• Martin Fuchs (8/8) Sep 18 2007 Is there a direct way to clear the content of associative arrays in one
• Bill Baxter (6/17) Sep 18 2007 "arr = null" or "arr = arr.init" works.
• Martin Fuchs (7/22) Sep 18 2007 Thanks.
• Stewart Gordon (6/11) Sep 18 2007
• Oskar Linde (22/31) Sep 18 2007 If you only want to clear the reference,

"Martin Fuchs" <martin-fuchs gmx.net> writes:

Is there a direct way to clear the content of associative arrays in one 
step?
I would expect a statement like "arr.clear();", "arr.erase();" or 
"arr.removeall();" to do the work, but couldn't find one.
Instead it seams I would have to use the following wordy an inefficient 
approach:

        foreach(x; arr)
            arr.remove(x); 

Bill Baxter <dnewsgroup billbaxter.com> writes:

Martin Fuchs wrote:
 Is there a direct way to clear the content of associative arrays in one 
 step?
 I would expect a statement like "arr.clear();", "arr.erase();" or 
 "arr.removeall();" to do the work, but couldn't find one.
 Instead it seams I would have to use the following wordy an inefficient 
 approach:
 
         foreach(x; arr)
             arr.remove(x); 
 
 

"arr = null" or "arr = arr.init" works.

http://www.prowiki.org/wiki4d/wiki.cgi?action=edit&id=DocComments/Arrays&section=16

(Check those "Comments" link pages on the doc whenever you don't see 
something in the doc that you should be there)

--bb

"Martin Fuchs" <martin-fuchs gmx.net> writes:

Thanks.

However your link doesn't work for me - it's using an edit action in the 
Wiki I would have to login before.
How do I register in the Wiki, I could only find a "login" link, but no 
"register" function?

"Bill Baxter" <dnewsgroup billbaxter.com> wrote in message 
news:fcnttu$m99$1 digitalmars.com...
 Martin Fuchs wrote:
 Is there a direct way to clear the content of associative arrays in one 
 step?
 I would expect a statement like "arr.clear();", "arr.erase();" or 
 "arr.removeall();" to do the work, but couldn't find one.
 Instead it seams I would have to use the following wordy an inefficient 
 approach:

         foreach(x; arr)
             arr.remove(x);

 "arr = null" or "arr = arr.init" works.

 http://www.prowiki.org/wiki4d/wiki.cgi?action=edit&id=DocComments/Arrays&section=16

 (Check those "Comments" link pages on the doc whenever you don't see 
 something in the doc that you should be there)

 --bb 

"Stewart Gordon" <smjg_1998 yahoo.com> writes:

"Martin Fuchs" <martin-fuchs gmx.net> wrote in message 
news:fcnufv$n5i$1 digitalmars.com...
 Thanks.

 However your link doesn't work for me - it's using an edit action in the 
 Wiki I would have to login before.
 How do I register in the Wiki, I could only find a "login" link, but no 
 "register" function?

<snip top of upside-down reply>

Wiki4D doesn't have user accounts as such - you just have to give yourself a 
name in the preferences.

Stewart. 

Oskar Linde <oskar.lindeREM OVEgmail.com> writes:

Martin Fuchs wrote:
 Is there a direct way to clear the content of associative arrays in one 
 step?
 I would expect a statement like "arr.clear();", "arr.erase();" or 
 "arr.removeall();" to do the work, but couldn't find one.
 Instead it seams I would have to use the following wordy an inefficient 
 approach:
 
         foreach(x; arr)
             arr.remove(x); 

If you only want to clear the reference,

arr = null;

will do the trick. Otherwise, you need to resort to non-portable hackery 
(something like this should definitely be included in the compiler/runtime:)

private struct BB { void*[]b; size_t nodes; }

private union ToPtr(T) {T x; void * ptr; }

void clear(T,E)(T[E] aa) {
     ToPtr!(typeof(aa)) toptr;
     toptr.x = aa;
     BB* b = cast(BB*) toptr.ptr;
     if (b) {
         b.b = null;
         b.nodes = 0;
     }
}

use:

arr.clear();

Warning: hardly tested, but should work with DMD 1.020/Phobos.

Regards,

-- 
Oskar