func addInterFieldComparator()

in rule/rule.go [575:612]
31 lines of code
7 McCabe index (conditional complexity)

func addInterFieldComparator(rule *ruleData, lhs, comparator, rhs string) error {
	op, found := operatorsTable[comparator]
	if !found {
		return fmt.Errorf("invalid operator '%v'", comparator)
	}

	switch op {
	case equalOperator, notEqualOperator:
	default:
		return fmt.Errorf("invalid operator '%v', only '=' or '!=' can be used", comparator)
	}

	leftField, found := fieldsTable[lhs]
	if !found {
		return fmt.Errorf("invalid field '%v' on left", lhs)
	}

	rightField, found := fieldsTable[rhs]
	if !found {
		return fmt.Errorf("invalid field '%v' on right", lhs)
	}

	table, found := comparisonsTable[leftField]
	if !found {
		return fmt.Errorf("field '%v' cannot be used in an interfield comparison", lhs)
	}

	comparison, found := table[rightField]
	if !found {
		return fmt.Errorf("field '%v' cannot be used in an interfield comparison", rhs)
	}

	rule.fields = append(rule.fields, fieldCompare)
	rule.fieldFlags = append(rule.fieldFlags, op)
	rule.values = append(rule.values, uint32(comparison))

	return nil
}