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digitalmars.D.bugs - [Issue 10845] New: std.range.Cycle broken for reference type forward ranges

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=10845

           Summary: std.range.Cycle broken for reference type forward
                    ranges
           Product: D
           Version: D2
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Phobos
        AssignedTo: nobody puremagic.com
        ReportedBy: peter.alexander.au gmail.com


--- Comment #0 from Peter Alexander <peter.alexander.au gmail.com> 2013-08-18
04:59:56 PDT ---
import std.stdio;
import std.range;
import std.algorithm;

void main()
{
    auto a = inputRangeObject(iota(3).filter!"true");
    writeln(a.cycle.take(10));
}

Outputs

[0, 1, 2, 0, 1, 2,

then asserts: http://dpaste.dzfl.pl/84de028d

The problem is Cycle.popFront:

void popFront()
{
    _current.popFront();
    if (_current.empty) _current = _original;
}

It should be _current = _original.save, otherwise the _original range is
consumed on the second iteration.

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parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=10845


monarchdodra gmail.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |monarchdodra gmail.com


--- Comment #1 from monarchdodra gmail.com 2013-08-18 05:47:49 PDT ---
(In reply to comment #0)
 import std.stdio;
 import std.range;
 import std.algorithm;
 
 void main()
 {
     auto a = inputRangeObject(iota(3).filter!"true");
     writeln(a.cycle.take(10));
 }
 
 Outputs
 
 [0, 1, 2, 0, 1, 2,
 
 then asserts: http://dpaste.dzfl.pl/84de028d
 
 The problem is Cycle.popFront:
 
 void popFront()
 {
     _current.popFront();
     if (_current.empty) _current = _original;
 }
 
 It should be _current = _original.save, otherwise the _original range is
 consumed on the second iteration.
I have an open pull for improving cycle: https://github.com/D-Programming-Language/phobos/pull/1149 So I integrated the fix in it. That said, given how often my pulls get reviewed and pulled, it might be best if you created a pull for this that _I_ could review and pull... -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Aug 18 2013