[with patch, positive review] deprecate the "order" method on elements of rings.

[was]

There was a vote in sage-devel in the thread entitled "order of elements in the field" to deprecate the order method on ring elements, and keep just the additive_order and multiplicative_order methods. The order method is too ambiguous in the context of rings, and does cause regular confusion.

This should be officially deprecated, and only removed after >= 6 months.

[jhpalmieri]

Here's a very simple patch.

[mabshoff]

Shouldn't this patch add a doctest while adding the deprecation warning? Otherwise it isn't obvious that the function is depreacted from looking at "order?"

Cheers,

Michael

[jhpalmieri]

Shouldn't this patch add a doctest while adding the deprecation warning?

No, I don't think so... Just kidding. Here's a new patch with a doctest.

[mvngu]

reviewer patch; fix trivial typo

[mvngu]

REFEREE REPORT

The patch trac_5997.patch applies OK against the "post-final" sage-3.4.2 and all doctests pass with the options -t -long. Now say we create an element in Z/12Z like so:

sage: a = Integers(12)(5)

Then both a.order() and a.additive_order() return the same result, but a.order() additionally gives a deprecation warning:

sage: a.order()
/scratch/mvngu/sage-3.4.2-sage.math-only-x86_64-Linux/local/lib/python2.5/site-packages/IPython/iplib.py:2073: DeprecationWarning: The function order is deprecated for ring elements; use additive_order or multiplicative_order instead.
  exec code_obj in self.user_global_ns, self.user_ns
12

However, there's one trivial typo in the patch. This is fixed in the reviewer patch trac_5997-reviewer.patch. Basically, I give positive review to John's patch. Only my patch needs to be reviewed.

[mabshoff]

Rubber stamp. We don't need no stinkin' review for trivial review patches fixing an obvious typo ;)

Cheers,

Michael

[mabshoff]

Merged both patches in Sage 4.0.alpha0.

Cheers,

Michael