Differences between revisions 1 and 2

SageX bug fixing example --- fix the mangled pow() function

Pyrex has an unfortunate bug in the way it handles the power function for cdef integers. Namely

   1 %pyrex
   2 
   3 def foo(int n):
   4     return 2**n

foo(3)
///
8.0

Looking at the c source code we see the the error on line 85

  __pyx_1 = PyFloat_FromDouble(pow(2, __pyx_v_n)); if (!__pyx_1) {__pyx_filename = __pyx_f[0]; __pyx_lineno = 7; goto __pyx_L1;}

Here the c function pow() is being used, which only operates on doubles. This is fine if the return type is a float, but if it is, say, a python object, then this code is incorrect. I will change this so that the resulting type is an integer in this case.

Some useful links:

[http://www.cosc.canterbury.ac.nz/greg.ewing/python/Pyrex/version/Doc/overview.html]

-  ⇤ ← Revision 1 as of 2007-02-20 21:10:26 → 
  Size: 831
  Editor: anonymous
  Comment:
+   ← Revision 2 as of 2007-02-20 21:11:03 → ⇥
  Size: 840
  Editor: anonymous
  Comment:
-Deletions are marked like this.
+Additions are marked like this.
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-= SageX bug fixing -- fix the mangled pow() function =
+= SageX bug fixing example --- fix the mangled pow() function =

Diff for "days3/sprints/sagex"

SageX bug fixing example --- fix the mangled pow() function