Method quote

rhino/src/main/java/org/mozilla/javascript/NativeJSON.java:524–575

(String string)

    }

    private static String quote(String string) {
        StringBuilder product =
                new StringBuilder(string.length() + 2); // two extra chars for " on either side
        product.append('"');
        int length = string.length();
        char prev = 0;
        for (int i = 0; i < length; i++) {
            char c = string.charAt(i);
            switch (c) {
                case '"':
                    product.append("\\\"");
                    break;
                case '\\':
                    product.append("\\\\");
                    break;
                case '\b':
                    product.append("\\b");
                    break;
                case '\f':
                    product.append("\\f");
                    break;
                case '\n':
                    product.append("\\n");
                    break;
                case '\r':
                    product.append("\\r");
                    break;
                case '\t':
                    product.append("\\t");
                    break;
                default:
                    if (isLeadingSurrogate(c)
                            && i < length - 1
                            && isTrailingSurrogate(string.charAt(i + 1))) {
                        // do nothing as the next case will add both surrogates
                        break;
                    } else if (isTrailingSurrogate(c) && isLeadingSurrogate(prev)) {
                        product.append(prev).append(c);
                    } else if (c < ' ' || isLeadingSurrogate(c) || isTrailingSurrogate(c)) {
                        product.append("\\u");
                        String hex = String.format("%04x", Integer.valueOf(c));
                        product.append(hex);
                    } else {
                        product.append(c);
                    }
                    break;
            }
            prev = c;
        }
        product.append('"');
        return product.toString();
    }

    static boolean isLeadingSurrogate(char c) {
        return c >= 0xD800 && c <= 0xDBFF;