ggandor/leap.nvim

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motion
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CREATED

2022-03-13

UPDATED

4 days ago


leap.nvim

Leap is a general-purpose motion plugin for Neovim, building and improving primarily on vim-sneak, with the ultimate goal of establishing a new standard interface for moving around in the visible area in Vim-like modal editors. It allows you to reach any target in a very fast, uniform way, and minimizes the required focus level while executing a jump.

showcase

How to use it (TL;DR)

Leap's default motions allow you to jump to any positions in the visible editor area by entering a 2-character search pattern, and then potentially a label character to pick your target from multiple matches, in a manner similar to Sneak. The main novel idea in Leap is that you get a preview of the target labels - Leap shows you which key you will need to press before you actually need to do that.

  • Initiate the search in the forward (s) or backward (S) direction, or in the other windows (gs). (Note: you can search bidirectionally in the current window, or even in the whole tab page, if you are okay with the trade-offs.)
  • Start typing a 2-character pattern ({char1}{char2}).
  • After typing the first character, you see "labels" appearing next to some of the {char1}{?} pairs. You cannot use the labels yet.
  • Enter {char2}. If the pair was not labeled, then voil, you're already there. No need to be bothered by remaining labels - those are guaranteed "safe" letters, and will disappear on the next keypress -, just continue editing.
  • Else: type the label character. If there are too many matches (more than ~50), you might need to switch to the desired group first, using <space> (step back with <tab>, if needed).

Bigrams give you full coverage of the screen:

  • s{char}<space> jumps to a character before the end of the line.
  • s<space><space> jumps to any EOL position, including empty lines.

At any stage, <enter> consistently jumps to the next available target:

  • s<enter>... repeats the previous search.
  • s{char}<enter>... can be used as a multiline substitute for fFtT motions.

Why is this method cool?

It is ridiculously fast: not counting the trigger key, leaping to literally anywhere on the screen rarely takes more than 3 keystrokes in total, that can be typed in one go. Often 2 is enough.

At the same time, it reduces mental effort to almost zero:

  • You don't have to weigh alternatives: a single universal motion type can be used in all non-trivial situations.

  • You don't have to compose in your head: one command achieves one logical movement.

  • You don't have to be aware of the context: the eyes can keep focusing on the target the whole time.

  • You don't have to make decisions on the fly: the sequence you should enter is determined from the very beginning.

  • You don't have to pause in the middle: if typing at a moderate speed, at each step you already know what the immediate next keypress should be, and your mind can process the rest in the background.

Down the kangaroo hole

This was just a teaser - mind that while Leap has deeply thought-through, opinionated defaults, its small(ish) but comprehensive API makes it flexible: you can configure it to resemble other similar plugins, extend it with custom targeting methods, and even do arbitrary actions with the selected target - read on to dig deeper.

Design considerations in detail

The ideal

Premise: jumping from point A to B on the screen should not be some exciting puzzle, for which you should train yourself; it should be a non-issue. An ideal keyboard-driven interface would impose almost no more cognitive burden than using a mouse, without the constant context-switching required by the latter.

That is, you do not want to think about

  • the command: we need one fundamental targeting method that can bring you anywhere: a "jetpack on the back", instead of "airline routes" ( EasyMotion and its derivatives)
  • the context: it should be enough to look at the target, and nothing else ( vanilla Vim motion combinations using relative line numbers and/or repeats)
  • the steps: the motion should be atomic ( Vim motion combos), and ideally you should be able to type the whole sequence in one go, on more or less autopilot ( any kind of "just-in-time" labeling method; note that the "search command on steroids" approach by Pounce and Flash, where the pattern length is not fixed, and thus the labels appear at an unknown time, makes this last goal impossible)

All the while using as few keystrokes as possible, and getting distracted by as little incidental visual noise as possible.

How do we measure up?

It is obviously impossible to achieve all of the above at the same time, without some trade-offs at least; but in our opinion Leap comes pretty close, occupying a sweet spot in the design space. (The worst remaining offender might be visual noise.)

The one-step shift between perception and action is the big idea that cuts the Gordian knot: a fixed pattern length combined with ahead-of-time labeling can eliminate the surprise factor from the search-based method (which is the only viable approach - see "jetpack" above). Fortunately, a 2-character pattern - the shortest one with which we can play this trick - is also long enough to sufficiently narrow down the matches in the vast majority of cases.

