src/main/java/com/bazaarvoice/jless/parser/Parser.java
Rule Escape() {
        return Sequence(
                Test('\\'), // for performance
                FirstOf(
                        Unicode(),
                        Sequence('\\', Sequence(TestNot(CharRange((char) 0, (char) 31)), ANY))
                )
        );
    }
Rule Escape() {
        return Sequence(
                Test('\\'), // for performance
                FirstOf(
                        Unicode(),
                        Sequence('\\', Sequence(TestNot(CharRange((char) 0, (char) 31)), ANY))
                )
        );
    }
unicode | '\' [^\x0-\x1F]