From 70f5c02d47818c8ea033984b39d26988771dca45 Mon Sep 17 00:00:00 2001
From: Aidan Woods <aidantwoods@gmail.com>
Date: Sun, 8 Apr 2018 20:38:21 +0100
Subject: [PATCH] Use non-nestable values as keys for O(1) lookup

---
 Parsedown.php | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/Parsedown.php b/Parsedown.php
index f7d0a27..62cbf5a 100644
--- a/Parsedown.php
+++ b/Parsedown.php
@@ -1114,6 +1114,8 @@ class Parsedown
     {
         $Elements = array();
 
+        $nonNestables = array_combine($nonNestables, $nonNestables);
+
         # $excerpt is based on the first occurrence of a marker
 
         while ($excerpt = strpbrk($text, $this->inlineMarkerList))
@@ -1128,7 +1130,7 @@ class Parsedown
             {
                 # check to see if the current inline type is nestable in the current context
 
-                if ( ! empty($nonNestables) and in_array($inlineType, $nonNestables))
+                if (isset($nonNestables[$inlineType]))
                 {
                     continue;
                 }