[Python-Dev] @decorator syntax is sugar, but for what exactly? (original) (raw)

James Y Knight foom at fuhm.net
Tue Aug 10 04:48:37 CEST 2004

On Aug 7, 2004, at 7:51 PM, Bengt Richter wrote:

ISTM that @limitedexpressionproducingfunction @another def func(): pass

is syntactic sugar for creating a hidden list of functions. (Using '|' in place of '@' doesn't change the picture much (except for people whose tools depend on '@' ;-)).

As I understand it, it's really syntax sugar for: func = limited_expression_producing_function(another( defbutdontbind func(): pass))

except that isn't actually valid python source code. ;) It's nearly, but not exactly, the same as def func(): pass func = another(func) func = limited_expression_producing_function(func)

Is this a special case of a more general idea? E.g., could it apply to right after ANY next name is bound, in general, not just a name bound by def?

Right now decorators only work before def.

I posted an idea earlier about a @public decorator, and wrote a quick proof-of-concept patch to allow decorators in front of funcdef, classdef, and "NAME '=' testlist". This much can work with little code change, if the functionality is deemed as desirable.

However, as I mentioned, @public in front of a arbitrary binding expression (e.g. not class or function) isn't useful unless the decorator gets the name of the variable being bound. I didn't quite figure out how to manage that part. :)

James

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