Only suggestions, we probably need microbenchmarks to choose between the alternatives, as AbstractMap is used a lot within applications (at least one per Widget, then an additional one per event type with a registered handler).
http://gwt-code-reviews.appspot.com/1877803/diff/1/user/super/com/google/gwt/emul/java/util/AbstractMap.java File user/super/com/google/gwt/emul/java/util/AbstractMap.java (right): http://gwt-code-reviews.appspot.com/1877803/diff/1/user/super/com/google/gwt/emul/java/util/AbstractMap.java#newcode144 user/super/com/google/gwt/emul/java/util/AbstractMap.java:144: for (Iterator<Entry<K, V>> iter = entrySet().iterator(); iter.hasNext();) { Instead of duplicating the code from implFindEntry, how about changing implFindEntry to return the entry's value instead? (using a marker value to signal that no entry was found). containsKey would then be: return implFindEntry(key, false) != ABSENT; and get and remove would use: return value == ABSENT ? null : value; The downside to that approach is that it introduces a clinit if ABSENT is made static, or an ABSENT instance per AbstractMap otherwise. Alternatively, implFindEntry could be changed to: if (remove) { entry = new MapEntryImpl<K, V>(entry.getKey(), entry.getValue()); iter.remove(); } only adding a small runtime overhead on removal. http://gwt-code-reviews.appspot.com/1877803/ -- http://groups.google.com/group/Google-Web-Toolkit-Contributors
