Method decode

src/main/java/org/dynjs/runtime/builtins/URLCodec.java:79–201

(ExecutionContext context, String str, String reservedSet)

    }

    public static String decode(ExecutionContext context, String str, String reservedSet) {

        int len = str.length();
        StringBuilder r = new StringBuilder();

        int k = 0;

        while (true) {
            String s = null;
            if (k == len) {
                return r.toString();
            }

            char c = str.charAt(k);

            if (c != '%') {
                s = "" + c;
            } else {
                int start = k;
                if ((k + 2) >= len) {
                    throw new ThrowException(context, context.createUriError("invalid escape (not enough chars follow %)"));
                }
                if (!isHexDigit(str.charAt(k + 1)) || !isHexDigit(str.charAt(k + 2))) {
                    throw new ThrowException(context, context.createUriError("invalid escape (non-hex follow %)"));
                }
                int b = Integer.parseInt(str.substring(k + 1, k + 3), 16);
                k = k + 2;

                if ((b & 0x80) == 0) {
                    String charStr = new String(new char[] { (char) b });

                    if (!reservedSet.contains(charStr)) {
                        s = charStr;
                    } else {
                        s = str.substring(start, k + 1);
                    }
                } else {
                    int n = 1;
                    for (int nPos = 1; nPos < 8; ++nPos) {
                        if (((b << nPos) & 0x80) == 0) {
                            n = nPos;
                            break;
                        }
                    }

                    if (n == 1 || n > 4) {
                        throw new ThrowException(context, context.createUriError("invalid escape (too many hex sequences)"));
                    }

                    int[] octets = new int[n];
                    octets[0] = b;

                    if ((k + (3 * (n - 1))) >= len) {
                        throw new ThrowException(context, context.createUriError("invalid escape (too many hex sequences)"));
                    }

                    for (int j = 1; j < n; ++j) {
                        ++k;