[eckzow]

The example definitely leaves a bit to be desired.

One great story for why this way might be better is that with a small tweak (to allow dynamic [de]registration of command functions) it is much more open to extension.

To continue using the somewhat creaky "text game" example, if possessing certain items or being in a particular room affects the available command set, this can be easily included: without a magic feather, "fly" returns "You don't know how to do that" but when you pick up said feather a new action is registered, and now "fly" works properly.

Now, I'm not sure I'd implement this particular game that way, but such an interface tends to be useful for building plugin systems, etc.

It's mainly for this reason that large switch statements, particularly those not doing "math" of some sort, tend to be a code smell.[1]

[1] http://en.wikipedia.org/wiki/Open/closed_principle