vim-patch:9.0.1958: cannot complete option values

Problem:  cannot complete option values
Solution: Add completion functions for several options

Add cmdline tab-completion for setting string options

Add tab-completion for setting string options on the cmdline using
`:set=` (along with `:set+=` and `:set-=`).

The existing tab completion for setting options currently only works
when nothing is typed yet, and it only fills in with the existing value,
e.g. when the user does `:set diffopt=<Tab>` it will be completed to
`set diffopt=internal,filler,closeoff` and nothing else. This isn't too
useful as a user usually wants auto-complete to suggest all the possible
values, such as 'iblank', or 'algorithm:patience'.

For set= and set+=, this adds a new optional callback function for each
option that can be invoked when doing completion. This allows for each
option to have control over how completion works. For example, in
'diffopt', it will suggest the default enumeration, but if `algorithm:`
is selected, it will further suggest different algorithm types like
'meyers' and 'patience'. When using set=, the existing option value will
be filled in as the first choice to preserve the existing behavior. When
using set+= this won't happen as it doesn't make sense.

For flag list options (e.g. 'mouse' and 'guioptions'), completion will
take into account existing typed values (and in the case of set+=, the
existing option value) to make sure it doesn't suggest duplicates.

For set-=, there is a new `ExpandSettingSubtract` function which will
handle flag list and comma-separated options smartly, by only suggesting
values that currently exist in the option.

Note that Vim has some existing code that adds special handling for
'filetype', 'syntax', and misc dir options like 'backupdir'. This change
preserves them as they already work, instead of converting to the new
callback API for each option.

closes: vim/vim#13182

https://github.com/vim/vim/commit/900894b09a95398dfc75599e9f0aa2ea25723384

Co-authored-by: Yee Cheng Chin <ychin.git@gmail.com>

1 files changed, 62 insertions, 4 deletions

diff --git a/src/nvim/options.lua b/src/nvim/options.lua
index cd1d760836..fd7e1586ac 100644
--- a/src/nvim/options.lua
+++ b/src/nvim/options.lua
@@ -6,7 +6,7 @@
 --- @field varname? string
 --- @field pv_name? string
 --- @field type 'bool'|'number'|'string'
---- @field list? 'comma'|'onecomma'|'flags'|'flagscomma'
+--- @field list? 'comma'|'onecomma'|'commacolon'|'onecommacolon'|'flags'|'flagscomma'
 --- @field scope vim.option_scope[]
 --- @field deny_duplicates? boolean
 --- @field enable_if? string|false
@@ -25,6 +25,7 @@
 --- @field alloced? true
 --- @field redraw? vim.option_redraw[]
 --- @field cb? string
+--- @field expand_cb? string
 --- @field tags? string[]
 
