(mini.jump) Add initial implementation from @xigoi (#8)

Co-authored-by: Evgeni Chasnovski <[email protected]>

lua/mini/jump.lua

@@ -0,0 +1,265 @@
+-- MIT License Copyright (c) 2021 Evgeni Chasnovski, Adam Blažek
+
+---@brief [[
+--- A module for smarter jumping, inspired by clever-f.
+--- By default it extends f, F, t, T to work on multiple lines,
+--- be repeatable by pressing f, F, t, T again,
+--- and highlight characters they're going to jump to.
+---
+--- # Setup
+---
+--- This module needs a setup with `require('mini.jump').setup({})`
+--- (replace `{}` with your `config` table).
+---
+--- Default `config`:
+--- <code>
+---   {
+---     -- Mappings. Use `''` (empty string) to disable one.
+---     mappings = {
+---       forward_1 = 'f',
+---       backward_1 = 'F',
+---       forward_1_till = 't',
+---       backward_1_till = 'T',
+---     },
+---
+---     -- Highlight matches when jumping
+---     highlight = true,
+---   }
+--- </code>
+--- # Disabling
+---
+--- To disable core functionality, set `g:minijump_disable` (globally) or
+--- `b:minijump_disable` (for a buffer) to `v:true`.
+---@brief ]]
+---@tag MiniJump mini.jump
+
+-- Module and its helper
+local MiniJump = {}
+local H = {}
+
+--- Module setup
+---
+---@param config table: Module config table.
+---@usage `require('mini.jump').setup({})` (replace `{}` with your `config` table)
+function MiniJump.setup(config)
+  -- Export module
+  _G.MiniJump = MiniJump
+
+  -- Setup config
+  config = H.setup_config(config)
+
+  -- Apply config
+  H.apply_config(config)
+
+  -- Module behavior
+  vim.cmd([[autocmd CursorMoved * lua MiniJump.on_cursormoved()]])
+  vim.cmd([[autocmd BufLeave,InsertEnter * lua MiniJump.stop_jumping()]])
+
+  -- Highlight groups
+  vim.cmd([[hi default link MiniJumpHighlight IncSearch]])
+end
+
+-- Module config
+MiniJump.config = {
+  mappings = {
+    forward_1 = 'f',
+    backward_1 = 'F',
+    forward_1_till = 't',
+    backward_1_till = 'T',
+  },
+
+  -- Highlight matches when jumping.
+  highlight = true,
+}
+
+-- Module functionality
+--- Jump to target
+---
+--- Takes a string and jumps to the first occurence of it after the cursor.
+---
+--- @param target string: The string to jump to.
+--- @param backward boolean: If `true`, jump backward.
+--- @param till boolean: If `true`, jump just before/after the match instead of to the first character.
+---   Also ignore matches that don't have space before/after them. (This will probably be changed in the future.)
+function MiniJump.jump(target, backward, till)
+  if H.is_disabled() then
+    return
+  end
+
+  backward = backward == nil and false or backward
+  till = till == nil and false or till
+
+  local flags = backward and 'Wb' or 'W'
+  local pattern, hl_pattern = [[\V%s]], [[\V%s]]
+  if till then
+    if backward then
+      pattern, hl_pattern = [[\V\(%s\)\@<=\.]], [[\V%s\.\@=]]
+      flags = flags .. 'e'
+    else
+      pattern, hl_pattern = [[\V\.\(%s\)\@=]], [[\V\.\@<=%s]]
+    end
+  end
+
+  target = vim.fn.escape(target, [[\]])
+  pattern, hl_pattern = pattern:format(target), hl_pattern:format(target)
+
+  H.highlight(hl_pattern)
+  vim.fn.search(pattern, flags)
+  -- Open enough folds to show jump
+  vim.cmd([[normal! zv]])
+end
+
+--- Smart jump
+---
+--- If the last movement was a jump, perform another jump with the same target.
+--- Otherwise, prompt for a target. Respects v:count.
+---
+--- @param num_chars number: The length of the target to prompt for.
+--- @param backward boolean: If true, jump backward.
+--- @param till boolean: If true, jump just before/after the match instead of to the first character.
+---   Also ignore matches that don't have space before/after them. (This will probably be changed in the future.)
+function MiniJump.smart_jump(num_chars, backward, till)
+  if H.is_disabled() then
+    return
+  end
+
+  num_chars = num_chars or 1
+  backward = backward == nil and false or backward
+  till = till == nil and false or till
+
+  H.target = H.target or H.get_chars(num_chars)
+  for _ = 1, vim.v.count1 do
+    MiniJump.jump(H.target, backward, till)
+  end
+
+  H.jumping = true
