[Python-Dev] Re: Python-Dev Digest, Vol 8, Issue 107 (original) (raw)

Michel Pelletier michel at dialnetwork.com
Wed Mar 31 19:50:32 EST 2004

On Wed, 2004-03-31 at 16:23, Phillip J. Eby wrote:

>The current system with no syntax is equally usable, what's gained >functionally?

It's not equally usable. It is 1) considerably more verbose, particularly in Bob's use case of long function names, and 2) hard to spot by a reader who's skimming to get an overview of a class or module.

Both true. Perhaps I should have said functionally equal. The proposed syntax is more usable from a syntax perspective, I agree, but offers no more "use" once you have the object in hand, so to speak. The aesthetics is another matter I've already voiced my opinion on.

>Another discussion point occurred to me regarding interfaces and >projects that use them heavily like Zope, Twisted, PEAK etc. Has the >decorator syntax as proposed been evaluated in the light of these >interfaces (and any future native language support for them), whose >methods have no body to interpose between the definition and decorators >as they exist now? I've seen the "Large Body" argument use several >times in defense of the decorator syntax being before or above the >definition.

I have seen virtually no use of decorators on interface methods in the frameworks you mention. In fact, I can't recall ever having seen a single use of decorators on interface methods. That's probably simply because the cost of using decorators is too high to waste on anything that's not part of the implementation,

I think there must be some decorators valid for interfaces. What about proposed decorators like "synchronized"? Are these part of the interface? Or something equivalent to Java's "throws", arguably a decoration and arguably part of a method's interface. What about decorations that can never be used in an interface, like "classmethod"? Would an error be raised if you tried to decorate an interface method with a classmethod decorator?

I don't think any of these things refute or validate the need for special syntax, I just wonder if it's been thought about enough, and that goes way beyond the syntax.

-Michel

More information about the Python-Dev mailing list