Initial QSfera import

Server/vendor/github.com/juliangruber/go-intersect/intersect.go

@@ -0,0 +1,73 @@
+package intersect
+
+import (
+	"reflect"
+	"sort"
+)
+
+// Simple has complexity: O(n^2)
+func Simple(a interface{}, b interface{}) []interface{} {
+	set := make([]interface{}, 0)
+	av := reflect.ValueOf(a)
+
+	for i := 0; i < av.Len(); i++ {
+		el := av.Index(i).Interface()
+		if contains(b, el) {
+			set = append(set, el)
+		}
+	}
+
+	return set
+}
+
+// Sorted has complexity: O(n * log(n)), a needs to be sorted
+func Sorted(a interface{}, b interface{}) []interface{} {
+	set := make([]interface{}, 0)
+	av := reflect.ValueOf(a)
+	bv := reflect.ValueOf(b)
+
+	for i := 0; i < av.Len(); i++ {
+		el := av.Index(i).Interface()
+		idx := sort.Search(bv.Len(), func(i int) bool {
+			return bv.Index(i).Interface() == el
+		})
+		if idx < bv.Len() && bv.Index(idx).Interface() == el {
+			set = append(set, el)
+		}
+	}
+
+	return set
+}
+
+// Hash has complexity: O(n * x) where x is a factor of hash function efficiency (between 1 and 2)
+func Hash(a interface{}, b interface{}) []interface{} {
+	set := make([]interface{}, 0)
+	hash := make(map[interface{}]bool)
+	av := reflect.ValueOf(a)
+	bv := reflect.ValueOf(b)
+
+	for i := 0; i < av.Len(); i++ {
+		el := av.Index(i).Interface()
+		hash[el] = true
+	}
+
+	for i := 0; i < bv.Len(); i++ {
+		el := bv.Index(i).Interface()
+		if _, found := hash[el]; found {
+			set = append(set, el)
+		}
+	}
+
+	return set
+}
+
+func contains(a interface{}, e interface{}) bool {
+	v := reflect.ValueOf(a)
+
+	for i := 0; i < v.Len(); i++ {
+		if v.Index(i).Interface() == e {
+			return true
+		}
+	}
+	return false
+}