main : (~str)*;

str
: '([rR])(")'{
    meta.string,
    1: storage.type.string,
    2: string.quoted.double punctuation.definition.string.begin
  }
  str-impl
;

str-impl{meta.string string.quoted.double}
: ( ~`""`{constant.character.escape.double-quote} )*
  ~( '"'{punctuation.definition.string.end}
   | '\n'{invalid.illegal.unclosed-string}
   )
;