Fixed pattern length also makes (safe) automatic jump to the first target possible. You cannot improve on jumping directly, just like how f and t works, not having to read a label at all, and not having to accept the match with <enter> either. However, we can do this in a smart way: if there are many targets (more than 15-20), we stay put, so we can use a bigger, "unsafe" label set - getting the best of both worlds. The non-determinism we're introducing is less of an issue here, since the outcome is known in advance.

In sum, compared to other methods based on labeling targets, Leap's approach is unique in that it

  • offers a smoother experience, by (somewhat) eliminating the pause before typing the label

  • feels natural to use for both distant and close targets

Auxiliary principles

A good example is using strictly one-character labels and switching between groups, which can become awkward beyond, say, 200 targets, but makes a whole bunch of edge cases and UI problems nonexistent.

Build on Vim's native features, aim for synergy, and don't reinvent the wheel (dot-repeat (.), inclusive/exclusive toggle (v), keymap support, autocommands via User events, <Plug> keys, etc.). (http://vimcasts.org/blog/2012/08/on-sharpening-the-saw/)

Complement the small and opinionated core by extension points, keeping the plugin flexible and future-proof.

Getting started

Status

The plugin is not 100% stable yet, but don't let that stop you - the usage basics are extremely unlikely to change. To follow breaking changes, subscribe to the corresponding issue.

Requirements

  • Neovim >= 0.7.0 stable, or latest nightly

Dependencies

Installation

Use your preferred method or plugin manager. (Note: Setting any kind of lazy loading is redundant, as Leap lazy loads itself. Using the keys feature of lazy.nvim might even cause problems.)

No extra steps needed besides defining keybindings - to use the default ones, put the following into your config (overrides s, S and gs in all modes):

require('leap').create_default_mappings() (init.lua)

lua require('leap').create_default_mappings() (init.vim)

Calling require('leap').create_default_mappings() is equivalent to:

vim.keymap.set({'n', 'x', 'o'}, 's',  '<Plug>(leap-forward)')
vim.keymap.set({'n', 'x', 'o'}, 'S',  '<Plug>(leap-backward)')
vim.keymap.set({'n', 'x', 'o'}, 'gs', '<Plug>(leap-from-window)')

A suggested alternative arrangement (bidirectional s for Normal mode):

vim.keymap.set('n',        's', '<Plug>(leap)')
vim.keymap.set('n',        'S', '<Plug>(leap-from-window)')
vim.keymap.set({'x', 'o'}, 's', '<Plug>(leap-forward)')
vim.keymap.set({'x', 'o'}, 'S', '<Plug>(leap-backward)')

<Plug>(leap) sorts matches by euclidean (beeline) distance from the cursor, with the exception that the current line, and on the current line, forward direction is prioritized. That is, you can always be sure that the targets right in front of you will be the first ones.

Note that you will get twice as many targets and thus half as many autojumps on average, but not needing to press the Shift key for backward motions might compensate for that. Another caveat is that you cannot traverse through the matches (:h leap-traversal), although invoking repeat right away (:h leap-repeat) can substitute for that.

Mapping to <Plug>(leap) is not recommended for Visual mode, as autojumping in a random direction might be too disorienting with the selection highlight on, and neither for Operator-pending mode, as dot-repeat cannot be used if the search is non-directional.

For further customization, see :h leap-custom-mappings.

-- Define equivalence classes for brackets and quotes, in addition to
-- the default whitespace group.
require('leap').opts.equivalence_classes = { ' \t\r\n', '([{', ')]}', '\'"`' }

-- Override some old defaults - use backspace instead of tab (see issue #165).
require('leap').opts.special_keys.prev_target = '<backspace>'
require('leap').opts.special_keys.prev_group = '<backspace>'

-- Use the traversal keys to repeat the previous motion without explicitly
-- invoking Leap.
require('leap.user').set_repeat_keys('<enter>', '<backspace>')

For Neovim versions < 0.10 (https://github.com/neovim/neovim/issues/20793):

-- Hide the (real) cursor when leaping, and restore it afterwards.
vim.api.nvim_create_autocmd('User', { pattern = 'LeapEnter',
    callback = function()
      vim.cmd.hi('Cursor', 'blend=100')
      vim.opt.guicursor:append { 'a:Cursor/lCursor' }
    end,
  }
)
vim.api.nvim_create_autocmd('User', { pattern = 'LeapLeave',
    callback = function()
      vim.cmd.hi('Cursor', 'blend=0')
      vim.opt.guicursor:remove { 'a:Cursor/lCursor' }
    end,
  }
)

Caveat: If you experience any problems after using the above snippet, check #70 and #143 to tweak it.

