I am a huge fan of ASPs and would prefer one of those (specifically a 21-inch Airweight) to a knife. Unfortunately, carry of an ASP is typically more restricted than knives, which are legal in some form in just about all jurisdictions. The ability to carry a potent, potentially lethal weapon legally just about everywhere was a determining factor in my choice to specialize in knives a long time ago.
A good tactical flashlight (high output, shock resistant, and large enough to use as an impact weapon) is a great tool and should be part of everyone's EDC kit. Even in non-permissive environments, you have a potent defensive tool. If you skip the "cheese grater" bezels, you also have an item that is PC enough to go virtually everywhere. That makes it a consistent "layer" of your defensive strategy and something you can escalate "up" to or fall "back" to.
If you don't ever travel outside your gun-friendly jurisdiction, don't mind taking the chance carrying a prohibited weapon (I used to do it, too), or answer every question with "I'd rather be tried by 12 than carried by 6," "Don't bring a knife to a gunfight," or some other tired cliche, that's your choice. Whatever you do, I hope it and good judgment in its application serve you well. But please remember the REAL issue here: If you don't have a gun, your gun runs out of ammo, or you suffer a catastrophic malfunction that can't be fixed in the middle of a fight, you need to have a backup plan, tools, and TRAINING to support it.
If your non-gun weapon is a knife, carry it and maintain it religiously and learn how to deploy it and use it under stress. If it's an ASP, the same rules apply. If your plan is to beat your attacker unconscious with your non-functioning or shot-dry pistol, get a blue gun and actually practice hitting a heavy bag with it. Then work with a partner and proper training equipment and practice fending, blocking, and controlling his strikes with a training weapon while you work on your pistol-whipping skills.
I don't mean to rant, but cliches are not a valid weapon and recycling them does little to really advance anyone's planning and training.
Stay safe,
Mike