mini-clue.txt

*mini.clue* Show next key clues
*MiniClue*

MIT License Copyright (c) 2023 Evgeni Chasnovski

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

Features:
- Implement custom key query process to reach target key combination:
    - Starts after customizable opt-in triggers (mode + keys).

    - Each key press narrows down set of possible targets.
      Pressing `<BS>` removes previous user entry.
      Pressing `<Esc>` or `<C-c>` leads to an early stop.
      Doesn't depend on 'timeoutlen' and has basic support for 'langmap'.

    - Ends when there is at most one target left or user pressed `<CR>`.
      Results into emulating pressing all query keys plus possible postkeys.

- Show window (after configurable delay) with clues. It lists available
  next keys along with their descriptions (auto generated from descriptions
  present keymaps and user-supplied clues; preferring the former).

- Configurable "postkeys" for key combinations - keys which will be emulated
  after combination is reached during key query process.

- Provide customizable sets of clues for common built-in keys/concepts:
    - `g` key.
    - `z` key.
    - Window commands.
    - Built-in completion.
    - Marks.
    - Registers.

- Lua functions to disable/enable triggers globally or per buffer.

For more details see:
- |MiniClue-key-query-process|.
- |MiniClue-examples|.
- |MiniClue.config|.
- |MiniClue.gen_clues|.

Notes:
- Works on all supported versions but using Neovim>=0.9 is recommended.

- There is no functionality to create mappings while defining clues.
  This is done to clearly separate these two different actions.
  The best suggested practice is to manually create mappings with
  descriptions (`desc` field in options), as they will be automatically
  used inside clue window.

- Triggers are implemented as special buffer-local mappings. This leads to
  several caveats:
    - They will override same regular buffer-local mappings and have
      precedence over global one.

      Example: having set `<C-w>` as Normal mode trigger means that
      there should not be another `<C-w>` mapping.

    - They need to be the latest created buffer-local mappings or they will
      not function properly. Most common indicator of this is that some
      mapping starts to work only after clue window is shown.

      Example: `g` is set as Normal mode trigger, but `gcc` from |mini.comment|
      doesn't work right away. This is probably because there are some
      other buffer-local mappings starting with `g` which were created after
      mapping for `g` trigger. Most common places for this are in LSP server's
      `on_attach` or during tree-sitter start in buffer.

      To check if trigger is the most recent buffer-local mapping, execute
      `:<mode-char>map <trigger-keys>` (like `:nmap g` for previous example).
      Mapping for trigger should be the first listed.

      This module makes the best effort to work out of the box and cover
      most common cases, but it is not full proof. The solution here is to
      ensure that triggers are created after making all buffer-local mappings:
      run either |MiniClue.setup()| or |MiniClue.ensure_buf_triggers()|.

- Descriptions from existing mappings take precedence over user-supplied
  clues. This is to ensure that information shown in clue window is as
  relevant as possible. To add/customize description of an already existing
  mapping, use |MiniClue.set_mapping_desc()|.

- Due to technical difficulties, there is no full proof support for
  Operator-pending mode triggers (like `a`/`i` from |mini.ai|):
    - Doesn't work as part of a command in "temporary Normal mode" (like
      after |i_CTRL-O|) due to implementation difficulties.
    - Can have unexpected behavior with custom operators.

- Has (mostly solved) issues with macros:
    - All triggers are disabled during macro recording due to technical
      reasons.
    - The `@` and `Q` keys are specially mapped inside |MiniClue.setup()|
      to temporarily disable triggers.

# Setup ~

This module needs a setup with `require('mini.clue').setup({})` (replace
`{}` with your `config` table). It will create global Lua table `MiniClue`
which you can use for scripting or manually (with `:lua MiniClue.*`).

Config table **needs to have triggers configured**, none is set up by default.

See |MiniClue.config| for available config settings.

You can override runtime config settings (like clues or window options)
locally to a buffer inside `vim.b.miniclue_config` which should have same
structure as `MiniClue.config`. See |mini.nvim-buffer-local-config| for
more details.

# Comparisons ~

- 'folke/which-key.nvim':
    - Both have the same main goal: show available next keys along with
      their customizable descriptions.
    - Has different UI and content layout.
    - Allows creating mappings inside its configuration, while this module
      doesn't have this by design (to clearly separate two different tasks).
    - Doesn't allow creating submodes, while this module does (via `postkeys`).