 --- @class vim.option_defaults
@@ -192,6 +193,7 @@ return {
         set to one of CJK locales.  See Unicode Standard Annex #11
         (https://www.unicode.org/reports/tr11).
       ]=],
+      expand_cb = 'expand_set_ambiwidth',
       full_name = 'ambiwidth',
       redraw = { 'all_windows', 'ui_option' },
       scope = { 'global' },
@@ -331,6 +333,7 @@ return {
         option, you must load syntax.vim again to see the result.  This can be
         done with ":syntax on".
       ]=],
+      expand_cb = 'expand_set_background',
       full_name = 'background',
       scope = { 'global' },
       short_desc = N_('"dark" or "light", used for highlight colors'),
@@ -357,6 +360,7 @@ return {
         When the value is empty, Vi compatible backspacing is used, none of
         the ways mentioned for the items above are possible.
       ]=],
+      expand_cb = 'expand_set_backspace',
       full_name = 'backspace',
       list = 'onecomma',
       scope = { 'global' },
@@ -453,6 +457,7 @@ return {
         the system may refuse to do this.  In that case the "auto" value will
         again not rename the file.
       ]=],
+      expand_cb = 'expand_set_backupcopy',
       full_name = 'backupcopy',
       list = 'onecomma',
       scope = { 'global', 'buffer' },
@@ -621,6 +626,7 @@ return {
         indicate that an error occurred. It can be silenced by adding the
         "error" keyword.
       ]=],
+      expand_cb = 'expand_set_belloff',
       full_name = 'belloff',
       list = 'comma',
       scope = { 'global' },
@@ -763,6 +769,7 @@ return {
         		    added for the 'showbreak' setting.
         		    (default: off)
       ]=],
+      expand_cb = 'expand_set_breakindentopt',
       full_name = 'breakindentopt',
       list = 'onecomma',
       redraw = { 'current_buffer' },
@@ -816,6 +823,7 @@ return {
         This option is used together with 'buftype' and 'swapfile' to specify
         special kinds of buffers.   See |special-buffers|.
       ]=],
+      expand_cb = 'expand_set_bufhidden',
       full_name = 'bufhidden',
       noglob = true,
       scope = { 'buffer' },
@@ -893,6 +901,7 @@ return {
         without saving.  For writing there must be matching |BufWriteCmd|,
         |FileWriteCmd| or |FileAppendCmd| autocommands.
       ]=],
+      expand_cb = 'expand_set_buftype',
       full_name = 'buftype',
       noglob = true,
       scope = { 'buffer' },
@@ -917,6 +926,7 @@ return {
         		case mapping, the current locale is not effective.
         		This probably only matters for Turkish.
       ]=],
+      expand_cb = 'expand_set_casemap',
       full_name = 'casemap',
       list = 'onecomma',
       scope = { 'global' },
@@ -1183,6 +1193,7 @@ return {
         		"*". See |clipboard|.
       ]=],
       deny_duplicates = true,
+      expand_cb = 'expand_set_clipboard',
       full_name = 'clipboard',
       list = 'onecomma',
       scope = { 'global' },
@@ -1369,6 +1380,7 @@ return {
         based expansion (e.g., dictionary |i_CTRL-X_CTRL-K|, included patterns
         |i_CTRL-X_CTRL-I|, tags |i_CTRL-X_CTRL-]| and normal expansions).
       ]=],
+      expand_cb = 'expand_set_complete',
       full_name = 'complete',
       list = 'onecomma',
       scope = { 'buffer' },
@@ -1399,7 +1411,9 @@ return {
         Keep in mind that the cursor position is not always where it's
         displayed.  E.g., when moving vertically it may change column.
       ]=],
+      expand_cb = 'expand_set_concealcursor',
       full_name = 'concealcursor',
+      list = 'flags',
       redraw = { 'current_window' },
       scope = { 'window' },
       short_desc = N_('whether concealable text is hidden in cursor line'),
@@ -1492,6 +1506,7 @@ return {
         	    select one from the menu. Only works in combination with
         	    "menu" or "menuone".
       ]=],
+      expand_cb = 'expand_set_completeopt',
       full_name = 'completeopt',
       list = 'onecomma',
       scope = { 'global' },
@@ -1517,6 +1532,7 @@ return {
         command line completion the global value is used.
       ]=],
       enable_if = 'BACKSLASH_IN_FILENAME',
+      expand_cb = 'expand_set_completeslash',
       full_name = 'completeslash',
       scope = { 'buffer' },
       type = 'string',
@@ -1797,6 +1813,7 @@ return {
         	_	When using |cw| on a word, do not include the
         		whitespace following the word in the motion.
       ]=],
+      expand_cb = 'expand_set_cpoptions',
       full_name = 'cpoptions',
       list = 'flags',
       redraw = { 'all_windows' },
@@ -1878,6 +1895,7 @@ return {
 
