileHUGS lycos.com> writes:

H. S. Teoh:

 Yet another reason foreach_reverse needs to go.


Nope, the specific kind of range of group not being what the OP 
desired is not foreach_reverse fault.

Bye,
bearophile

"Steven Schveighoffer" <schveiguy yahoo.com> writes:

On Fri, 11 May 2012 03:43:53 -0400, mta`chrono  
<chrono mta-international.net> wrote:

 group returns a lazy forward range. use foreach(i; group(retro(ints)))


 Yet another reason foreach_reverse needs to go.


 T


 No please don't! There are hundred and ten very usefull cases.


No, there is only one.

foreach_reverse(i; 0..10) {...}

Every other usage of foreach_reverse can be rewritten with foreach.

I would argue that this should work:

foreach(i; 10..0)

but it would be quite odd given that you would start with 9 and end with  
0.  I don't have a really good answer for this, foreach(i; 9..-1) isn't  
really acceptable, especially if i is unsigned.

-Steve