Index refactor

[apozharski]

Refactoring index definitions. Very work in progress.

[FreyJo]

2 minor comments.
LGTM

[FreyJo]

I just checked out of curiosity, ind_g_clock_state seems to never be used.
Can be removed later of course.

[nurkanovic]

a short description for add_variable (e.g., what are possible values for type)
would be useful, even though it is almost apparent what needs to be done.

[nurkanovic]

To make create_nlp_nosnoc shorter, I suggest to make some small stupid functions, e.g.,
create_empty_problem for initializing the problem struct

[nurkanovic]

we often use (which was my initial mistake) cells for stacking functions and variables, g = {problem.g{:}, g}, and do vertcat(g(:)) at the end. we could immediately just do
problem.g = [problem.g, g], right @FreyJo ?

[FreyJo]

we often use (which was my initial mistake) cells for stacking functions and variables, g = {problem.g{:}, g}, and do vertcat(g(:)) at the end. we could immediately just do problem.g = [problem.g, g], right @FreyJo ?

Right, it should be possible to just do vertcat in the new helper functions.
But, as Anton said this is one cleanup step and there are surely more to come.

[FreyJo]

a short description for add_variable (e.g., what are possible values for type) would be useful, even though it is almost apparent what needs to be done.

Personally, I would not put comments in such a self explaining function, which is anyway just a helper function for developers, and not part of the front-end.