Usage

See :h leap-usage for supplemental features not mentioned here (targeting empty lines, traversal mode, repeating motions, etc.)

Permalink to the example file, if you want to follow along.

Phase one

The search is invoked with s in the forward direction, S in the backward direction, and gs in the other windows. Let's target some word containing ol. After entering the letter o, the plugin processes all character pairs starting with it, and from here on, you have all the visual information you need to reach your specific target. (The highlighting of unlabeled matches - green underlined on the screenshots - is opt-in, turned on for clarity here.)

quick example 1

Phase two

Let's finish the pattern, i.e., type l. Leap now jumps to the first match (the unlabeled one) automatically - if you aimed for that, you are good to go, just continue your work! (The labels for the subsequent matches of ol will remain visible until the next keypress, but they are carefully chosen "safe" letters, guaranteed to not interfere with your following editing command.) Otherwise, type the label character next to your target match, and move on to that.

quick example 2

Note that Leap only jumps to the first match if the remaining matches can be covered by the limited set of safe target labels, but stays in place, and switches to an extended label set otherwise. For fine-tuning or disabling this behaviour, see :h leap-config (labels and safe_labels).

Multiple target groups

To show the last important feature, let's go back to the start position, and start a new jump - we will target the struct member fr_height on line 1100, near the bottom (available = oldwin->w_frame->fr_height;), using the pattern fr. Press s, and then f:

quick example 3

The blue labels indicate a secondary group of matches, where we start to reuse the available labels. You can reach those by pressing <space> first, which switches to the subsequent match group. To jump to our target (the blue j), you should now press r (to finish the pattern), and then <space>j.

In very rare cases, if the large number of matches cannot be covered even by two label groups, you might need to press <space> multiple times, until you see the target label, first in blue, and then in green. (Substitute "green" and "blue" with the actual colors in the current theme.)

Configuration

Options

Below is a list of all configurable values in the opts table, with their defaults. Set them like: require('leap').opts.<key> = <value>. For details on the particular fields, see :h leap-config.

case_sensitive = false
equivalence_classes = { ' \t\r\n', }
max_phase_one_targets = nil
highlight_unlabeled_phase_one_targets = false
max_highlighted_traversal_targets = 10
substitute_chars = {}
safe_labels = 'sfnut/SFNLHMUGTZ?'
labels = 'sfnjklhodweimbuyvrgtaqpcxz/SFNJKLHODWEIMBUYVRGTAQPCXZ?'
special_keys = {
  next_target = '<enter>',
  prev_target = '<tab>',
  next_group = '<space>',
  prev_group = '<tab>',
}

Mappings

See :h leap-default-mappings. To define alternative mappings, you can use the <Plug> keys listed at :h leap-custom-mappings. Besides the default motions, you can also find the bidirectional <Plug>(leap), and an alternative, evil-snipe-style key set for in-window jumps there.

To create custom motions with behaviours different from the predefined ones, see :h leap.leap().

To set repeat keys that work like ; and , that is, repeat the last motion without explicitly invoking Leap, see :h leap-repeat.

Highlight groups

For customizing the highlight colors, see :h leap-highlight.

In case you - as a user - are not happy with a certain colorscheme's integration, you could force reloading the default settings by calling leap.init_highlight(true). The call can even be wrapped in an autocommand to automatically re-init on every colorscheme change:

autocmd ColorScheme * lua require('leap').init_highlight(true)

This can be tweaked further, you could e.g. check the actual colorscheme, and only execute for certain ones, etc.

Autocommands

Leap triggers User events on entering/exiting (with patterns LeapEnter and LeapLeave), so that you can set up autocommands, e.g. to change the values of some editor options while the plugin is active (:h leap-events).

