On 11/21/2013 06:33 PM, David Holmes wrote:
On 22/11/2013 5:02 AM, Louis Wasserman wrote:
While I agree that case should be specified, I'm not certain I follow why
that's what's going on here.
The weird condition is that if oldValue is null, not value; oldValue
is the
old result of map.get(key). The Javadoc seems not just unspecified, but
actively wrong. Here's a worked example:
Map<String, Integer> map = new HashMap<>();
map.merge("foo", 3, Integer::plus);
Integer fooValue = map.get("foo");
Going through the Javadoc-specified default implementation:
V oldValue = map.get(key); // oldValue is null
V newValue = (oldValue == null) ? value :
remappingFunction.apply(oldValue, value);
// newValue is set to value, which is 3
if (newValue == null) // newValue is nonnull, branch not taken
map.remove(key);
else if (oldValue == null) // oldValue is null, branch taken
map.remove(key); // removes the entry from the map
else // else if was already triggered, branch not taken
map.put(key, newValue);
Seems like a document bug to me, we should fix this @implSpec.
Cheers,
Henry
