From b4f7a975e8b0cca7ecba0b188a359a4639a8fd37 Mon Sep 17 00:00:00 2001
From: shadowninja55 <49539636+shadowninja55@users.noreply.github.com>
Date: Tue, 16 Mar 2021 18:19:48 -0400
Subject: [PATCH] builtin.string: optimize string.count where substr.len == 1
 (#9337)

---
 vlib/builtin/string.v | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/vlib/builtin/string.v b/vlib/builtin/string.v
index e37491c81b..6fc72cd699 100644
--- a/vlib/builtin/string.v
+++ b/vlib/builtin/string.v
@@ -834,7 +834,21 @@ pub fn (s string) count(substr string) int {
 	if substr.len > s.len {
 		return 0
 	}
+
 	mut n := 0
+
+	if substr.len == 1 {
+		target := substr[0]
+
+		for letter in s {
+			if letter == target {
+				n++
+			}
+		}
+
+		return n
+	}
+
 	mut i := 0
 	for {
 		i = s.index_after(substr, i)