         "line" and "screenline" cannot be used together.
       ]=],
+      expand_cb = 'expand_set_cursorlineopt',
       full_name = 'cursorlineopt',
       list = 'onecomma',
       redraw = { 'current_window_only' },
@@ -1900,6 +1918,7 @@ return {
         "msg" and "throw" are useful for debugging 'foldexpr', 'formatexpr' or
         'indentexpr'.
       ]=],
+      expand_cb = 'expand_set_debug',
       full_name = 'debug',
       scope = { 'global' },
       short_desc = N_('to "msg" to see all error messages'),
@@ -2140,8 +2159,9 @@ return {
         	:set diffopt-=internal  " do NOT use the internal diff parser
         <
       ]=],
+      expand_cb = 'expand_set_diffopt',
       full_name = 'diffopt',
-      list = 'onecomma',
+      list = 'onecommacolon',
       redraw = { 'current_window' },
       scope = { 'global' },
       short_desc = N_('options for using diff mode'),
@@ -2242,6 +2262,7 @@ return {
         The "@" character can be changed by setting the "lastline" item in
         'fillchars'.  The character is highlighted with |hl-NonText|.
       ]=],
+      expand_cb = 'expand_set_display',
       full_name = 'display',
       list = 'onecomma',
       redraw = { 'all_windows' },
@@ -2260,6 +2281,7 @@ return {
         	hor	horizontally, height of windows is not affected
         	both	width and height of windows is affected
       ]=],
+      expand_cb = 'expand_set_eadirection',
       full_name = 'eadirection',
       scope = { 'global' },
       short_desc = N_("in which direction 'equalalways' works"),
@@ -2470,6 +2492,7 @@ return {
             :set ei=WinEnter,WinLeave
         <
       ]=],
+      expand_cb = 'expand_set_eventignore',
       full_name = 'eventignore',
       list = 'onecomma',
       scope = { 'global' },
@@ -2558,6 +2581,7 @@ return {
 
