pub fn apply_fold_level(folds: &mut [Fold], level: u32)Expand description
Close every fold deeper than level, open the rest.
This is what :set foldlevel=N does at the moment it is set. It is
deliberately a one-shot bulk action rather than a standing invariant:
a user who then presses za on one fold must not have it reopened by
the next rebuild, so recompute_folds carries manual state over by
identity and consults foldlevel only for folds it has not seen
before (see apply_fold_level_to_new).