Mapping

• :map - recursive version of mapping command
• :noremap - non-recursive version of mapping command
  • "Recursive" means that the mapping is expanded to a result, then the result is expanded to another result, and so on.
• below, j will be mapped to gg. Q will also be mapped to gg, because j will be expanded for the recursive mapping. W will be mapped to j (and not to gg) because j will not be expanded for the non-recursive mapping.
  • The expansion stops when one of these is true:
    1. the result is no longer mapped to anything else.
    2. a non-recursive mapping has been applied (i.e. the "noremap" [or one of its ilk] is the final expansion).

:map j gg
:map Q j
:noremap W j

• since VIM is a modal editor, there are corresponding mapping commands for each mode

  • ex. - :imap, :nmap, :map! (i mode and command line)

• Recursive map - the rhs says to the lhs "if you get triggered, when I get triggered. It stops with me, and nothing past me gets triggered"

• Non-recursive map (nore)- the rhs says "When you get triggered, I may server as the lhs of another mapping that will trigger something else."

• map is the "root" of all recursive mapping commands.

  • The root form applies to "normal", "visual+select", and "operator-pending" modes.

• "Recursive" means that the mapping is expanded to a result, then the result is expanded to another result, and so on.

• The expansion stops when one of these is true:

  1. the result is no longer mapped to anything else.
  2. a non-recursive mapping has been applied (i.e. the "noremap" [or one of its ilk] is the final expansion).

• At that point, Vim's default "meaning" of the final result is applied/executed.

• "Non-recursive" means the mapping is only expanded once, and that result is applied/executed.

  • Example:

nmap K H
nnoremap H G
nnoremap G gg

• The above causes K to expand to H, then H to expand to G and stop. It stops because of the nnoremap, which expands and stops immediately. The meaning of G will be executed (i.e. "jump to last line"). At most one non-recursive mapping will ever be applied in an expansion chain (it would be the last expansion to happen).
• The mapping of G to gg only applies if you press G, but not if you press K. This mapping doesn't affect pressing K regardless of whether G was mapped recursively or not, since it's line 2 that causes the expansion of K to stop, so line 3 wouldn't be used.