Nvim documentation: vim_diff

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*vim_diff.txt*    Nvim


			    NVIM REFERENCE MANUAL



Differences between Nvim and Vim			       *vim-differences*

Nvim differs from Vim in many ways, big and small.  This document is
a complete and centralized reference of those differences.

				      Type |gO| to see the table of contents.

==============================================================================

1. Configuration					    *nvim-configuration*

- Use `$XDG_CONFIG_HOME/nvim/init.vim` instead of `.vimrc` for configuration.
- Use `$XDG_CONFIG_HOME/nvim` instead of `.vim` to store configuration files.
- Use `$XDG_DATA_HOME/nvim/shada/main.shada` instead of `.viminfo` for persistent
  session information.  |shada|

==============================================================================

2. Defaults					            *nvim-defaults*

- Syntax highlighting is enabled by default
- ":filetype plugin indent on" is enabled by default

- 'autoindent' is set by default
- 'autoread' is set by default
- 'background' always defaults to "dark"
- 'backspace' defaults to "indent,eol,start"
- 'backupdir' defaults to .,~/.local/share/nvim/backup (|xdg|)
- 'belloff' defaults to "all"
- 'complete' doesn't include "i"
- 'cscopeverbose' is enabled
- 'directory' defaults to ~/.local/share/nvim/swap// (|xdg|), auto-created
- 'display' defaults to "lastline,msgsep"
- 'encoding' is UTF-8 (cf. 'fileencoding' for file-content encoding)
- 'fillchars' defaults (in effect) to "vert:│,fold:·"
- 'fsync' is disabled
- 'formatoptions' defaults to "tcqj"
- 'history' defaults to 10000 (the maximum)
- 'hlsearch' is set by default
- 'incsearch' is set by default
- 'langnoremap' is enabled by default
- 'langremap' is disabled by default
- 'laststatus' defaults to 2 (statusline is always shown)
- 'listchars' defaults to "tab:> ,trail:-,nbsp:+"
- 'nocompatible' is always set
- 'nrformats' defaults to "bin,hex"
- 'ruler' is set by default
- 'sessionoptions' doesn't include "options"
- 'shortmess' sets "F" flag
- 'showcmd' is set by default
- 'sidescroll' defaults to 1
- 'smarttab' is set by default
- 'tabpagemax' defaults to 50
- 'tags' defaults to "./tags;,tags"
- 'ttimeoutlen' defaults to 50
- 'ttyfast' is always set
- 'undodir' defaults to ~/.local/share/nvim/undo (|xdg|), auto-created
- 'viminfo' includes "!"
- 'wildmenu' is set by default

==============================================================================

3. New Features						       *nvim-features*

MAJOR COMPONENTS 

API				|API|
Lua scripting			|lua|
Job control			|job-control|
Remote plugins			|remote-plugin|
Providers
  Clipboard			|provider-clipboard|
  Node.js plugins		|provider-nodejs|
  Python plugins		|provider-python|
  Ruby plugins			|provider-ruby|
Shared data			|shada|
Embedded terminal		|terminal|
VimL parser			|nvim_parse_expression()|
XDG base directories		|xdg|

USER EXPERIENCE  

Working intuitively and consistently is a major goal of Nvim.


							*feature-compile*
- Nvim always includes ALL features, in contrast to Vim (which ships with
  various combinations of 100+ optional features). Think of it as a leaner
  version of Vim's "HUGE" build. This reduces surface area for bugs, and
  removes a common source of confusion and friction for users.

- Nvim avoids features that cannot be provided on all platforms; instead that
  is delegated to external plugins/extensions. E.g. the `-X` platform-specific
  option is "sometimes" available in Vim (with potential surprises:
	http://stackoverflow.com/q/14635295.

- Vim's internal test functions (test_autochdir(), test_settime(), etc.) are
  not exposed (nor implemented); instead Nvim has a robust API.

- Behaviors, options, documentation are removed if they cost users more time
  than they save.

Usability details have been improved where the benefit outweighs any
backwards-compatibility cost. Some examples:

- |K| in help documents can be used like |CTRL-]|.
- Directories for 'directory' and 'undodir' are auto-created.
- Terminal features such as 'guicursor' are enabled where possible.

ARCHITECTURE 

External plugins run in separate processes. |remote-plugin| This improves
stability and allows those plugins to work without blocking the editor. Even
"legacy" Python and Ruby plugins which use the old Vim interfaces (|if_pyth|,
|if_ruby|) run out-of-process.

Platform and I/O facilities are built upon libuv. Nvim benefits from libuv
features and bug fixes, and other projects benefit from improvements to libuv
by Nvim developers.

