On Mon, Jun 14, 2010 at 3:50 PM, Florent Hivert <florent.hiv...@univ-rouen.fr> wrote: > Hi Jason, > >>> Looking into sage library, I found the following code: file matrix0.pyx >>> >>> cdef class Matrix(sage.structure.element.Matrix): >>> ... >>> def __copy__(self): >>> """ >>> ... >>> """ >>> return self.__copy__() >>> >>> what is the intention here ? I hope this code is never executed ? Why not >>> return an error ? >>> >> >> Generic matrices have their own __copy__ method (overriding this). I hope >> the above code isn't ever executed either. >> >> Here is the result of executing the method, which gives the expected error: >> >> sage: import sage.matrix.matrix0 >> sage: A = sage.matrix.matrix0.Matrix(MatrixSpace(QQ,2)) >> sage: type(A) >> <type 'sage.matrix.matrix0.Matrix'> >> sage: copy(A) >> --------------------------------------------------------------------------- >> RuntimeError Traceback (most recent call last) >> >> /Users/grout/sage-4.4.2-test3/spkg/standard/sagenb-0.8.p3/src/sagenb/<ipython >> console> in <module>() >> >> /Users/grout/sage/local/lib/python/copy.pyc in copy(x) >> 77 copier = getattr(cls, "__copy__", None) >> 78 if copier: >> ---> 79 return copier(x) >> 80 >> 81 reductor = dispatch_table.get(cls) >> >> /Users/grout/sage/local/lib/python2.6/site-packages/sage/matrix/matrix0.so >> in sage.matrix.matrix0.Matrix.__copy__ (sage/matrix/matrix0.c:2718)() >> >> [snip] >> >> RuntimeError: maximum recursion depth exceeded while calling a Python object >> sage: >> >> So the doctests for that function are useless for testing that function, >> obviously. > > So this is just a strange way to raise an error ;-) No particular strange > Cython stuff to allows for inheritance or whatever...
Nope. You can (and I hope will) *definitely* safely just delete that whole function. The matrix_dense.pyx and matrix_sparse.pyx files both define their own __copy__, and all matrices derive from one or the other. This is now http://trac.sagemath.org/sage_trac/ticket/9239 William -- William -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
