[Python-3000] PEP 3124 - Overloading, Generic Functions, Interfaces, etc. (original) (raw)

Phillip J. Eby pje at telecommunity.com
Sat May 12 19:55:12 CEST 2007

At 01:43 PM 5/12/2007 +1200, Greg Ewing wrote:

Phillip J. Eby wrote: > At 01:27 PM 5/11/2007 -0400, Jim Jewett wrote: >>If there are two registrations for the same selection criteria, how >>can the user resolve things?

But what if there's already an @around method being used? Then you need an @evenmorearound method. Etc ad infinitum?

Yep, so simple things are simple, and complex things are possible. That's the Python Way(tm). :)

To put your comment in another perspective, "but what if somebody already defined a method in their class that I want to change? Then I need to subclass it. And if somebody wants to change that they have to subclass that, etc. ad infinitum? Clearly classes are too complicated!" :)

In practice, @around is mostly used for application-defined special cases, and there is no higher authority than the application who needs to override things. If a library needs special combinators internally, it's better off making them lower-than- at around precedence. Normal, before, and after methods are usually adequate for libraries. (Aside from special-purpose combinators like the @discount example.)

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