On 2021-12-02 01:35, Steven D'Aprano wrote:
- If "no" to question 1, is there some other spelling or other small
change that WOULD mean you would use it? (Some examples in the PEP.)
No. As I mentioned in the earlier thread, I don't support any proposal in which an argument can "have a default" but that default is not a first-class Python object of some sort.
I don't understand this criticism.
Of course the default value will be a first-class Python object of some sort.*Every* value in Python is a first-class object. There are no machine values or unboxed values, and this proposal will not change that.
All that this proposal changes is*when* and*how often* the default will be evaluated, not the nature of the value.
As has happened often in these threads, it seems different people mean different things by "default value".
What you are calling "the default value" is "a thing that is used at call time if no value is passed for the argument". What I am calling "the default value" is "a thing that is noted at definition time to be used later if no value is passed for the argument".
What I'm saying is that I want that "thing" to exist. At the time the function is defined, I want there to be a Python object which represents the behavior to be activated at call time if the argument is not passed. In the current proposal there is no such "thing". The function just has behavior melded with its body that does stuff, but there is no addressable "thing" where you can say "if you call the function and the argument isn't passed were are going to take this default-object-whatchamacallit and 'use' it (in some defined way) to get the default value". This is what we already have for early-bound defaults in the function's `__defaults__` attribute.