• "David Jeske" <dwj-d chat.net> Aug 16 2001
• "Sean L. Palmer" <spalmer iname.com> Oct 16 2001
• "Walter" <walter digitalmars.com> Dec 17 2001
• "Pavel Minayev" <evilone omen.ru> Dec 17 2001
• "Walter" <walter digitalmars.com> Dec 17 2001
• "Pavel Minayev" <evilone omen.ru> Dec 18 2001
• "Walter" <walter digitalmars.com> Dec 18 2001
• Russell Borogove <kaleja estarcion.com> Dec 18 2001

"David Jeske" <dwj-d chat.net> writes:

D looks promising, and very much like C#. If there was a compiler available
right now I'd be testing it out.

One thing that seems to be omitted but which is extremely important is
including some type of loop construct which uses an iteration interface. For
example, Python's "for XYZ in ABC:" or C#'s foreach. All standard collection
datatypes should be able to use it.

"Sean L. Palmer" <spalmer iname.com> writes:

I agree with this.  Something like:

char[] a = "blah";

for (char j in a)
{
  write(j);
}

On second thought it's just minor syntactic sugar for this:

char[] a = "blah";

for (int i=0; i<a.size; ++i)
{
  char j=a[i];
  write(j);
}

And the iteration probably can't guarantee order of traversal without making
speed sacrifices...  Then again, it'd keep the compiler from having to
optimize away all those multiplications by &a + i * char.size as the
compiler knows it's iterating an array and could just code up adds.

Also you'd want to keep in mind what might happen if the body of the
iterating for loop modified the container somehow... added or deleted a
portion maybe.  Sounds like it might be a standards nightmare.  ;)

Sean

"David Jeske" <dwj-d chat.net> wrote in message
news:9lic6v$q6u$1 digitaldaemon.com...
 D looks promising, and very much like C#. If there was a compiler


 right now I'd be testing it out.

 One thing that seems to be omitted but which is extremely important is
 including some type of loop construct which uses an iteration interface.


 example, Python's "for XYZ in ABC:" or C#'s foreach. All standard


 datatypes should be able to use it.

"Walter" <walter digitalmars.com> writes:

I'm so used to the for (int i=0; i<a.length; i++) idiom, my mind sees it as
one long keyword <g>.

"Sean L. Palmer" <spalmer iname.com> wrote in message
news:9qgt4j$1n9r$1 digitaldaemon.com...
 I agree with this.  Something like:

 char[] a = "blah";

 for (char j in a)
 {
   write(j);
 }

 On second thought it's just minor syntactic sugar for this:

 char[] a = "blah";

 for (int i=0; i<a.size; ++i)
 {
   char j=a[i];
   write(j);
 }

 And the iteration probably can't guarantee order of traversal without


 speed sacrifices...  Then again, it'd keep the compiler from having to
 optimize away all those multiplications by &a + i * char.size as the
 compiler knows it's iterating an array and could just code up adds.

 Also you'd want to keep in mind what might happen if the body of the
 iterating for loop modified the container somehow... added or deleted a
 portion maybe.  Sounds like it might be a standards nightmare.  ;)

 Sean

 "David Jeske" <dwj-d chat.net> wrote in message
 news:9lic6v$q6u$1 digitaldaemon.com...
 D looks promising, and very much like C#. If there was a compiler


 right now I'd be testing it out.

 One thing that seems to be omitted but which is extremely important is
 including some type of loop construct which uses an iteration interface.


 example, Python's "for XYZ in ABC:" or C#'s foreach. All standard


 datatypes should be able to use it.

"Pavel Minayev" <evilone omen.ru> writes:

"Walter" <walter digitalmars.com> wrote in message
news:9vmbr9$1hip$1 digitaldaemon.com...

 I'm so used to the for (int i=0; i<a.length; i++) idiom, my mind sees it


 one long keyword <g>.


But this won't work for associative arrays. And besides,
if you ever consider adding linked lists into D (BTW a
feature request!), you'll have to supply some way to
iterate through the list quickly.

"Walter" <walter digitalmars.com> writes:

"Pavel Minayev" <evilone omen.ru> wrote in message
news:9vmpk6$1q6h$1 digitaldaemon.com...
 "Walter" <walter digitalmars.com> wrote in message
 news:9vmbr9$1hip$1 digitaldaemon.com...

