Ex commands: blockwise, charwise range

[beyarkay]

Problem

(Originally asked about solutions here)

In vim/neovim, ranges are only line-wise. I'd like to be able to perform commands on column- and line-wise ranges. There are more examples in the Stack overflow post, but I find it odd that the vim help pages talk about line-based ranges as though column-based ranges were planned in the future:

							*:visual_example*
Currently the ":" command works on whole lines only.  When you select part of
a line, doing something like ":!date" will replace the whole line.  If you
want only part of the line to be replaced you will have to make a mapping for
it.  In a future release ":" may work on partial lines.

Is there any tracking issue for the comment "In a future release ":" may work on partial lines"? If not, I felt there should be one. It would be a big help.

There is a plugin that partially solves this: vis, although it's not as ergonomic as it could be.

Expected behavior

If a block of text were selected using ctrl-v (or even just a part of a line of text), then pressing : should auto-fill the partial-line range selector: :`<,`> instead of it's current behaviour, which auto-fills the line-based range selector: :'<,'>. I'm not sure if it's feasible (or possible) to migrate all line-based commands to the new selector.

[justinmk]

auto-fill the partial-line range selector: :`<,`>

This is in vim's todo.txt I believe. vim/vim#3292

It is relevant for all commands, not just :.

Closest thing I could find is: https://github.com/vim/vim/blob/1d87e11a1ef201b26ed87585fba70182ad0c468a/runtime/doc/todo.txt#L5743-L5745

7   Substitute in a block of text.  Use {line}.{column} notation in an Ex
    range, e.g.: ":1.3,$.5s" means to substitute from line 1 column 3 to the
    last line column 5.

But this could be for all commands, not just :s. And I agree that backtick mark notation should work charwise:

:`<,`>foo
:`a,`bfoo

Note that charwise is different than blockwise. Would need some way to disambiguate that.

[justinmk]

otoh, it's pretty easy to make a plugin that :

1. copies the selected block,
2. pastes it into a new scratch buffer
3. sets 'filetype' to match the original buffer
4. executes the command

Not perfect but could be pretty useful.

[ad-chaos]

You can use the \%V atom to only match in the visual area (thanks to chrisbra)

[justinmk]

use the \%V atom

That is a special case for search and :substitute, but doesn't answer the general idea of being able to pass a charwise or blockwise range to commands.

[beyarkay]

Good catch about blockwise selection being different from charwise selection. Maybe something like :`a,`bfoo for charwise and :1.3,$.5foo for blockwise?

I'm not fully up to date on nvims goals, does something like this belong in the main program or is it more suitable for a plugin? I don't have experience with plugins/nvim internals but would be keen to get my hands dirty

[justinmk]

This would probably need to be a core change

[beyarkay]

Okay, who would I speak to in order to get an idea about what the definition of done is? Maybe this would need to be broken into a charwise and a blockwise change, although I'm not sure what your status quo is.

[justinmk]

what the definition of done is? Maybe this would need to be broken into a charwise and a blockwise change

Yeah, let's start with charwise first. I'd say "done" for charwise is:

Proposal

• Support backtick ranges pass column info to the command

  :`<,`>foo
  :`a,`bfoo
  

  • Note: it's vaguely possible that parsing a backtick range might conflict with :help backtick-expansion. Probably isn't an issue because :help backtick-expansion does not happen in the "range" part (the start) of a command.
• Column info is available as <col1> , <col2> (like :help <line1>)
  • For user-defined command, :command -addr=lines
• Support "x.y" ranges pass column info to the command

  :1.2,2.2 foo
  

• Update nvim_parse_cmd() , nvim_cmd()
• Add charwise support to a few common Ex commands:
  • :read
  • :write
  • :substitute
  • :global
  • ...
  • Document the rest.
• Update docs: :help :range,