code: function stripPrefix(prefix) {
      return function(s) {
        var idx = prefix.length;
        return s.slice (0, idx) === prefix ? Just (s.slice (idx)) : Nothing;
      };
    }
docs: # stripPrefix :: String -> String -> Maybe String . . Returns Just the portion of the given string (the second argument) left . after removing the given prefix (the first argument) if the string starts . with the prefix; Nothing otherwise. . . See also [`stripSuffix`](#stripSuffix). . . ```javascript . > S.stripPrefix ('https://') ('https://sanctuary.js.org') . Just ('sanctuary.js.org') . . > S.stripPrefix ('https://') ('http://sanctuary.js.org') . Nothing . ```