Proposal: set operation

[haohanyuzmx]

There are toSet functions like keyify, but set operations only have slice-related functions. Are there plans to add set operations to set?

[samber]

Hey @haohanyuzmx

I'm not sure to understand. Can you provide some examples of methods and prototypes?

[haohanyuzmx]

such as

type Set[T comparable] map[T]struct{}

func Union[T comparable](s1, s2 Set[T]) Set[T] {
	result := make(map[T]struct{}, len(s1)+len(s2))
	for k := range s1 {
		result[k] = struct{}{}
	}
	for k := range s2 {
		result[k] = struct{}{}
	}
	return result
}

func Intersection[T comparable](s1, s2 Set[T]) Set[T] {
	result := map[T]struct{}{}
	for k := range s1 {
		if _, ok := s2[k]; ok {
			result[k] = struct{}{}
		}
	}
	return result
}

func Difference[T comparable](s1, s2 Set[T]) (Set[T],Set[T]) {
	// TODO
	return map[T]struct{}{}, map[T]struct{}{}
}
// TODO

[travel45]

This structure is really needed

Also, I suggest adding these methods:

package set

type Set[T comparable] map[T]struct{}

func (s Set[T]) Exists(el T) bool {
	if s != nil {
		if _, ok := s[el]; ok {
			return true
		}
	}
	return false
}

func CreateFromSlice[T comparable](slc []T) Set[T] {
	out := make(Set[T], len(slc))
	for _, i := range slc {
		out[i] = struct{}{}
	}
	return out
}

[ukpratik]

hey @samber should I take this up?