From 13beaf48a948e077b5cb510c8656bea6bdcecc18 Mon Sep 17 00:00:00 2001
From: Ruidy <rnemausat@newstore.com>
Date: Sun, 27 Mar 2022 00:32:25 -0400
Subject: [PATCH] add intersection

---
 docs/content/collections/intersection.md | 24 ++++++++++++++++++++++++
 intersection.go                          | 12 ++++++++++++
 intersection_test.go                     | 17 +++++++++++++++++
 3 files changed, 53 insertions(+)
 create mode 100644 docs/content/collections/intersection.md
 create mode 100644 intersection.go
 create mode 100644 intersection_test.go

diff --git a/docs/content/collections/intersection.md b/docs/content/collections/intersection.md
new file mode 100644
index 0000000..b7b4fdd
--- /dev/null
+++ b/docs/content/collections/intersection.md
@@ -0,0 +1,24 @@
+---
+title: "Intersection"
+date: 2022-03-27T00:24:11-04:00
+---
+
+Intersection computes the list of values that are the intersection of all the slices.
+Each value in the result is present in each of the slices.
+
+```go
+package main
+
+
+import (
+	"fmt"
+	u "github.com/rjNemo/underscore"
+)
+
+func main(){
+    a := []int{1, 3, 5, 7, 9}
+    b := []int{2, 3, 5, 8, 0}
+
+    fmt.Println(u.Intersection(a, b)) // {3, 5}
+}
+```
\ No newline at end of file
diff --git a/intersection.go b/intersection.go
new file mode 100644
index 0000000..40e571a
--- /dev/null
+++ b/intersection.go
@@ -0,0 +1,12 @@
+package underscore
+
+// Intersection computes the list of values that are the intersection of all the slices.
+// Each value in the result is present in each of the slices.
+func Intersection[T comparable](a, b []T) (res []T) {
+	for _, n := range a {
+		if Contains(b, n) {
+			res = append(res, n)
+		}
+	}
+	return res
+}
diff --git a/intersection_test.go b/intersection_test.go
new file mode 100644
index 0000000..c9f353b
--- /dev/null
+++ b/intersection_test.go
@@ -0,0 +1,17 @@
+package underscore_test
+
+import (
+	"testing"
+
+	u "github.com/rjNemo/underscore"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIntersection(t *testing.T) {
+	a := []int{1, 3, 5, 7, 9}
+	b := []int{2, 3, 5, 8, 0}
+	want := []int{3, 5}
+
+	assert.Equal(t, want, u.Intersection(a, b))
+}