fix: use luahl in treesitter

runtime/lua/vim/treesitter/highlighter.lua

@@ -3,7 +3,6 @@ local a = vim.api
 -- support reload for quick experimentation
 local TSHighlighter = rawget(vim.treesitter, 'TSHighlighter') or {}
 TSHighlighter.__index = TSHighlighter
-local ts_hs_ns = a.nvim_create_namespace("treesitter_hl")
 
 -- These are conventions defined by tree-sitter, though it
 -- needs to be user extensible also.
@@ -69,8 +68,15 @@ function TSHighlighter.new(query, bufnr, ft)
   self.edit_count = 0
   self.redraw_count = 0
   self.line_count = {}
+  self.root = self.parser:parse():root()
   a.nvim_buf_set_option(self.buf, "syntax", "")
 
+  a.nvim__buf_set_luahl(self.buf, {
+    on_start=function(...) return self:on_start(...) end,
+    on_window=function(...) return self:on_window(...) end,
+    on_line=function(...) return self:on_line(...) end,
+  })
+
   -- Tricky: if syntax hasn't been enabled, we need to reload color scheme
   -- but use synload.vim rather than syntax.vim to not enable
   -- syntax FileType autocmds. Later on we should integrate with the
@@ -100,6 +106,12 @@ function TSHighlighter:get_hl_from_capture(capture)
   end
 end
 
+function TSHighlighter:on_changedtree(changes)
+  for _, ch in ipairs(changes or {}) do
+    a.nvim__buf_redraw_range(self.buf, ch[1], ch[3]+1)
+  end
+end
+
 function TSHighlighter:set_query(query)
   if type(query) == "string" then
     query = vim.treesitter.parse_query(self.parser.lang, query)
@@ -123,26 +135,38 @@ function TSHighlighter:set_query(query)
     end
   })
 
-  self:on_changedtree({{self.parser:parse():root():range()}})
+  a.nvim__buf_redraw_range(self.buf, 0, a.nvim_buf_line_count(self.buf))
 end
 
-function TSHighlighter:on_changedtree(changes)
-  -- Get a fresh root
-  local root = self.parser:parse():root()
+function TSHighlighter:on_window(_, _win, _buf, _topline, botline)
+  self.iter = nil
+  self.nextrow = 0
+  self.botline = botline
+  self.redraw_count = self.redraw_count + 1
+end
 
-  for _, ch in ipairs(changes or {}) do
-    a.nvim_buf_clear_namespace(self.buf, ts_hs_ns, ch[1], ch[3]+1)
+function TSHighlighter:on_start(_, _buf, _tick)
+  local tree = self.parser:parse()
+  self.root = tree:root()
+end
 
-    for capture, node in self.query:iter_captures(root, self.buf, ch[1], ch[3] + 1) do
+
+function TSHighlighter:on_line(_, _win, buf, line)
+  if self.iter == nil then
+    self.iter = self.query:iter_captures(self.root,buf,line,self.botline)
+  end
+  while line >= self.nextrow do
+    local capture, node = self.iter()
+    if capture == nil then
+      break
+    end
     local start_row, start_col, end_row, end_col = node:range()
     local hl = self.hl_cache[capture]
-      if hl then
-        a.nvim_buf_set_extmark(self.buf, ts_hs_ns, start_row, start_col, {
-          end_col = end_col,
-          end_line = end_row,
-          hl_group = hl
-        })
+    if hl and end_row >= line then
+      a.nvim__put_attr(start_row, start_col, { end_line = end_row, end_col = end_col, hl_group = hl })
     end
+    if start_row > line then
+      self.nextrow = start_row
     end
   end
 end

test/functional/lua/treesitter_spec.lua

@@ -446,10 +446,7 @@ static int nlua_schedule(lua_State *const lstate)
     ]]}
 
     feed("5Goc<esc>dd")
-    if true == true then
-      pending('reenable this check in luahl PR')
-      return
-    end
+
     screen:expect{grid=[[
       {2:/// Schedule Lua callback on main loop's event queue}             |
       {3:static} {3:int} {11:nlua_schedule}({3:lua_State} *{3:const} lstate)                |
@@ -480,7 +477,7 @@ static int nlua_schedule(lua_State *const lstate)
             || {6:lstate} != {6:lstate}) {                                     |
           {11:lua_pushliteral}(lstate, {5:"vim.schedule: expected function"});  |
           {4:return} {11:lua_error}(lstate);                                    |
-      *^/                                                               |
+      {8:*^/}                                                               |
         }                                                              |
                                                                        |
         {7:LuaRef} cb = {11:nlua_ref}(lstate, {5:1});                               |