Hello, i'm trying to create a library with utilities classes like containers using Java API. Could anyone help me?

public interface Iterator(E) {
   bool hasNext();
   E next();
   void remove();
   int opApply(int delegate(ref E) delegation);
}

public class AbstractCollection(E) : Collection!E {

   .....

    E[] toArray(E[] dst = null) {
    	size_t count = size();
    	if( dst.length < count ) {
    		dst.length = count;
    	}
    	Iterator!E it = iterator();
    	foreach(int i,E e; it) { -> Error: cannot uniquely infer foreach argument types
    		dst[i] = e;
    	}
    	return dst[0 .. count];
    }

   .....

}

Agustin:

> Hello, i'm trying to create a library with utilities classes like containers using Java API.

The problem with this is that most Phobos works with ranges...


> Could anyone help me?

Maybe your code has multiple problems. If you want a precise answer, then give a complete little program. But a possible problem is in the opApply:

int opApply(int delegate(ref E) delegation);

If you want to use:

foreach (i, e; it) {

Then you need to put both in the opApply (or add a second opApply overload), something like:

int opApply(int delegate(ref int, ref E) delegation);

Bye,
bearophile

On Friday, 14 June 2013 at 17:17:46 UTC, bearophile wrote:
> Agustin:
>
>> Hello, i'm trying to create a library with utilities classes like containers using Java API.
>
> The problem with this is that most Phobos works with ranges...
>
>
>> Could anyone help me?
>
> Maybe your code has multiple problems. If you want a precise answer, then give a complete little program. But a possible problem is in the opApply:
>
> int opApply(int delegate(ref E) delegation);
>
> If you want to use:
>
> foreach (i, e; it) {
>
> Then you need to put both in the opApply (or add a second opApply overload), something like:
>
> int opApply(int delegate(ref int, ref E) delegation);
>
> Bye,
> bearophile

int opApply(int delegate(ref int, ref E) delegation);

Works!, thanks.

On Fri, 14 Jun 2013 13:13:06 -0400, Agustin <agustin.l.alvarez@hotmail.com> wrote:

> Hello, i'm trying to create a library with utilities classes like containers using Java API. Could anyone help me?
>
> public interface Iterator(E) {
>     bool hasNext();
>     E next();
>     void remove();

Here is the issue (as bearophile explained)

>     int opApply(int delegate(ref E) delegation);


Also, you may want to try an already-created library that's similar to Java in some respects:

http://schveiguy.github.io/dcollections/

-Steve

On 06/14/2013 10:25 AM, Agustin wrote:

> int opApply(int delegate(ref int, ref E) delegation);
>
> Works!, thanks.

I have just completed the translation of the "foreach with Structs and Classes" chapter:

  http://ddili.org/ders/d.en/foreach_opapply.html

Ali