FAQ

Bugs

For Neovim versions < 0.10 (https://github.com/neovim/neovim/issues/20793):

-- Hide the (real) cursor when leaping, and restore it afterwards.
vim.api.nvim_create_autocmd('User', { pattern = 'LeapEnter',
    callback = function()
      vim.cmd.hi('Cursor', 'blend=100')
      vim.opt.guicursor:append { 'a:Cursor/lCursor' }
    end,
  }
)
vim.api.nvim_create_autocmd('User', { pattern = 'LeapLeave',
    callback = function()
      vim.cmd.hi('Cursor', 'blend=0')
      vim.opt.guicursor:remove { 'a:Cursor/lCursor' }
    end,
  }
)

Caveat: If you experience any problems after using the above snippet, check #70 and #143 to tweak it.

Defaults

Common operations should use the fewest keystrokes and the most comfortable keys, so it makes sense to take those over by Leap, especially given that both native commands have synonyms:

Normal mode

  • s = cl (or xi)
  • S = cc

Visual mode

  • s = c
  • S = Vc, or c if already in linewise mode

If you are not convinced, just head to :h leap-custom-mappings.

Features

vim.keymap.set('n', 's', function ()
  require('leap').leap {
    target_windows = require('leap.user').get_focusable_windows()
  }
end)

Ahead-of-time labeling, unfortunately, makes them impossible, by design: for a potential match in phase one, we might need to show two different labels (corresponding to two different futures) at the same time. (1, 2, 3)

Basic template:

local function remote_action ()
  require('leap').leap {
    target_windows = require('leap.user').get_focusable_windows(),
    action = function (target)
      local winid = target.wininfo.winid
      local lnum, col = unpack(target.pos)  -- 1/1-based indexing!
      -- ... do something at the given position ...
    end,
  }
end

See Extending Leap for more.

You might be interested in telekinesis.

Configuration

require('leap').opts.safe_labels = {}
-- Or just set to grey directly, e.g. { fg = '#777777' },
-- if Comment is saturated.
vim.api.nvim_set_hl(0, 'LeapBackdrop', { link = 'Comment' })

You can hide the letters, and show emtpy boxes by tweaking the LeapLabelSecondary highlight group (that way you keep a visual indication that the target is labeled):

vim.api.nvim_create_autocmd('ColorScheme', {
  callback = function ()
    local bg = vim.api.nvim_get_hl(0, {name = 'LeapLabelSecondary'}).bg
    vim.api.nvim_set_hl(0, 'LeapLabelSecondary',{ fg = bg, bg = bg, })
  end
})
-- The below settings make Leap's highlighting closer to what you've been
-- used to in Lightspeed.

vim.api.nvim_set_hl(0, 'LeapBackdrop', { link = 'Comment' }) -- or some grey
vim.api.nvim_set_hl(0, 'LeapMatch', {
  -- For light themes, set to 'black' or similar.
  fg = 'white', bold = true, nocombine = true,
})

-- Lightspeed colors
-- primary labels: bg = "#f02077" (light theme) or "#ff2f87"  (dark theme)
-- secondary labels: bg = "#399d9f" (light theme) or "#99ddff" (dark theme)
-- shortcuts: bg = "#f00077", fg = "white"
-- You might want to use either the primary label or the shortcut colors
-- for Leap primary labels, depending on your taste.
vim.api.nvim_set_hl(0, 'LeapLabelPrimary', {
  fg = 'red', bold = true, nocombine = true,
})
vim.api.nvim_set_hl(0, 'LeapLabelSecondary', {
  fg = 'blue', bold = true, nocombine = true,
})
-- Try it without this setting first, you might find you don't even miss it.
require('leap').opts.highlight_unlabeled_phase_one_targets = true

Check out opts.equivalence_classes. For example, you can group accented vowels together: { 'a獺', 'e矇', 'i穩', ... }.

Miscellaneous

To paraphrase Steve Jobs about their logo and Turing's poison apple, I wish it were, but it is a coincidence. "Leap" is just another synonym for "jump", that happens to rhyme with Sneak. That said, in some respects you can indeed think of leap.nvim as a spiritual successor to Raskin's work, and thus the name as a little tribute to the great pioneer of interface design, even though embracing the modal paradigm is a fundamental difference in our approach.