 I'm so used to the for (int i=0; i<a.length; i++) idiom, my mind sees it


 one long keyword <g>.




Associative arrays can be easilly converted to dynamic arrays, from which
you can do the for loop idiom.

 And besides,
 if you ever consider adding linked lists into D (BTW a
 feature request!), you'll have to supply some way to
 iterate through the list quickly.


Linked lists already work:

    class Foo
    {    Foo next;
        ....
    }

"Pavel Minayev" <evilone omen.ru> writes:

"Walter" <walter digitalmars.com> wrote in message
news:9vmvvm$1v6v$1 digitaldaemon.com...

 "Pavel Minayev" <evilone omen.ru> wrote in message
 news:9vmpk6$1q6h$1 digitaldaemon.com...
 "Walter" <walter digitalmars.com> wrote in message
 news:9vmbr9$1hip$1 digitaldaemon.com...

 I'm so used to the for (int i=0; i<a.length; i++) idiom, my mind sees






 as
 one long keyword <g>.




 Associative arrays can be easilly converted to dynamic arrays, from which
 you can do the for loop idiom.


How exactly do you do that? Like this?

    int[char[]] dict;
    int[] col = cast(int[]) dict;
    for (int i = 0; i < col.length; i++) ...

 And besides,
 if you ever consider adding linked lists into D (BTW a
 feature request!), you'll have to supply some way to
 iterate through the list quickly.


 Linked lists already work:

     class Foo
     {    Foo next;
         ....
     }


Actually I meant something like std::list. Speaking of
syntax, since you can't have array of voids, it might be
used as indicator for linked lists:

    struct vector { int x, y, z; }
    vector a, b;
    void[vector] list;    // linked list of vectors
    list ~= a;
    list = list ~ b;

"Walter" <walter digitalmars.com> writes:

"Pavel Minayev" <evilone omen.ru> wrote in message
news:9vnn2u$2dr5$1 digitaldaemon.com...
 "Walter" <walter digitalmars.com> wrote in message
 news:9vmvvm$1v6v$1 digitaldaemon.com...

 "Pavel Minayev" <evilone omen.ru> wrote in message
 news:9vmpk6$1q6h$1 digitaldaemon.com...
 "Walter" <walter digitalmars.com> wrote in message
 news:9vmbr9$1hip$1 digitaldaemon.com...

 I'm so used to the for (int i=0; i<a.length; i++) idiom, my mind








 it
 as
 one long keyword <g>.




 Associative arrays can be easilly converted to dynamic arrays, from




 you can do the for loop idiom.


 How exactly do you do that? Like this?

     int[char[]] dict;
     int[] col = cast(int[]) dict;
     for (int i = 0; i < col.length; i++) ...


That's an interesting idea! But the way it works now is to use the .keys
property which returns an array of all the keys. Then, iterate over that
array, plugging the values into the associative array to return the values.


 And besides,
 if you ever consider adding linked lists into D (BTW a
 feature request!), you'll have to supply some way to
 iterate through the list quickly.


 Linked lists already work:

     class Foo
     {    Foo next;
         ....
     }


 Actually I meant something like std::list. Speaking of
 syntax, since you can't have array of voids, it might be
 used as indicator for linked lists:

     struct vector { int x, y, z; }
     vector a, b;
     void[vector] list;    // linked list of vectors
     list ~= a;
     list = list ~ b;


I admit I find std::list confusing.

Russell Borogove <kaleja estarcion.com> writes:

Walter wrote:
 But this won't work for associative arrays.


 Associative arrays can be easilly converted to dynamic arrays, from




 you can do the for loop idiom.


 How exactly do you do that? Like this?

     int[char[]] dict;
     int[] col = cast(int[]) dict;
     for (int i = 0; i < col.length; i++) ...


 That's an interesting idea! But the way it works now is to use the .keys
 property which returns an array of all the keys. Then, iterate over that
 array, plugging the values into the associative array to return the values.


But some sort of foreach keyword would be easier to write, clearer, 
and easily extensible to any added builtin collection types. The 
only scary parts would be dealing with added/deleted elements 
during the loop.

-RB