- 'anuvyklack/hydra.nvim':
    - Both allow creating submodes: state which starts at certain key
      combination; treats some keys differently; ends after `<Esc>`.
    - Doesn't show information about available next keys (outside of
      submodes), while that is this module's main goal.

# Highlight groups ~

* `MiniClueBorder` - window border.
* `MiniClueDescGroup` - group description in clue window.
* `MiniClueDescSingle` - single target description in clue window.
* `MiniClueNextKey` - next key label in clue window.
* `MiniClueNextKeyWithPostkeys` - next key label with postkeys in clue window.
* `MiniClueSeparator` - separator in clue window.
* `MiniClueTitle` - window title.

To change any highlight group, modify it directly with |:highlight|.

# Disabling ~

To disable creating triggers, set `vim.g.miniclue_disable` (globally) or
`vim.b.miniclue_disable` (for a buffer) to `true`. Considering high number
of different scenarios and customization intentions, writing exact rules
for disabling module's functionality is left to user. See
|mini.nvim-disabling-recipes| for common recipes.

------------------------------------------------------------------------------
                                                    *MiniClue-key-query-process*
# Key query process ~

## General info ~

This module implements custom key query process imitating a usual built-in
mechanism of user pressing keys in order to execute a mapping. General idea
is the same: narrow down key combinations until the target is reached.

Main goals of its existence are:

- Allow reaching certain mappings be independent of 'timeoutlen'. That is,
  there is no fixed timeout after which currently typed keys are executed.

- Enable automated showing of next key clues after user-supplied delay
  (also independent of 'timeoutlen').

- Allow emulating configurable key presses after certain key combination is
  reached. This granular control allows creating so called "submodes".
  See more at |MiniClue-examples-submodes|.

This process is primarily designed for nested `<Leader>` mappings in Normal
mode but works in all other main modes: Visual, Insert, Operator-pending
(with caveats; no full proof guarantees), Command-line, Terminal.

## Lifecycle ~

- Key query process starts when user types a trigger: certain keys in certain
  mode. Those keys are put into key query as a single user input. All possible
  mode key combinations are filtered to ones starting with the trigger keys.

  Note: trigger is implemented as a regular mapping, so if it has at least
  two keys, they should be pressed within 'timeoutlen' milliseconds.

- Wait (indefinitely) for user to press a key. Advance depending on the key:

    - Special key:

        - If `<Esc>` or `<C-c>`, stop the process without any action.

        - If `<CR>`, stop the process and execute current key query, meaning
          emulate (with |nvim_feedkeys()|) user pressing those keys.

        - If `<BS>`, remove previous user input from the query. If query becomes
          empty, stop the process without any action.

        - If a key for scrolling clue window (`scroll_down` / `scroll_up`
          in `config.window`; `<C-d>` / `<C-u>` by default), scroll clue window
          and wait for the next user key.

    - Not special key. Add key to the query while filtering all available
      key combinations to start with the current key query. Advance:

        - If there is a single available key combination matching current
          key query, execute it.

        - If there is no key combinations starting with the current query,
          execute it. This, for instance, allows a seamless execution of
          operators in presence of a longer key combinations. Example: with
          `g` as trigger in Normal mode and available mappings `gc` / `gcc`
          (like from |mini.comment|), this allows typing `gcip` to comment
          current paragraph, although there are no key combinations
          starting with `gci`.

        - Otherwise wait for the new user key press.

## Clue window ~

After initiating key query process and after each key press, a timer is
started to show a clue window: floating window with information about
available next keys along with their descriptions. Note: if window is
already shown, its content is updated right away.

Clues can have these types:

- "Terminal next key": when pressed, will lead to query execution.

- "Terminal next key with postkeys": when pressed, will lead to query
  execution plus some configured postkeys.

- "Group next key": when pressed, will narrow down available key combinations
  and wait for another key press. Note: can have configured description
  (inside `config.clues`) or it will be auto generated based on the number of
  available key combinations.