Extending Leap

There is more to Leap than meets the eye. On a general level, you should think of it as less of a motion plugin and more of an engine for selecting visible targets on the screen (acquired by arbitrary means), and doing arbitrary things with them. See :h leap.leap() and :h leap-events.

There are lots of ways you can extend the plugin and bend it to your will, and the combinations of them give you almost infinite possibilities. Some practical examples:

local function get_line_starts(winid, skip_range)
  local wininfo =  vim.fn.getwininfo(winid)[1]
  local cur_line = vim.fn.line('.')
  -- Skip lines close to the cursor.
  local skip_range = skip_range or 2

  -- Get targets.
  local targets = {}
  local lnum = wininfo.topline
  while lnum <= wininfo.botline do
    local fold_end = vim.fn.foldclosedend(lnum)
    -- Skip folded ranges.
    if fold_end ~= -1 then
      lnum = fold_end + 1
    else
      if (lnum < cur_line - skip_range) or (lnum > cur_line + skip_range) then
        table.insert(targets, { pos = { lnum, 1 } })
      end
      lnum = lnum + 1
    end
  end

  -- Sort them by vertical screen distance from cursor.
  local cur_screen_row = vim.fn.screenpos(winid, cur_line, 1)['row']
  local function screen_rows_from_cur(t)
    local t_screen_row = vim.fn.screenpos(winid, t.pos[1], t.pos[2])['row']
    return math.abs(cur_screen_row - t_screen_row)
  end
  table.sort(targets, function (t1, t2)
    return screen_rows_from_cur(t1) < screen_rows_from_cur(t2)
  end)

  if #targets >= 1 then
    return targets
  end
end

-- You can pass an argument to specify a range to be skipped
-- before/after the cursor (default is +/-2).
function leap_line_start(skip_range)
  local winid = vim.api.nvim_get_current_win()
  require('leap').leap {
    target_windows = { winid },
    targets = get_line_starts(winid, skip_range),
  }
end

-- For maximum comfort, force linewise selection in the mappings:
vim.keymap.set('x', '|', function ()
  -- Only force V if not already in it (otherwise it would exit Visual mode).
  if vim.fn.mode(1) ~= 'V' then vim.cmd('normal! V') end
  leap_line_start()
end)
vim.keymap.set('o', '|', "V<cmd>lua leap_line_start()<cr>")

Not as sophisticated as flash.nvim's implementation, but totally usable, in 50 lines:

local api = vim.api
local ts = vim.treesitter

local function get_ts_nodes()
  if not pcall(ts.get_parser) then return end
  local wininfo = vim.fn.getwininfo(api.nvim_get_current_win())[1]
  -- Get current node, and then its parent nodes recursively.
  local cur_node = ts.get_node()
  if not cur_node then return end
  local nodes = { cur_node }
  local parent = cur_node:parent()
  while parent do
    table.insert(nodes, parent)
    parent = parent:parent()
  end
  -- Create Leap targets from TS nodes.
  local targets = {}
  local startline, startcol
  for _, node in ipairs(nodes) do
    startline, startcol, endline, endcol = node:range()  -- (0,0)
    local startpos = { startline + 1, startcol + 1 }
    local endpos = { endline + 1, endcol + 1 }
    -- Add both ends of the node.
    if startline + 1 >= wininfo.topline then
      table.insert(targets, { pos = startpos, altpos = endpos })
    end
    if endline + 1 <= wininfo.botline then
      table.insert(targets, { pos = endpos, altpos = startpos })
    end
  end
  if #targets >= 1 then return targets end
end

local function select_node_range(target)
  local mode = api.nvim_get_mode().mode
  -- Force going back to Normal from Visual mode.
  if not mode:match('no?') then vim.cmd('normal! ' .. mode) end
  vim.fn.cursor(unpack(target.pos))
  local v = mode:match('V') and 'V' or mode:match('') and '' or 'v'
  vim.cmd('normal! ' .. v)
  vim.fn.cursor(unpack(target.altpos))
end

local function leap_ts()
  require('leap').leap {
    target_windows = { api.nvim_get_current_win() },
    targets = get_ts_nodes,
    action = select_node_range,
  }
end

vim.keymap.set({'x', 'o'}, '\\', leap_ts)

See leap-spooky.nvim.

See flit.nvim.