bloblang

type Field interface {
	// Bytes returns a byte slice representing the expression resolved for a
	// message of a batch.
	Bytes(index int, msg Message) []byte

	// String returns a string representing the expression resolved for a
	// message of a batch.
	String(index int, msg Message) string
}

type Mapping interface {
	// QueryPart executes a Bloblang mapping and expects a boolean result, which
	// is returned. If the execution fails or the result is not boolean an error
	// is returned.
	//
	// Bloblang is able to query other messages of a batch, and therefore this
	// function takes a message batch and index rather than a single message
	// part argument.
	QueryPart(index int, msg Message) (bool, error)

	// MapPart executes a Bloblang mapping on a message part and returns a new
	// resulting part, or an error if the execution fails.
	//
	// Bloblang is able to query other messages of a batch, and therefore this
	// function takes a message batch and index rather than a single message
	// part argument.
	MapPart(index int, msg Message) (types.Part, error)
}

type Message interface {
	Get(p int) types.Part
	Len() int
}