#19016: A more naive sage.structure.element.__hash__
-------------------------+-------------------------------------------------
Reporter: | Owner:
ncohen | Status: needs_work
Type: | Milestone: sage-duplicate/invalid/wontfix
defect | Resolution:
Priority: | Merged in:
blocker | Reviewers:
Component: misc | Work issues:
Keywords: | Commit:
Authors: | 754dc5794a1a7004c8844cf7cfb64220957c36a5
Nathann Cohen | Stopgaps:
Report Upstream: N/A |
Branch: |
u/ncohen/19016 |
Dependencies: |
-------------------------+-------------------------------------------------
Comment (by mmarco):
I definitely don't like to have 0 hashes everywhere. I like the solution
proposed by Volker: having __hash__ only on those parents where we
actually have a canonical form for each element.
On the other hand, it will take some time to be implemented, and in the
meantime, the problem stated by Nathan would persist. So my proposal for a
temporary quick fix for that is the following: for finitely presented
group elements, just hash its representation in the abelianization (or any
other invariant of the element that can be computed quickly). It would
work as a hash should (that is, it will distinguish elements in some
cases, but will not distnguish different representations of the same
element), even if there would still be some collisions.
--
Ticket URL: <http://trac.sagemath.org/ticket/19016#comment:19>
Sage <http://www.sagemath.org>
Sage: Creating a Viable Open Source Alternative to Magma, Maple, Mathematica,
and MATLAB
--
You received this message because you are subscribed to the Google Groups
"sage-trac" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to [email protected].
To post to this group, send email to [email protected].
Visit this group at http://groups.google.com/group/sage-trac.
For more options, visit https://groups.google.com/d/optout.
