digitalmars.D.learn - Access Violation in callback from sort
- Jabb (36/36) May 02 2012 Just got the TDPL book and it's a great read! I learn best when
- Steven Schveighoffer (7/41) May 03 2012 There shouldn't be any closure here, sort is not storing the delegate
- Stefan (6/12) Mar 21 2013 Did you try
- =?UTF-8?B?QWxpIMOHZWhyZWxp?= (4/15) Mar 21 2013 That should be ok. Unlike .byKey, .keys is eager; all of the keys are in...
- =?UTF-8?B?QWxpIMOHZWhyZWxp?= (7/15) Mar 21 2013 I can reproduce the bug with 2.062 as well as an earlier development
Just got the TDPL book and it's a great read! I learn best when typing out the code myself, so I decided to make a single VisualD project and put the different exercises in separate modules. I am having problems with sort in std.algorithms - well, actually it appears to be a closure problem when sort calls my delegate. Here's a sample of the problem - in main.d I have //------------------ module main; import std.algorithm; void main() { uint[string] counts = [ "a":4, "b":5, "c":3, "d":1 ]; string[] keys = counts.keys; sort!((a, b) { return counts[a] > counts[b]; })(keys); } //------------------ Alone this works just fine. But if I add another file called myalgs.d, and put the following in it: //------------------ module myalgs; import std.algorithm; //------------------ Then I get the following exception: object.Error: Access Violation ---------------- C:\D\dmd2\windows\bin\..\..\src\phobos\std\algorithm.d(7112): mainmain__T8sortImplS14main9__lambda3VE3std9algorithm12SwapStrategy0TAAyaZsortImpl ---------------- Steping through the code it appears that the Access Violation occurs when accessing counts[a]. I am using DMD32 v2.059; my compilation command line looks like: dmd -g -debug -X -Xf"$(IntDir)\$(TargetName).json" -deps="$(OutDir)\$(ProjectName).dep" -of"$(OutDir)\$(ProjectName).exe_cv" -map "$(INTDIR)\$(SAFEPROJECTNAME).map" -L/NOMAP Am I doing something wrong here? thanks for the help!
May 02 2012
On Wed, 02 May 2012 11:27:57 -0400, Jabb <jj.jabbaloo gmail.com> wrote:Just got the TDPL book and it's a great read! I learn best when typing out the code myself, so I decided to make a single VisualD project and put the different exercises in separate modules. I am having problems with sort in std.algorithms - well, actually it appears to be a closure problem when sort calls my delegate.There shouldn't be any closure here, sort is not storing the delegate pointer.Here's a sample of the problem - in main.d I have //------------------ module main; import std.algorithm; void main() { uint[string] counts = [ "a":4, "b":5, "c":3, "d":1 ]; string[] keys = counts.keys; sort!((a, b) { return counts[a] > counts[b]; })(keys); } //------------------ Alone this works just fine. But if I add another file called myalgs.d, and put the following in it: //------------------ module myalgs; import std.algorithm; //------------------ Then I get the following exception: object.Error: Access Violation ---------------- C:\D\dmd2\windows\bin\..\..\src\phobos\std\algorithm.d(7112): mainmain__T8sortImplS14main9__lambda3VE3std9algorithm12SwapStrategy0TAAyaZsortImpl ---------------- Steping through the code it appears that the Access Violation occurs when accessing counts[a]. I am using DMD32 v2.059; my compilation command line looks like: dmd -g -debug -X -Xf"$(IntDir)\$(TargetName).json" -deps="$(OutDir)\$(ProjectName).dep" -of"$(OutDir)\$(ProjectName).exe_cv" -map "$(INTDIR)\$(SAFEPROJECTNAME).map" -L/NOMAPI can't see any errors, I think this is worthy of a bug report, it's nice and small and self-contained. http://d.puremagic.com/issues -Steve
May 03 2012
On Wednesday, 2 May 2012 at 15:27:58 UTC, Jabb wrote:import std.algorithm; void main() { uint[string] counts = [ "a":4, "b":5, "c":3, "d":1 ]; string[] keys = counts.keys; sort!((a, b) { return counts[a] > counts[b]; })(keys); }Did you try string[] keys = counts.keys.dup; ? Sometimes you get weird aliasing issues, as the sort! template modifies the original array.
Mar 21 2013
On 03/21/2013 01:02 PM, Stefan wrote:On Wednesday, 2 May 2012 at 15:27:58 UTC, Jabb wrote:That should be ok. Unlike .byKey, .keys is eager; all of the keys are in the returned slice by the time it returns. Aliimport std.algorithm; void main() { uint[string] counts = [ "a":4, "b":5, "c":3, "d":1 ]; string[] keys = counts.keys; sort!((a, b) { return counts[a] > counts[b]; })(keys); }Did you try string[] keys = counts.keys.dup; ?
Mar 21 2013
On 05/02/2012 08:27 AM, Jabb wrote:Alone this works just fine. But if I add another file called myalgs.d, and put the following in it: //------------------ module myalgs; import std.algorithm; //------------------ Then I get the following exception: object.Error: Access ViolationI can reproduce the bug with 2.062 as well as an earlier development build of 2.063 (a fresher dmd does not build at the moment.) I have found a workaround: Put the second file later in the dmd command line: dmd main.d myalgs.d Ali
Mar 21 2013