hash

type BinaryFixedLengthHasher interface {
	BinaryHasher
	// FixedLengthSum returns digest of the first length bytes.
	FixedLengthSum(length frontend.Variable) []uints.U8
}

type BinaryHasher interface {
	// Sum finalises the current hash and returns the digest.
	Sum() []uints.U8

	// Write writes more bytes into the current hash state.
	Write([]uints.U8)

	// Size returns the number of bytes this hash function returns in a call to
	// [BinaryHasher.Sum].
	Size() int
}

type FieldHasher interface {
	// Sum computes the hash of the internal state of the hash function.
	Sum() frontend.Variable

	// Write populate the internal state of the hash function with data. The inputs are native field elements.
	Write(data ...frontend.Variable)

	// Reset empty the internal state and put the intermediate state to zero.
	Reset()
}

type StateStorer interface {
	FieldHasher
	// State retrieves the current state of the hash function. Calling this
	// method should not destroy the current state and allow continue the use of
	// the current hasher. The number of returned Variable is implementation
	// dependent.
	State() []frontend.Variable
	// SetState sets the state of the hash function from a previously stored
	// state retrieved using [StateStorer.State] method. The implementation
	// returns an error if the number of supplied Variable does not match the
	// number of Variable expected.
	SetState(state []frontend.Variable) error
}