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digitalmars.D.bugs - [Issue 6849] New: std.algorithm.remove design

reply d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=6849

           Summary: std.algorithm.remove design
           Product: D
           Version: D2
          Platform: x86
        OS/Version: Windows
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Phobos
        AssignedTo: nobody puremagic.com
        ReportedBy: bearophile_hugs eml.cc



A D2 program:

import std.stdio, std.algorithm;
void main() {
    dchar[] data = "abcde"d.dup;
    writeln(data);
    writeln(remove(data, 0));
    writeln(data);
    writeln(remove(data, 2));
    writeln(data);
}


With DMD 2.056beta3 it prints:

abcde
bcde
bcdee
bcee
bceee


Expected output:

abcde
bcde
bcde
bce
bce


Or maybe it's better for remove() to return void, to underline its in-place
nature (this is often done in Python, where functions the modify da in-place
usually return just None, and functions with a name that ends with "ed" create
new data and return it, like the sort/sorted pair):


import std.stdio, std.algorithm;
void main() {
    dchar[] data = "abcde"d.dup;
    writeln(data);
    data.remove(0);
    writeln(data);
    data.remove(2);
    writeln(data);
}


Expected output:

abcde
bcde
bce


This is similar to what happens in Python2:


 data = ['a', 'b', 'c', 'd', 'e']
 del data[0]
 data






['b', 'c', 'd', 'e']

 del data[2]
 data






['b', 'c', 'e']

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Oct 25 2011
next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=6849




I didn't fully understand the situation, as it often happens:

http://www.digitalmars.com/webnews/newsgroups.php?art_group=digitalmars.D.learn&article_id=30277

Yet I think the problem exists, and there are Python (and other languages)
programmers too coming to D. See some comments, with an alternative proposal
too, about a replaceInPlace() function:

http://www.digitalmars.com/webnews/newsgroups.php?art_group=digitalmars.D.learn&article_id=30281

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prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=6849




From the same thread:

http://www.digitalmars.com/webnews/newsgroups.php?art_group=digitalmars.D.learn&article_id=30294

Steven Schveighoffer:


 Here is the resulting array and final state of a:

 import std.stdio, std.algorithm;
 void main() {
      int[] a = [ 0, 1, 2, 3 ];
      writeln( remove!(SwapStrategy.unstable)(a, 1));
      writeln(a);
 }
 
 output:
 
 [3, 1, 2]
 [3, 1, 2, 3]
 
 Clearly, index 0 was removed, not index 1.  Please file a bug.


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Oct 26 2011
prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=6849




10:25:44 PDT ---


 From the same thread:
 
 http://www.digitalmars.com/webnews/newsgroups.php?art_group=digitalmars.D.learn&article_id=30294
 
 Steven Schveighoffer:
 

 
 Clearly, index 0 was removed, not index 1.  Please file a bug.




This is not a design bug, it's an actual bug in the code (does not work as
designed), it should be separate from this enhancement request.

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prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=6849








 From the same thread:
 
 http://www.digitalmars.com/webnews/newsgroups.php?art_group=digitalmars.D.learn&article_id=30294
 
 Steven Schveighoffer:
 

 
 Clearly, index 0 was removed, not index 1.  Please file a bug.




 
 This is not a design bug, it's an actual bug in the code (does not work as
 designed), it should be separate from this enhancement request.


Right, it's my mistake of mixing two different things in the same issue. Sorry.


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Oct 26 2011
prev sibling next sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=6849




To clear up this bug report I close it and replace it with a a bug report and a
more focused enhancement request.



See also bug 6957.

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Nov 15 2011
prev sibling parent d-bugmail puremagic.com writes:
http://d.puremagic.com/issues/show_bug.cgi?id=6849


bearophile_hugs eml.cc changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |RESOLVED
         Resolution|                            |INVALID


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