fastCompareChars.java

    private static PrimitiveIterator.OfInt alphaChars(CharSequence s) {
        return s.chars().filter(Character::isAlphabetic).map(Character::toLowerCase).iterator();
    }

    public static boolean compareAlphabeticCharacters(CharSequence a, CharSequence b) {
        PrimitiveIterator.OfInt aStream = alphaChars(a);
        PrimitiveIterator.OfInt bStream = alphaChars(b);
        while (aStream.hasNext() && bStream.hasNext()) {
            if (aStream.nextInt() != bStream.nextInt()) return false;
        }
        return !aStream.hasNext() && !bStream.hasNext();
    }