forEach on HashMap and IdentityHashMap (original) (raw)

Mike Duigou mike.duigou at oracle.com
Tue Jun 11 21:06:33 UTC 2013

On Jun 11 2013, at 09:59 , Remi Forax wrote:

Hi guys, This mail was originality sent to lambda-lib EG but Brian ask me to also send it here to not forget.

We should provide an implementation of forEach for HashMap that avoid to create an Iterator, HashMap is too common to not have it's dedicated implementation

I assume you mean the forEach on the entrySet.

(ArrayList by example has its own implementation of forEach).

There is also another implementation that should have a specific implementation IdentityHashMap because entrySet() creates map entries on the fly so having a specific implementation that will not allocatin entries will improve performance (a lot for big identity hashmap).

Are you suggesting adding a IdentityMap.forEach(BiConsumer) or re-using the Map.Entry passed to the consumer in entrySet().forEach(Consumer)?

Mike

cheers, Rémi

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