Method SDiff

structure/set.go:196–231

SDiff computes the difference between the first and subsequent sets. It returns keys unique to the first set and an error if applicable.

(keys ...string)

// SDiff computes the difference between the first and subsequent sets.
// It returns keys unique to the first set and an error if applicable.
func (s *SetStructure) SDiff(keys ...string) ([]string, error) {
	// If there are no keys, then there's no difference
	if len(keys) == 0 {
		return nil, nil
	}

	first, err := s.checkAndGetSet(keys[0], false)
	if err != nil {
		return nil, err
	}

	// Initialize a set for members of first set
	mem := make(map[string]struct{})
	for k := range *first {
		mem[k] = struct{}{}
	}

	var diffMembers []string
	// If member is in the first set and also in another set, remove it.
	for _, key := range keys[1:] {
		fs, err := s.checkAndGetSet(key, false)
		if err != nil {
			return nil, err
		}
		for k := range *fs {
			// Only delete the existing members in the first set. Do not add members from other sets
			delete(mem, k)
		}
	}
	// Remaining members in mem are unique to first set.
	for k := range mem {
		diffMembers = append(diffMembers, k)
	}

	return diffMembers, nil
}

// Keys returns all the keys of the set structure
func (s *SetStructure) Keys(regx string) ([]string, error) {