Change evaluation domain API for cosets about algebra HOT 6 CLOSED

Hmm these API changes do make the code more unified, but on the other hand it is nice to have a visual indicator that one is performing a coset FFT/IFFT. Do you have suggestions on how to get the best of both worlds?

from algebra.

I'm not really sure its useful to know if you're doing a coset FFT vs regular FFT. Are you worried about knowledge of the extra ~5% of runtime? If so, perhaps this difference can be made apparent in the traces.
(Also this overhead decreases with nlog(d) FFTs)

from algebra.

I just mean from a code clarity perspective

from algebra.

Had a discussion with @Pratyush regarding an API for this.

1. Make Domain have two constructors, new_subgroup(subgroup_size) and new_coset(coset_size, offset).
2. Remove cosetFFT / cosetIFFT methods
3. Add a convenience method domain.get_coset(offset), to make it easy to go from subgroup -> coset.

from algebra.

Are these changes still wanted? If so I'm happy to submit a pull request for this

from algebra.

Yes!

from algebra.