func literalToken(literal uint32) token { return token(literalType + literal) }

// Convert a < xlength, xoffset > pair into a match token.
func matchToken(xlength uint32, xoffset uint32) token {
	return token(matchType + xlength<<lengthShift + xoffset)
}

// Returns the literal of a literal token.
func (t token) literal() uint32 { return uint32(t - literalType) }

// Returns the extra offset of a match token.