diff --git a/src/highlight.js b/src/highlight.js
index 761c778d9b..32e8773b05 100644
--- a/src/highlight.js
+++ b/src/highlight.js
@@ -32,7 +32,6 @@ const HLJS = function(hljs) {
   // Regular expressions used throughout the highlight.js library.
   var fixMarkupRe      = /((^(<[^>]+>|\t|)+|(?:\n)))/gm;
 
-  var spanEndTag = '</span>';
   var LANGUAGE_NOT_FOUND = "Could not find the language '{}', did you forget to load/include a language module?";
 
   // Global options used when within external APIs. This is modified when
@@ -51,7 +50,7 @@ const HLJS = function(hljs) {
 
   /* Utility functions */
 
-  function isNotHighlighted(language) {
+  function shouldNotHighlight(language) {
     return options.noHighlightRe.test(language);
   }
 
@@ -74,7 +73,7 @@ const HLJS = function(hljs) {
 
     return classes
       .split(/\s+/)
-      .find((_class) => isNotHighlighted(_class) || getLanguage(_class))
+      .find((_class) => shouldNotHighlight(_class) || getLanguage(_class))
   }
 
 
@@ -132,8 +131,8 @@ const HLJS = function(hljs) {
         str = str.toLowerCase();
       }
       str.split(' ').forEach(function(keyword) {
-        var pair = keyword.split('|');
-        compiled_keywords[pair[0]] = [className, scoreForKeyword(pair[0], pair[1])];
+        var [kw, relevance] = keyword.split('|');
+        compiled_keywords[kw] = [className, scoreForKeyword(kw, relevance)];
       });
     }
   }
@@ -144,10 +143,10 @@ const HLJS = function(hljs) {
     if (providedScore)
       return Number(providedScore);
 
-    return commonKeyword(keyword) ? 0 : 1;
+    return isCommonKeyword(keyword) ? 0 : 1;
   }
 
-  function commonKeyword(word) {
+  function isCommonKeyword(word) {
     return COMMON_KEYWORDS.includes(word.toLowerCase());
   }
 
@@ -663,7 +662,7 @@ const HLJS = function(hljs) {
     var node, originalStream, result, resultNode, text;
     var language = blockLanguage(block);
 
-    if (isNotHighlighted(language))
+    if (shouldNotHighlight(language))
         return;
 
     fire("before:highlightBlock",