range: add extmark utilities

lua/u/range.lua

@@ -1,6 +1,13 @@
 local Pos = require 'u.pos'
 
 local ESC = vim.api.nvim_replace_termcodes('<Esc>', true, false, true)
+local NS = vim.api.nvim_create_namespace 'u.range'
+
+---@class u.ExtmarkRange
+---@field bufnr number
+---@field id number
+local ExtmarkRange = {}
+ExtmarkRange.__index = ExtmarkRange
 
 --- @class u.Range
 --- @field start u.Pos
@@ -83,6 +90,27 @@ function Range.from_marks(lpos, rpos)
   return Range.new(start, stop, mode)
 end
 
+--- @param bufnr number
+--- @param id number
+function Range.from_extmark(bufnr, id)
+  ---@type integer, integer, vim.api.keyset.extmark_details | nil
+  local start_row0, start_col0, details =
+    unpack(vim.api.nvim_buf_get_extmark_by_id(bufnr, NS, id, { details = true }))
+
+  local start = Pos.new(bufnr, start_row0 + 1, start_col0 + 1)
+  local stop = details and Pos.new(bufnr, details.end_row + 1, details.end_col)
+
+  local max_line_num = vim.api.nvim_buf_line_count(bufnr)
+  if stop and stop.lnum > max_line_num then
+    stop.lnum = max_line_num
+    stop.col = Pos.MAX_COL
+    stop = stop:as_real()
+  end
+  if stop and stop.col == 0 then stop = stop:must_next(-1) end
+
+  return Range.new(start, stop, 'v')
+end
+
 --- @param bufnr? number
 function Range.from_buf_text(bufnr)
   if bufnr == nil or bufnr == 0 then bufnr = vim.api.nvim_get_current_buf() end
@@ -272,6 +300,13 @@ function Range:to_linewise()
   return r
 end
 
+function Range:to_charwise()
+  local r = self:clone()
+  r.mode = 'v'
+  if r.stop:is_col_max() then r.stop = r.stop:as_real() end
+  return r
+end
+
 --- @param x u.Pos | u.Range
 function Range:contains(x)
   if getmetatable(x) == Pos then
@@ -334,6 +369,15 @@ function Range:save_to_marks(left, right)
   end
 end
 
+function Range:save_to_extmark()
+  local r = self:to_charwise()
+  local id = vim.api.nvim_buf_set_extmark(r.start.bufnr, NS, r.start.lnum - 1, r.start.col - 1, {
+    end_row = r.stop.lnum - 1,
+    end_col = r.stop.col,
+  })
+  return ExtmarkRange.new(r.start.bufnr, id)
+end
+
 function Range:set_visual_selection()
   if self:is_empty() then return end
   if vim.api.nvim_get_current_buf() ~= self.start.bufnr then
@@ -596,4 +640,10 @@ function Range:highlight(group, opts)
   }
 end
 
+function ExtmarkRange.new(bufnr, id) return setmetatable({ bufnr = bufnr, id = id }, ExtmarkRange) end
+
+function ExtmarkRange:range() return Range.from_extmark(self.bufnr, self.id) end
+
+function ExtmarkRange:delete() vim.api.nvim_buf_del_extmark(self.bufnr, NS, self.id) end
+
 return Range

lua/u/utils.lua

@@ -7,6 +7,8 @@ local M = {}
 --- @alias QfItem { col: number, filename: string, kind: string, lnum: number, text: string }
 --- @alias KeyMaps table<string, fun(): any | string> }
 -- luacheck: ignore
+--- @alias RawCmdArgs { args: string; bang: boolean; count: number; fargs: string[]; line1: number; line2: number; mods: string; name: string; range: 0|1|2; reg: string; smods: any }
+-- luacheck: ignore
 --- @alias CmdArgs { args: string; bang: boolean; count: number; fargs: string[]; line1: number; line2: number; mods: string; name: string; range: 0|1|2; reg: string; smods: any; info: u.Range|nil }
 
 --- @generic T
@@ -51,6 +53,17 @@ function M.ucmd(name, cmd, opts)
   vim.api.nvim_create_user_command(name, cmd2, opts or {})
 end
 
+--- @param current_args RawCmdArgs
+function M.create_forward_cmd_args(current_args)
+  local args = { args = current_args.fargs }
+  if current_args.range == 1 then
+    args.range = { current_args.line1 }
+  elseif current_args.range == 2 then
+    args.range = { current_args.line1, current_args.line2 }
+  end
+  return args
+end
+
 function M.get_editor_dimensions() return { width = vim.go.columns, height = vim.go.lines } end
 
 return M

spec/range_spec.lua

@@ -617,4 +617,29 @@ describe('Range', function()
       }, vim.api.nvim_buf_get_lines(b, 0, -1, false))
     end)
   end)
+
+  it('can save to extmark', function()
+    withbuf({
+      'The quick brown',
+      'fox',
+      'jumps',
+      'over',
+      'the lazy dog',
+    }, function()
+      -- Construct a range over 'fox jumps'
+      local r = Range.new(Pos.new(nil, 2, 1), Pos.new(nil, 3, Pos.MAX_COL), 'V')
+      local extrange = r:save_to_extmark()
+      assert.are.same({ 'fox', 'jumps' }, extrange:range():lines())
+      -- change 'jumps' to 'leaps':
+      vim.api.nvim_buf_set_text(extrange.bufnr, 2, 0, 2, 4, { 'leap' })
+      assert.are.same({
+        'The quick brown',
+        'fox',
+        'leaps',
+        'over',
+        'the lazy dog',
+      }, vim.api.nvim_buf_get_lines(extrange.bufnr, 0, -1, false))
+      assert.are.same({ 'fox', 'leaps' }, extrange:range():lines())
+    end)
+  end)
 end)