On Jan 28, 1:01 am, Steven D'Aprano <[EMAIL PROTECTED]
cybersource.com.au> wrote:
> On Mon, 28 Jan 2008 00:39:02 +0100, Wildemar Wildenburger wrote:
> > Dustan wrote:
> >>> Well, you save one or two lines per class. Not enough in my opinion.
>
> >> Are you referring to the alternate syntax or to the decorator? Either
> >> way, you could be saving 4 or 5 or more lines, if you have enough
> >> arguments.
>
> > OK, but then again, every decent IDE should give you the tools to write
> > an automation for that. Not that I don't like the idea of
> > auto-assignment, but, you know ...
>
> You know, not everybody uses a "decent IDE", by choice or necessity, and
> even if they did, having what is essentially a macro to type for you
> doesn't solve the essential problem that you're writing the same thing
> THREE TIMES instead of once. And then you have to keep it all in sync
> through who knows how many code revisions and refactorings.
>
> class Parrot(object): # after many revisions...
> def __init__(self, genus, species, variety, name, age, colours,
> wingspan, beaksize, healthstate, language, vocabulary):
> self.wingspan = wingspan
> self.beaksize = beaksize
> self.name = name
> self.age = age
> self.binomial_name = (genus, species)
> self.breed = variety
> self.colour = colour
> self.language = language
> self.state = get_state(healthstate)
> self.words = vocabulary
> self.colors = colours
>
> What IDE will spot the error(s) in the above?
>
> Here's another version, assuming syntax support for auto-assignment for
> names starting with an ampersand:
>
> class Parrot(object): # after many revisions...
> def __init__(self, genus, species, variety, &name, &age, &colours,
> &wingspan, &beaksize, healthstate, &language, vocabulary):
> self.binomial_name = (genus, species)
> self.breed = variety
> self.state = get_state(healthstate)
> self.words = vocabulary
>
> See how much easier it is to keep the attributes synced with the
> arguments? Don't Repeat Yourself in action.
>
> I think the biggest minus on this proposal is that it creates new syntax
> that is only meaningful in the __init__ method of a class. "Special cases
> aren't special enough to break the rules." I'd vote for it, but
> conditionally. What should this do?
>
> def foo(x, y, &z):
> pass
>
> Create foo.z perhaps?
>
Well, if:
def __init__(self, &foo):
pass
does:
def __init__(self, foo):
self.foo = foo
then:
def foo(x, y, &z):
pass
does:
def foo(x, y, &z):
x.z = z
Don't think that's useful, though...
--
http://mail.python.org/mailman/listinfo/python-list