+end
+
+--- Stop jumping
+---
+--- Removes highlights (if any) and forces the next smart jump to prompt for
+--- the target.
+function MiniJump.stop_jumping()
+  H.target = nil
+  H.unhighlight()
+end
+
+--- Act on every |CursorMoved|
+function MiniJump.on_cursormoved()
+  -- Stop jumping only if `CursorMoved` was not a result of smart jump
+  if not H.jumping then
+    MiniJump.stop_jumping()
+  end
+  H.jumping = false
+end
+
+-- Helpers
+---- Module default config
+H.default_config = MiniJump.config
+
+---- Current target
+H.target = nil
+
+---- Indicator of whether inside smart jumping
+H.jumping = false
+
+---- Information about last match highlighting (stored *per window*):
+---- - Key: windows' unique buffer identifiers.
+---- - Value: table with:
+----     - `id` field for match id (from `vim.fn.matchadd()`).
+----     - `pattern` field for highlighted pattern.
+H.window_matches = {}
+
+---- Settings
+function H.setup_config(config)
+  -- General idea: if some table elements are not present in user-supplied
+  -- `config`, take them from default config
+  vim.validate({ config = { config, 'table', true } })
+  config = vim.tbl_deep_extend('force', H.default_config, config or {})
+
+  vim.validate({
+    mappings = { config.mappings, 'table' },
+    ['mappings.forward_1'] = { config.mappings.forward_1, 'string' },
+    ['mappings.backward_1'] = { config.mappings.forward_1, 'string' },
+    ['mappings.forward_1_till'] = { config.mappings.forward_1, 'string' },
+    ['mappings.backward_1_till'] = { config.mappings.forward_1, 'string' },
+    highlight = { config.highlight, 'boolean' },
+  })
+
+  return config
+end
+
+function H.apply_config(config)
+  MiniJump.config = config
+
+  local modes = { 'n', 'o', 'x' }
+  H.map_cmd(modes, config.mappings.forward_1, [[lua MiniJump.smart_jump(1, false, false)]])
+  H.map_cmd(modes, config.mappings.backward_1, [[lua MiniJump.smart_jump(1, true, false)]])
+  H.map_cmd(modes, config.mappings.forward_1_till, [[lua MiniJump.smart_jump(1, false, true)]])
+  H.map_cmd(modes, config.mappings.backward_1_till, [[lua MiniJump.smart_jump(1, true, true)]])
+end
+
+function H.is_disabled()
+  return vim.g.minijump_disable == true or vim.b.minijump_disable == true
+end
+
+---- Various helpers
+function H.map_cmd(modes, key, command)
+  if key == '' then
+    return
+  end
+  for _, mode in ipairs(modes) do
+    local rhs = ('<cmd>%s<cr>'):format(command)
+    if mode == 'o' then
+      rhs = 'v' .. rhs
+    end
+    vim.api.nvim_set_keymap(mode, key, rhs, { noremap = true })
+  end
+end
+
+function H.get_chars(num_chars)
+  local chars = ''
+  for _ = 1, num_chars do
+    chars = chars .. vim.fn.nr2char(vim.fn.getchar())
+  end
+  return chars
+end
+
+function H.highlight(pattern)
+  if not MiniJump.config.highlight then
+    H.unhighlight()
+    return
+  end
+
+  local win_id = vim.api.nvim_get_current_win()
+  local match_info = H.window_matches[win_id]
+
+  -- Don't do anything if already highlighting input pattern
+  if match_info and match_info.pattern == pattern then
+    return
+  end
+
+  -- Stop highlighting possible previous pattern. Needed to adjust highlighting
+  -- when inside jumping but a different kind one. Example: first jump with
+  -- `till = false` and then, without jumping stop, jump to same character with
+  -- `till = true`. If this character is first on line, highlighting should change
+  H.unhighlight()
+
+  local match_id = vim.fn.matchadd('MiniJumpHighlight', pattern)
+  H.window_matches[win_id] = { id = match_id, pattern = pattern }
+end
+
+function H.unhighlight()
+  -- Remove highlighting from all windows as jumping is intended to work only
+  -- in current window. This will work also from other (usually popup) window.
+  for win_id, match_info in pairs(H.window_matches) do
+    if vim.api.nvim_win_is_valid(win_id) then
+      -- Use `pcall` because there is an error if match id is not present. It
+      -- can happen if something else called `clearmatches`.
+      pcall(vim.fn.matchdelete, match_info.id, win_id)
+      H.window_matches[win_id] = nil
+    end
+  end
+end
+
+return MiniJump