vim: add autohighlight toggle

my_configs.vim

@@ -1,3 +1,4 @@
+colorscheme twilight256
 set mouse=a relativenumber number foldmethod=indent nofoldenable "without nofoldenable all folds are closed at startup"
 set splitbelow splitright
 set autoread
@@ -22,3 +23,25 @@ packadd termdebug
 
 let g:gitgutter_enabled = 1
 
+" Highlight all instances of word under cursor, when idle.
+" Useful when studying strange source code.
+" Type z/ to toggle highlighting on/off.
+nnoremap z/ :if AutoHighlightToggle()<Bar>set hls<Bar>endif<CR>
+function! AutoHighlightToggle()
+   let @/ = ''
+   if exists('#auto_highlight')
+     au! auto_highlight
+     augroup! auto_highlight
+     setl updatetime=4000
+     echo 'Highlight current word: off'
+     return 0
+  else
+    augroup auto_highlight
+    au!
+    au CursorHold * let @/ = '\V\<'.escape(expand('<cword>'), '\').'\>'
+    augroup end
+    setl updatetime=500
+    echo 'Highlight current word: ON'
+  return 1
+ endif
+endfunction