Fix for adding flexible components

[MenBrial]

Use vim.tbl_contains to ensure a value is not already in the
priorties list. priorities[priority] may return erroneous answers.
For example, if the first component has a priority value of 2 and the
second component has a priority value of 1, priorities[1] returns
the priority of the first component (2) and not nil as expected. This
results in ignoring the second component.

[rebelot]

Good call, thanks. Also using a set like could solve it.

priorities[priority] = true and then use vim.tbl_keys to retrieve priorities. What approach do you think is more efficient?

[MenBrial]

I would think that priorities[priority] = true is faster: it uses only one internal call while my solution uses a call to vim.tbl_contains, which is a Neovim function implemented in Lua, and possibly an internal call in addition.

Therefore it is probably better to use priorities[priority] = true even if the impact is probably limited as I except there would only be a limited number of flexible components.