Why we will use obj$func() often

[David MacQuigg]

On Fri, 23 Apr 2004 11:21:16 -0700, "Mark Hahn" <mark at prothon.org>
wrote:

>"David MacQuigg" <dmq at gain.com> wrote
>> Adding syntax or making changes just because it allows you to do
>> something that can't be done in Python is not good. We have to look at
>> *use cases* for these features and compare them to a well-written
>> Python equivalent.  Then, we can see if the benefit is worth the extra
>> syntax.  We spend far to much time debating syntax without a clear
>> benefit in mind.  Show us a nice closure.
>
>The benefits of closures are well known.  I'll give you the canonical
>example, but I'm sure textbooks can give you many more (by the way, Python
>cannot do this):

Sorry for my ignorance, oh master. :>)

># tested example
>def getFunc():
>    counter = 0
>    def count():
>            &counter += 1
>            print &counter
>    return count
>
>c = getFunc()
>c()     # prints 1
>c()     # prints 2
>c()     # prints 3

Here is how I would do it in Python:

class Accumulator:
    def __init__(self):
        self.count = 0
    def bump(self):
        self.count += 1
        print self.count

c = Accumulator()
c.bump()
c.bump()
c.bump()

It took me a few minutes to understand what the "closure" was doing.
The Python code is more clear ( at least for anyone who will have to
be working with classes anyway).  There is nothing new to learn.

Functionality       = same
Size of Source Code = same
Transparency        = Python wins

-- Dave

P.S. A sincere apology for my gibe above.  I couldn't resist. :>)