• John C (27/27) Mar 26 2006 This compiles, but produces some strange output on the cmd line (DMD 0.1...
• Walter Bright (2/2) Mar 27 2006 It's a forward reference problem. Try reversing the declarations of keys...
• John C (6/8) Mar 28 2006 Thanks - that fixed it.
• Stewart Gordon (14/23) Mar 28 2006 Correct.
• Stewart Gordon (15/24) Mar 28 2006 Looking at your code again, it appears to be a case of
• Walter Bright (5/7) Mar 28 2006 Generally, it isn't. But the internal semantic routines need to be

"John C" <johnch_atms hotmail.com> writes:

This compiles, but produces some strange output on the cmd line (DMD 0.150, 
Windows XP SP2):

interface ICollection(T) {
  int length();
}

interface IMap(TKey, TValue) {
  ICollection!(TKey) keys();
}

class Map(TKey, TValue) : IMap!(TKey, TValue) {
  KeyCollection keys() {
    return new KeyCollection;
  }
  class KeyCollection : ICollection!(TKey) {
    int length() {
      return 5;
    }
  }
}

void main() {
    IMap!(int, int) map = new Map!(int, int);
    writefln(map.keys.length);
}

Output:
KeyCollection
10227584

Why does it output "KeyCollection"? Is it some kind of runtime error? And 
why is map.keys.length not 5? 

"Walter Bright" <newshound digitalmars.com> writes:

It's a forward reference problem. Try reversing the declarations of keys() 
and KeyCollection. 

"John C" <johnch_atms hotmail.com> writes:

"Walter Bright" <newshound digitalmars.com> wrote in message 
news:e09vmu$2ubc$1 digitaldaemon.com...
 It's a forward reference problem. Try reversing the declarations of keys() 
 and KeyCollection.

Thanks - that fixed it.

But surely it highlights a separate bug: forward referencing isn't supposed 
to be an issue in D, is it?

John. 

Stewart Gordon <smjg_1998 yahoo.com> writes:

John C wrote:
 "Walter Bright" <newshound digitalmars.com> wrote in message 
 news:e09vmu$2ubc$1 digitaldaemon.com...
 It's a forward reference problem. Try reversing the declarations of keys() 
 and KeyCollection.

 
 Thanks - that fixed it.
 
 But surely it highlights a separate bug: forward referencing isn't supposed 
 to be an issue in D, is it?

Correct.

You'll notice that many forward reference bugs have been filed both here 
and in DStress.  But a forward reference bug that leads to bad code 
generation is a new one on me.

Stewart.

-- 
-----BEGIN GEEK CODE BLOCK-----
Version: 3.1
GCS/M d- s:-  C++  a->--- UB  P+ L E  W++  N+++ o K-  w++  O? M V? PS- 
PE- Y? PGP- t- 5? X? R b DI? D G e++>++++ h-- r-- !y
------END GEEK CODE BLOCK------

My e-mail is valid but not my primary mailbox.  Please keep replies on 
the 'group where everyone may benefit.

Stewart Gordon <smjg_1998 yahoo.com> writes:

John C wrote:
 "Walter Bright" <newshound digitalmars.com> wrote in message 
 news:e09vmu$2ubc$1 digitaldaemon.com...
 It's a forward reference problem. Try reversing the declarations of keys() 
 and KeyCollection.

 
 Thanks - that fixed it.
 
 But surely it highlights a separate bug: forward referencing isn't supposed 
 to be an issue in D, is it?

Looking at your code again, it appears to be a case of

http://d.puremagic.com/bugzilla/show_bug.cgi?id=65

I've just noticed that my testcase contains a forward reference as well. 
   Guess I'll have to try rewriting it without the forward reference and 
see what happens.

Stewart.

-- 
-----BEGIN GEEK CODE BLOCK-----
Version: 3.1
GCS/M d- s:-  C++  a->--- UB  P+ L E  W++  N+++ o K-  w++  O? M V? PS- 
PE- Y? PGP- t- 5? X? R b DI? D G e++>++++ h-- r-- !y
------END GEEK CODE BLOCK------

My e-mail is valid but not my primary mailbox.  Please keep replies on 
the 'group where everyone may benefit.

"Walter Bright" <newshound digitalmars.com> writes:

"John C" <johnch_atms hotmail.com> wrote in message 
news:e0avij$1bpj$1 digitaldaemon.com...
 But surely it highlights a separate bug: forward referencing isn't 
 supposed to be an issue in D, is it?

Generally, it isn't. But the internal semantic routines need to be 
reorganized/reimplemented to do this better, and I'm not up for that right 
now.