use Language::MySort;

*french_sort = lang_sort(
  # *the character list*
  # only includes the characters remaining after
  # the identical-character map has been applied
  'a' .. 'z',

  {
    # *the identical-character map*
    # maps characters to the character
    # they should sort identically as
    # "AXYZ" means that X, Y, and Z are translated as A
    identical =>
      ["a\340", "c\347", "e\350\351\352\353", "o\364"],
  }
);
      
{ 
  local $, = " ";
  print french_sort(
    "\351tude",
    "\352tre",
    "tr\350s",
    "entrer",
    "\351t\351",
  );
}