feat(pos,range): pos:to_mark(), pos.mark(), range:to_mark(), range.mark()

Problem:
Ranges represented by marks are usually end-inclusive,
but the range utilities we provided are end-exclusive.

Solution:
Add pos:to_mark(), pos.mark(), range:to_mark(), and range.mark().

runtime/lua/vim/pos.lua

@@ -291,6 +291,25 @@ function M.cursor(buf, pos)
   return M.new(buf, pos[1] - 1, pos[2])
 end
 
+--- Converts |vim.Pos| to mark position (see |api-indexing|).
+---@param pos vim.Pos
+---@return integer, integer
+function M.to_mark(pos)
+  return pos[1] + 1, pos[2]
+end
+
+--- Creates a new |vim.Pos| from mark position (see |api-indexing|).
+---@param buf integer
+---@param row integer
+---@param col integer
+function M.mark(buf, row, col)
+  if buf == 0 then
+    buf = api.nvim_get_current_buf()
+  end
+
+  return M.new(buf, row - 1, col)
+end
+
 --- Converts |vim.Pos| to extmark position (see |api-indexing|).
 ---@param pos vim.Pos
 ---@return integer, integer

runtime/lua/vim/range.lua

@@ -160,6 +160,21 @@ local function to_inclusive_pos(buf, row, col)
   return row, col
 end
 
+---@param row integer
+---@param col integer
+---@param buf integer
+---@return integer, integer
+local function to_exclusive_pos(buf, row, col)
+  if col >= #get_line(buf, row) then
+    row = row + 1
+    col = 0
+  else
+    col = col + 1
+  end
+
+  return row, col
+end
+
 ---@private
 ---@param r1 vim.Range
 ---@param r2 vim.Range
@@ -314,6 +329,67 @@ function M.lsp(buf, range, position_encoding)
   return M.new(start, end_)
 end
 
+--- Converts |vim.Range| to extmark range (see |api-indexing|).
+---
+--- Example:
+--- ```lua
+--- local range = vim.range(0, 3, 5, 4, 0)
+---
+--- -- Convert to mark range, you can call it in a method style.
+--- local start_row, start_col, end_row, end_col = range:to_mark()
+--- ```
+---@param range vim.Range
+---@return integer, integer, integer, integer
+function M.to_mark(range)
+  validate('range', range, 'table')
+
+  local buf = range.buf
+  local start_row, start_col, end_row, end_col = range[1], range[2], range[3], range[4]
+  if vim.o.selection ~= 'exclusive' then
+    end_row, end_col = to_inclusive_pos(buf, end_row, end_col)
+  end
+
+  start_row, start_col = vim.pos(buf, start_row, start_col):to_mark()
+  end_row, end_col = vim.pos(buf, end_row, end_col):to_mark()
+  return start_row, start_col, end_row, end_col
+end
+
+--- Creates a new |vim.Range| from "mark-indexed" range (see |api-indexing|).
+---
+--- Example:
+--- ```lua
+--- -- A range represented by marks may be end-inclusive (decided by 'selection' option).
+--- local start_row, start_col = unpack(api.nvim_buf_get_mark(bufnr, '<'))
+--- local end_row, end_col = unpack(api.nvim_buf_get_mark(bufnr, '>'))
+---
+--- -- Create an end-exclusive range.
+--- local range = vim.range.mark(0, start_row, start_col, end_row, end_col)
+--- ```
+---@param buf integer
+---@param start_row integer
+---@param start_col integer
+---@param end_row integer
+---@param end_col integer
+function M.mark(buf, start_row, start_col, end_row, end_col)
+  validate('buf', buf, 'number')
+  validate('start_row', start_row, 'number')
+  validate('start_col', start_col, 'number')
+  validate('end_row', end_row, 'number')
+  validate('end_col', end_col, 'number')
+
+  if buf == 0 then
+    buf = api.nvim_get_current_buf()
+  end
+
+  local start = vim.pos.mark(buf, start_row, start_col)
+  local end_ = vim.pos.mark(buf, end_row, end_col)
+
+  if vim.o.selection ~= 'exclusive' then
+    end_[1], end_[2] = to_exclusive_pos(buf, end_[1], end_[2])
+  end
+  return M.new(start, end_)
+end
+
 --- Converts |vim.Range| to extmark range (see |api-indexing|).
 ---
 --- Example: