More flexible constructor of GroupHomomorphisms

[simonbrandhorst]

Right now a group homomorphism is defined on images of the generator of the group. In gap there are many more ways to define a group homomorphism.
With this ticket a group homomorphism in sage can be created from the one in gap.

CC: @tscrim @soehms

Component: group theory

Author: Simon Brandhorst

Branch/Commit: 21cb664

Reviewer: Sebastian Oehms

Issue created by migration from https://trac.sagemath.org/ticket/26420

[simonbrandhorst]

Branch: u/sbrandhorst/more_flexible_constructor_of__grouphomomorphisms

[sagetrac-git]

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

08a0735

a doctest

[sagetrac-git]

Commit: 08a0735

[sagetrac-git]

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

b2d9622

docs

[sagetrac-git]

Changed commit from 08a0735 to b2d9622

[soehms]

comment:6

Two lines of code in the _element_constructor_ (right above your changes) become redundant. You should remove them to avoid confusion.
Furthermore, you should adapt the description of the new argument gap_hom in the docstring of GroupMorphism_libgap.

If these things are done, you may switch to positive review.

FYI: I will create a ticket depending on this one, soon. Its purpose will be to include permutation groups within the GroupHomset_libgap setting.

[soehms]

Reviewer: Sebastian Oehms

[sagetrac-git]

Changed commit from b2d9622 to 21cb664

[sagetrac-git]

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

21cb664

correct docstring for argument `gap_hom`

[tscrim]

comment:8

Thanks for doing the review Sebastian. Simon, sorry that this fell off my radar.