 
 extension RegexTests {
   func testLex() {
-    _ = """
-        Note: Since everything's String-based, escape backslashes.
-              Literal backslashes are thus double-escaped, i.e. "\\\\"
+    _ = #"""
+        Note: Since everything's String-based, use raw strings for backslashes.
         Examples:
           "abc" -> ｢abc｣
-          "abc\\+d*" -> ｢abc+d｣ star
+          #"abc\+d*"# -> ｢abc+d｣ star
           "abc(de)+fghi*k|j" ->
               ｢abc｣ lparen ｢de｣ rparen plus ｢fghi｣ star ｢k｣ pipe ｢j｣
 
         Gramatically invalid but lexically accepted examples:
-          "|*\\\\" -> pipe star ｢\\｣
+          #"|*\\"# -> pipe star ｢\\｣
           ")ab(+" -> rparen ｢ab｣ lparen plus
-        """
+        """#
     func esc(_ c: Character) -> Token {
       .character(c, isEscaped: true)
     }

      "[a^]", charClass("a", "^"))

    parseTest(
      "\\D\\S\\W",
      concat(.characterClass(.digit.inverted),
             .characterClass(.whitespace.inverted),
             .characterClass(.word.inverted)))

    parseTest(
      "[\\dd]", charClass(.characterClass(.digit), "d"))

    parseTest(
      "[^[\\D]]",
      charClass(charClass(.characterClass(.digit.inverted)),
                inverted: true))
    parseTest(

      "[]]&&",
      .leftSquareBracket, .rightSquareBracket, "]", "&", "&")
    lexTest(
      #"[]]&\&"#,
      .leftSquareBracket, .rightSquareBracket, "]", "&", esc("&"))

    // Gramatically invalid (yet lexically valid)
    lexTest(
      #"|*\\"#, .pipe, .star, esc(#"\"#))
    lexTest(
      ")ab(+", .rightParen, "a", "b", .leftParen, .plus)
    lexTest(
