From 09dfc3f301e7e12cb691de130b3d115edb44a3c7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?R=C3=A9mi?= <33205215+remimimimi@users.noreply.github.com>
Date: Sun, 26 Sep 2021 16:41:50 +0000
Subject: [PATCH] arrays: add a generic `arrays.concat(os.args,'abc','xyz')`
 function (#11985)

---
 vlib/arrays/arrays.v      | 10 ++++++++++
 vlib/arrays/arrays_test.v | 14 ++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/vlib/arrays/arrays.v b/vlib/arrays/arrays.v
index cc6558e4fc..1dd3310755 100644
--- a/vlib/arrays/arrays.v
+++ b/vlib/arrays/arrays.v
@@ -280,3 +280,13 @@ pub fn group_by<K, V>(list []V, grouping_op fn (v V) K) map[K][]V {
 
 	return result
 }
+
+// concatenate two arrays
+pub fn concat<T>(a []T, b ...T) []T {
+	mut m := []T{cap: a.len + b.len}
+
+	m << a
+	m << b
+
+	return m
+}
diff --git a/vlib/arrays/arrays_test.v b/vlib/arrays/arrays_test.v
index 8beb413393..29cc248b2a 100644
--- a/vlib/arrays/arrays_test.v
+++ b/vlib/arrays/arrays_test.v
@@ -180,3 +180,17 @@ fn test_group_by() {
 		return 0
 	}) == map[int][]int{}
 }
+
+fn test_concat_int() {
+	mut a := [1, 2, 3]
+	mut b := [3, 2, 1]
+
+	assert concat(a, ...b) == [1, 2, 3, 3, 2, 1]
+}
+
+fn test_concat_string() {
+	mut a := ['1', '2', '3']
+	mut b := ['3', '2', '1']
+
+	assert concat(a, ...b) == ['1', '2', '3', '3', '2', '1']
+}