[Types-sig] Non-conservative inferencing considered harmful
Greg Stein
gstein@lyra.org
Wed, 22 Dec 1999 13:54:29 -0800 (PST)
On Thu, 23 Dec 1999, skaller wrote:
> Paul Prescod wrote:
> >
> > * if a variable is consistently assigned a particular type within its
> > scope, we inference the type.
> > * if a variable is inconsistently assigned we infer it as "Any"
>
> I'd like to suggest ONE extra case worth considering:
>
> * particular type OR None
>
> The reason I suggest this, is that it is common enough
> for either None or a single type to be used, for example,
> often function parameters have a default of None.
Agreed, but I believe Paul's response would simply be "then declare it."
But then: I have different thoughts on the base issue :-)
Cheers,
-g
--
Greg Stein, http://www.lyra.org/