Hash Set Implementation in Go

In logic building, hashsets are an important data structure used for many applications. Go, currently, doesn’t have a hashset data type implementation

A HashSet can easily be implemented using map by defining the value field as a boolean

myset := map[T]bool{} 

//add - value is type T
myset[value] = true

// contains
_, contains := myset[value]
if contains {

}

//remove
delete(myset, value)

//size
len(myset)

Example Problem

Common problem - Find if an element exists in a list

if list contains apple, don’t buy apple

fruitsInHouse := []string{"apple", "banana", "orange", "peach"}
// common solution - hint, it's inefficient! - O(n)
for _, fruit := range fruitsInHouse {
    if "peach" == fruit{
        //contains
    }
}

Example Solution

Find if something exists in a set

fruitsInHouse := map[string]bool{"apple": true, "banana": true, "orange": true, "peach": true}
// this solution is O(1)
_, contains := fruitsInHouse["apple"]