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

Paul Moore pf_moore at yahoo.co.uk
Sun Aug 8 18:35:16 CEST 2004

Fernando Perez <fperez528 at yahoo.com> writes:

def foo(arg1, arg2): Ok, a new function foo() goes in, it takes 2 args, arg1 and arg2. Make mental bucket labeled 'foo'. Anything that comes now, until we de-indent, goes into box 'foo'. No need to keep random bits of information up in the air until I know where they're supposed to go.

Add a double-take here, because this is a method whose first argument isn't "self". We can't be sure it's not right yet, because of the staticmethod decorator, but store that for later thinking about...

|classmethod Store 'classmethod' in bucket 'foo'.

Oops. If we recall, foo doesn't have a "self" first argument, but neither does it have "cls". probably an error somewhere here, but we have to wait until the decorators are over to be sure.

|accepts(int, int) Store 'accepts(int, int)' in bucket 'foo'. |returns(float) Store 'returns(float)' in bucket 'foo'. Done. All information is stored in mental bucket 'foo', where it belongs.

But we have a couple of inconsistencies to backtrack and resolve. (And the accepts/returns stuff is also inconsistent, but I'll stop picking holes in what is clearly just an example...)

I'm not saying that the same issues mightn't exist with the decorator-before-def form, but I don't think the mental model for the decorator-after-def form is quite as clean as you'd like either...

It's still subjective :-)

Paul

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