set

This module provides a Go implementation of a generic set data type along with a small library of common operations.

Installation:

go get -u github.com/jaz303/set

Usage Examples

Create a new empty set

// Standard make() function works fine
s := make(set.Set[int])

// Capacity hint can be specified
s := make(set.Set[int], 3000)

// The Make helper function saves a couple of keystrokes...
// (capacity is optional parameter)
s := set.Make[int]()

// ...and can also be used as a function parameter if necessary:
config := Config{
    SetFactory: set.Make[int],
}

Create a set from known values

s1 := set.Of("foo", "bar", "baz")
s2 := set.OfSlice([]string{"foo", "bar", "baz"})

Query the set

s.Empty() // returns true if s is empty, false otherwise
s.Size() // return number of items in s
s.Contains(1) // return true if s contains item, false otherwise
s.ContainsSlice([]int{1,2,3}) // returns true if s contains all items in slice, false otherwise
s.Items() // returns a slice of all items in s

A set is implemented as a map[T]struct{} so the standard length/iteration operations are of course available:

len(s) // return number of items in s

// iterate over s's contents
for v := range s {

}

Add/remove items

s.Add(1) // add a single item
s.AddSlice([]int{1,2,3}) // add all items from slice
s.AddSet(set.Of(4,5,6)) // add all items from other set

s.Remove(1) // remove a single item
s.RemoveSlice([]int{1,2,3}) // remove all items in slice
s.RemoveSet(set.Of(4,5,6)) // remove all items in other set

s.Clear() // remove all items from set

Set operations

set.Union(a, b) // returns a new set containing the union of sets a and b
set.Intersection(a, b) // returns a new set containing the intersection of sets a and b
set.Difference(a, b) // returns a new set containing the difference between sets a and b (i.e. a - b)

JSON Support

The Set type implements the json.Marshaler and json.Unmarshaler interfaces; sets are encoded as JSON arrays.

Unmarshalling into a non-empty set produces the union of the existing and unmarshalled data.