FEATURES 

Command-line highlighting:
  The expression prompt (|@=|, |c_CTRL-R_=|, |i_CTRL-R_=|) is highlighted
  using a built-in VimL expression parser. |expr-highlight|

					*E5408* *E5409*
  |input()|, |inputdialog()| support custom highlighting. |input()-highlight|

					*g:Nvim_color_cmdline*
  (Experimental) Command-line (|:|) is colored by callback defined in
  `g:Nvim_color_cmdline` (this callback is for testing only, and will be
  removed in the future).

Commands:
  |:checkhealth|
  |:cquit| can use [count] to set the exit code
  |:drop| is always available
  |:Man| is available by default, with many improvements such as completion
  |:sign-define| accepts a `numhl` argument, to highlight the line number
  |:tchdir| tab-local |current-directory|

Events:
  |DirChanged|
  |TabNewEntered|
  |TermClose|
  |TermOpen|
  |TextYankPost|
  |VimResume|
  |VimSuspend|

Functions:
  |dictwatcheradd()| notifies a callback whenever a |Dict| is modified
  |dictwatcherdel()|
  |menu_get()|
  |msgpackdump()|, |msgpackparse()| provide msgpack de/serialization
  |stdpath()|
  |system()|, |systemlist()| can run {cmd} directly (without 'shell')

Highlight groups:
  |expr-highlight| highlight groups (prefixed with "Nvim")
  |hl-NormalNC| highlights non-current windows
  |hl-MsgSeparator| highlights separator for scrolled messages
  |hl-QuickFixLine|
  |hl-Substitute|
  |hl-TermCursor|
  |hl-TermCursorNC|
  |hl-Whitespace| highlights 'listchars' whitespace

Input:
  ALT (|META|) chords always work (even in the |TUI|). Map |<M-| with any key:
  <M-1>, <M-BS>, <M-Del>, <M-Ins>, <M-/>, <M-\>, <M-Space>, <M-Enter>, etc.
  Case-sensitive: <M-a> and <M-A> are two different keycodes.

  ALT in insert-mode behaves like <Esc> if not mapped. |i_ALT|

Mappings:
  |<Cmd>| pseudokey

Normal commands:
  "Outline": Type |gO| in |:Man| and |:help| pages to see a document outline.

Options:
  'cpoptions' flags: |cpo-_|
  'display' flag `msgsep` to minimize scrolling when showing messages
  'guicursor' works in the terminal
  'fillchars' flags: `msgsep` (see 'display' above)
	      and `eob` for |hl-EndOfBuffer| marker
  'inccommand' shows interactive results for |:substitute|-like commands
  'scrollback'
  'statusline' supports unlimited alignment sections
'tabline' %@[email protected]%X can call any function on mouse-click 
  'winhighlight' window-local highlights

Variables:
  |v:event|
  |v:exiting|
  |v:progpath| is always absolute ("full")
  |v:windowid| is always available (for use by external UIs)

==============================================================================

4. Changed features					 *nvim-features-changed*

Nvim always builds with all features, in contrast to Vim which may have
certain features removed/added at compile-time. |feature-compile|

If a Python interpreter is available on your `$PATH`, |:python| and |:python3|
are always available and may be used simultaneously. See |provider-python|.

|:redir| nested in |execute()| works.

|mkdir()| behaviour changed:
1. Assuming /tmp/foo does not exist and /tmp can be written to
   mkdir('/tmp/foo/bar', 'p', 0700) will create both /tmp/foo and /tmp/foo/bar 
   with 0700 permissions. Vim mkdir will create /tmp/foo with 0755.
2. If you try to create an existing directory with `'p'` (e.g. mkdir('/',
   'p')) mkdir() will silently exit. In Vim this was an error.
3. mkdir() error messages now include strerror() text when mkdir fails.

|string()| and |:echo| behaviour changed:
1. No maximum recursion depth limit is applied to nested container
   structures.
2. |string()| fails immediately on nested containers, not when recursion limit
   was exceeded.
2. When |:echo| encounters duplicate containers like

       let l = []
       echo [l, l]
 
   it does not use "[...]" (was: "[[], [...]]", now: "[[], []]"). "..." is
   only used for recursive containers.
3. |:echo| printing nested containers adds "@level" after "..." designating
   the level at which recursive container was printed: |:echo-self-refer|.
   Same thing applies to |string()| (though it uses construct like
   "{[email protected]}"), but this is not reliable because |string()| continues to
   error out.
4. Stringifyed infinite and NaN values now use |str2float()| and can be evaled
   back.
5. (internal) Trying to print or stringify VAR_UNKNOWN in Vim results in 
   nothing, E908, in Nvim it is internal error.

|json_decode()| behaviour changed:
1. It may output |msgpack-special-dict|.
2. |msgpack-special-dict| is emitted also in case of duplicate keys, while in 
   Vim it errors out.
3. It accepts only valid JSON.  Trailing commas are not accepted.

|json_encode()| behaviour slightly changed: now |msgpack-special-dict| values 
are accepted, but |v:none| is not.


