On 02/03/2011 04:41 PM, Nrgyzer wrote:
== Auszug aus Steven Schveighoffer ([email protected])'s Artikel
On Thu, 03 Feb 2011 09:35:44 -0500, Nrgyzer<[email protected]>
wrote:
== Auszug aus bearophile ([email protected])'s Artikel
Nrgyzer:
Is there any chance to cast/convert this array to an indexed
array or
is it possible to iterate over specific indices? I know that
there is
something like next() for the foreach-statement but when the
array
contains some thousand instances and I only want iterate over
(for
example) 5 elements I think that's the wrong way.
Show a hypothetical code example of what you desire to do,
please.
Bye,
bearophile
Example:
...
class Example(T : Drawable) : Drawable {
T[hash_t] pObjectsToDraw;
uint pFrom, pTo;
void setLimit(from, to) {
pFrom = from;
pTo = to;
}
void remove(T objToRemove) {
pObjectsToDraw.remove(objToRemove.toHash());
}
override void draw() {
for (uint i = pFrom; i< pTo; i++) {
pOjectsToDraw[i].draw(); // cannot call
because pObjectsToDraw is an associative and no static or dynamic
array
}
}
}
First, hashes are not stored in any particular order, so I'm not
sure what
you expect to accomplish except "give me (pTo - pFrom) random
elements
from the array"
Second, you can use a foreach loop to get data out of an AA, and
then
break when you've retrieved enough elements.
Again, I'm not sure what the point is of starting in the middle of
the
array. Are you expecting something different from a hashtable?
-Steve
I know that hashes aren't stored in any order... but lets take the
LinkedHashSet in Java. The LinkedHashSet/Map stores the hashes in
order of inserting. With the toArray()-method I can loop over
specific elements/indices... but I can also remove the elements by
their hash. I'm looking for a similar technique in D - you can find
an Java example on http://www.java2s.com/Code/JavaAPI/java.util/
LinkedHashSettoArray.htm.
Ruby hashes are like that, but I don't think it would be easy to do in D. You'd
better maintain the insertion order yourself in a // array of keys, or make
elements link list nodes.
Denis
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