[Cython] CF based type inference
robertwb at gmail.com
Wed May 9 00:12:29 CEST 2012
On Tue, May 8, 2012 at 6:47 AM, Vitja Makarov <vitja.makarov at gmail.com> wrote:
> 2012/5/8 Stefan Behnel <stefan_ml at behnel.de>:
>> Vitja has rebased the type inference on the control flow, so I wonder if
>> this will enable us to properly infer this:
>> def partial_validity():
>> >>> partial_validity()
>> ('Python object', 'double', 'str object')
>> a = 1.0
>> b = a + 2 # definitely double
>> a = 'test'
>> c = a + 'toast' # definitely str
>> return typeof(a), typeof(b), typeof(c)
>> I think, what is mainly needed for this is that a NameNode with an
>> undeclared type should not report its own entry as dependency but that of
>> its own cf_assignments. Would this work?
>> (Haven't got the time to try it out right now, so I'm dumping it here.)
> Yeah, that might work. The other way to go is to split entries:
> def partial_validity():
> >>> partial_validity()
> ('str object', 'double', 'str object')
> a_1 = 1.0
> b = a_1 + 2 # definitely double
> a_2 = 'test'
> c = a_2 + 'toast' # definitely str
> return typeof(a_2), typeof(b), typeof(c)
> And this should work better because it allows to infer a_1 as a double
> and a_2 as a string.
This already works, right? I agree it's nicer in general to split
things up, but not being able to optimize a loop variable because it
was used earlier or later in a different context is a disadvantage of
the current system.
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