------------------------------------------------------------------------------
                                                             *MiniClue-examples*
# Full starter example ~

If not sure where to start, try this example with all provided clues from
this module plus all |<Leader>| mappings in Normal and Visual modes: >

  local miniclue = require('mini.clue')
  miniclue.setup({
    triggers = {
      -- Leader triggers
      { mode = 'n', keys = '<Leader>' },
      { mode = 'x', keys = '<Leader>' },

      -- Built-in completion
      { mode = 'i', keys = '<C-x>' },

      -- `g` key
      { mode = 'n', keys = 'g' },
      { mode = 'x', keys = 'g' },

      -- Marks
      { mode = 'n', keys = "'" },
      { mode = 'n', keys = '`' },
      { mode = 'x', keys = "'" },
      { mode = 'x', keys = '`' },

      -- Registers
      { mode = 'n', keys = '"' },
      { mode = 'x', keys = '"' },
      { mode = 'i', keys = '<C-r>' },
      { mode = 'c', keys = '<C-r>' },

      -- Window commands
      { mode = 'n', keys = '<C-w>' },

      -- `z` key
      { mode = 'n', keys = 'z' },
      { mode = 'x', keys = 'z' },
    },

    clues = {
      -- Enhance this by adding descriptions for <Leader> mapping groups
      miniclue.gen_clues.builtin_completion(),
      miniclue.gen_clues.g(),
      miniclue.gen_clues.marks(),
      miniclue.gen_clues.registers(),
      miniclue.gen_clues.windows(),
      miniclue.gen_clues.z(),
    },
  })

# Leader clues ~

Assume there are these |<Leader>| mappings set up: >

  -- Set `<Leader>` before making any mappings and configuring 'mini.clue'
  vim.g.mapleader = ' '

  local nmap_leader = function(suffix, rhs, desc)
    vim.keymap.set('n', '<Leader>' .. suffix, rhs, { desc = desc })
  end
  local xmap_leader = function(suffix, rhs, desc)
    vim.keymap.set('x', '<Leader>' .. suffix, rhs, { desc = desc })
  end

  nmap_leader('bd', '<Cmd>lua MiniBufremove.delete()<CR>',  'Delete')
  nmap_leader('bw', '<Cmd>lua MiniBufremove.wipeout()<CR>', 'Wipeout')

  nmap_leader('lf', '<Cmd>lua vim.lsp.buf.format()<CR>',     'Format')
  xmap_leader('lf', '<Cmd>lua vim.lsp.buf.format()<CR>',     'Format')
  nmap_leader('lr', '<Cmd>lua vim.lsp.buf.rename()<CR>',     'Rename')
  nmap_leader('lR', '<Cmd>lua vim.lsp.buf.references()<CR>', 'References')


The following setup will enable |<Leader>| as trigger in Normal and Visual
modes and add descriptions to mapping groups: >

  require('mini.clue').setup({
    -- Register `<Leader>` as trigger
    triggers = {
      { mode = 'n', keys = '<Leader>' },
      { mode = 'x', keys = '<Leader>' },
    },

    -- Add descriptions for mapping groups
    clues = {
      { mode = 'n', keys = '<Leader>b', desc = '+Buffers' },
      { mode = 'n', keys = '<Leader>l', desc = '+LSP' },
    },
  })

# Clues without mappings ~

Clues can be shown not only for actually present mappings. This is helpful for
showing clues for built-in key combinations. Here is an example of clues for
a subset of built-in completion (see |MiniClue.gen_clues.builtin_completion()|
to generate clues for all available completion sources): >

  require('mini.clue').setup({
    -- Make `<C-x>` a trigger. Otherwise, key query process won't start.
    triggers = {
      { mode = 'i', keys = '<C-x>' },
    },

    -- Register custom clues
    clues = {
      { mode = 'i', keys = '<C-x><C-f>', desc = 'File names' },
      { mode = 'i', keys = '<C-x><C-l>', desc = 'Whole lines' },
      { mode = 'i', keys = '<C-x><C-o>', desc = 'Omni completion' },
      { mode = 'i', keys = '<C-x><C-s>', desc = 'Spelling suggestions' },
      { mode = 'i', keys = '<C-x><C-u>', desc = "With 'completefunc'" },
    }
  })
<
                                                    *MiniClue-examples-submodes*
# Submodes ~

Submode is a state initiated after pressing certain key combination ("prefix")
during which some keys are interpreted differently.

