Hi

I have seen that it is possible to remove an element from a associative array, but dont find any reference, including in D's specification, about any element removing in dynamic array. I can use loops for that, but isnt any way to simple reduce a dynamic array size ?

Thank you

On Sunday, 9 August 2015 at 13:22:02 UTC, Reflexive wrote:
> Hi
>
> I have seen that it is possible to remove an element from a associative array, but dont find any reference, including in D's specification, about any element removing in dynamic array. I can use loops for that, but isnt any way to simple reduce a dynamic array size ?
>
> Thank you

You can use std.algorithm.remove for that. If you need more advanced ways to remove elements, you may want to switch from a regular dynamic array to a std.container.array.

On Sunday, 9 August 2015 at 13:40:51 UTC, cym13 wrote:
> On Sunday, 9 August 2015 at 13:22:02 UTC, Reflexive wrote:
>
> You can use std.algorithm.remove for that. If you need more advanced ways to remove elements, you may want to switch from a regular dynamic array to a std.container.array.

I get :

Error: module remove is in file 'std/algorithm/remove.d' which cannot be read
import path[0] = /usr/include/dmd/phobos
import path[1] = /usr/include/dmd/druntime/import

I'm in Linux Mint 17 ... maybe an permission problem ?

On 10/08/2015 2:24 a.m., Reflexive wrote:
> On Sunday, 9 August 2015 at 13:40:51 UTC, cym13 wrote:
>> On Sunday, 9 August 2015 at 13:22:02 UTC, Reflexive wrote:
>>
>> You can use std.algorithm.remove for that. If you need more advanced
>> ways to remove elements, you may want to switch from a regular dynamic
>> array to a std.container.array.
>
> I get :
>
> Error: module remove is in file 'std/algorithm/remove.d' which cannot be
> read
> import path[0] = /usr/include/dmd/phobos
> import path[1] = /usr/include/dmd/druntime/import
>
> I'm in Linux Mint 17 ... maybe an permission problem ?

You sure you are using it correctly (off top of my head)?

-----
import std.algorithm : remove;

...
arr.remove(e);

-----

On Sunday, 9 August 2015 at 14:24:38 UTC, Reflexive wrote:
> Error: module remove is in file 'std/algorithm/remove.d' which cannot be read

remove() is a function in module std.algorithm:

import std.algorithm: remove;
remove(foo);

I wrote import std.algorithm.remove ;, and I dont have any longer any error. But, it dont want to remove the item. Here is the source, the problem is in the shuffle() method :

// sabot.d
// version 0.0.1
import std.stdio ;
import std.random ;
import std.algorithm : remove ;


void main(){
	auto deck = new sabot ;
	deck.shuffle() ;

class sabot{
	card[] sabotarray ;

	(...)

	struct card {
		int id ;
		(...)
	}

	(...)

	this(){
		(the constructor builds up the array 'sabotarray'.)
}
	void shuffle(){
		card[] tempsabotarray ;
		card tempcard ;
		long id_card ;
		int counter ;
		while(this.sabotarray.length>1){
			if(counter>=60){break;}

			id_card = uniform(0,this.sabotarray.length-1) ;

			tempcard = this.sabotarray[id_card] ;
			this.sabotarray.remove(id_card) ;
			tempsabotarray ~= tempcard ;

			writeln ("Counter : " , counter, " ; id card : " , id_card, " ; sabot size : ", this.sabotarray.length) ;
			++counter ;
		}
		this.sabotarray = tempsabotarray ;
	}

	(...)
}

And I get in the terminal :

$ dmd -run sabot.d
Counter : 0 ; id card : 18 ; sabot size : 52
Counter : 1 ; id card : 40 ; sabot size : 52
Counter : 2 ; id card : 14 ; sabot size : 52
Counter : 3 ; id card : 44 ; sabot size : 52
(...)

Until counter is 60. Sabot size remains 52 all the time.

Without the break statement, the computer goes out of memory.

On Sunday, 9 August 2015 at 15:30:32 UTC, Reflexive wrote:
> I wrote import std.algorithm.remove ;, and I dont have any longer any error. But, it dont want to remove the item. Here is the source, the problem is in the shuffle() method :
>
> ...

Why not just use std.random.shuffle [1]?

    import std.random;

    void shuffle() {
        randomShuffle(this.sabotarray);
    }

(Also, this is more of a style opinion, but please don't define all your variables up front; define them when they're first used. The other way IMO has too much cognitive load, and you can't use `auto` in many cases)

[1]: http://dlang.org/phobos/std_random.html#.randomShuffle

On Sunday, 9 August 2015 at 15:41:33 UTC, Alex Parrill wrote:
>
> Why not just use std.random.shuffle [1]?
>

Well, I didn't knew about it, that's the reason ...

For the shuffle method, it is certainly the best to do, but I need the remove() method at other places. I see that remove() removes the value of the element but keeps the same size of the array, and replace the value by a new one at the end. The method :

class sabot{
	card[] sabotarray ;

	(...)

	card getCard(){
		card returncard = this.sabotarray[0] ;
		this.sabotarray.remove(0) ;
		return returncard ;
	}

The sabotarray before taking away cards :

$ dmd -run sabot.d
0. 🂡
1. 🂢
2. 🂣
...
48. 🃚
49. 🃛
50. 🃝
51. 🃞

The sabotarray after removing the two first cards :

$ dmd -run sabot.d
0. 🂣
1. 🂤
2. 🂥
...
47. 🃛
48. 🃝
49. 🃞
50. 🃞
51. 🃞

On Sunday, 9 August 2015 at 20:23:00 UTC, Reflexive wrote:
> I see that remove() removes the value of the element but keeps the same size of the array, and replace the value by a new one at the end. The method :
>
> class sabot{
> 	card[] sabotarray ;
>
> 	(...)
>
> 	card getCard(){
> 		card returncard = this.sabotarray[0] ;
> 		this.sabotarray.remove(0) ;
> 		return returncard ;
> 	}

`remove` doesn't update the passed array, but it returns a slice of it that doesn't include the removed element. To update the original array, assign the result of `remove` to it:

this.sabotarray = this.sabotarray.remove(0);

09.08.2015 23:22, Reflexive пишет:
>
Try to use
this.sabotarray = this.sabotarray.remove(id_card);

remove() removes element(s) but doesn't change length of 'old' array. To get new length you should use 'new' array that returned from remove(). In this case I get rid of two excessive kings in cards.