[Python-Dev] PEP 218 update questions
Brett Cannon
drifty@bigfoot.com
Sun, 13 Oct 2002 14:43:27 -0700 (PDT)
[A.M. Kuchling]
> How would instances of a built-in immutable set type be created?
> Would there be a second immutable_set() built-in, or would the set()
> function take an additional argument: set(iterable, immutable=True)?
>
I say have a single set() with an argument flag. Mutable or not, they are
both subsets of BaseSet and thus should be reflected in the constructor
function.
> 2)
> The PEP proposes {1,2,3} as the set notation and {-} for the empty
> set. Would there be different syntax for an immutable and a mutable
> set?
>
As long as mutable sets can be automatically converted to immutable, I say
keep only one syntax. If the user wants to explicitly create an immutable
set, call set(mutable_set, immutable=True) or have a very explicit way for
mutable sets to turn themselves into immutable sets. No need to add more
syntax for something that can automatically be done for the user.
-Brett C.