[Python-ideas] Before and after the colon in funciton defs.

[ron adam]

On Sat, 2011-09-24 at 11:12 +1200, Greg Ewing wrote:
> Ron Adam wrote:
> > On Fri, 2011-09-23 at 11:11 +1000, Nick Coghlan wrote:
> > 
> >>Framing the idea that way also suggests a fairly obvious spelling:
> >>
> >>    def f(x):
> >>        nonlocal i=i # Use 'f' as a closure over *itself*
> >>        return x + i
> 
> Sorry, but that spelling is very far from obvious to me.
> According to the current meaning of 'nonlocal', it looks like
> a no-op. I don't understand the reasoning that leads from
> there to your proposed semantics.
> 
> You'll also have to explain how that reasoning applies to
> the following variations:
> 
>    nonlocal i = i + i
>    nonlocal i = i + j
>    nonlocal i = j + k


Here's my view of what would happen, but you don't say weather or not
those are defined together or if they are separate cases. 


    nonlocal i

Gives read write access to i in a parent frame.


    nonlocal i=i

Creates a new 'i' in a functions own frame with the value of 'i' from a
parent frame at the time the function is defined.

(Note, it also makes sense to do it on the first time the function is
called.  I'm not sure there is any advantage to that.)


Once the function is called, the access of 'i' would be in the local
frame, and not effect the parent frames 'i' because the local 'i' is
found first.

As for the various cases, they would work the same except the initial
value would be different.

My 2cents for what it's worth.

Cheers,
   Ron