UniqueFactory for DirichletGroup

[saraedum]

Dirichlet groups use a generic dictionary to cache objects (instead of UniqueRepresentation or UniqueFactory). This ticket replaces this generic cache with a UniqueFactory implementation.

Component: modular forms

Author: Julian Rueth

Branch/Commit: ce3dfc0

Reviewer: Peter Bruin

Issue created by migration from https://trac.sagemath.org/ticket/15898

[saraedum]

Branch: u/saraedum/ticket/15898

[saraedum]

Author: Julian Rueth

[saraedum]

New commits:

55bf7be

Use a UniqueFactory to cache instances of DirichletGroup

[saraedum]

Commit: 55bf7be

[pjbruin]

comment:3

Looks good (although I haven't tested it yet). Two questions:

• why include base_ring in key? It can be recovered as the parent of zeta, and isn't used in create_object().
• could you add a doctest to show that it works as intended, i.e. really creates a unique instance?

[sagetrac-git]

Changed commit from 55bf7be to 3d01887

[sagetrac-git]

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

ebe6a39	Doctest to illustrate that caching of DirichletGroups works
0521e97	Doctest to illustrate that base_ring must be a part of the cache key created by the DirichletGroup factory
3d01887	cleaned up docstring of DirichletGroup

[pjbruin]

comment:6

Replying to @sagetrac-git:

0521e97	Doctest to illustrate that base_ring must be a part of the cache key created by the DirichletGroup factory
Nice, I hadn't thought of the fact that two roots of unity can still compare as equal when they are in different fields! Now testing.

[pjbruin]

Reviewer: Peter Bruin

[vbraun]

comment:8

Conflicts with #15990, please fix

[pjbruin]

Changed branch from u/saraedum/ticket/15898 to u/pbruin/15898-DirichletGroup_unique

[pjbruin]

comment:9

Merged with 6.2.beta8.

[pjbruin]

Changed commit from 3d01887 to ce3dfc0

[vbraun]

Changed branch from u/pbruin/15898-DirichletGroup_unique to ce3dfc0