GWT: How to avoiding calls to dynamicCast and canCastUnsafe in generated JavaScript code?

Question

I\'m writing some special purpose data structures in Java, intended for use in the browser, (compiled to JavaScript with GWT).

I\'m trying to match the performance o

Answer 1

Unfortunately I'm still not exactly clear on the cause, but from my experience, it seems from explicit casts, like:

((Comparable) obj).compareTo(other)

The Javascript generated looks like:

dynamicCast(obj, 1).compareTo(other);

Where 1 is a generated typeId representing the target of the cast. dynamicCast in turn calls canCastUnsafe and if false, it throws a ClassCastException. The value of this has been debated, since this would already be caught in hosted mode.

It can be sidestepped with JSNI:

public static native int compare(Object a, Object b) /*-{
    return a.@java.lang.Comparable::compareTo(Ljava/lang/Object;)(b); 
}-*/;