feat(lsp): more annotations

runtime/lua/vim/lsp/sync.lua

@@ -58,7 +58,7 @@ local function byte_to_utf(line, byte, offset_encoding)
   -- convert to 0 based indexing for str_utfindex
   byte = byte - 1
 
-  local utf_idx
+  local utf_idx --- @type integer
   local _
   -- Convert the byte range to utf-{8,16,32} and convert 1-based (lua) indexing to 0-based
   if offset_encoding == 'utf-16' then
@@ -73,8 +73,11 @@ local function byte_to_utf(line, byte, offset_encoding)
   return utf_idx + 1
 end
 
+---@param line string
+---@param offset_encoding string
+---@return integer
 local function compute_line_length(line, offset_encoding)
-  local length
+  local length --- @type integer
   local _
   if offset_encoding == 'utf-16' then
     _, length = str_utfindex(line)
@@ -94,7 +97,7 @@ end
 ---@return integer byte_idx of first change position
 ---@return integer char_idx of first change position
 local function align_end_position(line, byte, offset_encoding)
-  local char
+  local char --- @type integer
   -- If on the first byte, or an empty string: the trivial case
   if byte == 1 or #line == 0 then
     char = byte
@@ -120,8 +123,8 @@ local function align_end_position(line, byte, offset_encoding)
 end
 
 --- Finds the first line, byte, and char index of the difference between the previous and current lines buffer normalized to the previous codepoint.
----@param prev_lines table list of lines from previous buffer
----@param curr_lines table list of lines from current buffer
+---@param prev_lines string[] list of lines from previous buffer
+---@param curr_lines string[] list of lines from current buffer
 ---@param firstline integer firstline from on_lines, adjusted to 1-index
 ---@param lastline integer lastline from on_lines, adjusted to 1-index
 ---@param new_lastline integer new_lastline from on_lines, adjusted to 1-index
@@ -135,14 +138,14 @@ local function compute_start_range(
   new_lastline,
   offset_encoding
 )
-  local char_idx
-  local byte_idx
+  local char_idx --- @type integer?
+  local byte_idx --- @type integer?
   -- If firstline == lastline, no existing text is changed. All edit operations
   -- occur on a new line pointed to by lastline. This occurs during insertion of
   -- new lines(O), the new newline is inserted at the line indicated by
   -- new_lastline.
   if firstline == lastline then
-    local line_idx
+    local line_idx --- @type integer
     local line = prev_lines[firstline - 1]
     if line then
       line_idx = firstline - 1
@@ -343,6 +346,12 @@ end
 -- codeunits for utf-32
 -- Line endings count here as 2 chars for \r\n (dos), 1 char for \n (unix), and 1 char for \r (mac)
 -- These correspond to Windows, Linux/macOS (OSX and newer), and macOS (version 9 and prior)
+---@param lines string[]
+---@param start_range table
+---@param end_range table
+---@param offset_encoding string
+---@param line_ending string
+---@return integer
 local function compute_range_length(lines, start_range, end_range, offset_encoding, line_ending)
   local line_ending_length = #line_ending
   -- Single line case
@@ -351,7 +360,7 @@ local function compute_range_length(lines, start_range, end_range, offset_encodi
   end
 
   local start_line = lines[start_range.line_idx]
-  local range_length
+  local range_length --- @type integer
   if start_line and #start_line > 0 then
     range_length = compute_line_length(start_line, offset_encoding)
       - start_range.char_idx
@@ -387,6 +396,7 @@ end
 ---@param lastline integer line to begin search in old_lines for last difference
 ---@param new_lastline integer line to begin search in new_lines for last difference
 ---@param offset_encoding string encoding requested by language server
+---@param line_ending string
 ---@return table TextDocumentContentChangeEvent see https://microsoft.github.io/language-server-protocol/specification/#textDocumentContentChangeEvent
 function M.compute_diff(
   prev_lines,