In this module submode can be implemented following these steps:

- Create mappings for each key inside submode. Left hand side of mappings
  should consist from prefix followed by the key.

- Create clue for each key inside submode with `postkeys` value equal to
  prefix. It would mean that after executing particular key combination from
  this submode, pressing its prefix will be automatically emulated (leading
  back to being inside submode).

- Register submode prefix (or some of its starting part) as trigger.

## Submode examples ~

- Submode for moving with |mini.move|:
    - Press `<Leader>m` to start submode.
    - Press any of `h`/`j`/`k`/`l` to move selection/line.
    - Press `<Esc>` to stop submode.

  The code: >

  require('mini.move').setup({
    mappings = {
      left       = '<Leader>mh',
      right      = '<Leader>ml',
      down       = '<Leader>mj',
      up         = '<Leader>mk',
      line_left  = '<Leader>mh',
      line_right = '<Leader>ml',
      line_down  = '<Leader>mj',
      line_up    = '<Leader>mk',
    },
  })

  require('mini.clue').setup({
    triggers = {
      { mode = 'n', keys = '<Leader>m' },
      { mode = 'x', keys = '<Leader>m' },
    },
    clues = {
      { mode = 'n', keys = '<Leader>mh', postkeys = '<Leader>m' },
      { mode = 'n', keys = '<Leader>mj', postkeys = '<Leader>m' },
      { mode = 'n', keys = '<Leader>mk', postkeys = '<Leader>m' },
      { mode = 'n', keys = '<Leader>ml', postkeys = '<Leader>m' },
      { mode = 'x', keys = '<Leader>mh', postkeys = '<Leader>m' },
      { mode = 'x', keys = '<Leader>mj', postkeys = '<Leader>m' },
      { mode = 'x', keys = '<Leader>mk', postkeys = '<Leader>m' },
      { mode = 'x', keys = '<Leader>ml', postkeys = '<Leader>m' },
    },
  })

- Submode for iterating buffers and windows with |mini.bracketed|:
    - Press `[` or `]` to start key query process for certain direction.
    - Press `b` / `w` to iterate buffers/windows until reach target one.
    - Press `<Esc>` to stop submode.

  The code: >

  require('mini.bracketed').setup()

  require('mini.clue').setup({
    triggers = {
      { mode = 'n', keys = ']' },
      { mode = 'n', keys = '[' },
    },
    clues = {
      { mode = 'n', keys = ']b', postkeys = ']' },
      { mode = 'n', keys = ']w', postkeys = ']' },

      { mode = 'n', keys = '[b', postkeys = '[' },
      { mode = 'n', keys = '[w', postkeys = '[' },
    },
  })

- Submode for window commands using |MiniClue.gen_clues.windows()|:
    - Press `<C-w>` to start key query process.
    - Press keys which move / change focus / resize windows.
    - Press `<Esc>` to stop submode.

  The code: >

  local miniclue = require('mini.clue')
  miniclue.setup({
    triggers = {
      { mode = 'n', keys = '<C-w>' },
    },
    clues = {
      miniclue.gen_clues.windows({
        submode_move = true,
        submode_navigate = true,
        submode_resize = true,
      })
    },
  })

# Window config ~
>
  require('mini.clue').setup({
    triggers = { { mode = 'n', keys = '<Leader>' } },

    window = {
      -- Show window immediately
      delay = 0,

      config = {
        -- Compute window width automatically
        width = 'auto',

        -- Use double-line border
        border = 'double',
      },
    },
  })

------------------------------------------------------------------------------
                                                              *MiniClue.setup()*
                           `MiniClue.setup`({config})
Module setup

Parameters ~
{config} `(table|nil)` Module config table. See |MiniClue.config|.

Usage ~
`require('mini.clue').setup({})` (replace `{}` with your `config` table).
**Needs to have triggers configured**.

------------------------------------------------------------------------------
                                                               *MiniClue.config*
                               `MiniClue.config`
Module config

Default values:
>
  MiniClue.config = {
    -- Array of extra clues to show
    clues = {},

    -- Array of opt-in triggers which start custom key query process.
    -- **Needs to have something in order to show clues**.
    triggers = {},

    -- Clue window settings
    window = {
      -- Floating window config
      config = {},

      -- Delay before showing clue window
      delay = 1000,

      -- Keys to scroll inside the clue window
      scroll_down = '<C-d>',
      scroll_up = '<C-u>',
    },
  }
<
# General info ~

- To use |<Leader>| as part of the config (either as trigger or inside clues),
  set it prior to running |MiniClue.setup()|.

- See |MiniClue-examples| for examples.

# Clues ~

`config.clues` is an array with extra information about key combinations.
Each element can be one of:
- Clue table.
- Array (possibly nested) of clue tables.
- Callable (function) returning either of the previous two.

A clue table is a table with the following fields:
- <mode> `(string)` - single character describing **single** mode short-name of
  key combination as in `nvim_set_keymap()` ('n', 'x', 'i', 'o', 'c', etc.).
- <keys> `(string)` - key combination for which clue will be shown.
  "Human-readable" key names as in |key-notation| (like "<Leader>", "<Space>",
  "<Tab>", etc.) are allowed.
- <desc> `(string|nil)` - optional key combination description which will
  be shown in clue window.
- <postkeys> `(string|nil)` - optional postkeys which will be executed
  automatically after `keys`. Allows creation of submodes
  (see |MiniClue-examples-submodes|).

Notes:
- Postkeys are literal simulation of keypresses with |nvim_feedkeys()|.

- Suggested approach to configuring clues is to create mappings with `desc`
  field while supplying to `config.clues` only elements describing groups,
  postkeys, and built-in mappings.

# Triggers ~

`config.triggers` is an array with information when |MiniClue-key-query-process|
should start. Each element is a trigger table with the fields <mode> and
<keys> which are treated the same as in clue table.

# Window ~

`config.window` defines behavior of clue window.

`config.window.delay` is a number of milliseconds after which clue window will
appear. Can be 0 to show immediately.

`config.window.config` is a table defining floating window characteristics
or a callable returning such table (will be called with identifier of
window's buffer already showing all clues). It should have the same
structure as in |nvim_open_win()| with the following enhancements:
- <width> field can be equal to `"auto"` leading to window width being
  computed automatically based on its content. Default is fixed width of 30.
- <row> and <col> can be equal to `"auto"` in which case they will be
  computed to "stick" to set anchor ("SE" by default; see |nvim_open_win()|).
  This allows changing corner in which window is shown: >

  -- Pick one anchor
  local anchor = 'NW' -- top-left
  local anchor = 'NE' -- top-right
  local anchor = 'SW' -- bottom-left
  local anchor = 'SE' -- bottom-right

  require('mini.clue').setup({
    window = {
      config = { anchor = anchor, row = 'auto', col = 'auto' },
    },
  })

`config.window.scroll_down` / `config.window.scroll_up` are strings defining
keys which will scroll clue window down / up which is useful in case not
all clues fit in current window height. Set to empty string `''` to disable
either of them.

------------------------------------------------------------------------------
                                                *MiniClue.enable_all_triggers()*
                        `MiniClue.enable_all_triggers`()
Enable triggers in all listed buffers

------------------------------------------------------------------------------
                                                *MiniClue.enable_buf_triggers()*
                    `MiniClue.enable_buf_triggers`({buf_id})
Enable triggers in buffer

Parameters ~
{buf_id} `(number|nil)` Buffer identifier. Default: current buffer.

------------------------------------------------------------------------------
                                               *MiniClue.disable_all_triggers()*
                       `MiniClue.disable_all_triggers`()
Disable triggers in all buffers

------------------------------------------------------------------------------
                                               *MiniClue.disable_buf_triggers()*
                   `MiniClue.disable_buf_triggers`({buf_id})
Disable triggers in buffer

Parameters ~
{buf_id} `(number|nil)` Buffer identifier. Default: current buffer.

------------------------------------------------------------------------------
                                                *MiniClue.ensure_all_triggers()*
                        `MiniClue.ensure_all_triggers`()
Ensure all triggers are valid

------------------------------------------------------------------------------
                                                *MiniClue.ensure_buf_triggers()*
                    `MiniClue.ensure_buf_triggers`({buf_id})
Ensure buffer triggers are valid

Parameters ~
{buf_id} `(number|nil)` Buffer identifier. Default: current buffer.

