((comment) @injection.content 
 (#set! injection.language "comment"))

((regex) @injection.content 

((redirected_statement
   (heredoc_redirect
     (heredoc_start) @injection.language))
 (heredoc_body) @injection.content
 (#offset! @injection.content 0 0 -1 0)
 (#downcase! @injection.language))(#set! injection.language "regex"))