*v:none* variable is absent.  In Vim it represents “no value” in “js” strings 
like "[,]" parsed as "[v:none]" by |js_decode()|.


*js_encode()* and *js_decode()* functions are also absent.

Viminfo text files were replaced with binary (messagepack) ShaDa files.
Additional differences:

- |shada-c| has no effect.
- |shada-s| now limits size of every item and not just registers.
- 'viminfo' option got renamed to 'shada'. Old option is kept as an alias for
  compatibility reasons.
- |:wviminfo| was renamed to |:wshada|, |:rviminfo| to |:rshada|.  Old
  commands are still kept.
- ShaDa file format was designed with forward and backward compatibility in
  mind. |shada-compatibility|
- Some errors make ShaDa code keep temporary file in-place for user to decide
  what to do with it.  Vim deletes temporary file in these cases.
  |shada-error-handling|
- ShaDa file keeps search direction (|v:searchforward|), viminfo does not.

|printf()| returns something meaningful when used with `%p` argument: in Vim 
it used to return useless address of the string (strings are copied to the 
newly allocated memory all over the place) and fail on types which cannot be 
coerced to strings. See |id()| for more details, currently it uses 
`printf("%p", {expr})` internally.

|c_CTRL-R| pasting a non-special register into |cmdline| omits the last <CR>.

Lua interface (|if_lua.txt|):

- `:lua print("a\0b")` will print `a^@b`, like with `:echomsg "a\nb"` . In Vim
  that prints `a` and `b` on separate lines, exactly like
  `:lua print("a\nb")` .
- `:lua error('TEST')` emits the error “E5105: Error while calling lua chunk:
  [string "<VimL compiled string>"]:1: TEST”, whereas Vim emits only “TEST”.
- Lua has direct access to Nvim |API| via `vim.api`.
- Lua package.path and package.cpath are automatically updated according to
  'runtimepath': |lua-require|.

|input()| and |inputdialog()| support for each other’s features (return on
cancel and completion respectively) via dictionary argument (replaces all
other arguments if used).

|input()| and |inputdialog()| support user-defined cmdline highlighting.

Highlight groups:
  |hl-ColorColumn|, |hl-CursorColumn| are lower priority than most other
  groups
  |hl-CursorLine| is low-priority unless foreground color is set

Macro/|recording| behavior
  Replay of a macro recorded during :lmap produces the same actions as when it
  was recorded. In Vim if a macro is recorded while using :lmap'ped keys then
  the behaviour during record and replay differs.

  'keymap' is implemented via :lmap instead of :lnoremap so that you can use
  macros and 'keymap' at the same time. This also means you can use |:imap| on
  the results of keys from 'keymap'.

Normal commands:
  |Q| is the same as |gQ|

Options:
  'ttimeout', 'ttimeoutlen' behavior was simplified

Shell:
  Shell output (|:!|, |:make|, …) is always routed through the UI, so it
  cannot "mess up" the screen. (You can still use "chansend(v:stderr,…)" if
  you want to mess up the screen :)

  Nvim throttles (skips) messages from shell commands (|:!|, |:grep|, |:make|)
  if there is too much output. No data is lost, this only affects display and
  improves performance. |:terminal| output is never throttled.

  |:!| does not support "interactive" commands. Use |:terminal| instead.
  (GUI Vim has a similar limitation, see ":help gui-pty" in Vim.)

  :!start is not special-cased on Windows.

  |system()| does not support writing/reading "backgrounded" commands. |E5677|

Startup:
  |-e| and |-es| invoke the same "improved Ex mode" as -E and -Es.
  |-E| and |-Es| reads stdin as text (into buffer 1).
  |-s| reads Normal commands from stdin if the script name is "-".
  Reading text (instead of commands) from stdin YXXY--|:
    - works by default: "-" file is optional
    - works in more cases: |-Es|, file args

TUI:

			*:set-termcap*
  Start Nvim with 'verbose' level 3 to show terminal capabilities:
	nvim -V3
 

			*'term'* *E529* *E530* *E531*
  'term' reflects the terminal type derived from |$TERM| and other environment
  checks.  For debugging only; not reliable during startup.
	  :echo &term
   "builtin_x" means one of the |builtin-terms| was chosen, because the expected
  terminfo file was not found on the system.

  Nvim will use 256-colour capability on Linux virtual terminals.  Vim uses
  only 8 colours plus bright foreground on Linux VTs.

