[Python-Dev] Simple Switch statementZ
python-dev at zesty.ca
Mon Jun 26 02:43:27 CEST 2006
On Sun, 25 Jun 2006, Guido van Rossum wrote:
> What do you think of Nick C's 'once'?
It's a bit closer to the right meaning... but what about:
return y + once x
Does "once" mean not really once here, but "once for each new function
object that's created for g"?
> Right. But there are all sorts of objects that are compared by object
> identity (e.g. classes, modules, even functions) which may contain
> mutable components but are nevertheless "constant" for the purpose of
> switch or optimization. Let's not confuse this concept of constness
> with immutability.
That's a good point. We need a concept like "stable for equality"
separate from "constant", since "constant" and "immutable" will mislead
those who are used to the meanings of these words in other languages.
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