On Apr 11, 2008, at 5:51 AM, Dag Sverre Seljebotn wrote: > >> This is (again) sort of an in-between C and Python question. >> "cdef" enters C >> space, where block-scoping makes sense. However, we'd have to >> resolve all >> sorts of weird semantic nonsense, such as: >> >> cdef object i >> for i in range(10): >> cdef long i = i >> ... >> >> I don't feel like bothering with that... >> > Hmm. You're right. Even worse: > > if mytest: > cdef float x = 2 > else: > cdef int x = 2 > print x > > One would either have to use "C-like scope" for typed variables > (doesn't smell good), or know about execution paths and raise > compiler errors on the wrong scenarios (don't like that either). If > there are some simple rules to allow it in a few simple obvious > cases it would be good though, and just don't allow any possible > nonsense. Something like: > > syntax error: The variable "x" is used outside of the typed block. > Move the type declaration. > syntax error: "x" has a type declared more than once within a > function. > > If one can do this check it should handle most cases, and can be > implement it simply by moving all the cdefs (splitting cdef and > assignment if necesarry) to the top of the function during compile. > > But perhaps better left for later.
This is really easy to change, as currently one can do if mytest: x = 2 else: x = 2 print x which is implicitly if mytest: cdef object x = 2 else: cdef object x = 2 print x and all variable declarations are moved to the top of the function at compile time anyways. One is not allowed to redeclare variables, so there would be a compile-time error. The only question is if it is misleading that the variables are not block-level (and shouldn't be, otherwise things will be very inconsistant and confusing to Python developers)? - Robert _______________________________________________ Cython-dev mailing list Cython-dev@codespeak.net http://codespeak.net/mailman/listinfo/cython-dev
