Iterator for maps of type int and Object.
The iterator semantics for Trove's primitive maps is slightly different
from those defined in java.util.Iterator, but still well within
the scope of the pattern, as defined by Gamma, et al.
This iterator does not implicitly advance to the next entry when
the value at the current position is retrieved. Rather, you must explicitly
ask the iterator to advance() and then retrieve either the key(),
the value() or both. This is done so that you have the option, but not
the obligation, to retrieve keys and/or values as your application requires, and
without introducing wrapper objects that would carry both. As the iteration is
stateful, access to the key/value parts of the current map entry happens in
constant time.
In practice, the iterator is akin to a "search finger" that you move from
position to position. Read or write operations affect the current entry only and
do not assume responsibility for moving the finger.
Here are some sample scenarios for this class of iterator:
// accessing keys/values through an iterator:
for (TIntObjectIterator it = map.iterator();
it.hasNext();) {
it.forward();
if (satisfiesCondition(it.key()) {
doSomethingWithValue(it.value());
}
}
// modifying values in-place through iteration:
for (TIntObjectIterator it = map.iterator();
it.hasNext();) {
it.forward();
if (satisfiesCondition(it.key()) {
it.setValue(newValueForKey(it.key()));
}
}
// deleting entries during iteration:
for (TIntObjectIterator it = map.iterator();
it.hasNext();) {
it.forward();
if (satisfiesCondition(it.key()) {
it.remove();
}
}
// faster iteration by avoiding hasNext():
TIntObjectIterator iterator = map.iterator();
for (int i = map.size(); i-- > 0;) {
iterator.advance();
doSomethingWithKeyAndValue(iterator.key(), iterator.value());
}