Weight revision for fastcrystals

[dwbump]

This extends the revision of the patch in #2853

The previous patch reimplemented the weight function for vertices in crystals of letters and crystals of tableaux. The patch at hand does the corresponding reimplementation for fastcrystals. These are crystals whose definition is limited to types A2, B2, C2. They are isomorphic to crystals of tableaux but have better speed when the crystal is large, since the root operators are implemented by table lookup.

The revised weight function should be very fast since the weight is computed by adding a few numbers together.

This patch corrects the same defect for type A2 that the previous patch addressed.

The tests in the patch were written BEFORE the weight function was reimplemented, so I am confident that it is correct.

CC: @sagetrac-sage-combinat

Component: combinatorics

Issue created by migration from https://trac.sagemath.org/ticket/2868

[dwbump]

Attachment: weight_fastcrystal.patch.gz

[mwhansen]

Attachment: 2868.patch.gz

[mwhansen]

comment:5

I attached a new patch which removes a print statement and moves the tests down to the docstring of weight.