• BLS (38/38) Oct 11 2006 Hi,
• Jarrett Billingsley (29/64) Oct 11 2006 Serializable doesn't really have much of an analogue in D.. Java seems t...
• BLS (12/97) Oct 11 2006 Thanks Jarret,

BLS <nanali wanadoo.fr> writes:

Hi,
I like to translate the following Java code into D. (reason follows)

**
  * Collection interface; the root of all Java 1.5 collections.
  */
public interface Collection<AnyType> extends Iterable<AnyType>, 
java.io.Serializable
{
     int size( );

     boolean isEmpty( );

     // and so on ..............
     /**
      * Obtains an Iterator object used to traverse the collection.
      *  return an iterator positioned prior to the first element.
      */
     Iterator<AnyType> iterator( );

     /**
      * Obtains a primitive array view of the collection.
      *  return the primitive array view.
      */
     Object [ ] toArray( );
	
     /**
      * Obtains a primitive array view of the collection.
      *  return the primitive array view.
      */
     <OtherType> OtherType [ ] toArray( OtherType [ ] arr );
}

Reason :
Converting (a lot of ) Java code into D requires java collections in D. 
(also automatic Java2D translation will benefit)

Questions :
1) exists allready something simular to ITERABLE, SERIALIZABLE (have not 
seen the interf. yet)

2) <OtherType> OtherType [ ] toArray( OtherType [ ] arr );
Simply ??????.

Many thanks in advance! ,
Björn

"Jarrett Billingsley" <kb3ctd2 yahoo.com> writes:

"BLS" <nanali wanadoo.fr> wrote in message 
news:egj4g4$1gpa$1 digitaldaemon.com...
 Hi,
 I like to translate the following Java code into D. (reason follows)

 **
  * Collection interface; the root of all Java 1.5 collections.
  */
 public interface Collection<AnyType> extends Iterable<AnyType>, 
 java.io.Serializable
 {
     int size( );

     boolean isEmpty( );

     // and so on ..............
     /**
      * Obtains an Iterator object used to traverse the collection.
      *  return an iterator positioned prior to the first element.
      */
     Iterator<AnyType> iterator( );

     /**
      * Obtains a primitive array view of the collection.
      *  return the primitive array view.
      */
     Object [ ] toArray( );

     /**
      * Obtains a primitive array view of the collection.
      *  return the primitive array view.
      */
     <OtherType> OtherType [ ] toArray( OtherType [ ] arr );
 }

 Reason :
 Converting (a lot of ) Java code into D requires java collections in D. 
 (also automatic Java2D translation will benefit)

 Questions :
 1) exists allready something simular to ITERABLE, SERIALIZABLE (have not 
 seen the interf. yet)

Serializable doesn't really have much of an analogue in D.. Java seems to 
treat it as special (even going so far as to have a keyword to prevent 
serialization of a member variable, "transient"), but there is no standard 
serializing mechanism in D.  It's useful if you want to have all your 
collection types able to be serialized to some kind of file (disk, over 
network etc.), but if you don't need that kind of ability..

As for Iterable?  The way Java does "foreach" (for(member : collection)) is 
also different than how D does it.  D accomplishes foreach iteration through 
an opApply method.  I suppose it would be possible to make an Iterable 
templated interface which means that the derived class must implement 
opApply, like:

interface Iterable(Type)
{
    int opApply(int delegate(inout Type index) dg);
}

class Foo(T) : Iterable!(T)
{
    int opApply(int delegate(inout T index) dg)
    {
        // whatever
    }
}

 2) <OtherType> OtherType [ ] toArray( OtherType [ ] arr );
 Simply ??????.

In D, this would just be

OtherType[] toArray(OtherType[] arr);

According to the Java specs, it will attempt to put the collection's 
contents into the passed-in array, but if it doesn't fit, it'll make a new 
one and return that instead. 

BLS <nanali wanadoo.fr> writes:

Thanks Jarret,
regarding Serializeable, i guess I have seen something in the Mango Tree 
     (IO)

Another thread on D language :
Walter: any plan to add support for yield/return Iterators/generators?


I' ll try your code but I am afraid there are some drawbacks. found 
something in the *lazy evaluation /iterator* thread again on D language. 
Somebody tries something similar to your implementation. as mixin

Have to investigate. again, thanks
björn






Jarrett Billingsley schrieb:
 "BLS" <nanali wanadoo.fr> wrote in message 
 news:egj4g4$1gpa$1 digitaldaemon.com...
 
Hi,
I like to translate the following Java code into D. (reason follows)

**
 * Collection interface; the root of all Java 1.5 collections.
 */
public interface Collection<AnyType> extends Iterable<AnyType>, 
java.io.Serializable
{
    int size( );

    boolean isEmpty( );

    // and so on ..............
    /**
     * Obtains an Iterator object used to traverse the collection.
     *  return an iterator positioned prior to the first element.
     */
    Iterator<AnyType> iterator( );

    /**
     * Obtains a primitive array view of the collection.
     *  return the primitive array view.
     */
    Object [ ] toArray( );

    /**
     * Obtains a primitive array view of the collection.
     *  return the primitive array view.
     */
    <OtherType> OtherType [ ] toArray( OtherType [ ] arr );
}

Reason :
Converting (a lot of ) Java code into D requires java collections in D. 
(also automatic Java2D translation will benefit)

Questions :
1) exists allready something simular to ITERABLE, SERIALIZABLE (have not 
seen the interf. yet)

 
 
 Serializable doesn't really have much of an analogue in D.. Java seems to 
 treat it as special (even going so far as to have a keyword to prevent 
 serialization of a member variable, "transient"), but there is no standard 
 serializing mechanism in D.  It's useful if you want to have all your 
 collection types able to be serialized to some kind of file (disk, over 
 network etc.), but if you don't need that kind of ability..
 
 As for Iterable?  The way Java does "foreach" (for(member : collection)) is 
 also different than how D does it.  D accomplishes foreach iteration through 
 an opApply method.  I suppose it would be possible to make an Iterable 
 templated interface which means that the derived class must implement 
 opApply, like:
 
 interface Iterable(Type)
 {
     int opApply(int delegate(inout Type index) dg);
 }
 
 class Foo(T) : Iterable!(T)
 {
     int opApply(int delegate(inout T index) dg)
     {
         // whatever
     }
 }
 
 
2) <OtherType> OtherType [ ] toArray( OtherType [ ] arr );
Simply ??????.

 
 
 In D, this would just be
 
 OtherType[] toArray(OtherType[] arr);
 
 According to the Java specs, it will attempt to put the collection's 
 contents into the passed-in array, but if it doesn't fit, it'll make a new 
 one and return that instead.