         This option cannot be changed when 'modifiable' is off.
       ]=],
+      expand_cb = 'expand_set_encoding',
       full_name = 'fileencoding',
       no_mkrc = true,
       redraw = { 'statuslines', 'current_buffer' },
@@ -2619,6 +2643,7 @@ return {
         Setting this option does not have an effect until the next time a file
         is read.
       ]=],
+      expand_cb = 'expand_set_encoding',
       full_name = 'fileencodings',
       list = 'onecomma',
       scope = { 'global' },
@@ -2651,6 +2676,7 @@ return {
         option is set, because the file would be different when written.
         This option cannot be changed when 'modifiable' is off.
       ]=],
+      expand_cb = 'expand_set_fileformat',
       full_name = 'fileformat',
       no_mkrc = true,
       redraw = { 'curswant', 'statuslines' },
@@ -2714,6 +2740,7 @@ return {
           used.
         Also see |file-formats|.
       ]=],
+      expand_cb = 'expand_set_fileformat',
       full_name = 'fileformats',
       list = 'onecomma',
       scope = { 'global' },
@@ -2846,6 +2873,7 @@ return {
           eob		EndOfBuffer		|hl-EndOfBuffer|
           lastline	NonText			|hl-NonText|
       ]=],
+      expand_cb = 'expand_set_chars_option',
       full_name = 'fillchars',
       list = 'onecomma',
       redraw = { 'current_window' },
@@ -2884,6 +2912,7 @@ return {
         its level is higher than 'foldlevel'.  Useful if you want folds to
         automatically close when moving out of them.
       ]=],
+      expand_cb = 'expand_set_foldclose',
       full_name = 'foldclose',
       list = 'onecomma',
       redraw = { 'current_window' },
@@ -3045,6 +3074,7 @@ return {
         |fold-syntax|	syntax	    Syntax highlighting items specify folds.
         |fold-diff|	diff	    Fold text that is not changed.
       ]=],
+      expand_cb = 'expand_set_foldmethod',
       full_name = 'foldmethod',
       redraw = { 'current_window' },
       scope = { 'window' },
@@ -3122,6 +3152,7 @@ return {
         To close folds you can re-apply 'foldlevel' with the |zx| command or
         set the 'foldclose' option to "all".
       ]=],
+      expand_cb = 'expand_set_foldopen',
       full_name = 'foldopen',
       list = 'onecomma',
       redraw = { 'curswant' },
@@ -3218,6 +3249,7 @@ return {
         To avoid problems with flags that are added in the future, use the
         "+=" and "-=" feature of ":set" |add-option-flags|.
       ]=],
+      expand_cb = 'expand_set_formatoptions',
       full_name = 'formatoptions',
       list = 'flags',
       scope = { 'buffer' },
@@ -4451,6 +4483,7 @@ return {
         		|alternate-file| or using |mark-motions| try to
         		restore the |mark-view| in which the action occurred.
       ]=],
+      expand_cb = 'expand_set_jumpoptions',
       full_name = 'jumpoptions',
       list = 'onecomma',
       scope = { 'global' },
@@ -4495,6 +4528,7 @@ return {
         Special keys in this context are the cursor keys, <End>, <Home>,
         <PageUp> and <PageDown>.
       ]=],
+      expand_cb = 'expand_set_keymodel',
       full_name = 'keymodel',
       list = 'onecomma',
       scope = { 'global' },
@@ -4779,6 +4813,7 @@ return {
         Note that when using 'indentexpr' the `=` operator indents all the
         lines, otherwise the first line is not indented (Vi-compatible).
       ]=],
+      expand_cb = 'expand_set_lispoptions',
       full_name = 'lispoptions',
       list = 'onecomma',
       pv_name = 'p_lop',
@@ -4933,6 +4968,7 @@ return {
         "precedes". |hl-Whitespace| for "nbsp", "space", "tab", "multispace",
         "lead" and "trail".
       ]=],
+      expand_cb = 'expand_set_chars_option',
       full_name = 'listchars',
       list = 'onecomma',
       redraw = { 'current_window' },
@@ -5015,6 +5051,7 @@ return {
         	:set makeencoding=char	" system locale is used
         <
       ]=],
+      expand_cb = 'expand_set_encoding',
       full_name = 'makeencoding',
       scope = { 'global', 'buffer' },
       short_desc = N_('Converts the output of external commands'),
@@ -5377,6 +5414,7 @@ return {
         'mousehide'	hide mouse pointer while typing text
         'selectmode'	whether to start Select mode or Visual mode
       ]=],
+      expand_cb = 'expand_set_mouse',
       full_name = 'mouse',
       list = 'flags',
       scope = { 'global' },
@@ -5468,6 +5506,7 @@ return {
             "g<LeftMouse>"  is "<C-LeftMouse>	(jump to tag under mouse click)
             "g<RightMouse>" is "<C-RightMouse>	("CTRL-T")
       ]=],
+      expand_cb = 'expand_set_mousemodel',
       full_name = 'mousemodel',
       scope = { 'global' },
       short_desc = N_('changes meaning of mouse buttons'),
@@ -5645,6 +5684,7 @@ return {
         considered decimal.  This also happens for numbers that are not
         recognized as octal or hex.
       ]=],
+      expand_cb = 'expand_set_nrformats',
       full_name = 'nrformats',
       list = 'onecomma',
       scope = { 'buffer' },
@@ -6307,6 +6347,7 @@ return {
         This is useful for languages such as Hebrew, Arabic and Farsi.
         The 'rightleft' option must be set for 'rightleftcmd' to take effect.
       ]=],
+      expand_cb = 'expand_set_rightleftcmd',
       full_name = 'rightleftcmd',
       redraw = { 'current_window' },
       scope = { 'window' },
@@ -6634,6 +6675,7 @@ return {
