Hi, On Sun, Jan 4, 2015 at 4:22 PM, Konrad Hinsen <konrad.hinsen@fastmail.net> wrote:
2) Changes that yield to different results for unmodified legacy code should never be allowed.
I think this is a very reasonable rule. Case in point - I have some fairly old code in https://github.com/matthew-brett/transforms3d . I haven't updated this code since 2011. Now I test it, I get the following warning: ====================================================================== ERROR: Failure: ValueError (assignment destination is read-only) ---------------------------------------------------------------------- Traceback (most recent call last): File "/Users/mb312/.virtualenvs/scipy-devel/lib/python2.7/site-packages/nose/loader.py", line 251, in generate for test in g(): File "/Users/mb312/dev_trees/transforms3d/transforms3d/tests/test_affines.py", line 74, in test_rand_de_compose T, R, Z, S = func(M) File "/Users/mb312/dev_trees/transforms3d/transforms3d/affines.py", line 298, in decompose Z[0] *= -1 ValueError: assignment destination is read-only If I had waited until 1.10 (or whatever) - I would have had to hope that my tests were good enough to pick this up, otherwise anyone using this code would be subject to some very strange bugs. Cheers, Matthew