cluster seed is no longer hashable

[fchapoton]

With the recent change in the cluster code,

sage: Q= ClusterQuiver(['D',4])
sage: hash(Q)
Traceback (most recent call last):
...
TypeError: <class 'sage.combinat.cluster_algebra_quiver.quiver.ClusterQuiver'> is not hashable

And this has very bad consequences !

CC: @tscrim @darijgr @egunawan @sagetrac-gmoose05 @stumpc5

Component: combinatorics

Keywords: cluster

Author: Frédéric Chapoton

Branch/Commit: be4fa45

Reviewer: Christian Stump

Issue created by migration from https://trac.sagemath.org/ticket/19440

[fchapoton]

Changed keywords from none to cluster

[fchapoton]

comment:2

here is a branch not working yet

---

New commits:

01b2b3c

trac #19440 trying to fix the hash for cluster quivers and cluster seeds

[fchapoton]

Branch: public/19440

[fchapoton]

Commit: 01b2b3c

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

704edce

trac #19440 another try for the hash

[sagetrac-git]

Changed commit from 01b2b3c to 704edce

[stumpc5]

comment:5

Your changes look fine to me. In general, I am worried that the code gets slower and slower... I would like to do a few tests whether this also applies to your proposed changes.

[stumpc5]

comment:6

stupid question (here and elsewhere): how do I see which version your code is based on? I would prefer not to pull it and check it out to then see that I first have to recompile sage for many hours.

[stumpc5]

comment:7

Okay, got it: git log trac/public/19440. I first made the mistake to try to look at the local version using git log public/19440.

[stumpc5]

comment:8

Okay, it was slow and it is not slower now...

[stumpc5]

Reviewer: Christian Stump

[stumpc5]

Author: Frédéric Chapoton

[vbraun]

comment:10

Fails on 32-bit

sage -t --long src/sage/combinat/cluster_algebra_quiver/cluster_seed.py
**********************************************************************
File "src/sage/combinat/cluster_algebra_quiver/cluster_seed.py", line 871, in sage.combinat.cluster_algebra_quiver.cluster_seed.ClusterSeed.__hash__
Failed example:
    hash(Q)  # indirect doctest
Expected:
    -5649412990944896369
Got:
    222337679
**********************************************************************
1 item had failures:
   1 of   3 in sage.combinat.cluster_algebra_quiver.cluster_seed.ClusterSeed.__hash__
    [538 tests, 1 failure, 133.37 s]

[sagetrac-git]

Changed commit from 704edce to be4fa45

[sagetrac-git]

Branch pushed to git repo; I updated commit sha1. New commits:

be4fa45

trac #19440 hash for 32 and 64-bit

[vbraun]

Changed branch from public/19440 to be4fa45