From 7fef1562f208898a966450fdc895136c60b10ebc Mon Sep 17 00:00:00 2001
From: Ruidy <nemausatpro@gmail.com>
Date: Tue, 12 Apr 2022 17:32:13 -0400
Subject: [PATCH] unique function (#27)

Co-authored-by: Ruidy <rnemausat@newstore.com>
---
 docs/content/collections/unique.md | 21 +++++++++++++++++++++
 unique.go                          | 12 ++++++++++++
 unique_test.go                     | 16 ++++++++++++++++
 3 files changed, 49 insertions(+)
 create mode 100644 docs/content/collections/unique.md
 create mode 100644 unique.go
 create mode 100644 unique_test.go

diff --git a/docs/content/collections/unique.md b/docs/content/collections/unique.md
new file mode 100644
index 0000000..4b1ba12
--- /dev/null
+++ b/docs/content/collections/unique.md
@@ -0,0 +1,21 @@
+---
+title: "Unique"
+date: 2022-04-12T17:18:04-04:00
+---
+
+`Unique` returns a duplicate-free version of the slice. Only the first occurrence of each value is kept.
+
+```go
+package main
+
+import (
+	"fmt"
+	u "github.com/rjNemo/underscore"
+)
+
+func main() {
+	nums := []int{1, 4, 2, 5, 3, 1, 5, 2, 8, 9}
+	
+	fmt.Println(u.Unique(nums)) // 1, 4, 2, 5, 3, 8, 9
+}
+```
diff --git a/unique.go b/unique.go
new file mode 100644
index 0000000..718ddc8
--- /dev/null
+++ b/unique.go
@@ -0,0 +1,12 @@
+package underscore
+
+func Unique[T comparable](values []T) (uniques []T) {
+	seen := make(map[T]bool, 0)
+	for _, v := range values {
+		if _, ok := seen[v]; !ok {
+			uniques = append(uniques, v)
+			seen[v] = true
+		}
+	}
+	return uniques
+}
diff --git a/unique_test.go b/unique_test.go
new file mode 100644
index 0000000..03ff72b
--- /dev/null
+++ b/unique_test.go
@@ -0,0 +1,16 @@
+package underscore_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	u "github.com/rjNemo/underscore"
+)
+
+func TestUnique(t *testing.T) {
+	nums := []int{1, 4, 2, 5, 3, 1, 5, 2, 8, 9}
+	want := []int{1, 4, 2, 5, 3, 8, 9}
+
+	assert.Equal(t, want, u.Unique(nums))
+}