Is it a good idea to silently statically accept duplicated keys in both dynamic array literals and in associative array literals?


void main() {
    int[]     a = [0:10, 0:20];
    int[int] aa = [0:10, 0:20];
}


I don't remember having ever had the need for this, and on the other hand I have had some mistakes like this in my D code not caught statically by the compiler.

-----------------------

Note that in this post I am not discussing about inserting multiple times a key-pair in an associative array, this is normal and useful:

void main() {
    int[int] aa;
    aa[0] = 10;
    aa[0] = 20;
}

Bye,
bearophile

"bearophile" <bearophileHUGS@lycos.com> wrote in message news:befwnwpitihpcjfbdarl@forum.dlang.org...
> Is it a good idea to silently statically accept duplicated keys in both dynamic array literals and in associative array literals?
>

Looks like a bug to me.

On 28.11.2013. 12:23, bearophile wrote:
> Is it a good idea to silently statically accept duplicated keys in both dynamic array literals and in associative array literals?
> 
> 
> void main() {
>     int[]     a = [0:10, 0:20];
>     int[int] aa = [0:10, 0:20];
> }
> 
> 
> I don't remember having ever had the need for this, and on the other hand I have had some mistakes like this in my D code not caught statically by the compiler.
> 
> -----------------------
> 
> Note that in this post I am not discussing about inserting multiple times a key-pair in an associative array, this is normal and useful:
> 
> void main() {
>     int[int] aa;
>     aa[0] = 10;
>     aa[0] = 20;
> }
> 
> Bye,
> bearophile

PHP also allows it:

$data = array('a' => 1, 'a' => 2);

And I find it to be only a source of bugs.

28.11.2013 15:23, bearophile пишет:
> Is it a good idea to silently statically accept duplicated keys in both
> dynamic array literals and in associative array literals?
>
>
> void main() {
>      int[]     a = [0:10, 0:20];
>      int[int] aa = [0:10, 0:20];
> }
>
>
> I don't remember having ever had the need for this, and on the other
> hand I have had some mistakes like this in my D code not caught
> statically by the compiler.
>
> -----------------------
>
> Note that in this post I am not discussing about inserting multiple
> times a key-pair in an associative array, this is normal and useful:
>
> void main() {
>      int[int] aa;
>      aa[0] = 10;
>      aa[0] = 20;
> }
>
> Bye,
> bearophile

File the issue please.

-- 
Денис В. Шеломовский
Denis V. Shelomovskij

On 2013-11-28 18:55, luka8088 wrote:

> PHP also allows it:
>
> $data = array('a' => 1, 'a' => 2);
>
> And I find it to be only a source of bugs.

Arrays are a weird beast in PHP. They're both arrays and associative arrays, at the same time, somehow.

-- 
/Jacob Carlborg

On 28.11.2013. 21:01, Jacob Carlborg wrote:
> On 2013-11-28 18:55, luka8088 wrote:
> 
>> PHP also allows it:
>>
>> $data = array('a' => 1, 'a' => 2);
>>
>> And I find it to be only a source of bugs.
> 
> Arrays are a weird beast in PHP. They're both arrays and associative arrays, at the same time, somehow.
> 

They are associative array which can emulate array like behavior. But unfortunately that has also in my experience turned out to be just another source of bugs.

Denis Shelomovskij:

> File the issue please.

I have opened an issue, currently it's not an enhancement request:
https://d.puremagic.com/issues/show_bug.cgi?id=11637

In that issue I have also added more explanations and more code examples, with an extra small discussion about arrays with strongly typed indexes, that I have never stopped missing in D, being used to them since Delphi.

Bye,
bearophile