  Vim combines what is in its |builtin-terms| with what it reads from terminfo,
  and has a 'ttybuiltin' setting to control how that combination works.  Nvim
  uses one or the other, it does not attempt to merge the two.

VimL (Vim script) compatibility:
  `count` does not alias to |v:count|
  `errmsg` does not alias to |v:errmsg|
  `shell_error` does not alias to |v:shell_error|
  `this_session` does not alias to |v:this_session|

==============================================================================

5. Missing legacy features				 *nvim-features-missing*

Some legacy Vim features are not implemented:

- |if_py|: vim.bindeval() and vim.Function() are not supported
- |if_lua|: the `vim` object is missing some legacy methods

- *if_perl*

- *if_mzscheme*

- *if_tcl*

==============================================================================

6. Removed features					 *nvim-features-removed*

These Vim features were intentionally removed from Nvim.

Aliases:
  ex        (alias for "nvim -e")
  exim      (alias for "nvim -E")
  gex       (GUI)
  gview     (GUI)
  gvim      (GUI)
  gvimdiff  (GUI)
  rgview    (GUI)
  rgvim     (GUI)
  rview     (alias for "nvim -RZ")
  rvim      (alias for "nvim -Z")
  view      (alias for "nvim -R")
  vimdiff   (alias for "nvim -d" |diff-mode|)

Commands:
  :fixdel
  :helpfind
  :mode (no longer accepts an argument)
  :open
  :Print
  :shell
  :smile
  :tearoff

Compile-time features:
  EBCDIC
  Emacs tags support
  X11 integration (see |x11-selection|)

Options:
  'antialias'
  'bioskey' (MS-DOS)
  'conskey' (MS-DOS)

  *'cp'* *'nocompatible'* *'nocp'* *'compatible'* (Nvim is always "nocompatible".)
  'cpoptions' (gjkHw<*- and all POSIX flags were removed)

  *'cryptmethod'* *'cm'* *'key'* (Vim encryption implementation)

  *'ed'* *'edcompatible'* *'noed'* *'noedcompatible'*
  'encoding' ("utf-8" is always used)
  'esckeys'
  'guioptions' "t" flag was removed

  *'guipty'* (Nvim uses pipes and PTYs consistently on all platforms.)
  'highlight' (Names of builtin |highlight-groups| cannot be changed.)

  *'imactivatefunc'* *'imaf'*

  *'imactivatekey'* *'imak'*

  *'imstatusfunc'* *'imsf'*

  *'macatsui'*
  'maxmem' Nvim delegates memory-management to the OS.
  'maxmemtot' Nvim delegates memory-management to the OS.
  'maxcombine' (6 is always used)

  *'restorescreen'* *'rs'* *'norestorescreen'* *'nors'*
  'shelltype'

  *'shortname'* *'sn'* *'noshortname'* *'nosn'*

  *'swapsync'* *'sws'*

  *'termencoding'* *'tenc'* (Vim 7.4.852 also removed this for Windows)
  'textauto'
  'textmode'

  *'toolbar'* *'tb'*

  *'toolbariconsize'* *'tbis'*

  *'ttybuiltin'* *'tbi'* *'nottybuiltin'* *'notbi'*

  *'ttymouse'* *'ttym'*

  *'ttyscroll'* *'tsl'*

  *'ttytype'* *'tty'*
  'ttyfast'
  'weirdinvert'

Startup:
  --literal (file args are always literal; to expand wildcards on Windows, use
    |:n| e.g. `nvim +"n *"`)
  Easy mode: eview, evim, nvim -y
  Vi mode: nvim -v

Test functions:
  test_alloc_fail()
  test_autochdir()
  test_disable_char_avail()
  test_garbagecollect_now()
  test_null_channel()
  test_null_dict()
  test_null_job()
  test_null_list()
  test_null_partial()
  test_null_string()
  test_override()
  test_settime()

TUI:

			  *t_xx* *termcap-options* *t_AB* *t_Sb* *t_vb* *t_SI*
  Nvim does not have special `t_XX` options nor <t_XX> keycodes to configure
  terminal capabilities. Instead Nvim treats the terminal as any other UI,
  e.g. 'guicursor' sets the terminal cursor style if possible.


			  *termcap*
  Nvim never uses the termcap database, only |terminfo| and |builtin-terms|.


			  *xterm-8bit* *xterm-8-bit*
  Xterm can be run in a mode where it uses true 8-bit CSI.  Supporting this
  requires autodetection of whether the terminal is in UTF-8 mode or non-UTF-8
  mode, as the 8-bit CSI character has to be written differently in each case.
  Vim issues a "request version" sequence to the terminal at startup and looks
  at how the terminal is sending CSI.  Nvim does not issue such a sequence and
  always uses 7-bit control sequences.

==============================================================================
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