Fixed printer and added more tests

Signed-off-by: Diwank Singh <diwank.singh@gmail.com>
Added tests, failing at the moment

Signed-off-by: Diwank Singh <diwank.singh@gmail.com>
Removed NIL empty equivalence, added ROOT' back, reworking printer

Signed-off-by: Diwank Singh <diwank.singh@gmail.com>
Unified tests; printer broken

Signed-off-by: Diwank Singh <diwank.singh@gmail.com>
Fixed parser; printer still broken

Signed-off-by: Diwank Singh <diwank.singh@gmail.com>
Added some todos

Signed-off-by: Diwank Singh <diwank.singh@gmail.com>
Moved todos to separate file

Signed-off-by: Diwank Singh <diwank.singh@gmail.com>
Reconstituted NIL as empty list

Signed-off-by: Diwank Singh <diwank.singh@gmail.com>