Base lattices on the concept of symmetry
Kwant contains both the concept of spatial symmetries and the concept of regular (Bravais) lattices. Both are related:
TranslationalSymmetry works only with the lattices as defined in the
This integration could be improved. For example, the flood-fill code of
shape() in the lattice module and
fill() in the builder module is similar. It should be possible to redefine lattices on top of (translational?) symmetries, and factor out as much common code as possible.