[Python-Dev] (Specific syntax of) PEP 318 - function/method/class decoration

[Phillip J. Eby]

At 01:21 PM 3/8/04 -0500, Jewett, Jim J wrote:
>Bob Ippolito:
>
> > I would like to focus this thread to, specifically, if *this syntax*
> > should become part of Python.
>
>         def name(args)[something_else]:
>
>-1.  With more explicit and extensible syntax, I would
>be +1, but with *this* syntax, I'm -1.
>
>Why are you so insistent on the bare syntax?  The only
>arguments I have seen are:
>
>(1)  We already have it.
>
>The author himself said that the patch isn't final, and
>he can change the syntax.  Even some semantic changes
>(testlist vs exprlist) may be OK.
>
>(2)  It is shorter to type.
>
>Adding "as" or "mods" is fairly small compared to the names
>of the wrappers themselves, even in your examples.
>
>(3) New keywords are bad.
>
>Not as bad as overloading an old one with a new meaning.

(4) C# uses the [] to designate "attributes" of functions, classes, and 
parameters.

The positioning is different, though.  C# puts the bracketed list of 
"attributes" at the *beginning* of the declarations, so if we were really 
following C#'s lead, the syntax would actually be:

class [interface] Foo:

    def [classmethod] foo(cls):
        ...

or, even closer to C#:

[interface] class Foo:

    [classmethod] def foo(cls):
        ...

but that's really ugly.

Anyway, I seem to recall that the bracketed syntax was originally inspired 
by C#'s attribute mechanism, but you'd have to ask the original author to 
be sure.