         When 'diff' mode is active there always is vertical scroll binding,
         even when "ver" isn't there.
       ]=],
+      expand_cb = 'expand_set_scrollopt',
       full_name = 'scrollopt',
       list = 'onecomma',
       scope = { 'global' },
@@ -6687,6 +6729,7 @@ return {
         backwards, you cannot include the last character of a line, when
         starting in Normal mode and 'virtualedit' empty.
       ]=],
+      expand_cb = 'expand_set_selection',
       full_name = 'selection',
       scope = { 'global' },
       short_desc = N_('what type of selection to use'),
@@ -6707,6 +6750,7 @@ return {
            cmd		when using "v", "V" or CTRL-V
         See |Select-mode|.
       ]=],
+      expand_cb = 'expand_set_selectmode',
       full_name = 'selectmode',
       list = 'onecomma',
       scope = { 'global' },
@@ -6758,6 +6802,7 @@ return {
         If you leave out "options" many things won't work well after restoring
         the session.
       ]=],
+      expand_cb = 'expand_set_sessionoptions',
       full_name = 'sessionoptions',
       list = 'onecomma',
       scope = { 'global' },
@@ -7292,6 +7337,7 @@ return {
             shm=a	Abbreviation, but no loss of information.
             shm=at	Abbreviation, and truncate message when necessary.
       ]=],
+      expand_cb = 'expand_set_shortmess',
       full_name = 'shortmess',
       list = 'flags',
       scope = { 'global' },
@@ -7368,6 +7414,7 @@ return {
         place the text.  Without a custom 'statusline' or 'tabline' it will be
         displayed in a convenient location.
       ]=],
+      expand_cb = 'expand_set_showcmdloc',
       full_name = 'showcmdloc',
       scope = { 'global' },
       short_desc = N_('change location of partial command'),
@@ -7530,6 +7577,7 @@ return {
         This is done in order for the signcolumn appearance not appear weird
         during line deletion.
       ]=],
+      expand_cb = 'expand_set_signcolumn',
       full_name = 'signcolumn',
       redraw = { 'current_window' },
       scope = { 'window' },
@@ -7828,6 +7876,7 @@ return {
         security reasons.
       ]=],
       expand = true,
+      expand_cb = 'expand_set_spellsuggest',
       full_name = 'spellsuggest',
       list = 'onecomma',
       scope = { 'global' },
@@ -7852,7 +7901,7 @@ return {
         		designated regions of the buffer are spellchecked in
         		this case.
       ]=],
-      expand = true,
+      expand_cb = 'expand_set_spelloptions',
       full_name = 'spelloptions',
       list = 'onecomma',
       redraw = { 'current_buffer' },
@@ -7892,6 +7941,7 @@ return {
         with the previous cursor position. For "screen", the text cannot always
         be kept on the same screen line when 'wrap' is enabled.
       ]=],
+      expand_cb = 'expand_set_splitkeep',
       full_name = 'splitkeep',
       scope = { 'global' },
       short_desc = N_('determines scroll behavior for split windows'),
@@ -8326,6 +8376,7 @@ return {
            uselast	If included, jump to the previously used window when
         		jumping to errors with |quickfix| commands.
       ]=],
+      expand_cb = 'expand_set_switchbuf',
       full_name = 'switchbuf',
       list = 'onecomma',
       scope = { 'global' },
@@ -8580,6 +8631,7 @@ return {
            match	Match case
            smart	Ignore case unless an upper case letter is used
       ]=],
+      expand_cb = 'expand_set_tagcase',
       full_name = 'tagcase',
       scope = { 'global', 'buffer' },
       short_desc = N_('how to handle case when searching in tags files'),
@@ -9275,6 +9327,7 @@ return {
            slash	|deprecated| Always enabled. Uses "/" in filenames.
            unix		|deprecated| Always enabled. Uses "\n" line endings.
       ]=],
+      expand_cb = 'expand_set_sessionoptions',
       full_name = 'viewoptions',
       list = 'onecomma',
       scope = { 'global' },
@@ -9331,6 +9384,7 @@ return {
         not get a warning for it.
         When combined with other words, "none" is ignored.
       ]=],
+      expand_cb = 'expand_set_virtualedit',
       full_name = 'virtualedit',
       list = 'onecomma',
       redraw = { 'curswant' },
@@ -9395,6 +9449,7 @@ return {
         line (not an empty line) then it will not move to the next line.  This
         makes "dl", "cl", "yl" etc. work normally.
       ]=],
+      expand_cb = 'expand_set_whichwrap',
       full_name = 'whichwrap',
       list = 'flagscomma',
       scope = { 'global' },
@@ -9578,8 +9633,9 @@ return {
         <	Complete longest common string, then list alternatives.
         More info here: |cmdline-completion|.
       ]=],
+      expand_cb = 'expand_set_wildmode',
       full_name = 'wildmode',
-      list = 'onecomma',
+      list = 'onecommacolon',
       scope = { 'global' },
       short_desc = N_("mode for 'wildchar' command-line expansion"),
       type = 'string',
@@ -9609,6 +9665,7 @@ return {
         			d	#define
         			f	function
       ]=],
+      expand_cb = 'expand_set_wildoptions',
       full_name = 'wildoptions',
       list = 'onecomma',
       scope = { 'global' },
@@ -9637,6 +9694,7 @@ return {
         key is never used for the menu.
         This option is not used for <F10>; on Win32.
       ]=],
+      expand_cb = 'expand_set_winaltkeys',
       full_name = 'winaltkeys',
       scope = { 'global' },
       short_desc = N_('when the windows system handles ALT keys'),