Erick Tryzelaar wrote:
On Thu, Apr 10, 2008 at 8:47 AM, Mathias Panzenböck
grosser.meister.morti@gmx.net wrote:
It would also help with local functions!
def foo(): var x = 1
def bar(y):
x += y * 2
bar(55)
They've added something to py3k to handle this:
def foo(): x = 1
def bar(y): nonlocal x x += y * 2
bar(55)
Indeed. Funny enough, it was a similar plea for a variable declaration keyword (mine, in fact) that was the final straw. Thus, after a bit of bike shedding and collision checking on the keyword spelling, "nonlocal" was born...
Since the foremost use case has been handled, I expect a "var" proposal to go nowhere. The rationale, IIRC, is rather compression-oriented: in a language where only functions define inner scopes, it's far more likely that an assignment is meant to refer to the current scope than an outer scope. A declaration keyword is provided for the unlikely case, leaving the likely case declaration-free.
In general, the more compressed your code is, the harder it is to detect encoding errors. In this case, Python's designers decided on compression over easy error detection.
Neil