strlit test.pl

grammar NewStrLiteralTest {
    token TOP { <string> }

    proto token string { * }
    token string:sym<single-quoted> { \' ~ \' ( <-[\\\x00\n']>+ | <str_escape> )* }
    token string:sym<double-quoted> { \" ~ \" ( <-[\\\x00\n"]>+ | <str_escape> )* }

    token str_escape {
        [ <hex-escape> | <oct-escape> | <char-escape> ]
    }

    token hex-escape    { '\\' <[xX]> <.xdigit> ** 1..2 }
    token oct-escape    { '\\' <[0..7]> ** 1..3 }
    token char-escape   { '\\' <[abfnrtv\\?'"]> }
}

say NewStrLiteralTest.parse('"hello \nworl\x00d"');
say NewStrLiteralTest.parse('\'hello w"h\nirld\'');