Weighted degree term orders added

[kwankyu]

Weighted degree term orders (wp,Wp,ws,Ws as in Singular) added to TermOrder.

New term orders as well as matrix term orders can be used in block term orders.

Apply:

1. attachment: trac_11316.4.patch

2. attachment: trac11316_reviewer.patch

CC: @burcin @qed777

Component: basic arithmetic

Author: Kwankyu Lee

Reviewer: Simon King

Merged: sage-4.7.2.alpha1

Issue created by migration from https://trac.sagemath.org/ticket/11316

[kwankyu]

Author: Kwankyu Lee

[kwankyu]

comment:1

I think that using a method is a preferred way to get a property of an object rather than using an attribute, in Sage. So the attribute "blocks" of TermOrder is now a method. Use

t.blocks()

instead of

t.blocks

Perhaps this change will require a deprecation warning. I am not sure how to do this for attributes.

[kwankyu]

comment:3

Regarding to converting "blocks" to "blocks()", Jason remarks:

To my understanding, we prefer methods to properties because:

1. Methods have docstrings and can be introspected (using question mark)
   to obtain the docs.

2. We want to be consistent, as it can be confusing for a user if some
   things require parentheses (methods) while others don't (properties).

I really wish we could use properties more, as it is more pythonic and
looks cleaner, but those are two good points above...

[malb]

comment:4

• the patch does not apply cleanly against 4.7.rc2, but the failure is minor: only an update of a docstring in pbori.pyx fails.
  • Doctests do not pass for 4.7.rc2:
  • pbori.pyx I didn't fix the patch to apply cleanly, hence was to be expected that this one fails.
  • sage_object.pyx the patch seems to break pickling

So, the only real issue seems to be pickling.