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digitalmars.D.learn - Do you have a better way to remove element from a array?

reply "FrankLike" <1150015857 qq.com> writes:
Now I can remove element from a array:

module removeOne;
import std.stdio;
import std.array;
import std.algorithm;

void main()
{
    int[] aa =[1,2,3,4,5];
	
	 aa = aa[0..2] ~aa[3..$];
	 writeln(aa); //ok
	  remove(aa,1);
	 writeln(aa);//get error result
}

You will found the error result,why?

Thank you.
Feb 05 2015
parent reply "Tobias Pankrath" <tobias pankrath.net> writes:
On Thursday, 5 February 2015 at 13:25:37 UTC, FrankLike wrote:

 Now I can remove element from a array:

 module removeOne;
 import std.stdio;
 import std.array;
 import std.algorithm;

 void main()
 {
    int[] aa =[1,2,3,4,5];
 	
 	 aa = aa[0..2] ~aa[3..$];
 	 writeln(aa); //ok
 	  remove(aa,1);
 	 writeln(aa);//get error result
 }

 You will found the error result,why?

 Thank you.


Works as designed:
Feb 05 2015
next sibling parent reply "FrankLike" <1150015857 qq.com> writes:
On Thursday, 5 February 2015 at 13:29:30 UTC, Tobias Pankrath 
wrote:


 Works as designed: 



Thank you.
aa = remove(aa,1);//ok

but how to remove one item?
such as aa.remove(2) ?
Feb 05 2015
parent "Tobias Pankrath" <tobias pankrath.net> writes:
On Thursday, 5 February 2015 at 13:55:59 UTC, FrankLike wrote:

 On Thursday, 5 February 2015 at 13:29:30 UTC, Tobias Pankrath 
 wrote:


 Works as designed: 



 Thank you.
 aa = remove(aa,1);//ok

 but how to remove one item?
 such as aa.remove(2) ?


I don't get your question.
Feb 05 2015
prev sibling parent reply "bearophile" <bearophileHUGS lycos.com> writes:
Tobias Pankrath:


 Works as designed: 



Unfortunately it's one of the worst designed functions of Phobos:
https://issues.dlang.org/show_bug.cgi?id=10959

Bye,
bearophile
Feb 05 2015
next sibling parent "FrankLike" <1150015857 qq.com> writes:
On Thursday, 5 February 2015 at 14:09:10 UTC, bearophile wrote:

 Tobias Pankrath:


 Works as designed: 



 Unfortunately it's one of the worst designed functions of 
 Phobos:
 https://issues.dlang.org/show_bug.cgi?id=10959

 Bye,
 bearophile


Yes,A.remove(item) or A.removeAt(index)
They is better than now.
Feb 05 2015
prev sibling next sibling parent "FrankLike" <1150015857 qq.com> writes:
On Thursday, 5 February 2015 at 14:09:10 UTC, bearophile wrote:

Yes,A.remove(item) or A.removeAt(index)

They are better than now.
Feb 05 2015
prev sibling parent reply "bachmeier" <no spam.net> writes:
On Thursday, 5 February 2015 at 14:09:10 UTC, bearophile wrote:

 Tobias Pankrath:


 Works as designed: 



 Unfortunately it's one of the worst designed functions of 
 Phobos:
 https://issues.dlang.org/show_bug.cgi?id=10959

 Bye,
 bearophile


It seems your argument is that remove is poorly designed because 
it's not destructive. Or am I missing your argument?
Feb 05 2015
parent reply "bearophile" <bearophileHUGS lycos.com> writes:
bachmeier:


 It seems your argument is that remove is poorly designed 
 because it's not destructive. Or am I missing your argument?


It has to be a void function (or perhaps bettter it can return 
true/false if it has removed the item, so it becomes  nogc and 
nothrow).
And it has to remove the first item equal to the given one.
You can then add a second function that removes at a given index 
(like removeAt).

Bye,
bearophile
Feb 05 2015
parent FG <home fgda.pl> writes:
On 2015-02-05 at 17:25, bearophile wrote:

 It has to be a void function (or perhaps bettter it can return true/false if
it has removed the item, so it becomes  nogc and nothrow).
 And it has to remove the first item equal to the given one.
 You can then add a second function that removes at a given index (like
removeAt).


I was never a fan of STL's erase-remove idiom, although the decoupling of
algorithms and containers is in general a great idea. However, in D algorithms
can be smarter, because they operate on ranges instead of iterators. I don't
see why remove has to follow the C++ example. Therefore I have to ask:

Is there any reason why `remove` doesn't take the range by reference and
`popBack` as many elements as were removed?
Feb 05 2015