#8506: Inefficient hash for homsets
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Reporter: robertwb | Owner: cremona
Type: defect | Status: needs_review
Priority: major | Milestone: sage-4.3.4
Component: elliptic curves | Keywords:
Author: | Upstream: N/A
Reviewer: | Merged:
Work_issues: |
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Comment(by hivert):
Replying to [comment:2 robertwb]:
Hi robert,
The problem is not only for homset ! See #8119
{{{
sage: h = Hom(ZZ, QQ)
sage: hash(h)
-8106914618552251573
sage: h.rename("toto")
sage: hash(h)
2314052222105390764
}}}
I don't know exactly what would be a generic solution of this problem.
There is one if the parent inherits from {{{UniqueRepresentation}}} (see
##8120) instead of using one of the at least three other mechanisms I've
seen troughout sage library. Not that as I said in that ticket, I'm not
sure how robust my solution is I've a proposal for a better option. If you
have any comment, please do not hesitate.
Cheers,
Florent
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/8506#comment:3>
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