Merge pull request #9 from fidgetingbits/get-buffer-selection

refactor: improve cursorless.lua function readability

Author: saidelike

cursorless.nvim/lua/cursorless/cursorless.lua

@@ -7,118 +7,44 @@ local M = {}
 --   window_get_visible_lines
 --  { [1] = 28, [2] = 74 }
 function M.window_get_visible_lines()
-  -- print('window_get_visible_lines()')
-  return { vim.fn.line("w0"), vim.fn.line("w$") }
+	-- print('window_get_visible_lines()')
+	return { vim.fn.line("w0"), vim.fn.line("w$") }
 end
 
--- https://www.reddit.com/r/neovim/comments/p4u4zy/how_to_pass_visual_selection_range_to_lua_function/
--- https://neovim.io/doc/user/api.html#nvim_win_get_cursor()
+-- Get the coordinates of the current selection
+-- To manually test follow these steps:
+-- 1. In command mode :vmap <c-a> <Cmd>lua print(vim.inspect(require('cursorless').buffer_get_selection()))<Cr>
+-- 2. type "hello" on the first line and "world" on the second line
+-- 3. Enter visual mode and select "hello" on the first line and continue selection with "world"
+--    on the second line.
+-- 4. Hit ctrl+a to show the selection: {1, 1, 2, 5, false}
+-- 5. Hit 'o' to swap the cursor position and hit ctrl+a again: {1, 1, 2, 5, true}
 --
--- luacheck:ignore 631
--- e.g. run in command mode :vmap <c-a> <Cmd>lua print(vim.inspect(require('cursorless').buffer_get_selection()))<Cr>
--- then go in visual mode with "v" and select "hello" on the first line and continue selection with "air"
--- on the second line.
--- Then hit ctrl+b and it will show the selection
--- cline=2, ccol=2, vline=1, vcol=1
--- sline=1, scol=1, eline=2, ecol=3, reverse=false
--- { 1, 1, 2, 3, false }
---
--- if instead you select from the end of the "air" word on the second line
--- and select up to the beginning of "hello" on the first line
--- cline=1, ccol=0, vline=3, vcol=3
--- sline=1, scol=1, eline=2, ecol=3, reverse=true
--- { 1, 1, 2, 3, true }
---
--- if you want to directly see how it is parsed in the node extension, you can use the below:
--- e.g. run in command mode :vmap <c-a> <Cmd>:call CursorlessLoadExtension()<Cr>
--- and again use ctrl+a after selecting the text
+-- If you want to directly see how it is parsed in the node extension:
+-- 1. run in command mode :vmap <c-a> <Cmd>:call CursorlessLoadExtension()<Cr>
+-- 2. Select some text and hit ctrl+a
 function M.buffer_get_selection()
-  -- print('buffer_get_selection()')
-  local modeInfo = vim.api.nvim_get_mode()
-  local mode = modeInfo.mode
-
-  local cursor = vim.api.nvim_win_get_cursor(0)
-  local cline, ccol = cursor[1], cursor[2]
-  local vline, vcol = vim.fn.line("v"), vim.fn.col("v")
-  -- print(('cline=%d, ccol=%d, vline=%d, vcol=%d'):format(cline, ccol, vcol, vcol))
-
-  local sline, scol
-  local eline, ecol
-  local reverse
-  if cline == vline then
-    --   if ccol <= vcol then
-    if ccol < vcol then
-      sline, scol = cline, ccol
-      eline, ecol = vline, vcol
-      scol = scol + 1
-      reverse = true
-    else
-      sline, scol = vline, vcol
-      eline, ecol = cline, ccol
-      ecol = ecol + 1
-      reverse = false
-    end
-  elseif cline < vline then
-    sline, scol = cline, ccol
-    eline, ecol = vline, vcol
-    scol = scol + 1
-    reverse = true
-  else
-    sline, scol = vline, vcol
-    eline, ecol = cline, ccol
-    ecol = ecol + 1
-    reverse = false
-  end
-
-  if mode == "V" or mode == "CTRL-V" or mode == "\22" then
-    scol = 1
-    ecol = nil
-  end
-
-  -- print(
-  --   ('sline=%d, scol=%d, eline=%d, ecol=%d, reverse=%s'):format(
-  --     sline,
-  --     scol,
-  --     eline,
-  --     ecol,
-  --     tostring(reverse)
-  --   )
-  -- )
-  return { sline, scol, eline, ecol, reverse }
-end
-
--- https://www.reddit.com/r/neovim/comments/p4u4zy/how_to_pass_visual_selection_range_to_lua_function/
--- luacheck:ignore 631
--- e.g. run in command mode :vmap <c-b> <Cmd>lua print(vim.inspect(require('cursorless').buffer_get_selection_text()))<Cr>
--- then go in visual mode with "v" and select "hello" on the first line and continue selection with "air"
--- on the second line.
--- Then hit ctrl+b and it will show the selection
--- { "hello", "air" }
-function M.buffer_get_selection_text()
-  -- print('buffer_get_selection_text()')
-  local sline, scol, eline, ecol, _ =
-    unpack(require("talon.cursorless").buffer_get_selection())
-
-  local lines = vim.api.nvim_buf_get_lines(0, sline - 1, eline, 0)
-  if #lines == 0 then
-    return
-  end
+	local start_pos = vim.fn.getpos("v") -- start of visual selection
+	local start_line, start_col = start_pos[2], start_pos[3]
+	local end_pos = vim.fn.getpos(".") -- end of visual selection (cursor position)
+	local end_line, end_col = end_pos[2], end_pos[3]
+	local reverse = false
+	local mode = vim.api.nvim_get_mode().mode
 
