Add

 Set.difference
 Set.intersection
 Set.union
 Set.symmetricDifference
 Set.isSubsetOf
 Set.isSupersetOf
 Set.isDisjointFrom
 Set.toArray

src/Core__Set.res

@@ -15,3 +15,13 @@ type t<'a> = Js.Set.t<'a>
 @send external forEach: (t<'a>, 'a => unit) => unit = "forEach"
 
 @send external values: t<'a> => Core__Iterator.t<'a> = "values"
+
+@send external difference: (t<'a>, t<'a>) => t<'a> = "difference"
+@send external intersection: (t<'a>, t<'a>) => t<'a> = "intersection"
+@send external union: (t<'a>, t<'a>) => t<'a> = "union"
+@send external symmetricDifference: (t<'a>, t<'a>) => t<'a> = "symmetricDifference"
+@send external isSubsetOf: (t<'a>, t<'a>) => bool = "isSubsetOf"
+@send external isSupersetOf: (t<'a>, t<'a>) => bool = "isSupersetOf"
+@send external isDisjointFrom: (t<'a>, t<'a>) => bool = "isDisjointFrom"
+
+external toArray: t<'a> => array<'a> = "Array.from"

src/Core__Set.resi

@@ -183,3 +183,98 @@ Console.log(set->Set.values->Iterator.toArray)
 */
 @send
 external values: t<'a> => Core__Iterator.t<'a> = "values"
+
+/** 
+ Returns a new set with the values of the set that are not in the other set.
+
+ ## Examples
+ ```rescript
+ let set1 = Set.fromArray(["apple", "orange", "banana"])
+ let set2 = Set.fromArray(["apple", "banana", "pear"])
+ set1->Set.difference(set2) // Set.fromArray(["orange"])
+ ```
+*/
+@send external difference: (t<'a>, t<'a>) => t<'a> = "difference"
+
+/**
+ Returns a new set with the values containing the values which are in either the set, but not in both.
+
+ ## Examples
+ ```rescript
+ let set1 = Set.fromArray(["apple", "orange", "banana"])
+ let set2 = Set.fromArray(["apple", "banana", "pear"])
+ set1->Set.symmetricDifference(set2) // Set.fromArray(["orange", "pear"])
+ ```
+
+*/
+@send external symmetricDifference: (t<'a>, t<'a>) => t<'a> = "symmetricDifference"
+
+/**
+ Returns a new set with the values containing the values which are in both the set and the other set.
+
+ ## Examples
+ ```rescript
+ let set1 = Set.fromArray(["apple", "orange", "banana"])
+ let set2 = Set.fromArray(["apple", "banana", "pear"])
+ set1->Set.intersection(set2) // Set.fromArray(["apple", "banana"])
+ ```
+*/
+@send external intersection: (t<'a>, t<'a>) => t<'a> = "intersection"
+
+/**
+ Returns a bool indicating if this set has no elements in common with the given set.
+
+ ## Examples
+ ```rescript
+ let set1 = Set.fromArray(["apple", "orange", "banana"])
+ let set2 = Set.fromArray(["kiwi", "melon", "pear"])
+ set1->Set.isDisjointFrom(set2) // true
+ ```
+*/
+@send external isDisjointFrom: (t<'a>, t<'a>) => bool = "isDisjointFrom"
+
+/**
+ Returns a bool indicating if the all values in the set are in the given set.
+
+ ## Examples
+ ```rescript
+ let set1 = Set.fromArray(["apple", "banana"])
+ let set2 = Set.fromArray(["apple", "banana", "pear"])
+ set1->Set.isSubsetOf(set2) // true
+ */
+@send external isSubsetOf: (t<'a>, t<'a>) => bool = "isSubsetOf"
+
+/**
+ Returns a bool indicating if the all values in the given set are in the set.
+
+ ## Examples
+ ```rescript
+ let set1 = Set.fromArray(["apple", "banana", "pear"])
+ let set2 = Set.fromArray(["apple", "banana"])
+ set1->Set.isSupersetOf(set2) // true
+ ```
+*/
+@send external isSupersetOf: (t<'a>, t<'a>) => bool = "isSupersetOf"
+
+/**
+ Returns a new set with the values of the set that are in both the set and the other set.
+
+ ## Examples
+ ```rescript
+ let set1 = Set.fromArray(["apple", "orange", "banana"])
+ let set2 = Set.fromArray(["apple", "banana", "pear"])
+ set1->Set.union(set2) // Set.fromArray(["apple", "orange", "banana", "pear"])
+ ```
+*/
+@send external union: (t<'a>, t<'a>) => t<'a> = "union"
+
+/**
+  `toArray(set)` returns an array of all values of the set.
+
+  ## Examples
+  ```rescript
+  let set = Set.fromArray(["apple", "orange", "apple", "banana"])
+  set->Set.toArray // ["apple", "orange", "banana"]
+  ```
+*/
+external toArray: t<'a> => array<'a> = "Array.from"