Motion to jump back one level of indentation, not including blank lines

Question

I've been authoring a lot of F# in Vim lately. Like Python it is pretty strictly indentation-based. However, unlike Python mode for Vim, it does not appear that the standard F# Vim plugin supports any kinds of motions. I would like the ability to rapidly navigate over modules and functions, in the spirit of what is done with motions for classes and functions in Python mode:

[M      Jump to previous class or method (normal, visual, operator modes)
]M      Jump to next class or method (normal, visual, operator modes)
aC      Select a class. Ex: vaC, daC, yaC, caC (normal, operator modes)
iC      Select inner class. Ex: viC, diC, yiC, ciC (normal, operator modes)
aM      Select a function or method. Ex: vaM, daM, yaM, caM (normal, operator modes)
iM      Select inner function or method. Ex: viM, diM, yiM, ciM (normal, operator modes)

So specifically, given some code like this:

module Foobar =
    let private foo'() =
        bar'()
        |> baz'()
        |> qux'()

    let foo() =
        bar()
        |> baz()
        |> qux()

I would like to be able to quick jump to the beginning and end of functions and modules.

I can write some code to do this based on Python mode, but before jumping to that I was wondering, since Vim comes with so many motions built in, Is there a way to say, "move to the first place where there is a nonblank line that is set back n indentation levels from current line"?

I have not been able to find anything, maybe because Vim was built originally more for C-style code, but I wanted to know if there was any existing functionality (or existing plugin for that matter) that handled this case, because if so that would probably take care of 95% of what I need without having to implement the motions for F#-specific semantics.

Answer 1

Plugin indentwise by jeetsukumaran

Movements by Relative Indent-Depth

• [- : Move to previous line of lesser indent than the current line.
• [+ : Move to previous line of greater indent than the current line.
• [= : Move to previous line of same indent as the current line that is separated from the current line by lines of different indents.
• ]- : Move to next line of lesser indent than the current line.
• ]+ : Move to next line of greater indent than the current line.
• ]= : Move to next line of same indent as the current line that is separated from the current line by lines of different indents.

Movements by Absolute Indent-Levels

• {count}[_ : Move to previous line with indent-level of {count}.
• {count}]_ : Move to next line with indent-level of {count}.

Movements by Indent-Block Scope

• [% : Move to beginning of indent-block scope (i.e., move to the line just after the previous line of lesser indent); repeat for {count} outer scopes.

• ]% : Move to end of indent-block scope (i.e., move to the line just before the next line of lesser indent); repeat for {count} outer scopes.

  If you use matchit's (matchup) [% and ]%, you have to pick different ones (#issue 6).

Remarks

• This question is possibly a duplicate of How do I move vertically until reaching a non-whitespace character? similar as the question Structural navigation by indentation level.
  However, I would like to emphasize that the idea is about navigating based on different indentation levels which is not the focus of the title How do I move vertically until reaching a non-whitespace character?.

• see also wiki page 'Move to next/previous line with same indentation'

Futher related plugins are

• tmhedberg/indent-motion
• inkarkat/vim-JumpToVerticalOccurrence
• michaeljsmith/vim-indent-object
• qstrahl/vim-dentures