mio5_utils.pyx cythonizing fails with Cython 0.17 (Trac #1707)

[scipy-gitbot]

Original ticket http://projects.scipy.org/scipy/ticket/1707 on 2012-07-24 by @rgommers, assigned to trac user mbrett.

From #274

$ cython  -V
Cython version 0.17.beta1
$ cython mio5_utils.pyx 
warning: mio5_utils.pyx:302:16: Unreachable code
warning: mio5_utils.pyx:481:12: Unreachable code

Error compiling Cython file:
------------------------------------------------------------
...
            mod8 = byte_count % 8
            if mod8:
                self.cstream.seek(8 - mod8, 1)
        return 0

    cpdef inline cnp.ndarray read_numeric(self, int copy=True):
         ^
------------------------------------------------------------

mio5_utils.pyx:412:10: Only final types can have final Python (def/cpdef) methods

With Cython 0.16 there's no problem. The explanation by bfroehle on the PR is:

It isn't possible to have an inline'd def or cpdef method, as
otherwise you'd get conflicting results depending on whether you 
called the method from C or Python if a subclass overrode the method.

[scipy-gitbot]

@rgommers wrote on 2012-07-24

PR already has a suggested fix.

[scipy-gitbot]

trac user bfroehle wrote on 2012-07-24

The fix should be a simple patch (+ recompiling with Cython). See also https://groups.google.com/forum/?fromgroups#!topic/cython-users/4EeMY_6ATqs for more background on why this is a compile failure.

--- a/scipy/io/matlab/mio5_utils.pyx
+++ b/scipy/io/matlab/mio5_utils.pyx
@@ -409,7 +409,7 @@ cdef class VarReader5:
                 self.cstream.seek(8 - mod8, 1)
         return 0

-    cpdef inline cnp.ndarray read_numeric(self, int copy=True):
+    cpdef cnp.ndarray read_numeric(self, int copy=True):
         ''' Read numeric data element into ndarray

         Reads element, then casts to ndarray. 

[scipy-gitbot]

@pv wrote on 2012-11-25

c0f0fa2a

[scipy-gitbot]

Milestone changed to 0.12.0 by @pv on 2012-11-25