On 10/09/2013 10:46 PM, Mark Shannon wrote:
There is no need to create an "undefined" value.
Rather than define a parameter by assigning a fake value, just don't
define it. We already do this for non-parameter locals and it could be
extended to parameters.
'range' would be defined thus:
def range([start,] stop, [step], /):
try:
start
except UnboundLocalError:
start = 0
try:
step
except UnboundLocalError:
step = 1
...
That's a clever, and intuitive, idea. Though the try/excepts look
awfully clumsy.
Perhaps we could add (egad, no, I can't believe I'm saying this) a new
built-in function that tells you whether or not a local variable has
been assigned to yet?
def range([start,] stop, [step], /):
if not bound(start):
start = 0
if not bound(step):
step = 1
...
Anyway, this section is in the "Notes For Future Implementors" section,
so as long as we never actually implement the syntax we don't need to
solve the problem.
//arry/
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