import "utils/pack/bool/nonStrictUnpack256" as unpack256;

// Compress JubJub Curve Point to 256bit array using big endianness bit order
// Python reference code from pycrypto:
// def compress(self):
//     x = self.x.n
//     y = self.y.n
//     return int.to_bytes(y | ((x & 1) << 255), 32, "big")

def main(field[2] pt)  -> bool[256] {
    field x = pt[0];
    field y = pt[1];

    bool[256] xBits = unpack256(x);
    bool[256] mut yBits = unpack256(y);

    bool sign = xBits[255];
    yBits[0] = sign;

    return yBits;
}