Re: mail() into separate extension?

On Jul 18, 2005, at 10:30 AM, Andrew Yochum wrote:

On Jul 18, 2005, at 10:15 AM, George Schlossnagle wrote:

Drop-in replacements are evil. If you want to do this, you should just create a new function that does what you need to do and name it differently. If you're dead-set on doing a name-based replacement, then you should have your extension modify the symbol table directly, but again, this is evil. George

George, Can you please substantiate your statement that drop-in replacements are evil? I could only see them being a problem if they don't fully implement the existing API.

Sure. They inevitably will have differing behaviors (if not, why not just have a single unified function). Given that, you'll have different behaviors on different machines in a way that is not terribly transparent to end-users. That's evil. Not that there's anything wrong with being evil from time to time. That's the reason that apd had a replace_function call for mucking with the symbol table. But that's something that should be done locally. George