[Python-Dev] Decorators: vertical bar syntax (original) (raw)

Nick Bastin nbastin at opnet.com
Sat Aug 7 06:56:34 CEST 2004

On Aug 7, 2004, at 12:35 AM, Edward Loper wrote:

The new "vertical bar" syntax was proposed recently, and has gotten almost unanimously positive feedback. In particular, of 17 responses to the syntax, only one has been negative (see table, below).

I'm including both of the following variants: |classmethod |accepts(int, int) |returns(float) def foo(arg1, arg2): ... def foo(arg1, arg2): |classmethod |accepts(int, int) |returns(float)

I have to admit that at first look, the decorator-after-def syntax wasn't very appealing. However, although it's not how other languages generally do it (does anybody know of one?), it might be easier for new users to understand. i.e., I'm decorating 'this' thing, rather than the 'next' thing.

Does anybody suggest how this syntax plays with docstrings? Are decorators after the doc string, or before, or doesn't it matter? My vote would be for after the doc string, but I thought I'd throw that out there. It's also entirely possible that no one else likes the after-def syntax, so maybe this isn't a bridge we'll have to cross.. :-)

As for pipe versus @, I couldn't really care less, since my syntax highlighter will take care of it, but for new users I think '@' stands out much better. On the other hand, we might want to reserve '@' for some future use more aligned to its' usual meaning. Heck, I'm surprised that any rational discussion is happening at all at this point.

Seriously, we've been discussing this for longer than I care to think about, and it's obvious that we're not going to get something that everyone agrees upon. If there were something that everyone could agree upon, we'd already have found it - it's not like a pile of new discussion is likely to change that, so if we stick with '@'-before-def, that's fine by me too.

-- Nick

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