# TODO-list for version 2.1 (or is it 3.0 at this point?)

## Rework solver

### Architecture

* Nail down the theory first
* One generic solve module that does not depend on anything else,
  not even on cube if possible
* The generic file includes the logic for branching and calls functions
  provided as parameters to move the cube and check the status etc...
* This includes the logic for single/multithreading (simplify if compiled
  with N_THREADS = 1 or whatever this option is going to be)
* The data representing the cube is a void pointer
* Move two-step solve to a different module
* Each other solver (solve coord, solve fst, solve multistep)
  should go in a separate module

### Other practicalities

* remove cube from dfsarg? (i still need to save the scramble somewhere,
  but I really only use it in dfs_niss)
* Re-work prepare_step process for solve_generic (nxopt table is special).
* is_valid should also unnis and / or cleanup the alg.

## New optimal solver (use fst)

* Implement nxopt31 with fst_cube. Remember that the function
  move_check_solved() should do one axis at the time, so that we don't move
  everything before checking.

## Simplify steps

* Remove one type of rotation.
* Change steps to choicestep and stepalt to step (or was this already done?).

## Add missing coordinates and steps

* Check the old file for a list. Many are missing.
* Checkers in steps.c should use coordinates.

## Missing and new commands

* gen
* freemem
* twophase

## Easy improvements

* Solve should re-orient the cube if centers are off
* Solve: add options for -I (inverse only) and -L (linear = normal + inverse).