Re: Why Generics?


Dale King wrote:

> [../] the new enumerations are (in my
> > understanding) just a little syntactic sugar provided by the javac
> > compiler. So clearly type safe enums were always possible.
>
> There is actually one part of enums that was not possible before and
> that was the ability to use them as cases in a switch statement.

It was always possible, the new enums don't generate code that couldn't be
expressed in "normal" Java. Supporting switch would require a fairly
unpleasant amount of wordy duplication, though. You'd have to have a public
static final int field corresponding the the 'ordinal' of each enum object,
which is obviously error prone unless the compiler does it for you.

OTOH, if you use your own implementation of the type-safe enum pattern, then
their object-nature is not hidden by the compiler and so you can use
polymorphism to avoid having to use switch statements in the first place.

-- chris


.

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