On Wed, 2004-03-31 at 12:52, python-dev-request@python.org wrote:

Message: 6 Date: Wed, 31 Mar 2004 12:49:14 -0800 From: Guido van Rossum Subject: Re: [Python-Dev] PEP 318: Decorators last before colon To: "Phillip J. Eby" Cc: python-dev@python.org Message-ID: <200403312049.i2VKnEi14444@guido.python.org>

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There appears to be a strong correlation between people who have specific use cases for decorators, and the people who want the last-before-colon syntax. Whereas, people who have few use cases (or don't like decorators at all) appear to favor syntaxes that move decorators earlier. Whether that means the "earlier" syntaxes are better or worse, I don't know. <0.5 wink>

Maybe the practitioners are so eager to have something usable that they aren't swayed as much by esthetics.

The current system with no syntax is equally usable, what's gained functionally? This argument was and is often used against interface syntax; it's a strong argument. In the case of interfaces the argument was against one nine letter keyword that could not possibly be confused with a list or anything else. This syntax is riskier.

The human brain is a lot more flexible in picking up patterns than the Python parser; as shown many times in this discussion, most people have no clue about the actual syntax accepted by the Python parser, and simply copy (and generalize!) patterns they see in examples.

Or like me, they just do what Emacs tells 'em, which does argue for decorators of any or no syntax. Javadoc coming before a method is another precedent in favor of something coming before, but these are without run-time function.

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It also seems to be working against the AST branch a bit, in that I would expect the decorator expressions to be part of the function definition node, rather than in an unrelated statement.

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. -Michel