Initial PoC works

autoload/clap/api.vim

@@ -65,7 +65,7 @@ else
   endfunction
 endif
 
-function! s:api.get_screenlinesrange() abort
+function! s:api.get_screen_lines_range() abort
   return [win_getid(), line('w0'), line('w$')]
 endfunction
 

autoload/clap/highlighter.vim

@@ -6,12 +6,23 @@ set cpoptions&vim
 
 let s:default_priority = 10
 
+if has('nvim')
+  let s:tree_sitter_ns_id = nvim_create_namespace('clap_tree_sitter_highlight')
+else
+  let s:ts_types = []
+endif
+
 if has('nvim')
   " lnum is 0-based.
   function! s:add_highlight_at(bufnr, lnum, col, length, hl_group) abort
     call nvim_buf_add_highlight(a:bufnr, -1, a:hl_group, a:lnum, a:col, a:col+a:length)
   endfunction
 
+  " lnum is 0-based.
+  function! s:add_ts_highlight_at(bufnr, lnum, col, length, hl_group) abort
+    call nvim_buf_add_highlight(a:bufnr, s:tree_sitter_ns_id, a:hl_group, a:lnum, a:col, a:col+a:length)
+  endfunction
+
   " lnum and col are 0-based.
   function! s:add_highlight_at_using_matchaddpos(lnum, col, hl_group) abort
     return matchaddpos(a:hl_group, [[a:lnum+1, a:col+1, 1]])
@@ -132,16 +143,22 @@ function! clap#highlighter#highlight_line(bufnr, lnum, token_highlights) abort
   endfor
 endfunction
 
+function! clap#highlighter#add_ts_highlights(bufnr, highlights) abort
+  if has('nvim')
+    call nvim_buf_clear_namespace(a:bufnr, s:tree_sitter_ns_id, 0, -1)
+  else
+    call prop_remove({ 'types': s:ts_types, 'all': v:true, 'bufnr': a:bufnr } )
+  endif
 
-function! clap#highlighter#add_line_highlights(bufnr, highlights) abort
   for [line_number, highlights] in a:highlights
     for [column_start, length, group_name] in highlights
       if !has('nvim')
         if empty(prop_type_get(group_name))
-          call prop_type_add(group_name, {'highlight': group_name})
+          call add(s:ts_types, 'clap_ts_'.group_name)
+          call prop_type_add('clap_ts_'.group_name, {'highlight': group_name})
         endif
       endif
-      call s:add_highlight_at(a:bufnr, line_number, column_start, length, group_name)
+      call s:add_ts_highlight_at(a:bufnr, line_number, column_start, length, group_name)
     endfor
   endfor
 endfunction

crates/maple_core/src/stdio_server/plugin/cursorword.rs

@@ -206,7 +206,7 @@ impl Cursorword {
         }
 
         // Lines in view.
-        let (winid, line_start, line_end) = self.vim.get_screenlinesrange().await?;
+        let (winid, line_start, line_end) = self.vim.get_screen_lines_range().await?;
 
         let maybe_new_highlights = if self.vim.bufmodified(bufnr).await? {
             let lines = self.vim.getbufline(bufnr, line_start, line_end).await?;

crates/maple_core/src/stdio_server/plugin/mod.rs

@@ -43,6 +43,12 @@ impl Toggle {
         }
     }
 
+    pub fn turn_on(&mut self) {
+        if self.is_off() {
+            *self = Self::On;
+        }
+    }
+
     pub fn is_off(&self) -> bool {
         matches!(self, Self::Off)
     }