------------------------------------------------------------------------------
                                                   *MiniClue.set_mapping_desc()*
               `MiniClue.set_mapping_desc`({mode}, {lhs}, {desc})
Update description of an existing mapping

Notes:
- Uses buffer-local mapping in case there are both global and buffer-local
  mappings with same mode and LHS. Similar to |maparg()|.
- Requires Neovim>=0.8.

Parameters ~
{mode} `(string)` Mapping mode (as in `maparg()`).
{lhs} `(string)` Mapping left hand side (as `name` in `maparg()`).
{desc} `(string)` New description to set.

------------------------------------------------------------------------------
                                                            *MiniClue.gen_clues*
                              `MiniClue.gen_clues`
Generate pre-configured clues

This is a table with function elements. Call to actually get array of clues.

------------------------------------------------------------------------------
                                       *MiniClue.gen_clues.builtin_completion()*
                   `MiniClue.gen_clues.builtin_completion`()
Generate clues for built-in completion

Contains clues for the following triggers: >

  { mode = 'i', keys = '<C-x>' }

Return ~
`(table)` Array of clues.

------------------------------------------------------------------------------
                                                        *MiniClue.gen_clues.g()*
                            `MiniClue.gen_clues.g`()
Generate clues for `g` key

Contains clues for the following triggers: >

  { mode = 'n', keys = 'g' }
  { mode = 'x', keys = 'g' }

Return ~
`(table)` Array of clues.

------------------------------------------------------------------------------
                                                    *MiniClue.gen_clues.marks()*
                          `MiniClue.gen_clues.marks`()
Generate clues for marks

Contains clues for the following triggers: >

  { mode = 'n', keys = "'" }
  { mode = 'n', keys = "g'" }
  { mode = 'n', keys = '`' }
  { mode = 'n', keys = 'g`' }
  { mode = 'x', keys = "'" }
  { mode = 'x', keys = "g'" }
  { mode = 'x', keys = '`' }
  { mode = 'x', keys = 'g`' }

Note: if you use "g" as trigger (like to enable |MiniClue.gen_clues.g()|),
don't add "g'" and "g`" as triggers: they already will be taken into account.

Return ~
`(table)` Array of clues.

See also ~
|mark-motions|

------------------------------------------------------------------------------
                                                *MiniClue.gen_clues.registers()*
                     `MiniClue.gen_clues.registers`({opts})
Generate clues for registers

Contains clues for the following triggers: >

  { mode = 'n', keys = '"' }
  { mode = 'x', keys = '"' }
  { mode = 'i', keys = '<C-r>' }
  { mode = 'c', keys = '<C-r>' }

Parameters ~
{opts} `(table|nil)` Options. Possible keys:
  - <show_contents> `(boolean)` - whether to show contents of all possible
    registers. If `false`, only description of special registers is shown.
    Default: `false`.

Return ~
`(table)` Array of clues.

See also ~
|registers|

------------------------------------------------------------------------------
                                                  *MiniClue.gen_clues.windows()*
                      `MiniClue.gen_clues.windows`({opts})
Generate clues for window commands

Contains clues for the following triggers: >

  { mode = 'n', keys = '<C-w>' }

Note: only non-duplicated commands are included. For full list see |CTRL-W|.

Parameters ~
{opts} `(table|nil)` Options. Possible keys:
  - <submode_move> `(boolean)` - whether to make move (change layout)
    commands a submode by using `postkeys` field. Default: `false`.
  - <submode_navigate> `(boolean)` - whether to make navigation (change
    focus) commands a submode by using `postkeys` field. Default: `false`.
  - <submode_resize> `(boolean)` - whether to make resize (change size)
    commands a submode by using `postkeys` field. Default: `false`.

Return ~
`(table)` Array of clues.

------------------------------------------------------------------------------
                                                        *MiniClue.gen_clues.z()*
                            `MiniClue.gen_clues.z`()
Generate clues for `z` key

Contains clues for the following triggers: >

  { mode = 'n', keys = 'z' }
  { mode = 'x', keys = 'z' }

Return ~
`(table)` Array of clues.


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