On Fri, 07 Jun 2013 19:10:34 +0600, Stefan Behnel <stefan...@behnel.de>
wrote:
Nikita Nemkin, 07.06.2013 13:24:
Currently, conditional casts like <Name?>obj do not allow None values.
This might seem like an inconsistency, because <Name>obj does allow None
values, just like a normal assignment. However, it's a special case that
asks explicitly for the given type, so I think it's ok to be stricter.
I have found it useful to allow None sometimes.
The syntax could be one of:
* <Name or None?>obj
* <Name? or None>obj
* <Name??>obj
Use case (without this feature):
tn_obj = self.any.non_trivial.nullable.expression()
cdef TypeName tn
if tn_obj is not None:
tn = <TypeName?>tn_obj
...
Use case (with this feature):
cdef TypeName tn = <TypeName or
None?>self.any.non_trivial.nullable.expression()
if tn is not None:
...
Why not just
cdef TypeName tn = self.any.non_trivial.nullable.expression()
if tn is not None:
...
?
I.e. why do you need that cast in the first place?
You are right. The behavior I want is actually the default
assignment behavior.
Writing almost fully typed code, I started to percieve Cython
as a statically typed language...
Please disregard my feature request and thank you.
Best regards,
Nikita Nemkin
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