digitalmars.D.bugs - [Issue 4347] New: foreach over range should save range.
- d-bugmail puremagic.com (46/46) Jun 19 2010 http://d.puremagic.com/issues/show_bug.cgi?id=4347
- d-bugmail puremagic.com (10/10) Jan 09 2011 http://d.puremagic.com/issues/show_bug.cgi?id=4347
- d-bugmail puremagic.com (13/13) May 05 2011 http://d.puremagic.com/issues/show_bug.cgi?id=4347
http://d.puremagic.com/issues/show_bug.cgi?id=4347 Summary: foreach over range should save range. Product: D Version: D2 Platform: Other OS/Version: Windows Status: NEW Severity: normal Priority: P2 Component: DMD AssignedTo: nobody puremagic.com ReportedBy: dsimcha yahoo.com To be consistent with the old definition of forward ranges, and with arrays and opApply-based ranges, a foreach loop should call save() if it's available. The example below demonstrates why not doing so is problematic. import std.stdio; class SomeRange { uint num; uint front() { return num; } void popFront() { num++; } bool empty() property { return num >= 10; } typeof(this) save() property { auto ret = new typeof(this); ret.num = num; return ret; } } void main() { auto r = new SomeRange; foreach(elem; r) { writeln(elem); // Prints numbers 0-9. } foreach(elem; r) { writeln(elem); // Nothing. } } -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Jun 19 2010
http://d.puremagic.com/issues/show_bug.cgi?id=4347 Andrei Alexandrescu <andrei metalanguage.com> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |ASSIGNED CC| |andrei metalanguage.com AssignedTo|nobody puremagic.com |andrei metalanguage.com -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Jan 09 2011
http://d.puremagic.com/issues/show_bug.cgi?id=4347 Torarin <torarind gmail.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |torarind gmail.com I think save() should be required, since the semantics of foreach when iterating over arrays imply a save() on the array. Letting forward range behaviour depend on whether the range is a class or a struct is bound to be confusing. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
May 05 2011