-  local startText, endText
-  if #lines == 1 then
-    startText = string.sub(lines[1], scol, ecol)
-  else
-    startText = string.sub(lines[1], scol)
-    endText = string.sub(lines[#lines], 1, ecol)
-  end
+	-- Invert the values depending on if the cursor is before the start
+	if end_line < start_line or end_col < start_col then
+		start_line, start_col, end_line, end_col = end_line, end_col, start_line, start_col
+		reverse = true
+	end
 
-  local selection = { startText }
-  if #lines > 2 then
-    vim.list_extend(selection, vim.list_slice(lines, 2, #lines - 1))
-  end
-  table.insert(selection, endText)
+	-- See https://github.com/cursorless-dev/cursorless/issues/2537 if you want to add more modes
+	if mode == "V" then
+		-- Line and block-based visual modes are line-based, so we don't need to track the columns
+		start_col = 1
+		end_col = nil
+	end
 
-  return selection
+	return { start_line, start_col, end_line, end_col, reverse }
 end
 
 -- https://github.com/nvim-treesitter/nvim-treesitter/blob/master/lua/nvim-treesitter/ts_utils.lua#L278
@@ -131,11 +57,11 @@ end
 -- for example it will highlight the last function name (nvim_win_set_cursor).
 -- another example is :tmap <c-b> <Cmd>lua require("talon.cursorless").select_range(4, 0, 4, 38)<Cr>
 -- NOTE: works for any mode (n,i,v,nt) except in t mode
-function M.select_range(start_x, start_y, end_x, end_y)
-  vim.cmd([[normal! :noh]])
-  vim.api.nvim_win_set_cursor(0, { start_x, start_y })
-  vim.cmd([[normal v]])
-  vim.api.nvim_win_set_cursor(0, { end_x, end_y })
+function M.select_range(start_line, start_col, end_line, end_col)
+	vim.cmd([[normal! :noh]])
+	vim.api.nvim_win_set_cursor(0, { start_line, start_col })
+	vim.cmd([[normal v]])
+	vim.api.nvim_win_set_cursor(0, { end_line, end_col })
 end
 
 return M